WO2024033615A1

WO2024033615A1 - Heater assembly and method

Info

Publication number: WO2024033615A1
Application number: PCT/GB2023/052069
Authority: WO
Inventors: Matthew Hodgson; Howard ROTHWELL; David LEADLEY; Ugurhan Yilmaz
Original assignee: Nicoventures Trading Limited
Priority date: 2022-08-08
Filing date: 2023-08-04
Publication date: 2024-02-15
Also published as: GB202211516D0

Abstract

Heater assembly (6) for an aerosol provision system (1), including: a substrate (62); a heater layer (64) configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; and one or more capillary tubes (66) extending from another surface of the substrate through the heater layer provided on the first surface of the substrate. The ends of the one or more capillary tubes at the heater layer are configured to provide a flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer. Also described is a cartomiser (3), an aerosol provision system and a method for manufacturing the heater assembly.

Description

HEATER ASSEMBLY AND METHOD

Field

The present disclosure relates to electronic 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 a reservoir of a source liquid containing a formulation, typically including nicotine, from which an aerosol is generated, e.g. through heat vaporisation. An aerosol source for an aerosol provision system may thus comprise a heater having a heating element arranged to receive source liquid from the reservoir, for example through wicking I capillary action. While a user inhales on the device, electrical power is supplied to the heating element to vaporise source liquid in the vicinity of the heating element to generate an aerosol for inhalation by the user. Such devices are usually provided with one or more air inlet holes located away from a mouthpiece end of the system. When a user sucks on a mouthpiece connected to the mouthpiece end of the system, air is drawn in through the inlet holes and past the aerosol source. There is a flow path connecting between the aerosol source and an opening in the mouthpiece so that air drawn past the aerosol source continues along the flow path to the mouthpiece opening, carrying some of the aerosol from the aerosol source with it. The aerosol-carrying air exits the aerosol provision system through the mouthpiece opening for inhalation by the user.

Typically, such aerosol provision systems are provided with heater assemblies suitable for heating the source liquid to form an aerosol. However, conventional heater assemblies do not necessarily provide an efficient liquid supply to the heater element of the heater assembly in various circumstances.

Moreover, heater assemblies generally provide thermal energy to an aerosol-generating material with the aerosol-generating material subsequently being vaporised I aerosolise. The precise amount of energy required to vaporise the material varies in part on the properties of the material. Providing heating assemblies which are not only provide a more efficient or effective liquid supply but also help facilitate aerosol generation are desired.

Various approaches are described which seek to help address some of these issues.

Summary

According to a first aspect of certain embodiments there is provided a heater assembly for an aerosol provision system, the heater assembly including: a substrate; a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; and one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate, wherein the ends of the one or more capillary tubes at the heater layer are configured to provide a flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer.

According to a second aspect of certain embodiments there is provided a cartomiser for use with an aerosol-generating device for generating aerosol from an aerosol-generating material, the cartomiser including: a reservoir for storing aerosol-generating material, and a heater assembly according to the first aspect, wherein the heater assembly is provided in fluid communication with the reservoir.

According to a third aspect of certain embodiments there is provided an aerosol provision system for generating aerosol from an aerosol-generating material, the aerosol provision system including the heater assembly of the first aspect.

According to a fourth aspect of certain embodiments there is provided a method of manufacturing a heater assembly for an aerosol provision system, the method including: providing a substrate comprising a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; forming one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate; and forming flared ends of the one or more capillary tubes at the ends of the one or more capillary tubes at the heater layer, the flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer.

According to a fifth aspect of certain embodiments there is provided heater means for an aerosol provision system, the heater means including a substrate; heater layer means configured to generate heat when supplied with energy, the heater layer means provided on a first surface of the substrate; and capillary means extending from another surface of the substrate through the heater layer means provided on the first surface of the substrate, wherein ends of the capillary means at the heater layer means are configured to provide a flared end having an opening at the surface of the heater layer means opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer means.

It will be appreciated that features and aspects of the invention described above in relation to the first and other 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 above.

