EP4199764A1

EP4199764A1 - Aerosol provision system

Info

Publication number: EP4199764A1
Application number: EP21778535.1A
Authority: EP
Inventors: David LEADLEY; Zhihuang Xiao; David Alan Nelson; Martin Conrad MULLIN
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2020-09-22
Filing date: 2021-09-10
Publication date: 2023-06-28
Also published as: US20230389607A1; WO2022064171A1; MX2023003320A; CA3173128A1

Abstract

An aerosol provision system (1) comprising a reservoir (31) for aerosolisable material; a wick (42) configured to receive the aerosolisable material from the reservoir (31), a vaporiser (40) configured to vaporise the aerosolisable material received in the wick (42), wherein the aerosol provision system (1) is configured to measure at least one parameter of the wick (42) to determine a status of the wick (42). The parameter may be the moisture content of the wick (42), at least one physical dimension of the wick (42), and/or an optical parameter, such as the colour of an external surface of the wick (42), or the reflectivity of an external surface of the wick (42).

Description

AEROSOL PROVISION SYSTEM

Field

The present disclosure relates to aerosol provision systems such as nicotine delivery systems (e.g. electronic cigarettes and the like).

Background

Electronic aerosol provision systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol precursor material, such as a reservoir of a source liquid containing a formulation, typically including nicotine, or a solid material such a tobacco-based product, from which an aerosol is generated for inhalation by a user, for example through heat vaporisation. Thus, an aerosol provision system will typically comprise a vaporiser, e.g. a heating element, arranged to vaporise a portion of precursor material to generate an aerosol in an aerosol generation region of an air channel through the aerosol provision system. As a user inhales on the device and electrical power is supplied to the vaporiser, air is drawn into the device through one or more inlet holes and along the air channel to the aerosol generation region, where the air mixes with the vaporised precursor material and forms a condensation aerosol. The air drawn through the aerosol generation region continues along the air channel to a mouthpiece opening, carrying some of the aerosol with it, and out through the mouthpiece opening for inhalation by the user.

It is common for aerosol provision systems to comprise a modular assembly, often having two main functional parts, namely a control unit and disposable I replaceable cartridge part. Typically the cartridge part will comprise the consumable aerosol precursor material and the vaporiser (atomiser), while the control unit part will comprise longer-life items, such as a rechargeable battery, device control circuitry, activation sensors and user interface features. The control unit may also be referred to as a reusable part or battery section and the replaceable cartridge may also be referred to as a disposable part or cartomiser.

The control unit and cartridge are mechanically coupled together at an interface for use, for example using a screw thread, bayonet, latched or friction fit fixing. When the aerosol precursor material in a cartridge has been exhausted, or the user wishes to switch to a different cartridge having a different aerosol precursor material, the cartridge may be removed from the control unit and a replacement cartridge may be attached to the device in its place.

A potential drawbacks for cartridges containing liquid aerosol precursor (e-liquid) is the risk of leakage. An e-cigarette cartridge will typically have a mechanism, e.g. a capillary wick, for drawing aerosolisable material from an aerosolisable material reservoir to a vaporiser located in an air path I channel connecting from an air inlet to an aerosol outlet for the cartridge. Because there is a fluid transport path from the aerosolisable material reservoir into the open air channel through the cartridge, there is a corresponding risk of aerosolisable material leaking from the cartridge. Leakage is undesirable both from the perspective of the end user naturally not wanting to get the e-liquid on their hands or other items, and also from a reliability perspective, since leakage from an end of the cartridge connected to the control unit may damage the control unit, for example due to corrosion. Some approaches to reduce the risk of leakage may involve restricting the flow of aerosolisable material to the vaporiser, for example by tightly clamping a wick where it enters the air channel. In normal use, the aerosolisable material taken up by the wick is sufficient to keep the vaporiser cool (i.e., at an ideal operating temperature), but when the aerosolisable material taken up is insufficient (e.g., when the aerosolisable material in the reservoir runs low) this can in some scenarios give rise to overheating and undesirable flavours.

Various approaches are therefore described herein which seek to help address or mitigate some of the issues discussed above.

Summary

According to a first aspect of certain embodiments there is provided an aerosol provision system comprising a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir, a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the aerosol provision system is configured to measure at least one parameter of the wick to determine a status of the wick.

According to a second aspect of certain embodiments there is provided a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir; and a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the cartridge is configured to measure at least one parameter of the wick to determine a status of the wick.

According to a third aspect of certain embodiments there is provided an aerosolisable material for use in an aerosol provision system, wherein the aerosolisable material comprises at least one doping agent comprising a thermochromic material, wherein the thermochromic material is configured to adopt a first colour at a first predetermined temperature, and is configured to adopt a second colour at a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature.

According to a fourth aspect of certain embodiments there is provided a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element, and at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

According to a fifth aspect of certain embodiments there is provided an aerosol provision system comprising an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element; wherein the aerosol provision system further comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

According to a sixth aspect of certain embodiments there is provided an aerosolisable material transport element for receiving aerosolisable material, wherein the aerosolisable material transport element comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

According to a seventh aspect of certain embodiments there is provided a method of indicating a change in condition of an aerosolisable material transport element which is configured to receive aerosolisable material from a reservoir of aerosolisable material, wherein the method comprises: colouring the aerosolisable material transport element a first colour at a first predetermined condition using a doping agent; and colouring the aerosolisable material transport element a second colour at a second predetermined condition, using the doping agent, wherein the second predetermined condition is different from the first predetermined condition.

According to an eighth aspect of certain embodiments there is provided an aerosol provision system comprising: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the aerosol provision system is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system.

According to a ninth aspect of certain embodiments there is provided a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the cartridge is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the cartridge.

It will be appreciated that features and aspects of the invention described above in relation to the various aspects of the invention are equally applicable to, and may be combined with, embodiments of the invention according to other aspects of the invention as appropriate, and not just in the specific combinations described herein.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 schematically represents in perspective view an aerosol provision system comprising a cartridge and control unit (shown separated) in accordance with certain embodiments of the disclosure;

Figure 2 schematically represents in exploded perspective view of components of the cartridge of the aerosol provision system of Figure 1;

Figures 3A to 3C schematically represent various cross-section views of a housing part of the cartridge of the aerosol provision system of Figure 1 ; Figures 4A and 4B schematically represent a perspective view and a plan view of a dividing wall element of the cartridge of the aerosol provision system of Figure 1 ;

Figures 5A to 5C schematically represent two perspective views and a plan view of a resilient plug of the cartridge of the aerosol provision system of Figure 1;

Figures 6A and 6B schematically represent a perspective view and a plan view of a bottom cap of the cartridge of the aerosol provision system of Figure 1 ;

Figure 7 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figure 8 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figure 9 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figure 10 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figures 11 A-11C represents schematic views of a portion of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figure 12 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure;

Figure 13 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure; and

Figure 14 represents a schematic view of an aerosol provision system in accordance with certain embodiments of the disclosure.

Detailed Description

Aspects and features of certain examples and embodiments are discussed I described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed I described in detail in the interests of brevity. It will thus be appreciated that aspects and features of apparatus and methods discussed herein which are not described in detail may be implemented in accordance with any conventional techniques for implementing such aspects and features.

The present disclosure relates to non-combustible aerosol provision systems, which may also be referred to as aerosol provision systems, such as e-cigarettes. According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosolisable material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery to a user. Aerosolisable material, which also may be referred to herein as aerosol generating material or aerosol precursor material, is material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way.

Throughout the following description the term “e-cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used interchangeably with aerosol provision system I device and electronic aerosol provision system I device. An electronic cigarette may also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosolisable material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosolisable materials, one or a plurality of which may be heated. In some embodiments, the hybrid system comprises a liquid or gel aerosolisable material and a solid aerosolisable material. The solid aerosolisable material may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and an article for use with the non-combustible aerosol provision device. However, it is envisaged that articles which themselves comprise a means for powering an aerosol generating component may themselves form the non-combustible aerosol provision system.

In some embodiments, the article for use with the non-combustible aerosol provision device may comprise an aerosolisable material (or aerosol precursor material), an aerosol generating component (or vaporiser), an aerosol generating area, a mouthpiece, and/or an area for receiving aerosolisable material.

In some embodiments, the aerosol generating component is a heater capable of interacting with the aerosolisable material so as to release one or more volatiles from the aerosolisable material to form an aerosol. In some embodiments, the aerosol generating component is capable of generating an aerosol from the aerosolisable material without heating. For example, the aerosol generating component may be capable of generating an aerosol from the aerosolisable material without applying heat thereto, for example via one or more of vibrational, mechanical, pressurisation or electrostatic means.

In some embodiments, the substance to be delivered may be an aerosolisable material which may comprise an active constituent, a carrier constituent and optionally one or more other functional constituents. The active constituent may comprise one or more physiologically and/or olfactory active constituents which are included in the aerosolisable material in order to achieve a physiological and/or olfactory response in the user. The active constituent may for example be selected from nutraceuticals, nootropics, and psychoactives. The active constituent may be naturally occurring or synthetically obtained. The active constituent may comprise for example nicotine, caffeine, taurine, theine, a vitamin such as B6 or B12 or C, melatonin, a cannabinoid, or a constituent, derivative, or combinations thereof. The active constituent may comprise a constituent, derivative or extract of tobacco or of another botanical. In some embodiments, the active constituent is a physiologically active constituent and may be selected from nicotine, nicotine salts (e.g. nicotine ditartrate/nicotine bitartrate), nicotine-free tobacco substitutes, other alkaloids such as caffeine, or mixtures thereof.

In some embodiments, the active constituent is an olfactory active constituent and may be selected from a "flavour" and/or "flavourant" which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. In some instances such constituents may be referred to as flavours, flavourants, cooling agents, heating agents, and/or sweetening agents. They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, Wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gasone or more of extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, Wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, or powder.

In some embodiments, the flavour comprises menthol, spearmint and/or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucalyptol, WS-3.

The carrier constituent may comprise one or more constituents capable of forming an aerosol. In some embodiments, the carrier constituent may comprise one or more of glycerine, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyl laurate, a diethyl suberate, triethyl citrate, triacetin, a diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

The one or more other functional constituents may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.

As noted above, aerosol provision systems (e-cigarettes) often comprise a modular assembly including both a reusable part (control unit) and a replaceable (disposable) cartridge part. Devices conforming to this type of two-part modular configuration may generally be referred to as two-part devices. It is also common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure described herein comprise this kind of generally elongate two-part device employing disposable cartridges. However, it will be appreciated the underlying principles described herein may equally be adopted for other electronic cigarette configurations, for example modular devices comprising more than two parts, as devices conforming to other overall shapes, for example based on so-called box-mod high performance devices that typically have a more boxy shape..

Figure 1 is a schematic perspective view of an example aerosol provision system I device (e- cigarette) 1 in accordance with certain embodiments of the disclosure. Terms concerning the relative location of various aspects of the electronic cigarette (e.g. terms such as upper, lower, above, below, top, bottom etc.) are used herein with reference to the orientation of the electronic cigarette as shown in Figure 1 (unless the context indicates otherwise). However, it will be appreciated this is purely for ease of explanation and is not intended to indicate there is any required orientation for the electronic cigarette in use.

The e-cigarette 1 comprises two main components, namely a cartridge 2 and a control unit 4. The control unit 4 and the cartridge 2 are shown separated in Figure 1 , but are coupled together when in use.

The cartridge 2 and control unit 4 are coupled by establishing a mechanical and electrical connection between them. The specific manner in which the mechanical and electrical connection is established is not of primary significance to the principles described herein and may be established in accordance with conventional techniques, for example based around a screw thread, bayonet, latched or friction-fit mechanical fixing with appropriately arranged electrical contacts I electrodes for establishing the electrical connection between the two parts as appropriate. For example electronic cigarette 1 represented in Figure 1, the cartridge comprises a mouthpiece end 52 and an interface end 54 and is coupled to the control unit by inserting an interface end portion 6 at the interface end of the cartridge into a corresponding receptacle 81 cartridge receiving section of the control unit. The interface end portion 6 of the cartridge is a close fit to be receptacle 8 and includes protrusions 56 which engage with corresponding detents in the interior surface of a receptacle wall 12 defining the receptacle 8 to provide a releasable mechanical engagement between the cartridge and the control unit. An electrical connection is established between the control unit and the cartridge via a pair of electrical contacts on the bottom of the cartridge (not shown in Figure 1) and corresponding sprung contact pins in the base of the receptacle 8 (not shown in Figure 1). As noted above, the specific manner in which the electrical connection is established is not significant to the principles described herein, and indeed some implementations might not have an electrical connection between the cartridge and a control unit at all, for example because the transfer of electrical power from the reusable part to the cartridge may be wireless (e.g. based on electromagnetic induction techniques).

The electronic cigarette 1 has a generally elongate shape extending along a longitudinal axis L. When the cartridge is coupled to the control unit, the overall length of the electronic cigarette in this example (along the longitudinal axis) is around 12.5 cm. The overall length of the control unit is around 9 cm and the overall length of the cartridge is around 5 cm (i.e. there is around 1.5 cm of overlap between the interface end portion 6 of the cartridge and the receptacle 8 of the control unit when they are coupled together). The electronic cigarette has a cross-section which is generally oval and which is largest around the middle of the electronic cigarette and tapers in a curved manner towards the ends. The cross-section around the middle of the electronic cigarette has a width of around 2.5 cm and a thickness of around 1.7 cm. The end of the cartridge has a width of around 2 cm and a thickness of around 0.6 mm, whereas the other end of the electronic cigarette has a width of around 2 cm and a thickness of around 1.2 cm. The outer housing of the electronic cigarette is in this example is formed from plastic. It will be appreciated the specific size and shape of the electronic cigarette and the material from which it is made is not of primary significance to the principles described herein and may be different in different implementations. That is to say, the principles described herein may equally be adopted for electronic cigarettes having different sizes, shapes and I or materials.

The control unit 4 may in accordance with certain embodiments of the disclosure be broadly conventional in terms of its functionality and general construction techniques. In the example of Figure 1, the control unit 4 comprises a plastic outer housing 10 including the receptacle wall 12 that defines the receptacle 8 for receiving the end of the cartridge as noted above. The outer housing 10 of the control unit 4 in this example has a generally oval cross section conforming to the shape and size of the cartridge 2 at their interface to provide a smooth transition between the two parts. The receptacle 8 and the end portion 6 of the cartridge 2 are symmetric when rotated through 180° so the cartridge can be inserted into the control unit in two different orientations. The receptacle wall 12 includes two control unit air inlet openings 14 (i.e. holes in the wall). These openings 14 are positioned to align with an air inlet 50 for the cartridge when the cartridge is coupled to the control unit. A different one of the openings 14 aligns with the air inlet 50 of the cartridge in the different orientations. It will be appreciated some implementations may not have any degree of rotational symmetry such that the cartridge is couplable to the control unit in only one orientation while other implementations may have a higher degree of rotational symmetry such that the cartridge is couplable to the control unit in more orientations.

The control unit further comprises a battery 16 for providing operating power for the electronic cigarette, control circuitry 18 for controlling and monitoring the operation of the electronic cigarette, a user input button 20, an indicator light 22, and a charging port 24.

The battery 16 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The battery 16 may be recharged through the charging port 24, which may, for example, comprise a USB connector.

The input button 20 in this example is a conventional mechanical button, for example comprising a sprung mounted component which may be pressed by a user to establish an electrical contact in underlying circuitry. In this regard, the input button may be considered an input device for detecting user input, e.g. to trigger aerosol generation, and the specific manner in which the button is implemented is not significant. For example, other forms of mechanical button or touch-sensitive button (e.g. based on capacitive or optical sensing techniques) may be used in other implementations, or there may be no button and the device may rely on a puff detector for triggering aerosol generation.

The indicator light 22 is provided to give a user with a visual indication of various characteristics associated with the electronic cigarette, for example, an indication of an operating state (e.g. on / off / standby), and other characteristics, such as battery life or fault conditions. Different characteristics may, for example, be indicated through different colours and I or different flash sequences in accordance with generally conventional techniques.

The control circuitry 18 is suitably configured I programmed to control the operation of the electronic cigarette to provide conventional operating functions in line with the established techniques for controlling electronic cigarettes. The control circuitry (processor circuitry) 18 may be considered to logically comprise various sub-units I circuitry elements associated with different aspects of the electronic cigarette's operation. For example, depending on the functionality provided in different implementations, the control circuitry 18 may comprises power supply control circuitry for controlling the supply of power from the battery/power supply to the cartridge in response to user input, user programming circuitry for establishing configuration settings (e.g. user-defined power settings) in response to user input, as well as other functional units I circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of electronic cigarettes, such as indicator light display driving circuitry and user input detection circuitry. It will be appreciated the functionality of the control circuitry 18 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and I or one or more suitably configured application-specific integrated circuit(s) I circuitry I chip(s) I chipset(s) configured to provide the desired functionality.

Figure 2 is an exploded schematic perspective view of the cartridge 2 (exploded along the longitudinal axis L). The cartridge 2 comprises a housing part 32, an air channel seal 34, a dividing wall element 36, an outlet tube 38, a vaporiser/heating element 40, an aerosolisable material transport element 42, a plug 44, and an end cap 48 with contact electrodes 46. Figures 3 to 6 schematically represents some of these components in more detail.

Figure 3A is a schematic cut-away view of the housing part 32 through the longitudinal axis L where the housing part 32 is thinnest. Figure 3B is a schematic cut-away view of the housing part 32 through the longitudinal axis L where the housing part 32 is widest. Figure 3C is a schematic view of the housing part along the longitudinal axis L from the interface end 54 (i.e. viewed from below in the orientation of Figures 3A and 3B).

Figures 4A is a schematic perspective view of the dividing wall element 36 as seen from below. Figure 4B is a schematic cross-section through an upper part of the dividing wall element 36 as viewed from below.

Figure 5A is a schematic perspective view of the plug 44 from above and Figure 5B is a schematic perspective view of the plug 44 from below. Figure 5C is a schematic view of the plug 44 along the longitudinal axis L seen from the mouthpiece end 52 of the cartridge (i.e. viewed from above for the orientation in Figures 1 and 2).

Figure 6A is a schematic perspective view of the end cap 48 from above. Figure 6B is a schematic view of the end cap 48 along the longitudinal axis L seen from the mouthpiece end 52 of the cartridge (i.e. from above).

The housing part 32 in this example comprises a housing outer wall 64 and a housing inner tube 62 which in this example are formed from a single moulding of polypropylene. The housing outer wall 64 defines the external appearance of the cartridge 2 and the housing inner tube 62 defines a part the air channel through the cartridge. The housing part is open at the interface end 54 of the cartridge and closed at the mouthpiece end 52 of the cartridge except for a mouthpiece opening I aerosol outlet 60 in fluid communication with the housing inner tube 62. The housing part 32 includes an opening in a sidewall which provides the air inlet 50 for the cartridge. The air inlet 50 in this example has an area of around 2 mm². The outer surface of the outer wall 64 of the housing part 32 includes the protrusions 56 discussed above which engage with corresponding detents in the interior surface of the receptacle wall 12 defining the receptacle 8 to provide a releasable mechanical engagement between the cartridge and the control unit. The inner surface of the outer wall 64 of the housing part includes further protrusions 66 which act to provide an abutment stop for locating the dividing wall element 36 along the longitudinal axis L when the cartridge is assembled. The outer wall 64 of the housing part 32 further comprises holes which provide latch recesses 68 arranged to receive corresponding latch projections 70 in the end cap to fix the end cap to be housing part when the cartridge is assembled.

The outer wall 64 of the housing part 32 includes a double-walled section 74 that defines a gap 76 in fluid communication with the air inlet 50. The gap 76 provides a portion of the air channel through the cartridge. In this example the doubled-walled section 74 of the housing part 32 is arranged so the gap defines an air channel running within the housing outer wall 64 parallel to the longitudinal axis with a cross-section in a plane perpendicular to the longitudinal axis of around 3 mm². The gap I portion of air channel 76 defined by the doublewalled section of the housing part extends down to the open end of the housing part 32.

The air channel seal 34 is a silicone moulding generally in the form of a tube having a through hole 80. The outer wall of the air channel seal 34 includes circumferential ridges 84 and an upper collar 82. The inner wall of the air channel seal 34 also includes circumferential ridges, but these are not visible in Figure 2. When the cartridge is assembled the air channel seal 34 is mounted to the housing inner tube 62 with an end of the housing inner tube 62 extending partly into the through hole 80 of the air channel seal 34. The through hole 80 in the air channel seal has a diameter of around 5.8 mm in its relaxed state whereas the end of the housing inner tube 62 has a diameter of around 6.2 mm so that a seal is formed when the air channel seal 34 is stretched to accommodate the housing inner tube 62. This seal is facilitated by the ridges on the inner surface of the air channel seal 34.

The outlet tube 38 comprises a tubular section of ANSI 304 stainless steel with an internal diameter of around 8.6 mm and a wall thickness of around 0.2 mm. The bottom end of the outlet tube 38 includes a pair of diametrically opposing slots 88 with an end of each slot having a semi-circular recess 90. When the cartridge is assembled the outlet tube 38 mounts to the outer surface of the air channel seal 34. The outer diameter of the air channel seal is around 9.0 mm in its relaxed state so that a seal is formed when the air channel seal 34 is compressed to fit inside the outlet tube 38. This seal is facilitated by the ridges 84 on the outer surface of the air channel seal 34. The collar 80 on the air channel seal 34 provides a stop for the outlet tube 38.

The aerosolisable material transport element 42 comprises a capillary wick and the vaporiser 40 comprises a resistance wire heater wound around the capillary wick. In addition to the portion of the resistance wire wound around the capillary wick, the vaporiser comprises electrical leads 41 which pass through holes in the plug 44 to contact electrodes 46 mounted to the end cap 54 to allow power to be supplied to the vaporiser via the electrical interface the established when the cartridge is connected to a control unit. The vaporiser leads 41 may comprise the same material as the resistance wire wound around the capillary wick, or may comprise a different material (e.g. lower-resistance material) connected to the resistance wire wound around the capillary wick. In this example the heater coil 40 comprises a nickel iron alloy wire and the wick 42 comprises a glass fibre bundle. The vaporiser and aerosolisable material transport element may be provided in accordance with any conventional techniques and is may comprise different forms and I or different materials. For example, in some implementations the wick may comprise fibrous or solid a ceramic material and the heater may comprise a different alloy. In other examples the heater and wick may be combined, for example in the form of a porous and a resistive material. More generally, it will be appreciated the specific nature aerosolisable material transport element and vaporiser is not of primary significance to the principles described herein.

When the cartridge is assembled, the wick 42 is received in the semi-circular recesses 90 of the outlet tube 38 so that a central portion of the wick about which the heating coil is would is inside the outlet tube while end portions of the wick are outside the outlet tube 38.

The plug 44 in this example comprises a single moulding of silicone, may be resilient. The plug comprises a base part 100 with an outer wall 102 extending upwardly therefrom (i.e. towards the mouthpiece end of the cartridge). The plug further comprises an inner wall 104 extending upwardly from the base part 100 and surrounding a through hole 106 through the base part 100.

The outer wall 102 of the plug 44 conforms to an inner surface of the housing part 32 so that when the cartridge is assembled the plug in 44 forms a seal with the housing part 32. The inner wall 104 of the plug 44 conforms to an inner surface of the outlet tube 38 so that when the cartridge is assembled the plug 44 also forms a seal with the outlet tube 38. The inner wall 104 includes a pair of diametrically opposing slots 108 with the end of each slot having a semi-circular recess 110. Extended outwardly (i.e. in a direction away from the longitudinal axis of the cartridge) from the bottom of each slot in the inner wall 104 is a cradle section 112 shaped to receive a section of the aerosolisable material transport element 42 when the cartridge is assembled. The slots 108 and semi-circular recesses 110 provided by the inner wall of the plug 44 and the slots 88 and semi-circular recesses 90 of the outlet tube 38 are aligned so that the slots 88 in the outlet tube 38 accommodate respective ones of the cradles 112 with the respective semi-circular recesses in the outlet tube and plug cooperating to define holes through which the aerosolisable material transport element passes. The size of the holes provided by the semi-circular recesses through which the aerosolisable material transport element passes correspond closely to the size and shape of the aerosolisable material transport element, but are slightly smaller so a degree of compression is provided by the resilience of the plug 44. This allows aerosolisable material to be transported along the aerosolisable material transport element by capillary action while restricting the extent to which aerosolisable material which is not transported by capillary action can pass through the openings. As noted above, the plug 44 includes further openings 114 in the base part 100 through which the contact leads 41 for the vaporiser pass when the cartridge is assembled. The bottom of the base part of the plug includes spacers 116 which maintain an offset between the remaining surface of the bottom of the base part and the end cap 48. These spacers 116 include the openings 114 through which the electrical contact leads 41 for the vaporiser pass.

The end cap 48 comprises a polypropylene moulding with a pair of gold-plated copper electrode posts 46 mounted therein.

The ends of the electrode posts 44 on the bottom side of the end cap are close to flush with the interface end 54 of the cartridge provided by the end cap 48. These are the parts of the electrodes to which correspondingly aligned sprung contacts in the control unit connect when the cartridge is assembled and connected to the control unit. The ends of the electrode posts on the inside of the cartridge extend away from the end cap 48 and into the holes 114 in the plug 44 through which the contact leads 41 pass. The electrode posts are slightly oversized relative to the holes 114 and include a chamfer at their upper ends to facilitate insertion into the holes 114 in the plug where they are maintained in pressed contact with the contact leads for the vaporiser by virtue of the plug.

The end cap has a base section 124 and an upstanding wall 120 which conforms to the inner surface of the housing part 32. The upstanding wall 120 of the end cap 48 is inserted into the housing part 32 so the latch projections 70 engage with the latch recesses 68 in the housing part 32 to snap-fit the end cap 48 to the housing part when the cartridge is assembled. The top of the upstanding wall 120 of the end cap 48 abuts a peripheral part of the plug 44 and the lower face of the spacers 116 on the plug also abut the base section 124 of the plug so that when the end cap 48 is attached to the housing part it presses against the resilient part 44 to maintain it in slight compression.

The base portion 124 of the end cap 48 includes a peripheral lip 126 beyond the base of the upstanding wall 112 with a thickness which corresponds with the thickness of the outer wall of the housing part at the interface end of the cartridge. The end cap also includes an upstanding locating pin 122 which aligns with a corresponding locating hole 128 in the plug to help establish their relative location during assembly. The dividing wall element 36 comprises a single moulding of polypropylene and includes a dividing wall 130 and a collar 132 formed by projections from the dividing wall 130 in the direction towards the interface end of the cartridge. The dividing wall element 36 has a central opening 134 through which the outlet tube 38 passes (i.e. the dividing wall is arranged around the outlet tube 38). When the cartridge is assembled, the upper surface of the outer wall 102 of the plug 44 engages with the lower surface of the dividing wall 130, and the upper surface of the dividing wall 130 in turn engages with the projections 66 on the inner surface of the outer wall 64 of the housing part 32. Thus, the dividing wall 130 prevents the plug from being pushed too far into the housing part 32 - i.e. the dividing wall 130 is fixedly located along the longitudinal axis of the cartridge by the protrusions 66 in the housing part and so provides the plug with a fixed surface to push against. The collar 132 formed by projections from the dividing wall includes a first pair of opposing projections I tongues 134 which engage with corresponding recesses on an inner surface of the outer wall 102 of the plug 44. The protrusions from the dividing wall 130 further provide a pair of cradle sections 136 configured to engage with corresponding ones of the cradle sections 112 in the part 44 when the cartridge is assembled to further define the opening through which the aerosolisable material transport element passes.

When the cartridge is assembled an air channel extending from the air inlet 50 to the aerosol outlet 60 through the cartridge is formed. Starting from the air inlet 50 in the side wall of the housing part 32, a first section of the air channel is provided by the gap 76 formed by the double-walled section 74 in the outer wall 64 of the housing part 32 and extends from the air inlet 50 towards the interface end 54 of the cartridge and past the plug 44. A second portion of the air channel is provided by the gap between the base of the plug 44 and the end cap 48. A third portion of the air channel is provided by the hole 106 through the plug 44. A fourth portion of the air channel is provided by the region within the inner wall 104 of the plug and the outlet tube around the vaporiser 40. This fourth portion of the air channel may also be referred to as an aerosol/aerosol generation region, it being the primary region in which aerosol is generated during use. The air channel from the air inlet 50 to the aerosol generation region may be referred to as an air inlet section of the air channel. A fifth portion of the air channel is provided by the remainder of the outlet tube 38. A sixth portion of the air channel is provided by the outer housing inner tube 62 which connects the air channel to the aerosol outlet 60. The air channel from the aerosol generation region to be the aerosol outlet may be referred to as an aerosol outlet section of the air channel.