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 is a perspective view of an aerosol provision system in accordance with aspects of the present disclosure;

Figure 2 is an exploded perspective view of a cartomiser suitable for use in the aerosol provision system of Figure 1;

Figure 3 is a cross-sectional view of the cartomiser of Figure 2 in an assembled state, in particular showing the arrangement of the heater assembly relative to the remaining components of the cartomiser;

Figure 4 is a perspective view of a heater assembly in accordance with aspects of the present disclosure, wherein the heater assembly comprises a substrate, an electrically resistive layer, and capillary tubes extending through the substrate and electrically resistive layer;

Figures 5a to 5c are cross-sectional views of a section of the heater assembly of Figure 4 showing capillary tubes comprising flared ends at the electrically resistive layer; Figure 5a shows a capillary tube comprising a flared end that flares following a linear profile according to a first implementation, Figure 5b shows a capillary tube comprising a flared end that flares following a non-linear profile according to a second implementation, and Figure 5c shows a capillary tube comprising a flared end that flares following a stepped profile according to a third implementation;

Figures 6a and 6b are cross-sectional views of a section of the heater assembly of Figure 4 showing capillary tubes comprising flared ends at the electrically resistive layer in addition to tapered side walls; Figure 6a shows a capillary tube comprising a flared end and tapered side walls that extend part-way along the capillary tube according to a first implementation, while Figure 6b shows a capillary tube comprising a flared end and tapered side walls that extend to the flared end of the capillary tube according to a second implementation; and Figure 7 is a method in accordance with aspects of the present disclosure for forming a heater assembly.

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.

According to the present disclosure, a “non-combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is not combusted or burned in order to facilitate delivery of at least one substance to a user.

In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device, electronic cigarette or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement. Throughout the following description the term “e-cigarette” is sometimes used but this term may be used interchangeably with aerosol (vapour) provision system.

In some embodiments, the non-combustible aerosol provision system is a hybrid system to generate aerosol using a combination of aerosol-generating materials, one or a plurality of which may be heated. Each of the aerosol-generating materials may be, for example, in the form of a solid, liquid or gel and may or may not contain nicotine. In some embodiments, the hybrid system comprises a liquid or gel aerosol-generating material and a solid aerosolgenerating material. The solid aerosol-generating material may comprise, for example, tobacco or a non-tobacco product.

In some embodiments, the or each aerosol-generating material may comprise one or more active constituents, one or more flavours, one or more aerosol-former materials, and/or one or more other functional materials.

The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.

As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term "botanical" includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like. Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, Wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v..Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens

In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is tobacco.

In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, star anise, cocoa and hemp.

In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from rooibos and fennel. As used herein, the terms "flavour" and "flavourant" refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers. 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.

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 comprises flavour components extracted from cannabis.

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 eucolyptol, WS-3. The aerosol-former material may comprise one or more constituents capable of forming an aerosol. In some embodiments, the aerosol-former material 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 materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.

An aerosol-modifying agent is a substance, typically located downstream of the aerosol generation area, that is configured to modify the aerosol generated, for example by changing the taste, flavour, acidity or another characteristic of the aerosol. The aerosol-modifying agent may be provided in an aerosol-modifying agent release component, that is operable to selectively release the aerosol-modifying agent.

The aerosol-modifying agent may, for example, be an additive or a sorbent. The aerosolmodifying agent may, for example, comprise one or more of a flavourant, a colourant, water, and a carbon adsorbent. The aerosol-modifying agent may, for example, be a solid, a liquid, or a gel. The aerosol-modifying agent may be in powder, thread or granule form. The aerosol-modifying agent may be free from filtration material.

Typically, the non-combustible aerosol provision system may comprise a non-combustible aerosol provision device and a consumable for use with the non-combustible aerosol provision device. In some embodiments, the disclosure relates to consumables comprising aerosol-generating material and configured to be used with non-combustible aerosol provision devices. These consumables are sometimes referred to as articles throughout the disclosure.

In some embodiments, the non-combustible aerosol provision system, such as a non- combustible aerosol provision device thereof, may comprise a power source and a controller. The power source may, for example, be an electric power source.