Also, when the cartridge is assembled a reservoir 31 for aerosolisable material is formed by the space outside the air channel and inside the housing part 32. This may be filled during manufacture, for example through a filling hole which is then sealed, or by other means. The specific nature of the aerosolisable material, for example in terms of its composition, is not of primary significance to the principles described herein, and in general any conventional aerosolisable material of the type normally used in electronic cigarettes may be used. The present disclosure may refer to a liquid as the aerosolisable material, which as mentioned above may be a conventional e-liquid. However, the principles of the present disclosure apply to any aerosolisable material which has the ability to flow, and may include a liquid, a gel, or a solid, where for a solid a plurality of solid particles may be considered to have the ability to flow when considered as a bulk.

The reservoir is closed at the interface end of the cartridge by the plug 44. The reservoir includes a first region above the dividing wall 130 and a second region below the dividing wall 130 within the space formed between the air channel and the outer wall of the plug. The aerosolisable material transport element (capillary wick) 42 passes through openings in the wall of the air channel provided by the semi-circular recesses 108, 90 in the plug 44 and the outlet tube 38 and the cradle sections 112, 136 in the plug 44 and the dividing wall element 36 that engage with one another as discussed above. Thus, the ends of the aerosolisable material transport element extend into the second region of the reservoir from which they draw aerosolisable material through the openings in the air channel to the vaporiser 40 for subsequent vaporisation.

In normal use, the cartridge 2 is coupled to the control unit 4 and the control unit activated to supply power to the cartridge via the contact electrodes 46 in the end cap 48. Power then passes through the connection leads 41 to the vaporiser 40. The vaporiser is thus electrically heated and so vaporises a portion of the aerosolisable material from the aerosolisable material transport element in the vicinity of the vaporiser. This generates aerosol in the aerosol generation region of the air path. Aerosolisable material that is vaporised from the aerosolisable material transport element is replaced by more aerosolisable material drawn from the reservoir by capillary action. While the vaporiser is activated, a user inhales on the mouthpiece end 52 of the cartridge. This causes air to be drawn through whichever control unit air inlet 14 aligns with the air inlet 50 of the cartridge (which will depend on the orientation in which the cartridge was inserted into the control unit receptacle 8). Air then enters the cartridge through the air inlet 50, passes along the gap 76 in the double-walled section 74 of the housing part 32, passes between the plug 44 and the end cap 48 before entering the aerosol generation region surrounding the vaporiser 40 through the hole 106 in the base part 100 of the plug 44. The incoming air mixes with aerosol generated from the vaporiser to form a condensation aerosol, which is then drawn along the outlet tube 38 and the housing part inner 62 before exiting through the mouthpiece outlet/aerosol outlet 60 for user inhalation. With reference to Figures 7-10 and 12, there is shown schematically a cross section view of a modified cartridge 2 for use with a control unit 4 to form an aerosol provision system 1 in accordance with certain embodiments of the disclosure. The aerosol provision system 1 ; cartridge 2; and control unit 4 shown in Figures 7-10 and 12 are based on the construction of the corresponding aerosol provision system 1; cartridge 2; and control unit 4; shown in Figures 1-6B, and comprise similar components as set out by the reference numerals that are common to both sets of Figures. For instance, the cartridge 2 defines a reservoir 31 which extends around an aerosol outlet tube 38. In accordance with such embodiments, the reservoir 31 may be annular, and is configured for containing aerosolisable material for aerosolising. Similarly, the control unit 4 may comprise the plastic outer housing 10 including the receptacle wall 12 that defines the receptacle 8 for receiving the end of the cartridge 2. The control unit 4 may also comprise the control circuitry 18 and the power supply/battery 16.

Noting the above, and with initial reference to the aerosol provision system 1 shown in Figure 7, a first modification over the aerosol provision system shown 1 in Figures 1-6B is the introduction of a configuration to measure at least one parameter of the wick to determine a status of the wick.. In essence therefore, and at a broad level, Figure 7 illustrates an aerosol provision system 1 comprising a reservoir 31 for aerosolisable material; a wick 42 configured to receive the aerosolisable material from the reservoir 31 , a vaporiser 40 configured to vaporise the aerosolisable material received in the wick 42, wherein the aerosol provision system 1 is configured to measure at least one parameter of the wick 42 to determine a status of the wick 42.

In principal, this status of the wick 42 (or aerosolisable material transport element 42) could relate to variety of different statuses for the aerosolisable material transport element I wick 42. However, in accordance with some particular embodiments, the status may be the wick containing 42 less than a predetermined amount of aerosolisable material, and/or the wick exceeding a predetermined temperature. Both these may therefore correspond to a dry-out status of the wick 42, whereby the wick 42 is not saturated with aerosolisable material. During such dry-out conditions, as the vaporiser 40 is operated, this may cause the wick 42 to become excessively hot, as a result of the heat generated by the vaporiser 40, and as result of there not being sufficient aerosolisable material to help cool the temperature of the wick 42.

In such a dry-out status, in so far as the aerosol provision system 1 is configured to measure at least one parameter of the wick 42 to determine a status of the wick 42, this may allow the aerosol provision system 1 to react in such instances where a dry-out status is detected, as will be described. In that respect, and in accordance with some embodiments, the aerosol provision system 1 may be provided with the control circuitry 18, and at least one sensor 200 for detecting the at least one parameter. In such embodiments, each sensor 200 is configured to output a sensor signal containing data related to the at least one parameter. In this way, the control circuitry 18 may be then configured to process the data from the sensor signal of each sensor 200 to determine the status of the wick 42.

It is envisaged herein that the type of sensor(s) 200 used will depend on the parameter which the sensor 200 is configured to detect.

In that respect therefore, in accordance with some embodiments, and with reference to Figure 7, the at least one parameter may comprise the moisture content of the wick 42; wherein the at least one sensor 200 comprises at least one load cell 202 on which the wick 42 is supported. In this embodiment, each load cell 202 may be configured to output a sensor signal containing mass data related to the mass of the wick 42. The control circuitry 18 may be then further configured to process the mass data from the sensor signal of each load cell 200 to determine a mass value for the wick 42, and then compare the mass value for the wick against a predetermined mass value. In this embodiment therefore, as the wick becomes wet/saturated in use with aerosolisable material, the mass of the wick 42 will vary depending on the quantity of aerosolisable material therein. Noting each load cell 200 supports the wick 42, each load cell 202 may be therefore configured to output the sensor signal containing mass data related to the mass of the wick 42. In respect of the predetermined mass value, this in accordance with some embodiments may be selected to correspond to the mass of the wick at the cusp of a dry-out status, whereby an insufficient amount of aerosolisable material is contained in the wick 42 and/or whereby the wick 42 is not saturated with aerosolisable material.

Accordingly, in the event the mass value is less than the predetermined mass value, the control circuitry 18 may be then configured to output a control signal, e.g. to affect/control the subsequent working of the aerosol provision system 1. In that respect, and in accordance with some embodiments, the control signal may comprise a command to disable the operation of the aerosol provision system 1 and/or a command to disable the operation of the vaporiser 40. In some particular embodiments thereof, the control circuity 18 may be then configured to disable the operation of the aerosol provision system 1 and/or the vaporiser 40 until the control circuitry 18 determines that a different cartridge 2 has been coupled to the control unit 4, or until the control circuitry 18 subsequently determines a mass value for the wick as being more than the predetermined mass value. In accordance with some embodiments, the control signal may comprise a command to provide a notification to a user. In accordance with some embodiments thereof, the control signal may comprise at least one of: an optical signal, an acoustic signal, and a haptic signal, which can be used to provide a notification to the user. Such a notification, in accordance with some particular embodiments, may include any of: a notification to the user that the aerosolisable material requires refilling; that the cartridge 2 requires replacing (where a cartridge 2/control unit 4 arrangement is employed); and/or a notification to the user that at least a portion of the aerosol provision system 1 has overheated.

To implement the above indications, as required, in accordance with some embodiments, the aerosol provision system 1 may further comprise any one or combination of an optic element (such as an LED), an acoustic element (such as a speaker) and a haptic feedback element (such as a vibrator). Appreciably, in some particular embodiments to those set out above, any such optical/acoustic/haptic feedback element(s) may be most conveniently located on the control unit 4 (where such a cartridge 2/control unit 4 arrangement is employed).

Whatever the control signal that may be employed, in the embodiments where at least one cell 202 is provided, in accordance with some embodiments thereof, to better support the wick 42, and to allow for a more accurate mass value to be determined, in accordance with some embodiments (such as that shown in Figure 7), the at least one load cell 202 may comprise a first load cell 202A which supports a first end 42A of the wick 42, and a second load cell 202B which supports a second end 42A of the wick 42.

Aside from the possible use of a load cell(s) 202 in the context of the parameter being the moisture content of the wick 42, in accordance with some embodiments, the at least one parameter may additionally/alternatively comprises at least one physical dimension of the wick, and wherein the at least one sensor 200 comprise a dimension sensor 204 for detecting the at least one physical dimension of the wick 204. In such embodiments, the dimension sensor 204 (as shown in Figures 8 or 9, for instance) is configured to output a sensor signal containing dimension data related to the at least one physical dimension of the wick 42, such that the control circuitry 18 is configured to process the dimension data from the sensor signal of the dimension sensor 204 to determine a dimension value for the wick 42, and then compare the dimension value for the wick 42 against a predetermined dimension value. In this embodiment therefore, as the wick becomes wet/saturated in use with aerosolisable material, the physical dimensions of the wick 42 will vary depending on the quantity of aerosolisable material therein (in other words, the physical dimensions of the wick 42 will slightly swell/contract depending on the quantity of aerosolisable material therein). That being the case, each dimension sensor(s) 204 may be therefore configured to output the sensor signal containing dimension data related to the at least one physical dimension of the wick 42. In respect of the predetermined dimension value, this in accordance with some embodiments may be selected to correspond to a dimension value of the wick at the cusp of a dry-out status, whereby an insufficient amount of aerosolisable material is contained in the wick 42 and/or whereby the wick 42 is not saturated with aerosolisable material (i.e. in a state where the dimension value is sufficiently reduced as a result of there being an insufficient amount of aerosolisable material in the wick 42).

Accordingly, in the event the dimension value is less than the predetermined dimension value, the control circuitry 18 may then be configured to output a control signal, e.g. to affect/control the subsequent working of the aerosol provision system 1. Such a control signal in accordance with some particular embodiments thereof, as explained previously in respect of Figure 7, could provide a notification to the user and/or comprise a command to disable the operation of all, or at least a part of, the aerosol provision system 1.

With regard to what the physical dimension of the wick 42 might expressly be, it will be appreciated that this physical dimension could be any dimension whose quantity will change as the wick 42 starts to dry out. In that respect therefore, and in accordance with some embodiments, the at least one physical dimension may comprise the length L of the wick, wherein the length L extends from the first end 42A to the second end 42B of the wick 42, and wherein the dimension data is related to the length L of the wick. Such a psychical dimension may be detected in the arrangement shown in Figure 9, where the dimension sensor 204 in accordance with some embodiments may comprise at least one laser measure sensor located at the first and second ends 42A;42B of the wick 42. In that respect however, it will be entirely appreciated that any other type of dimension sensor(s) may be used/positioned in the aerosol provision system 1 to measure the length L of the wick 42, and which may be a contact sensor and/or a non-contact sensor, as required..

In accordance with some embodiments, the at least one physical dimension may comprise a width of the wick 42, wherein the dimension data is related to the width of the wick (as shown in the arrangement Figure 8). Again, in accordance with some of these embodiments, the dimension sensor 204 may comprise at least one laser measure sensor appropriately located with respect to the wick 42 such to determine the width of the wick 42. And in that respect again, it will be entirely appreciated that any other type of dimension sensor(s) may be used/positioned in the aerosol provision system 1 in such embodiments to appropriately measure the width of the wick 42.

Where the dimension data is related to the width of the wick 42, in accordance with some embodiments thereof, such as that shown in Figure 8, the width may corresponds to a width of the wick 42 which is located between the first end 42A and the second end 42B of the wick 42, wherein the wick is configured to receive the aerosolisable material at the first end 42A and the second end of the wick 42B. In such embodiments, the width in some particular embodiments thereof may be conveniently located at the midpoint along the length L of the wick (such as in Figure 8). In such arrangements, by measuring the parameter (in this case, the width) at a position from the wick 42 which is between the locations where the aerosolisable material is configured to be received in the wick 42, or put differently which is in a position from the wick 42 which is most distal from one or all of the locations where the aerosolisable material is configured to be received in the wick 42, the measured parameter may correspond to a position of the wick 42 where a dry-out status is first likely to occur. In which case, such a position for the measured parameter may allow the aerosol provision system 1 to determine a (dry-out) status of the wick quicker.

Aside from the possible use of a dimension sensor 204 in the context of the parameter being at least one physical dimension of the wick, in accordance with some embodiments, the at least one parameter may additionally/alternatively comprise an optical parameter, wherein the at least one sensor comprises an optical sensor 206, as shown in Figures 10 an 12. In accordance with such embodiments, the optical sensor 206 may be configured to output a sensor signal containing data related to the optical parameter. In accordance with such embodiments, the control circuitry 18 may be further configured to process the data from the sensor signal of each optical sensor 206 to determine an optical value for the wick, and from there compare the optical value for the wick against a predetermined optical value.

With reference to the terms optical parameter and optical value, these are intended to cover any measureable optical property of the wick which is configured to change as the wick becomes hot/cool, and/or as the level of aerosolisable material in the wick changes. In that respect therefore, and in accordance with some non-limiting embodiments, the optical parameter may comprise the colour of at least a portion 208 of the wick 42, and/or may comprise the reflectivity a portion of at least a portion 208 of the wick 42. In accordance with some particular embodiments thereof, such a portion 208 may correspond to an external surface of the wick 42. In a very particular embodiment thereof, and for the reasons explained previously, the external surface of the wick may be located between the first end 42A and the second end 42B of the wick 42 at which the wick 42 is configured to receive the aerosolisable material. And in such embodiments, to facilitate the aerosol provision system 1 being able to determine a (dry-out) status of the wick quicker, the portion/external surface of the wick 42 may be conveniently located at any of: the midpoint along the length L of the wick 42; a position from the wick 42 which is between the locations where the aerosolisable material is configured to be received in the wick 42; and/or in a position from the wick 42 which is most distal from one or all of the locations where the aerosolisable material is configured to be received in the wick 42.

In accordance with the above embodiment therefore, as the wick 42 (aerosolisable material transport element) 42 is cool and/or is wet/saturated in use with aerosolisable material, the optical value of the wick 42 will vary. In that respect, where the wick 42 starts to become excessively hot and/or dry, the wick 42 may begin to discolour and/or exhibit a change in colour or reflectance caused by the excess heat or dryness, which can be measured by the optical sensor(s) 206 and output as part of the sensor signal to the control circuitry 18. With reference to Figures 11 A-11 C, such a change in colour (or reflectance) of the wick is visualised. In that respect, with reference to Figures 11A-11 C, there is shown a portion of an aerosol provision system 1 , including an optical sensor 206 configured to output a sensor signal containing data related to the optical parameter of the wick 42.

In the above respect, and considering first the operation of Figure 11 A, in this operation the wick 42 may be configured to be operating in a sufficiently cool and/or wet configuration, wherein the wick is saturated with aerosolisable material that is supplied to the wick 42 (shown in Figure 11 A as aerosolisable material ingress points AM_in, which are located at the first end 42A and the second end 42B of the wick 42).

In operations where the wick 42 starts to become excessively hot and/dry through the wick 42 no longer being saturated with aerosolisable material (i.e. a dry-out status) via the aerosolisable material ingress points AM_in, the optical parameter (such as the colour of the portion 208 of the wick 42, and/or the reflectivity of the portion 208 the wick 42) of the wick 42 may begin to change. In that respect for instance, in Figure 11 B, there is shown only the portion 208 of the wick 42 changing colour/reflectance as a result of it becoming sufficiently hot and dry.

As the dry-out status continues to further manifest itself, the result may be that shown in Figure 11 C, which shows the entirety of the wick 42 changing colour/reflectance as a result of it becoming sufficiently hot and dry.

From the foregoing therefore, for a given wick (aerosolisable material transport element) 42, each optical sensor 208 may be configured to output a sensor signal containing data related to the optical parameter being sensed (such as the colour and/or reflectance of the portion 208 of the wick 42 as shown in Figures 10 and 12, and Figures 11A-11C), and such that the control circuitry 18 may be configured to process the data from the sensor signal of each optical sensor 206 to determine an optical value for the wick 42. From there, the control circuitry 18 may be then configured to compare the optical value for the wick against a predetermined optical value; and finally output a control signal in the event the optical value is greater than, and/or less than, a predetermined optical value. Put differently, the control signal might be configured to output the control signal in the event the optical value is indicative of a (dry-out) status of the wick.

In the above respect, the predetermined optical value may notionally correspond to an optical value where the wick is in a dry-out status, whereby an insufficient amount of aerosolisable material is contained in the wick 42 and/or whereby the wick 42 is not saturated with aerosolisable material (as shown for instance, in either Figures 11 B or 11C). In that respect as well, whether the optical value should be greater than, and/or less than, the predetermined optical value will notionally depend on the particular optical parameter being measured by the optical sensor(s) 206, and what the optical value is (such as the optical value comprising a set of Red, Green, and Blue values; the optical value comprising a light reflectance value; and/or the optical value comprising a lumen value; and/or the optical value comprising a lux value).

Whatever the optical value used, and whatever the optical parameter being measured, in the event the control circuitry 18 determines the optical value as being indicative of the status of the wick, the control circuitry 18 may then be configured to output a control signal, e.g. to affect/control the subsequent working of the aerosol provision system 1. Such a control signal in accordance with some particular embodiments thereof, as explained previously in respect of Figure 7, could for instance provide a notification to the user and/or comprise a command to disable the operation of all, or at least a part of, the aerosol provision system 1.

From the foregoing therefore, it can be seen that there may be provided an aerosol provision system 1 comprising a reservoir 31 for aerosolisable material; a wick (aerosolisable material transport element) 42 configured to receive the aerosolisable material from the reservoir 31, a vaporiser 40 configured to vaporise the aerosolisable material received in the wick 42, wherein the aerosol provision system 1 is configured to measure at least one parameter of the wick to determine a status of the wick, such as (but not necessarily limited to) a dry-out status.

In respect of any such operation of the aerosol provision system 1 to determine the status of the wick, it is envisaged that this operation may be implemented in any of the aerosol provision systems 1 described herein, such as those disclosed in Figures 1-6B, and which comprise the cartridge 2 and a control unit 4. In accordance with such embodiments, the reservoir 31 may be located in the cartridge, and wherein the control unit 4 comprises the cartridge receiving section 8 that includes an interface arranged to cooperatively engage with the cartridge 2 so as to releasably couple the cartridge 2 to the control unit 4, wherein the control unit further comprises the power supply 16 for delivering power to the vaporiser 40. Where a cartridge 2 and control unit 4 is employed in the aerosol provision system 1 , in accordance with such embodiments any provided control circuitry 18 may be located in either the control unit 4 and/or the cartridge 2.

In the above respect as well, it is envisaged that any determining of the status of the wick may in accordance with some embodiments be performed by the cartridge 2. In which case, in such embodiments, there may be effectively provided a cartridge 2 for an aerosol provision system 1 comprising the cartridge 2 and a control unit 4, wherein the cartridge comprises: the reservoir 31 for aerosolisable material; the wick 42 configured to receive the aerosolisable material from the reservoir 31 ; and the vaporiser 40 configured to vaporise the aerosolisable material received in the wick 42, wherein the cartridge 2 is configured to measure at least one parameter of the wick 42 to determine a status of the wick 42.

Conscious of the above embodiments which employ a cartridge 2 and a control unit 4, for the avoidance of any doubt, the aerosol provision systems 1 described herein may be equally applicable in other embodiments which do not employ a cartridge 2 which is configured to be received in a control unit 4.

In respect of the wick/aerosolisable material transport element arrangements shown in Figures 7-12, the vaporiser 40 is shown as extending around the wick/aerosolisable material transport element 40, though it will be appreciated that the teachings herein described may be applicable to other arrangements of wick 42 and/or vaporiser 40. In that respect for instance, it will be appreciated that the teachings herein may be applicable to other types of wick 42, such as where the wick 42 comprises a ceramic wick. In accordance with such embodiments, the vaporiser 40 may comprise a conductive material located on an external surface of the wick 42. Such conductive material may appreciably take any required shape on the surface of the wick 42, e.g. a spiral pattern; a raster pattern; or a zig-zag pattern such to allow the vaporiser 40 to efficiently vaporise the aerosolisable material in the wick 42. As will be appreciated, the conductive material may be connected to the connection leads 41 which deliver power to the vaporiser 40, as is also the case for the embodiments shown in Figures 7-12 where the vaporiser 40 may be similarly connected to the connection leads 41.

For the sake of completeness therefore, whilst the vaporiser 40 in accordance with some embodiments may be configured to extend around the wick 42, and/or be located on an external surface of the wick 42, which provides for a convenient arrangement for efficiently vaporising aerosolisable material form the wick 42, in accordance with other embodiments the vaporiser 40 may be configured to adopt other shapes and/or positions with respect to the wick 42 in the aerosol provision system 1. Turning to each sensor 200, in terms of how each sensor 200 may be configured to output a sensor signal to the control circuitry 18, it will be appreciated that each such signal may be sent using either a wired or wireless connection between the control circuitry 18 and the respective sensor 200. In the particular non-limiting embodiments shown in Figures 7-12, a wired connection is provided between each sensor 200 and the control circuitry 18, and which extends across the interface end 54 and corresponding receptacle 8 between the control unit 4 and the cartridge 2 via the contact electrodes 46.

Similarly, in terms of how each sensor 200 may be powered, it will be appreciated that this may be achieved using either the power supply 16 (as shown in the embodiments of Figures 7-10), or each sensor 200 comprising its own power source (not shown in the Figures).

Finally, in respect of the exact type of each sensor 200, it will be appreciated that the type of sensor 200 will depend on the parameter which it is configured to measure. In that respect therefore, in accordance with some embodiments, each sensor 200 may be configured to be in contact with the wick 42 for detecting the at least one parameter of the wick 42. Alternatively, depending on the type of sensor 200 used, each sensor 200 may be configured to not be in contact with the wick 42 for detecting the at least one parameter of the wick 42. Put differently, in such embodiments, each sensor 200 may comprise a noncontact sensor. Such a non-contact sensor 200, purely as non-limiting example, in accordance with some embodiments might comprise a laser measure sensor (e.g. for detecting a physical dimension parameter of the wick 42), and/or comprise a light emitter and a light receiver (e.g. for detecting an optical parameter of the wick 42, such as its colour and/or reflectivity).

Returning to the disclosure of Figures 10 and 11A-11C, another aspect of the present disclosure relates to the aerosol provision system 1 herein described but which further comprises at least one doping agent which is configured to colour the aerosolisable material transport element I wick 42 a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element 42 a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

In essence, and with reference to the operations described with reference to Figures 10 and 11A-11 C, the above doping agent is configured to make it more easy to identify, either visually, or for the optical sensor to identify, any change in the colour of the wick in instances when a dry-out status of the aerosolisable material transport element 42 is starting to occur. In this way, the presence of the doping agent may be configured to speed up the response time, and improve the accuracy, of the aerosol provision system 1 to detect a dry-out status of the wick.

In the above respect therefore, at a broad level, there may be herein provided an aerosol provision system 1 comprising an aerosolisable material transport element (wick) 42 for receiving aerosolisable material, and a vaporiser 42 configured to vaporise the aerosolisable material received in the aerosolisable material transport element 42. The aerosol provision system 1 may further comprise at least one doping agent which is configured to colour the aerosolisable material transport element 42 a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

In terms of what the first and second predetermined condition might be, in accordance with some embodiments, the first predetermined condition may comprises a condition when a dry-out status of the aerosolisable material transport element has not occurred, and wherein the second predetermined condition comprises a condition when a dry-out status of the aerosolisable material transport element has occurred. In such embodiments therefore, as explained previously, the doping agent may be configured to speed up the response time, and improve the accuracy, of the aerosol provision system 1 to detect a dry-out status of the aerosolisable material transport element.

In accordance with a more specific embodiment, the first predetermined condition may comprise a first moisture content of the aerosolisable material transport element, and the second predetermined condition may comprise a second moisture content of the aerosolisable material transport element which is less than the first moisture content. In this way therefore, in such embodiments the first moisture content may correspond to a moisture content for an aerosolisable material transport element which is saturated with aerosolisable material. Whereas the second moisture content may correspond to a moisture content for the aerosolisable material transport element which is not saturated with aerosolisable material, and/or which is subject to a dry-out status.

In respect of the above embodiments, it is envisaged that the doping agent might comprise a hydrochromic material, i.e. a material which is configured to change colour when sufficiently exposed to moisture. In this way, when the hydrochromic material is sufficiently exposed to the aerosolisable material, the hydrochromic material may contribute to the formation of the first colour, whereas when the hydrochromic material is insufficiently exposed to the aerosolisable material (e.g. in a dry-out status), the hydrochromic material may contribute to the formation of the second colour. Conveniently therefore, the implementation of the hydrochromic material may significantly increase the effectiveness of the aerosol provision system 1 , and/or any corresponding optical sensor 206, in so far as it may create a much greater contrast in colour between conditions when the aerosolisable material transport element 42 is saturated with aerosolisable material and conditions when the aerosolisable material transport element 42 is in a dry-out status with insufficient aerosolisable material in it. Put differently, and explained illustratively, the surprising introduction of the hydrochromic material has been found to increase the contrast in colour experienced between the colour of the aerosolisable material transport element shown in Figure 11A and the colour of the aerosolisable material transport element 42 shown in Figures 11 B/11C.

With respect to the placement of the hydrochromic material in the above embodiments, in accordance with particular embodiments thereof, the aerosolisable material transport element may comprise the doping agent and/or the hydrochromic material.

In terms of the exact positioning of the hydrochromic material in the aerosolisable material transport element, in accordance with some particular embodiments, the hydrochromic material may be provided as a coating on at least a portion of the aerosolisable material transport element, and/or the hydrochromic material may be deposited or located on an external surface of the aerosolisable material transport element 42, such as the portion 208.

Alongside, or in addition to, any potential use of a hydrochromic material in the doping agent, it is envisaged that the doping agent might comprise a thermochromic material, i.e. a material which is configured to change colour dependent on its temperature. In this way, when the thermochromic material is sufficiently cool (i.e. when the aerosolisable material transport element 42 is saturated with aerosolisable material), the thermochromic material may contribute to the formation of the first colour, whereas when the thermochromic material is sufficiently hot (e.g. in a dry-out status, as a result of the elevated temperature in the aerosolisable material transport element 42), the thermochromic material may contribute to the formation of the second colour. Put differently therefore, in embodiments where a thermochromic material is provided in the doping agent, in accordance with such embodiments at least, the first predetermined condition may comprise a first predetermined temperature of the aerosolisable material transport element, and the second predetermined condition may comprise a second predetermined temperature which is higher than the first predetermined temperature of the aerosolisable material transport element.

Conveniently, the implementation of the thermochromic material may significantly increase the effectiveness of the aerosol provision system 1 , and/or any corresponding optical sensor 206, in so far as it may create a much greater contrast in colour between conditions when the aerosolisable material transport element 42 is saturated with aerosolisable material and conditions when the aerosolisable material transport element 42 is in a dry-out status with an elevated temperature. Put differently, and explained illustratively, the presence of the thermochromic material may assist in the creation of an increased contrast in colour experienced between the colour of the aerosolisable material transport element shown in Figure 11A and the colour of the wick shown in Figures 11 B/11C where the aerosolisable material transport element is at an elevated temperature.

With respect to the placement of the thermochromic material in the above embodiments, in accordance with particular embodiments thereof, the aerosolisable material transport element may comprise the doping agent and/or the thermochromic material.

Where the thermochromic material is implemented in the aerosolisable material transport element, in accordance with some particular embodiments, the thermochromic material may be provided as a coating on at least a portion of the aerosolisable material transport element, and/or the thermochromic material may be deposited or located on an external surface of the aerosolisable material transport element 42, such as the portion 208.

Alternatively, it may be that the aerosolisable material comprises the doping agent and/or the thermochromic material. In accordance with such embodiments, upon the delivery of the thermochromic material to the aerosolisable material transport element 42 as part of the aerosolisable material, depending on the temperature of the aerosolisable material transport element 42, the colour of the thermochromic material may change between the first colour and the second colour. Specifically, in instances where the aerosolisable material transport element 42 is starting to dry out, and thus increases to an elevated temperature, at the point where the aerosolisable material is introduced to the aerosolisable material transport element 42 (AM_in), this elevation in temperature may cause the thermochromic material from the aerosolisable material at this point to adopt the second colour. Conversely, in a non dryout status, the reduced temperature of the aerosolisable material transport element 42 may cause the thermochromic material which is introduced to the aerosolisable material transport element 42 at the point AM_in to adopt/retain the first colour.