In some embodiments, the non-combustible aerosol provision system may comprise an area for receiving the consumable, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, a filter and/or an aerosol-modifying agent.

In some embodiments, the consumable for use with the non-combustible aerosol provision device may comprise aerosol-generating material, an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generator, an aerosol generation area, a housing, a mouthpiece, and/or an aerosol-modifying agent. An aerosol generator is an apparatus configured to cause aerosol to be generated from the aerosol-generating material. In some embodiments, the aerosol generator is a heater configured to subject the aerosol-generating material to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol.

Figure 1 shows an aerosol provision system 1 comprising an aerosol provision device 2 and a consumable 3, herein shown and referred to as a cartomiser 3. The cartomiser 3 is configured to engage and disengage with the aerosol provision device 2. That is, the cartomiser 3 is releasably connected I connectable to the aerosol provision device 2. More specifically, the cartomiser 3 is configured to engage I disengage with the aerosol provision device 2 along the longitudinal axis L1. The cartomiser 3 and aerosol provision device 2 are provided with suitable interfaces to allow the cartomiser 3 and aerosol provision device 2 to engage I disengage from one another, e.g., a push fit interface, a screwthread interface, etc. The specific way in which the cartomiser 3 engages with the aerosol provision device 2 is not significant for the principles of the present disclosure.

The cartomiser 3 comprises a reservoir which stores an aerosol-generating material. In the following, the aerosol-generating material is a liquid aerosol-generating material. The liquid aerosol-generating material (herein sometimes referred to as liquid) may be a conventional e-liquid which may or may not contain nicotine. However, other liquids and/or aerosol generating materials may be used in accordance with the principles of the present disclosure. The cartomiser 3 is able to be removed from the aerosol provision device 2 when, for example, the cartomiser 3 requires refilling with liquid or replacement with another (full) cartomiser 3.

The aerosol provision device 2 comprises a power source (such as a rechargeable battery) and control electronics. As will be described below, the cartomiser 3 comprises an electrically powered heater assembly. When the cartomiser 3 is coupled to the aerosol provision device 2, the control electronics is configured to supply electrical power to the heater assembly of the cartomiser 3 to cause the heater assembly to generate an aerosol from the liquid aerosol-generating material. The control electronics may be provided with various components to facilitate I control the supply of power to the cartomiser 3. For example, the control electronics may be provided with an airflow sensor configured to detect when a user of the aerosol provision system 1 inhales on the aerosol provision system and to supply power in response to such a detection and / or a push button which is pressed by the user and to supply power in response to such a detection. However, it should be understood that additional functions may be controlled by the control electronics depending on the configuration of the aerosol provision device 2 (for example, the control electronics may be configured to control / regulate recharging of the power source, or to facilitate wireless communication with another electronic device, such as a smartphone). The features and functions of the aerosol provision device 2 are not of primary significance in respect of the present disclosure.

Figure 2 shows an example cartomiser 3 suitable for use in the aerosol provision system of Figure 1. From the exploded view of Figure 2, it may be seen that the cartomiser 3 is assembled from a stack of components: an outer housing 4, an upper clamping unit 5, a heater assembly 6, a lower support unit 7 and an end cap 8.

The cartomiser 3 has a top end 31 and a bottom end 32 which are spaced apart along the longitudinal axis L1 , which is the longitudinal axis of the cartomiser as well as being the longitudinal axis of the aerosol provision system 1. The top end 31 of the cartomiser defines a mouthpiece end of the aerosol provision system 1 (on which a user may place their mouth and inhale), and the mouthpiece 33 includes a mouthpiece orifice 41 which is provided at the top end 42 of outer housing 4 in the centre of a top face 43.

The outer housing 4 includes a circumferential side wall 44 which leads down from the top end 42 to a bottom end 45 of the outer housing 4 and which defines an internal reservoir (not shown) for holding the liquid aerosol-generating material. Prior to assembly of the cartomiser 3, the bottom end 45 of the outer housing is open, but upon assembly the bottom end 45 is closed by a plug formed by the upper clamping unit 5 and the lower support unit 7 which are stacked together with the heater assembly 6 sandwiched therebetween.