Where the doping agent comprises a thermochromic material, in accordance with some embodiments, the thermochromic material may also provide more of a striking colour to the aerosolisable material, which can make it more easily identifiable by the optical sensor 206 in the embodiments where the optical sensor 206 is positioned as shown in Figures 10 and 11A-11 C, i.e. in the position which measures a portion 208 which is most distal from the locations where the aerosolisable material is configured to be received in the wick 42 (AM_in). In that respect specifically, the presence of the thermochromic material in such embodiments may again conveniently increase the effectiveness of the aerosol provision system 1 , and/or any corresponding optical sensor 206, in so far as it may create a much greater contrast in colour between conditions when the aerosolisable material transport element 42 is saturated with aerosolisable material and the coloured thermochromic material (as per Figure 11A) and conditions when the aerosolisable material transport element 42 is in a dry-out status (as in Figures 11 B and 11C) with insufficient aerosolisable material in it.

In accordance with the foregoing therefore, the introduction of the thermochromic material in the doping agent may conveniently increase the contrast in colour experienced between the colour of the aerosolisable material transport element shown in Figure 11 A and the colour of the aerosolisable material transport element 42 shown in Figures 11 B/11 C. And where the aerosolisable material comprises the thermochromic material, this may effectively also allow for an aerosolisable material for use in an aerosol provision system 1, wherein the aerosolisable material comprises at least one doping agent comprising a thermochromic material, wherein the thermochromic material is configured to adopt a first colour at a first predetermined temperature, and is configured to adopt a second colour at a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature.

In so far as any doping agent is provided, such as the above described thermochromic material and/or hydrochromic material, where any resultant vapour from the aerosol provision system 1 is configured to be inhaled by the user, in accordance with such embodiments the doping agent may be non-toxic. Also in so far as any doping agent is provided, such as the above described thermochromic material and/or hydrochromic material, it will be appreciated that the doping agent may be organic or inorganic, and may comprise any combination of a dye; paint; ink; or pigment, depending on how and where the doping agent is provided in the aerosol provision system 1 (such as in the aerosolisable material transport element 42 or in the aerosolisable material itself), as explained previously.

For the sake of completeness, in accordance with these embodiments where the doping agent is provided, the aerosol provision system 1 in accordance with some particular embodiments therefor may nonetheless include the control circuitry 18 and the at least one sensor 200;206 for detecting the colour of the aerosolisable material transport element 42. In such embodiments, as mentioned previously, each sensor 200;206 may be then configured to output a sensor signal containing data related to the colour of the aerosolisable material transport element; wherein the control circuitry 18 is configured to process the data from the sensor signal of each sensor 200;206 to determine the colour of the aerosolisable material transport element. In response to the control circuitry 18 in such embodiments determining the colour of the aerosolisable material transport element as being the second colour, the control circuitry 18 in some particular embodiments thereof may be then configured to output the control signal, as explained previously with respect to Figures 7-9 at least, and which might for instance comprise a command to disable the operation of the aerosol provision system 1 and/or a command to disable the operation of the vaporiser 40; and/or which might comprise a command to provide a notification to a user.

In accordance with some embodiments provided herein, to potentially avoid the need for the control circuitry 18, a portion of the aerosolisable material transport element may be made visible to the user for detecting the colour of the aerosolisable material transport element. This might be achieved, for instance, by providing at least one window 212 or at least one transparent/translucent portion 212 in the aerosol provision system 1 through which the user may be configured to manually observe the colour of the aerosolisable material transport element 42, from a position outside the aerosol provision system 1. Such an embodiment is shown in Figure 12.

Thus, described herein are a number of configurations for the aerosol provision system 1 which conveniently allow it to measure at least one parameter of the aerosolisable material transport element (wick) 42 to determine a status of thereof, such as a dry-out status thereof.

Moving away from Figure 7-12, and turning now to the embodiments of Figure 13 (and also Figure 14), there is shown schematically a cross section view of another modified version of the aerosol provision system 1 , including the cartridge 2 and the control unit 4. The aerosol provision system 1 ; cartridge 2; and control unit 4 shown in Figures 13 and 14 are based on the construction of the corresponding aerosol provision system 1; cartridge 2; and control unit 4; shown in Figures 1-6B, and comprise similar components as set out by the reference numerals that are common to both sets of Figures. For instance, the cartridge 2 from Figures 13 and 14 comprise a vaporiser 40, which comprises a heating element, and wherein the cartridge 2 defines a reservoir 31 which extends around an aerosol outlet tube 38. In accordance with such embodiments, the reservoir 31 may be annular, and is configured for containing aerosolisable material for aerosolising. Similarly, the control unit 4 from Figures 13-14 may comprise the plastic outer housing 10 including the receptacle wall 12 that defines the receptacle 8 for receiving the end of the cartridge 2. The control unit 4 from Figure 13-14 may also comprise the control circuitry 18 and the power supply/battery 16. In such embodiments, the cartridge 2 may comprise the contact electrodes 46 for engaging with the control unit 4 for transferring power between the control circuitry 18 in the control unit 4 and the vaporiser 40 in the cartridge 2. Conscious of the above, and starting with Figure 13, a first modification to the aerosol provision system is it being configured to monitor at least one parameter of the vaporiser 40, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system 1. At its broadest level, it is envisaged that such a failure state could correspond to any adverse state in the aerosol provision system. Though in accordance with some particular embodiments, the failure state could correspond to the vaporiser exceeding a predetermined temperature, and/or the vaporiser experiencing a dryout state. In such a dry-out state, this may correspond to a state where the vaporiser 40 is not saturated with aerosolisable material. During such a dry-out state therefore, as the vaporiser 40 is operated, this may cause the vaporiser 40 to become excessively hot, as a result of there being an insufficient amount of aerosolisable material in the proximity of the vaporiser 40 to help cool the vaporiser 40 down.

In such a dry-out state, in so far as the aerosol provision system 1 is configured to monitor at least one parameter of the vaporiser 40 to determine a failure state of the aerosol provision system 1 (which in some particular embodiments could correspond to a failure state of the vaporiser 40), this may allow the aerosol provision system 1 to react in such instances where a dry-out state is detected, as will be described.

From the foregoing therefore, there may be effectively provided an aerosol provision system comprising 1 a reservoir 31 for aerosolisable material; and a vaporiser 40, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the aerosol provision system 1 is configured to monitor at least one parameter of the vaporiser 40, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system 1.

In accordance with some embodiments, the aerosol provision system 1 may further comprise the control circuitry 18, such that the control circuitry 18 is configured to determine the failure state of the aerosol provision system 1. In accordance with such embodiments, the aerosol provision system may be further provided with at least one sensor 300 for monitoring the at least one parameter, wherein each sensor 300 is configured to output a sensor signal containing data related to the at least one parameter to the control circuitry 18. With such data, the control circuitry 18 may be configured to process the data from the sensor signal of each sensor 300 to determine the failure state of the aerosol provision system 1.

In terms of what the above described at least one parameter may be, it is envisaged that this at least one parameter could comprise a number of different parameters relating to the vaporiser 40 as will be described. In the above respect, and with reference to Figure 13, in accordance with some embodiments, the at least one parameter may comprise a magnetic parameter of the vaporiser 40. In accordance with some particular embodiments thereof, the at least one sensor 300 may then comprise a first sensor 302 for detecting the magnetic parameter, and for outputting a first sensor signal containing first data related to the magnetic parameter. In terms of what such a first sensor 302 might be, it is envisioned that this sensor may be any sensor which is able to monitor the magnetic parameter. In that respect, and in a very particular embodiment, the first sensor may comprise a Hall effect sensor.

In accordance with a particular embodiment where the parameter is a magnetic parameter, the magnetic parameter may comprise the magnetic field strength generated by the vaporiser 40. In accordance with such embodiments, the control circuitry 18 may be then configured to determine a magnetic field strength value from the first data of the first sensor signal; compare the magnetic field strength value against a predetermined magnetic field strength value; and then determine the failure state of the aerosol provision system 1 in the event that the magnetic field strength value is less than the predetermined magnetic field strength value. In the above respect, and particularly where the failure state corresponds to a dry-out state of the vaporiser 40, as the temperature of the vaporiser 40 increases, the magnetic field strength from the vaporiser 40 may be begin to decrease. Accordingly, by setting the predetermined magnetic field strength value to a temperature of the vaporiser 40 which corresponds to the failure/dry-out state of the vaporiser 40, the above embodiments may provide for a convenient arrangement for detecting the failure state of the aerosol provision system 1.

In accordance with some embodiments where the at least one parameter comprises a magnetic parameter, to further facilitate the aerosol provision system 1 being able to determine the failure state, the vaporiser 40 may comprise a ferromagnetic material, which in accordance with some particular embodiments may comprise a Curie temperature which is greater than a first predetermined temperature, and which is less than a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature. In accordance with such particular embodiments, the first predetermined temperature may correspond to an operating temperature of the vaporiser where the vaporiser is saturated with aerosolisable material. Conversely, the higher second predetermined temperature may correspond to a temperature of the vaporiser 40 when the vaporiser 40 is no longer saturated with aerosolisable material, i.e. when the vaporiser is subject to a dry-out state.

Where such a Curie temperature is employed, in accordance with some embodiments thereof, the predetermined magnetic field strength value may correspond to the magnetic field strength of the vaporiser 40 at the Curie temperature, i.e. at a temperature when the failure state of the aerosol provision system 1 is indicative. As to the exact material for the vaporiser 40 which may provide such a required Curie temperature, it will be appreciated that this material may be selected depending on the particular relative geometry and materials used in the aerosol provision system 1. In accordance with some very particular non-limiting embodiments, however, it has been found that a ferromagnetic material comprising an alloy comprising nickel and chromium may provide a particularly suitable Curie temperature in accordance with the aerosol provision systems 1 comprising the geometry and features described herein, and as shown in the Figures.

Aside from the monitoring of any magnetic parameter, yet staying with Figure 13, in accordance with some embodiments, the at least one parameter may alternatively/additionally comprise an emissivity parameter of the vaporiser 40. In accordance with such embodiments, the at least one sensor 300 may then comprise a second sensor 304 (as shown in Figure 13), such as (but not limited to) an infrared sensor, for detecting the emissivity parameter, and for outputting a second sensor signal containing second data related to the emissivity parameter. With respect to such an emissivity parameter, as the temperature of vaporiser 40 changes (e.g. between a first operating temperature of the vaporiser where the vaporiser is saturated with aerosolisable material, and a higher second temperature when the vaporiser is no longer saturated with aerosolisable material), the emissivity of the vaporiser will change in accordance with this temperature change. From the foregoing therefore, and in accordance with some embodiments, the second data may be related to the emissivity parameter from any relevant portion of the vaporiser 40, such as an external surface thereof.

With any such second data, the control circuitry 18 may be configured to determine an emissivity value from the second data of the second sensor signal, and then compare the emissivity value against at least one predetermined emissivity value to determine the failure state of the aerosol provision system 1. Such an emissivity value in accordance with some particular embodiments may vary between 0 and 1. In terms of the predetermined emissivity value, this will appreciably depend on the composition of the vaporiser 40, and its notional emissivity at the point where the failure/dry-out state occurs. In that respect therefore, where the control circuitry 18 determines that the emissivity value sufficiently deviates from the predetermined emissivity value, i.e. is greater than and/or less than the predetermined emissivity value by a predetermined amount, the control circuitry 18 may be then configured to determine the failure state of the aerosol provision system 1.

In accordance with some embodiments, the at least one parameter may comprise a resonant frequency of the vaporiser 40, such that the control circuitry 18 may be further configured to determine the resonant frequency of the vaporiser; and compare the resonant frequency against at least one predetermined frequency value to determine the failure state of the aerosol provision system.

In accordance with such embodiments, it will be appreciated that as the temperature of the vaporiser 40 changes, the corresponding resonant frequency of the vaporiser will also change. Any such changes in the resonant frequency will be particularly noticeable where the vaporiser comprises a heating element such as a heating coil, such as in the arrangement shown in Figures 13 and 14. More specifically in the above respects, as the temperature of the vaporiser 40 changes, any perceived reactance (capacitive and/or inductance) properties of the vaporiser 40 will change based on the temperature of the vaporiser 40. Commensurately therefore, any temperature of the vaporiser 40 will cause the vaporiser to exhibit a particular resonant frequency for that temperature, which can be determined by the control circuitry 18, and then compared with the predetermined frequency value.

With respect to how the resonant frequency may be determined by the control circuitry 18, it will be appreciated that this may be achieved in a number of different ways. In accordance with a particular (non-limiting) embodiment, the resonant frequency could be determined by the control circuitry 18 applying a predetermined voltage to the vaporiser 40, at a plurality of different frequencies. The control circuitry 18 may then compare the voltage response across the vaporiser 40 for each frequency to determine the resonant frequency. In accordance with some particular embodiments thereof, the predetermined voltage may be provided by the power supply 16.

Similarly, in respect of the predetermined frequency value, it is envisaged that the predetermined frequency value may correspond to the resonant frequency of the vaporiser at the cusp of a failure (dry-out) state, whereat the vaporiser is no longer saturated with aerosolisable material.

In accordance with the above embodiments, and other embodiment alike, the aerosol provision system 1 may comprise a power supply 16 configured to provide alternating current, AC, power to the vaporiser 40, for facilitating the determination of the resonant frequency.

Staying with a frequency response of the vaporiser 40, and turning to Figure 14, in accordance with some embodiments, the at least one parameter may comprise a frequency of vibration of the vaporiser, wherein the aerosol provision system 1 further comprises a third sensor 306 for detecting the frequency of vibration of the vaporiser 40. In accordance with such embodiments, during the operation of the vaporiser 40, a vibrational effect may be created therein as a result of the power provided by the power supply 16 to the vaporiser 40. Such a vibrational effect may therefore result in a vibration frequency creating an audible and/or visible response, which can be detected by the third sensor 306. Although not limited thereto, such vibrations may be particularly prevalent for a vaporiser 40 taking the form of a heating coil 40, shown in the Figure 14, where the reactance properties of the coil shape may create more prevalent vibrations.

As to the type of third sensor 306 employed in the above embodiments, in accordance with some particular embodiments thereof, the third sensor 306 may comprise a vibration sensor; a microphone; and/or a piezoelectric sensor for detecting the vibration frequency of the vaporiser 40. Any such third sensor 306, as required, may also be a contact sensor which is in contact with the vaporiser 40 (as shown in Figure 14), or a non-contact sensor (e.g. in the case of the third sensor being a microphone).

Whatever the type of third sensor 306 which is employed, in accordance with some embodiments, the third sensor 306 may be configured to output a third sensor signal, to the control circuitry 18, containing data related to the frequency of vibration of the vaporiser 40. In such embodiments, the control circuitry 18 may be then configured to process the data from the third sensor signal to determine the vibration frequency of the vaporiser 40, and then compare the vibration frequency against at least one predetermined vibration frequency value to determine the failure state of the aerosol provision system.

In the above respect, and concerning the predetermined vibration frequency value, it is envisaged that this may correspond to the exhibited vibration frequency of the vaporiser at the cusp of a failure (dry-out) state, whereby the vaporiser 40 is no longer saturated with aerosolisable material.

From the foregoing therefore, it will be seen that a variety of different parameters of the vaporiser 40 have been described, and which can be monitored by the aerosol provision system 1 to determine a failure state of the aerosol provision system 1, such as a dry-out state.

Whatever the parameter(s) of the vaporiser 40 which is monitored, in response to detecting the failure state, the control circuitry 18 in accordance with some embodiments may be configured to control an operation of the aerosol provision system, such as disabling the operation of the aerosol provision system 1 and/or disabling the operation of the vaporiser 40. In accordance with some embodiments, the control circuitry 18 may be further configured to generate an output signal for providing a notification to a user. In accordance with some embodiments thereof, the output signal may comprise at least one of: an optical signal, an acoustic signal, and a haptic signal, which can be used to provide a notification to the user. Such a notification, in accordance with some particular embodiments, may include any of: a notification to the user that the aerosolisable material requires refilling; that the cartridge 2 requires replacing (where a cartridge 2/control unit 4 arrangement is employed); and/or a notification to the user that at least a portion of the aerosol provision system 1 has overheated.

To implement the above notifications, as required, in accordance with some embodiments, the aerosol provision system 1 may further comprise any one or combination of an optic element (such as an LED), an acoustic element (such as a speaker) and a haptic feedback element (such as a vibrator). Appreciably, in some particular embodiments to those set out above, any such optical/acoustic/haptic feedback element(s) may be most conveniently located on the control unit 4 (where such a cartridge 2/control unit 4 arrangement is employed).

With regards to the mechanisms described herein for determining the failure state of the aerosol provision system 1 , it will be appreciated these mechanisms may be applicable to any aerosol provision system 1 whereby the vaporiser 40 is configured for vaporising aerosolisable material from a reservoir 31 of such aerosolisable material. In that respect, any delivery mechanism may be provided for transferring the aerosolisable material from the reservoir 31 to the vaporiser 40. In accordance with some embodiments, this delivery mechanism may comprise the wick 42. In such embodiments, the wick 42 may be configured to receive the aerosolisable material from the reservoir 31 , wherein the vaporiser 40 is configured to vaporise the aerosolisable material received in the wick 42.

Where the wick 42 is present, it will be appreciated that the wick 42 may take several forms. In accordance with some embodiments, such as the aerosol provision systems 1 shown in the Figures, the wick 42 may be a capillary wick comprising a first end 42A and a second end 42B which is opposite the first end 42A. Equally, the wick 42 may comprise a fibrous material, and/or in some embodiments may comprise a ceramic material.

Where the wick 42 comprises a ceramic material, in some particular embodiments thereof, the vaporiser 40 may comprise a conductive material located on an external surface of the wick 42. Such conductive material may appreciably take any required shape on the surface of the wick 42, e.g. a spiral pattern; a raster pattern; or a zig-zag pattern such to allow the vaporiser 40 to efficiently vaporise the aerosolisable material in the wick 42. As will be appreciated, the conductive material may be connected to the connection leads 41 which deliver power to the vaporiser 40.

With regard to the construction of the vaporiser 40 which might be used with the aerosol provision systems 1 described herein, it will be appreciated that the vaporiser 40 may take a variety of different forms. In that respect, and in accordance with some particular embodiments, the vaporiser 40 may comprise a heating element such as a heating coil. In accordance with some particular embodiments where the wick 42 is present, in such embodiments the heating coil may be coiled, and/or extend around, the wick 42 (e.g. as shown in the Figures). Equally, as noted above, in accordance with some other embodiments, the vaporiser 40 might be located on a wick 42 comprising a ceramic material.

Appreciating the foregoing, it is envisaged that the mechanisms described herein for determining the failure state of the aerosol provision system 1 may be located in a number of different aerosol provision system 1, and in a number of different configurations with respect to the remaining components of each such aerosol provision system 1. In accordance with some embodiments, such as that shown in Figures 13 and 14, the mechanism may be located in an aerosol provision system 1 comprising the cartridge and the control unit 4. In such embodiments, the reservoir 31 and the vaporiser 40, along with any provided sensor(s) 300 may be located in the cartridge 2. In such embodiments, the control unit 4 may then comprise the cartridge receiving section 8 that includes the interface arranged to cooperatively engage with the cartridge 2 so as to releasably couple the cartridge 2 to the control unit 4.

Equally, in some embodiments, the entirety of the detecting mechanism may be located in the cartridge 2. In such embodiments, there may be provided, at least, a cartridge 2 for an aerosol provision system 1 comprising the cartridge 2 and a control unit 4, wherein the cartridge 2 comprises: the reservoir 31 for aerosolisable material; and the vaporiser 40, comprising the heating element, for vaporising aerosolisable material from the reservoir 31. In accordance with such embodiments, the cartridge 2 may be configured to monitor at least one parameter of the vaporiser 40, which is not the electrical resistance of the heating element 40, to determine a failure state of the cartridge 2, such as (but not limited to) a dryout state of the cartridge 2.

In embodiments where the control unit 4 comprises a portion of the detecting mechanism, such as the control circuitry 18 and the power supply 16, there may be provided a corresponding mechanism for transferring power and/or any signals between the portion of the detecting mechanism in the control unit 4, and the remaining portion (such as the vaporiser 40 and any sensor(s) 300) present in the cartridge 2. In that respect therefore, and in accordance with some embodiments such as those shown in Figures 13 and 14, a wired connection may be provided between the cartridge 2 and the control unit 4, and which extends across the interface end 54 and corresponding receptacle 8 between the control unit 4 and the cartridge 2 via the contact electrodes 46, for transferring power/signals between the cartridge and the control unit 4. It will be appreciated that in such embodiments however, a wireless connection could equally be used to bridge any required power/signals between the cartridge 2 and the control unit 4, such to obviate the need for the contact electrodes 46.

In accordance with certain embodiments of the disclosure, a cartridge for an aerosol provision system may generally comprise a housing part having a mouthpiece end and an interface end, wherein the mouthpiece end includes an aerosol outlet for the cartridge and the interface end includes an interface for coupling the cartridge to a control unit. An air channel wall (which may be formed by various components of the cartridge) extends from an air inlet for the cartridge to the aerosol outlet via an aerosol generation region in the vicinity of a vaporiser. The cartridge has a reservoir within the housing part containing aerosolisable material for aerosolisation. The reservoir is defined by a region within the housing part which is outside the air channel and an end of the reservoir at the interface end of the housing part is sealed by a resilient plug comprising a base part and an outer wall, wherein the outer wall of the resilient plug forms a seal with an inner surface of the housing part. Respective ends of a aerosolisable material transport element pass through opening in the air channel or into the reservoir so as to convey aerosolisable material from the reservoir to the vaporiser.

One aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the resilient plug 44 provides a seal to the housing part 32. In particular, in accordance with some example implementations the outer wall 102 of the resilient plug 44 which seals to the inner surface of the housing part 32 to form the end of the aerosolisable material reservoir extends in direction parallel to the longitudinal axis of the cartridge to a position which is further from the interface end of the cartridge than the aerosolisable material transport element I vaporiser. That is to say, the ends of the aerosolisable material transport element extends into the aerosolisable material reservoir in a region which is surrounded by the outer sealing wall of the resilient plug. Not only does this help seal the reservoir against leakage, it allows the geometry of the reservoir in the region which supplies the aerosolisable material transport element with aerosolisable material to be governed by the geometry of the resilient plug. For example, the radial thickness of the reservoir in this region can readily be made smaller than the radial thickness in other longitudinal positions along the air channel, which can help trap aerosolisable material in the vicinity of the aerosolisable material transport element, thereby helping to reduce the risk of dry out for different orientations of the cartridge during use.

The outer wall of the resilient plug may, for example, contact the inner surface of the housing part at locations over a distance of at least 5 mm, 6 mm, 7 mm, 8 mm, 9 mm and 10 mm in a direction extending from the interface end to the mouthpiece end (i.e. parallel to the longitudinal axis). The outer wall of the resilient plug may be in contact with the inner surface of the housing over the majority of this distance, or the outer wall of the resilient plug may include a number of (e.g. four) circumferential ridges 140 to help improve sealing. The resilient plug may be slightly oversized relative to the opening in the housing part so that it is biased into slight compression. For example, for the implementation shown in Figure 3B, the interior width of the housing part into which the resilient plug is inserted in the plane of this figure is around 17.5 mm, whereas the corresponding width of the resilient plug is around 18 mm, thereby placing the resilient plug into compression when inserted into the housing part. As can be most readily seen in Figures 5A to 5C, whereas the outer cross section of the cartridge housing part is symmetric under a 180° rotation, the resilient plug 44 does not have the same symmetry because it includes a flat 142 on one side to accommodate the air channel gap 76 provided by the double-walled section 74 of the housing part (i.e. the resilient plug is asymmetric in a plane perpendicular to a longitudinal axis of the cartridge to accommodate the double-walled section of the housing part).

In terms of the radial size I width of the reservoir in the annular region where the aerosolisable material transport element extends into the reservoir, a distance between the air channel wall and the outer wall of the resilient plug in this region may, for example, be in the range 3 mm to 8 mm. In the example cartridge discussed above which has a generally oval housing part and a generally circular air channel, it will be appreciated the thickness of the reservoir is different at different locations around the air channel. In this example the aerosolisable material transport element is arranged to extend into the reservoir in the region where it is widest in the axial direction, i.e. into the "lobes" of the oval reservoir around the air channel. The portions of the aerosolisable material transport element that extend into the reservoir may, for example, have a length, as measured from the interior of the air channel wall, in the range 2 mm to 8 mm, e.g. in the range 3 mm to 7 mm or in the range 4 mm to 6 mm. The specific geometry in this regard (and for other aspects of the configuration) may be chosen having regard to a desired rate of aerosolisable material transport, for example having regard to the capillary strength of the aerosolisable material transport element and the viscosity of the aerosolisable material, and may be established for a given cartridge design through modelling or empirical testing.

Another aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the air channel is routed through the cartridge, and in particular from the air inlet to the vicinity of the vaporiser (the aerosol generation region). In particular, whereas in a conventional cartridges an air inlet is typically provided at the interface end of the cartridge, in accordance with certain embodiments of the disclosure, an air inlet for the cartridge is located in a side wall of the housing part at a position which is further from the interface end than at least a part of the resilient plug that seals an end of the reservoir. Thus, the air channel in the cartridge is initially routed from the air inlet towards the interface end and bypasses the resilient plug before changing direction and entering the aerosol generation chamber through the resilient plug. This can allow the outer surface of the cartridge at the interface end, where it is closest to the vaporiser, to be closed, thereby helping to reduce the risk of leakage from the cartridge, both in terms of aerosolisable material coming through the openings in the air channel which is not retained by the aerosolisable material transport element in the air channel (e.g. due to saturation I agitation) or aerosolisable material that has being vaporised but condensed back to aerosolisable material in the air channel during use. In some implementations, a distance from air inlet to the interface end of the housing part may be at least 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

In some example implementations an absorbent element, for example a portion of sponge material or a series of channels forming a capillary trap, may be provided between the air inlet and the aerosol generation chamber, for example in the region air channel formed between the base of the resilient plug and the end cap, to further help reduce the risk of leakage by absorbing aerosolisable material that forms in the air channel and so helping prevent the aerosolisable material travelling around the air channel through the air inlet or towards the aerosol outlet.

In some example implementations the air channel from the air inlet to the aerosol outlet may have its smallest cross-sectional area where it passes through the hole 106 in the resilient plug. That is to say, the hole in the resilient plug may be primarily responsible for governing the overall resistance to draw for the electronic cigarette.

Another aspect of some particular cartridge configurations in accordance with certain embodiments of the disclosure is the manner in which the dividing wall element divides the air reservoir into two regions, namely a main region above the dividing wall (i.e. towards a mouthpiece end of the cartridge) and a aerosolisable-material-supply region below the dividing wall (i.e. on the same side of the dividing wall as where the aerosolisable material transport element extends from the vaporiser into the reservoir). The dividing wall includes openings to govern the flow of aerosolisable material on the main region to the aerosolisable material supply region. The dividing wall can help retain aerosolisable material in the aerosolisable material supply region of the reservoir, example when the electronic cigarette is tilted through various orientations, which can help avoid dry out. The dividing wall can also conveniently provide a mechanical stop for the resilient plug to abut I press against so as to help correctly locate the resilient plug during assembly and maintain the resilient plug in slight compression between the dividing wall and the end cap when the cartridge is assembled. In the example discussed above, the dividing wall is formed as a separate element form the housing part, wherein an inner surface of the housing part includes one or more protrusions arranged to contact the side of the dividing wall facing the mouthpiece end of the cartridge to locate the dividing wall along a longitudinal axis of the cartridge, but in other examples the dividing wall may be integrally formed with the housing part.

In the example discussed above the dividing wall is in the form of an annular band around the air channel and comprises four fluid communication openings 150 located in respective quadrants of the band. However, more or fewer openings through the dividing wall may be provided in different implementations. Individual openings may, for example, have an area of between 4 mm² and 15 mm².

A combined area for the at least one openings as a fraction of the total area of the dividing wall exposed to aerosolisable material supply region of the reservoir region may be, for example, from 20% to 80%; 30% to 70% or 40% to 60%.

It will be appreciated that while the above description has focused on some specific cartridge configurations comprising a number of different features, cartridges in accordance with other embodiments of the disclosure may not include all these features. For example, in some implementations an air path generally of the kind discussed above, i.e. with an air inlet which is in a sidewall of the cartridge and closer to the mouthpiece end of the cartridge than the vaporiser, may be provided in a cartridge which does not include a resilient plug with an outer sealing wall which extends around the vaporiser and I or does not include a dividing wall element of the kind discussed above. Similarly, a cartridge which does include a resilient plug with an outer sealing wall which extends around the vaporiser may have an air inlet into the cartridge which is at the interface end of the cartridge, and not in a sidewall, and which may also not have a dividing wall element of the kind discussed above. Furthermore, a cartridge which does include a dividing wall element, might not include an air inlet located further from the interface end of the cartridge than the vaporiser and I or an extended outer sealing wall for a resilient plug as discussed above.

Thus, there has been described an aerosol provision system comprising a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir, a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the aerosol provision system is configured to measure at least one parameter of the wick to determine a status of the wick.

There has also been described a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir; and a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the cartridge is configured to measure at least one parameter of the wick to determine a status of the wick.

There has also been described an aerosolisable material for use in an aerosol provision system, wherein the aerosolisable material comprises at least one doping agent comprising a thermochromic material, wherein the thermochromic material is configured to adopt a first colour at a first predetermined temperature, and is configured to adopt a second colour at a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature.

There has also been described a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element, and at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

There has also been described an aerosol provision system comprising an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element; wherein the aerosol provision system further comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

There has also been described an aerosolisable material transport element for receiving aerosolisable material, wherein the aerosolisable material transport element comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition. There has also been described an aerosol provision system comprising: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the aerosol provision system is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system.

There has also been described a cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the cartridge is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the cartridge.

There has also been described an aerosol provision system 1 comprising a reservoir 31 for aerosolisable material; a wick 42 configured to receive the aerosolisable material from the reservoir 31 , a vaporiser 40 configured to vaporise the aerosolisable material received in the wick 42, wherein the aerosol provision system 1 is configured to measure at least one parameter of the wick 42 to determine a status of the wick 42. The parameter may be the moisture content of the wick 42, at least one physical dimension of the wick 42, and/or an optical parameter, such as the colour of an external surface of the wick 42, or the reflectivity of an external surface of the wick 42.

While the above described embodiments have in some respects focussed on some specific example aerosol provision systems, it will be appreciated the same principles can be applied for aerosol provision systems using other technologies. That is to say, the specific manner in which various aspects of the aerosol provision system function, for example in terms of the underlying form of the vaporiser or vaporiser technology used are not directly relevant to the principles underlying the examples described herein.

In that respect, it will also be appreciated that various modifications may be made to the embodiments of aerosol provision system described herein. For instance, although the vaporiser 40 has been described in a number of the above embodiments as being located in the cartridge, it will be appreciated that in some embodiments the vaporiser may be located in the control unit of the aerosol provision system. In order to address various issues and advance the art, this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and to teach the claimed invention(s). It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the claims. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. other than those specifically described herein, and it will thus be appreciated that features of the dependent claims or clauses may be combined with features of the independent claims or independent clauses in combinations other than those explicitly set out in the claims and clauses. The disclosure may include other inventions not presently claimed, but which may be claimed in future. In effect, any combination of feature(s) from one set of claims many be combined with any other individual feature(s) from any of the remaining set of claims or clauses.

First Set of Clauses

1. An aerosolisable material for use in an aerosol provision system, wherein the aerosolisable material comprises at least one doping agent comprising a thermochromic material, wherein the thermochromic material is configured to adopt a first colour at a first predetermined temperature, and is configured to adopt a second colour at a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature.

2. An aerosolisable material according to clause 1, wherein the aerosolisable material is liquid.

3. An aerosolisable material according to any preceding clause, wherein the aerosolisable material is a gel.

4. A cartridge for an aerosol provision system, wherein the cartridge contains a reservoir containing the aerosolisable material according to any preceding clause, and an aerosol forming substrate for receiving the aerosolisable material from the reservoir.

5. An aerosol provision system according to any of clauses 1-3, wherein the aerosol provision system contains a reservoir for containing the aerosolisable material according to clause 1 , and an aerosol forming substrate for receiving the aerosolisable material from the reservoir.

6. A cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element, and at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

7. A cartridge for an aerosol provision system according to clause 6, wherein the cartridge further comprises a reservoir for containing aerosolisable material, and wherein the aerosolisable material transport element is configured to receive the aerosolisable material from the reservoir.

8. An aerosol provision system comprising an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element; wherein the aerosol provision system further comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

9. An aerosol provision system according to clause 8, wherein the aerosol provision system further comprises a reservoir for containing aerosolisable material, and wherein the aerosolisable material transport element is configured to receive the aerosolisable material from the reservoir.

10. An aerosol provision system according to clause 8 or 9, wherein the aerosolisable material transport element comprises the doping agent.

11. An aerosol provision system according to any of clauses 8 to 10, further comprising the aerosolisable material.

12. An aerosol provision system according to clause 11 , wherein the aerosolisable material comprises the doping agent.

13. An aerosol provision system according to clause 11 or 12, wherein the aerosolisable material comprises a liquid.

14. An aerosol provision system according to clause 11 or 12, wherein the aerosolisable material comprises a gel.

15. An aerosol provision system according to any of clauses 8 to 14, wherein the doping agent comprises a hydrochromic material.

16. An aerosol provision system according to any of clauses 8 to 15, wherein the first predetermined condition comprises a first moisture content of the aerosolisable material transport element, and the second predetermined condition comprises a second moisture content of the aerosolisable material transport element which is less than the first moisture content.

17. An aerosol provision system according to any of clauses 8-16, wherein the doping agent comprises a thermochromic material.

18. An aerosol provision system according to any of clauses 8-17, wherein the first predetermined condition comprises a first predetermined temperature of the aerosolisable material transport element, and the second predetermined condition comprises a second predetermined temperature which is higher than the first predetermined temperature of the aerosolisable material transport element.

19. An aerosol provision system according to any of clauses 8-18, wherein the doping agent comprises a dye or pigment.

20. An aerosol provision system according to any of clauses 8-19, wherein the aerosol provision system comprises control circuitry and at least one sensor for detecting the colour of the aerosolisable material transport element, wherein each sensor is configured to output a sensor signal containing data related to the colour of the aerosolisable material transport element; and wherein the control circuitry is configured to process the data from the sensor signal of each sensor to determine the colour of the aerosolisable material transport element.

21. An aerosol provision system according to clause 20, wherein response to the control circuitry determining the colour of the aerosolisable material transport element as being the second colour, the control circuitry is configured to output a control signal.

22. An aerosol provision system according to any of clauses 8-21, wherein a portion of the aerosolisable material transport element is visible to the user for detecting the colour of the aerosolisable material transport element.

23. An aerosol provision system according to any of clauses 8-22, further comprising a cartridge and a control unit, wherein the aerosolisable material transport element and the vaporiser is located in the cartridge, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the cartridge so as to releasably couple the cartridge to the control unit, wherein the control unit further comprises a power supply for delivering power to the vaporiser.

24. An aerosolisable material transport element for receiving aerosolisable material, wherein the aerosolisable material transport element comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

25. A method of indicating a change in condition of an aerosolisable material transport element which is configured to receive aerosolisable material from a reservoir of aerosolisable material, wherein the method comprises: colouring the aerosolisable material transport element a first colour at a first predetermined condition using a doping agent; and colouring the aerosolisable material transport element a second colour at a second predetermined condition, using the doping agent, wherein the second predetermined condition is different from the first predetermined condition.

26. A method according to clause 25, wherein the first predetermined condition comprises a first predetermined temperature of the aerosolisable material transport element, and the second predetermined condition comprises a second predetermined temperature which is higher than the first predetermined temperature of the aerosolisable material transport element.

27. A method according to clause 25 or 26, wherein the aerosolisable material transport and the reservoir are located in an aerosol provision system further comprising a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element.

28. A method according to clause 25 or 26, wherein the aerosolisable material transport and the reservoir are located in a cartridge for an aerosol provision system, the cartridge further comprising a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element. Second Set of Clauses

1. An aerosol provision system comprising: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the aerosol provision system is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system.

2. The aerosol provision system according to clause 1 , wherein the aerosol provision system further comprises control circuitry which is configured to determine the failure state of the aerosol provision system.

3. The aerosol provision system according to clause 2, further comprising at least one sensor for monitoring the at least one parameter, wherein each sensor is configured to output a sensor signal containing data related to the at least one parameter to the control circuitry; wherein the control circuitry is configured to process the data from the sensor signal of each sensor to determine the failure state of the aerosol provision system.

4. The aerosol provision system of clause 3, wherein the at least one parameter comprises a magnetic parameter of the vaporiser; and wherein the at least one sensor comprises a first sensor for detecting the magnetic parameter, and for outputting a first sensor signal containing first data related to the magnetic parameter.

5. The aerosol provision system of clause 4, wherein the magnetic parameter is the magnetic field strength generated by the vaporiser, and wherein the control circuitry is further configured to: determine a magnetic field strength value from the first data of the first sensor signal; compare the magnetic field strength value against a predetermined magnetic field strength value; and determine the failure state of the aerosol provision system in the event that the magnetic field strength value is less than the predetermined magnetic field strength value. 6. The aerosol provision system of clause 5, wherein the vaporiser comprises a ferromagnetic material which comprises a Curie temperature which is greater than a first predetermined temperature, and which is less than a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature; wherein the predetermined magnetic field strength value corresponds to the magnetic field strength of the vaporiser at the Curie temperature.

7. The aerosol provision system of clause 6, wherein the ferromagnetic material comprises an alloy comprising nickel and chromium.

8. The aerosol provision system of any of clauses 4-7, wherein the first sensor comprises a Hall effect sensor.

9. The aerosol provision system of any of clauses 3-8, wherein the at least one parameter comprises an emissivity parameter of the vaporiser; and wherein the at least one sensor comprises a second sensor for detecting the emissivity parameter, and for outputting a second sensor signal containing second data related to the emissivity parameter.

10. The aerosol provision system of clause 9, wherein the second sensor comprises an infrared sensor.

11. The aerosol provision system of clause 9 or 10, wherein the control circuitry is configured to: determine an emissivity value from the second data of the second sensor signal; and compare the emissivity value against a predetermined emissivity value to determine the failure state of the aerosol provision system.

12. The aerosol provision system of any of clauses 3-11, wherein the at least one parameter comprises a frequency of vibration of the vaporiser, wherein the aerosol provision system further comprises a third sensor for detecting the frequency of vibration of the vaporiser, wherein the third sensor is configured to output a third sensor signal, to the control circuitry, containing data related to the frequency of vibration of the vaporiser; wherein the control circuitry is further configured to process the data from the third sensor signal to determine the vibration frequency of the vaporiser; and compare the vibration frequency against at least one predetermined vibration frequency value to determine the failure state of the aerosol provision system.

13. The aerosol provision system of any of clauses 2-12, wherein the at least one parameter comprises a resonant frequency of the vaporiser, wherein the control circuitry is further configured to: determine the resonant frequency of the vaporiser; and compare the resonant frequency against at least one predetermined frequency value to determine the failure state of the aerosol provision system.

14. The aerosol provision system of any of preceding clause, further comprising a power supply configured to provide alternating current, AC, power to the vaporiser.

15. The aerosol provision system of clause 14, when further dependent on clause 13, wherein the control circuitry is configured to vary the frequency of the AC power provided to the vaporiser to determine the resonant frequency of the vaporiser.

16. An aerosol provision system according to any preceding clause, wherein the failure state of the aerosol provision system comprises the vaporiser exceeding a predetermined temperature.

17. An aerosol provision system according to any preceding clause, wherein the failure state of the aerosol provision system comprises the vaporiser experiencing a dry-out state.

18. An aerosol provision system according to any of clauses 2-17, wherein response to detecting the failure state, the control circuitry is further configured to: disable the operation of the aerosol provision system.

19. An aerosol provision system according to any of clauses 2-18, wherein response to detecting the failure state, the control circuitry is further configured to: disable the operation of the vaporiser.

20. An aerosol provision system according to any of clauses 2-19, wherein response to detecting the failure state, the control circuitry is further configured to: generate an output signal for providing a notification to a user. 21. An aerosol provision system according to clause 20, wherein the output signal is at least one of: an optical signal, an acoustic signal, and a haptic signal.

22. An aerosol provision system according to any preceding clause, further comprising a cartridge and a control unit, wherein the reservoir and the vaporiser are located in the cartridge, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the cartridge so as to releasably couple the cartridge to the control unit.

23. The aerosol provision system of clause 22 when further dependent on clause 3, wherein the cartridge comprises the at least one sensor.

24. The aerosol provision system of clause 22 or 23 when further dependent on clause 14, wherein the control unit comprises the power supply.

25. An aerosol provision system according to any preceding clause, further comprising a wick for receiving aerosolisable material from the reservoir, wherein the vaporiser is configured to vaporise the aerosolisable material received in the wick.

26. An aerosol provision system according to any preceding clause, wherein the heating element comprises a heating coil.

27. A cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the cartridge is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the cartridge.

Claims

1. An aerosol provision system comprising a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir, a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the aerosol provision system is configured to measure at least one parameter of the wick to determine a status of the wick.

2. An aerosol provision system according to claim 1 , wherein the status is the wick containing less than a predetermined amount of aerosolisable material.

3. An aerosol provision system according to any preceding claim, wherein the status is the wick exceeding a predetermined temperature.

4. An aerosol provision system according to any preceding claim, wherein the aerosol provision system comprises control circuitry and at least one sensor for detecting the at least one parameter; wherein each sensor is configured to output a sensor signal containing data related to the at least one parameter; and wherein the control circuitry is configured to process the data from the sensor signal of each sensor to determine the status of the wick.

5. An aerosol provision system according to claim 4, wherein the at least one parameter comprises the moisture content of the wick; wherein the at least one sensor comprises at least one load cell on which the wick is supported, wherein each load cell is configured to output a sensor signal containing mass data related to the mass of the wick; and wherein the control circuitry is further configured to: process the mass data from the sensor signal of each load cell to determine a mass value for the wick; compare the mass value for the wick against a predetermined mass value; and output a control signal in the event the mass value is less than the predetermined mass value.

6. An aerosol provision system according to claim 5, wherein the at least one load cell comprises a first load cell which supports a first end of the wick, and a second load cell which supports a second end of the wick.

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7. An aerosol provision system according to any of claims 4-6, wherein the at least one parameter comprises at least one physical dimension of the wick, wherein the at least one sensor comprises a dimension sensor for detecting the at least one physical dimension of the wick, wherein the dimension sensor is configured to output a sensor signal containing dimension data related to the at least one physical dimension of the wick; and wherein the control circuitry is further configured to: process the dimension data from the sensor signal of the dimension sensor to determine a dimension value for the wick; compare the dimension value for the wick against a predetermined dimension value; and output a control signal in the event the dimension value is less than predetermined dimension value.

8. An aerosol provision system according to claim 7, wherein the at least one physical dimension comprises a length of the wick, wherein the length extends from a first end to a second end of the wick, and wherein the dimension data is related to the length of the wick.

9. An aerosol provision system according to claim 7 or 8, wherein the at least one physical dimension comprises a width of the wick, and wherein the dimension data is related to the width of the wick.

10. An aerosol provision system according to any of claim 9, wherein the width corresponds to a width of the wick which is located between a first end and a second end of the wick, wherein the wick is configured to receive the aerosolisable material at the first end and the second end of the wick.

11. An aerosol provision system according to claim 10, wherein the width is located at the midpoint along a length of the wick, wherein the length extends from the first end and the second end.

12. An aerosol provision system according to any of claims 4-11 , wherein the at least one sensor comprises an optical sensor, wherein the at least one parameter comprises an optical parameter, and wherein the optical sensor is configured to output a sensor signal containing data related to the optical parameter.

13. An aerosol provision system according to claim 12, wherein the control circuitry is further configured to:

55 process the data from the sensor signal of each optical sensor to determine an optical value for the wick; compare the optical value for the wick against a predetermined optical value; and output a control signal in the event the optical value is greater than, and/or less than, a predetermined optical value.

14. An aerosol provision system according to claim 12 or 13, wherein the optical parameter is the colour of an external surface of the wick.

15. An aerosol provision system according to any of claim 12-14, wherein the optical parameter is the reflectivity of an external surface of the wick.

16. An aerosol provision system according to claim 14 or 15, wherein the wick is configured to receive the aerosolisable material from the reservoir at a first end and a second end of the wick, wherein the external surface of the wick is located between the first end and the second end.

17. An aerosol provision system according to claim 16, wherein the external surface is located at the midpoint along a length of the wick, wherein the length extends from the first end and the second end.

18. An aerosol provision system according to any of claims 5, 7, or 13, wherein the control signal comprises a command to disable the operation of the aerosol provision system.

19. An aerosol provision system according to any of claims 5, 7, 13, or 18, wherein the control signal comprises a command to disable the operation of the vaporiser.

20. An aerosol provision system according to any of claims 5, 7, 13, 18, or 19, wherein the control signal comprises a command to provide a notification to a user.

21. An aerosol provision system according to claim 20, wherein the control signal is at least one of: an optical signal, an acoustic signal, and a haptic signal.

22. An aerosol provision system according to any preceding claim, wherein the aerosol provision system comprises at least one doping agent which is configured to colour the wick a first colour at a first predetermined condition, and which is configured to colour the wick a

56 second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

23. An aerosol provision system according to claim 22, wherein the wick comprises the doping agent.

24. An aerosol provision system according to claim 22 or 23, further comprising the aerosolisable material in the reservoir, wherein the aerosolisable material comprises the doping agent.

25. An aerosol provision system according to claim 22 or 23, wherein the doping agent comprises a hydrochromic material.

26. An aerosol provision system according to any of claims 22-25, wherein the first predetermined condition comprises a first moisture content of the wick, and the second predetermined condition comprises a second moisture content of the wick which is less than the first moisture content.

27. An aerosol provision system according to any of claims 22-26, wherein the doping agent comprises a thermochromic material.

28. An aerosol provision system according to any of claims 22-27, wherein the first predetermined condition comprises a first predetermined temperature of the wick, and the second predetermined condition comprises a second predetermined temperature which is higher than the first predetermined temperature of the wick.

29. An aerosol provision system according to any of claims 22-28, wherein the doping agent comprises a dye or pigment.

30. An aerosol provision system according to any preceding claim, further comprising a cartridge and a control unit, wherein the reservoir is located in the cartridge, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the cartridge so as to releasably couple the cartridge to the control unit, wherein the control unit further comprises a power supply for delivering power to the vaporiser.

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31. An aerosol provision system according to claim 30 when further dependent on claim 4, wherein the control circuitry is located in the control unit.

32. An aerosol provision system according to any preceding claim, wherein the vaporiser extends around the wick.

33. An aerosol provision system according to any preceding claim, wherein the vaporiser is located on an external surface of the wick.

34. An aerosol provision system according to any preceding claim, wherein the vaporiser comprises a heating coil.

35. A cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; a wick configured to receive the aerosolisable material from the reservoir; and a vaporiser configured to vaporise the aerosolisable material received in the wick, wherein the cartridge is configured to measure at least one parameter of the wick to determine a status of the wick.

36. An aerosolisable material for use in an aerosol provision system, wherein the aerosolisable material comprises at least one doping agent comprising a thermochromic material, wherein the thermochromic material is configured to adopt a first colour at a first predetermined temperature, and is configured to adopt a second colour at a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature.

37. An aerosolisable material according to claim 36, wherein the aerosolisable material is liquid.

38. An aerosolisable material according to any preceding claim, wherein the aerosolisable material is a gel.

39. A cartridge for an aerosol provision system, wherein the cartridge contains a reservoir containing the aerosolisable material according to any preceding claim, and an aerosol forming substrate for receiving the aerosolisable material from the reservoir.

40. An aerosol provision system according to any of claims 36-39, wherein the aerosol provision system contains a reservoir for containing the aerosolisable material according to claim 36, and an aerosol forming substrate for receiving the aerosolisable material from the reservoir.

41. A cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element, and at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

42. A cartridge for an aerosol provision system according to claim 41 , wherein the cartridge further comprises a reservoir for containing aerosolisable material, and wherein the aerosolisable material transport element is configured to receive the aerosolisable material from the reservoir.

43. An aerosol provision system comprising an aerosolisable material transport element for receiving aerosolisable material, and a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element; wherein the aerosol provision system further comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

44. An aerosol provision system according to claim 43, wherein the aerosol provision system further comprises a reservoir for containing aerosolisable material, and wherein the aerosolisable material transport element is configured to receive the aerosolisable material from the reservoir.

45. An aerosol provision system according to claim 43 or 44, wherein the aerosolisable material transport element comprises the doping agent.

46. An aerosol provision system according to any of claims 43 to 45, further comprising the aerosolisable material.

47. An aerosol provision system according to claim 46, wherein the aerosolisable material comprises the doping agent.

48. An aerosol provision system according to claim 46 or 47, wherein the aerosolisable material comprises a liquid.

49. An aerosol provision system according to claim 46 or 47, wherein the aerosolisable material comprises a gel.

50. An aerosol provision system according to any of claims 43 to 49, wherein the doping agent comprises a hydrochromic material.

51. An aerosol provision system according to any of claims 43 to 50, wherein the first predetermined condition comprises a first moisture content of the aerosolisable material transport element, and the second predetermined condition comprises a second moisture content of the aerosolisable material transport element which is less than the first moisture content.

52. An aerosol provision system according to any of claims 43-51, wherein the doping agent comprises a thermochromic material.

53. An aerosol provision system according to any of claims 43-52, wherein the first predetermined condition comprises a first predetermined temperature of the aerosolisable material transport element, and the second predetermined condition comprises a second predetermined temperature which is higher than the first predetermined temperature of the aerosolisable material transport element.

54. An aerosol provision system according to any of claims 43-53, wherein the doping agent comprises a dye or pigment.

55. An aerosol provision system according to any of claims 43-54, wherein the aerosol provision system comprises control circuitry and at least one sensor for detecting the colour of the aerosolisable material transport element, wherein each sensor is configured to output a sensor signal containing data related to the colour of the aerosolisable material transport element; and wherein the control circuitry is configured to process the data from the sensor signal of each sensor to determine the colour of the aerosolisable material transport element.

56. An aerosol provision system according to claim 55, wherein response to the control circuitry determining the colour of the aerosolisable material transport element as being the second colour, the control circuitry is configured to output a control signal.

57. An aerosol provision system according to any of claims 43-56, wherein a portion of the aerosolisable material transport element is visible to the user for detecting the colour of the aerosolisable material transport element.

58. An aerosol provision system according to any of claims 43-57, further comprising a cartridge and a control unit, wherein the aerosolisable material transport element and the vaporiser is located in the cartridge, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the cartridge so as to releasably couple the cartridge to the control unit, wherein the control unit further comprises a power supply for delivering power to the vaporiser.

59. An aerosolisable material transport element for receiving aerosolisable material, wherein the aerosolisable material transport element comprises at least one doping agent which is configured to colour the aerosolisable material transport element a first colour at a first predetermined condition, and which is configured to colour the aerosolisable material transport element a second colour, which is different from the first colour, at a second predetermined condition which is different from the first predetermined condition.

60. A method of indicating a change in condition of an aerosolisable material transport element which is configured to receive aerosolisable material from a reservoir of aerosolisable material, wherein the method comprises: colouring the aerosolisable material transport element a first colour at a first predetermined condition using a doping agent; and colouring the aerosolisable material transport element a second colour at a second predetermined condition, using the doping agent, wherein the second predetermined condition is different from the first predetermined condition.

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61. A method according to claim 60, wherein the first predetermined condition comprises a first predetermined temperature of the aerosolisable material transport element, and the second predetermined condition comprises a second predetermined temperature which is higher than the first predetermined temperature of the aerosolisable material transport element.

62. A method according to claim 60 or 61, wherein the aerosolisable material transport and the reservoir are located in an aerosol provision system further comprising a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element.

63. A method according to claim 60 or 61, wherein the aerosolisable material transport and the reservoir are located in a cartridge for an aerosol provision system, the cartridge further comprising a vaporiser configured to vaporise the aerosolisable material received in the aerosolisable material transport element.

64. An aerosol provision system comprising: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the aerosol provision system is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the aerosol provision system.

65. The aerosol provision system according to claim 64, wherein the aerosol provision system further comprises control circuitry which is configured to determine the failure state of the aerosol provision system.

66. The aerosol provision system according to claim 65, further comprising at least one sensor for monitoring the at least one parameter, wherein each sensor is configured to output a sensor signal containing data related to the at least one parameter to the control circuitry; wherein the control circuitry is configured to process the data from the sensor signal of each sensor to determine the failure state of the aerosol provision system.

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67. The aerosol provision system of claim 66, wherein the at least one parameter comprises a magnetic parameter of the vaporiser; and wherein the at least one sensor comprises a first sensor for detecting the magnetic parameter, and for outputting a first sensor signal containing first data related to the magnetic parameter.

68. The aerosol provision system of claim 67, wherein the magnetic parameter is the magnetic field strength generated by the vaporiser, and wherein the control circuitry is further configured to: determine a magnetic field strength value from the first data of the first sensor signal; compare the magnetic field strength value against a predetermined magnetic field strength value; and determine the failure state of the aerosol provision system in the event that the magnetic field strength value is less than the predetermined magnetic field strength value.

69. The aerosol provision system of claim 68, wherein the vaporiser comprises a ferromagnetic material which comprises a Curie temperature which is greater than a first predetermined temperature, and which is less than a second predetermined temperature, wherein the second predetermined temperature is higher than the first predetermined temperature; wherein the predetermined magnetic field strength value corresponds to the magnetic field strength of the vaporiser at the Curie temperature.

70. The aerosol provision system of claim 69, wherein the ferromagnetic material comprises an alloy comprising nickel and chromium.

71 . The aerosol provision system of any of claims 67-70, wherein the first sensor comprises a Hall effect sensor.

72. The aerosol provision system of any of claims 66-71 , wherein the at least one parameter comprises an emissivity parameter of the vaporiser; and wherein the at least one sensor comprises a second sensor for detecting the emissivity parameter, and for outputting a second sensor signal containing second data related to the emissivity parameter.

73. The aerosol provision system of claim 72, wherein the second sensor comprises an infrared sensor.

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74. The aerosol provision system of claim 72 or 73, wherein the control circuitry is configured to: determine an emissivity value from the second data of the second sensor signal; and compare the emissivity value against a predetermined emissivity value to determine the failure state of the aerosol provision system.

75. The aerosol provision system of any of claims 66-74, wherein the at least one parameter comprises a frequency of vibration of the vaporiser, wherein the aerosol provision system further comprises a third sensor for detecting the frequency of vibration of the vaporiser, wherein the third sensor is configured to output a third sensor signal, to the control circuitry, containing data related to the frequency of vibration of the vaporiser; wherein the control circuitry is further configured to process the data from the third sensor signal to determine the vibration frequency of the vaporiser; and compare the vibration frequency against at least one predetermined vibration frequency value to determine the failure state of the aerosol provision system.

76. The aerosol provision system of any of claims 65-75, wherein the at least one parameter comprises a resonant frequency of the vaporiser, wherein the control circuitry is further configured to: determine the resonant frequency of the vaporiser; and compare the resonant frequency against at least one predetermined frequency value to determine the failure state of the aerosol provision system.

77. The aerosol provision system of any of preceding claim, further comprising a power supply configured to provide alternating current, AC, power to the vaporiser.

78. The aerosol provision system of claim 77, when further dependent on claim 76, wherein the control circuitry is configured to vary the frequency of the AC power provided to the vaporiser to determine the resonant frequency of the vaporiser.

79. An aerosol provision system according to any of claims 64-78, wherein the failure state of the aerosol provision system comprises the vaporiser exceeding a predetermined temperature.

80. An aerosol provision system according to any of claims 64-79, wherein the failure state of the aerosol provision system comprises the vaporiser experiencing a dry-out state.

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81. An aerosol provision system according to any of claims 65-80, wherein response to detecting the failure state, the control circuitry is further configured to: disable the operation of the aerosol provision system.

82. An aerosol provision system according to any of claims 65-81, wherein response to detecting the failure state, the control circuitry is further configured to: disable the operation of the vaporiser.

83. An aerosol provision system according to any of claims 65-82, wherein response to detecting the failure state, the control circuitry is further configured to: generate an output signal for providing a notification to a user.

84. An aerosol provision system according to claim 83, wherein the output signal is at least one of: an optical signal, an acoustic signal, and a haptic signal.

85. An aerosol provision system according to any preceding claim, further comprising a cartridge and a control unit, wherein the reservoir and the vaporiser are located in the cartridge, wherein the control unit comprises a cartridge receiving section that includes an interface arranged to cooperatively engage with the cartridge so as to releasably couple the cartridge to the control unit.

86. The aerosol provision system of claim 85 when further dependent on claim 66, wherein the cartridge comprises the at least one sensor.

87. The aerosol provision system of claim 85 or 86 when further dependent on claim 77, wherein the control unit comprises the power supply.

88. An aerosol provision system according to any preceding claim, further comprising a wick for receiving aerosolisable material from the reservoir, wherein the vaporiser is configured to vaporise the aerosolisable material received in the wick.

89. An aerosol provision system according to any of claims 64-88, wherein the heating element comprises a heating coil.

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90. A cartridge for an aerosol provision system comprising the cartridge and a control unit, wherein the cartridge comprises: a reservoir for aerosolisable material; and a vaporiser, comprising a heating element, for vaporising aerosolisable material from the reservoir, wherein the cartridge is configured to monitor at least one parameter of the vaporiser, which is not the electrical resistance of the heating element, to determine a failure state of the cartridge.

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