The upper clamping unit 5 is an intermediate component of the stack of components. The upper clamping unit 5 includes a foot 51 in the form of a block and an upwardly extending air tube 52. On each side of the air tube 52, the foot 51 includes a well 53 which descends from a flat top surface 54 to a flat bottom surface (not shown in Figure 2) of the foot 51. At the bottom surface, each well 53 is open and, specifically, opens into an elongate recess formed in the bottom surface, with the depth of the recess broadly matching the size I shape and thickness of the heater assembly 6. The foot 51 is designed to engage with the outer housing 4 (more specifically, such that the outer circumferential surface of the foot is pressed against an inner circumferential surface of the outer housing 4). The foot 51 may have a suitable shape and include suitable sealing components to reduce or prevent liquid from leaking between the outer surface of the foot 51 and the inner surface of the housing 4.

The air tube 52 extends up from the bottom of the wells 53 and defines an internal air passage 58. When the upper clamping unit 5 is engaged with the outer housing 4, the air tube 52 extends up to and encircles the mouthpiece orifice 41. The outer housing 4 and/or the air tube 52 may be suitably configured so as to provide a liquid- (and optionally air-) tight seal between the two. As will be understood below, air / aerosol is intended to pass along the air tube 52 and out of the mouthpiece orifice 41 , while the space around the air tube 52 and within the outer housing 4 defines the reservoir for storing the liquid aerosol-generating material. Hence, it should be understood that, with the exception of the openings of the wells 53, the reservoir is a sealed volume defined by the outer housing 4, the outer surface of the air tube 52, and the foot 51.

The lower support unit 7 is in the form of a block having a broadly flat top surface 71 and a flat bottom surface 72. A central air passage 73 extends upwardly from the bottom surface 72 to the top surface 71. On each side of the air passage 73, the block of the lower support unit 7 includes a through hole 74. In the example cartomiser 3 of Figure 2, a co-moulded contact pad 75 in the form of a pin is inserted into the through holes 74. More specifically, each contact pad 75 is press fit in its respective through hole 74. Each contact pad 75 provides an electrical connection path from the bottom surface 72 to a respective end portion of the heater assembly 6 when the heater assembly 6 is sandwiched between the top surface 71 of the lower support unit 7 and the recess of the bottom surface 55 of the upper clamping unit 5.

Much like the upper clamping unit 5, the lower support unit 7 is designed to engage with the outer housing 4 (more specifically, such that the outer circumferential surface of the lower support unit 7 is pressed against an inner circumferential surface of the outer housing 4). The lower support unit 7 may have a suitable shape and include suitable sealing components to reduce or prevent liquid from leaking between the outer surface of the lower support unit 7 and the inner surface of the housing 4. The foot 51 of the upper clamping unit 5 and the lower support unit 7 (with its block-like form) combine together to form a plug which seals the bottom end of the reservoir.

As shown in Figure 2, the cartomiser 3 includes an end cap 8 at its bottom end. The end cap 8 is made of metal and serves to assist with retaining the cartomiser 3 in the aerosol provision device 2 when the cartomiser 3 is plugged in to the top end of the aerosol provision device 2, because, in this example, the aerosol provision device 2 is provided with magnets which are attracted to the metal of the end cap 8. The end cap 8 has a bottom wall 81 with a central opening (not shown in Figure 2). The end cap 8 also has a circumferential side wall 83 which has two opposed cut-outs 84 which latch onto corresponding projections 49 on the outer surface of the bottom end of the side wall 44 of the outer housing 4, so that the end cap 8 has a snap-fit type connection onto the bottom end of the outer housing 4. When the end cap 8 has been fitted in position, it holds in position the lower support unit 7, the upper clamping unit 5 and the heater assembly 6 which is sandwiched between the lower support unit 7 and the upper clamping unit 5. It would be possible to omit the end cap 8 (in order to reduce the component count) by arranging for the lower support unit 7 to form a snap-fit type connection with the bottom end of the side wall 44 of the outer housing 4. Additionally, the cartomiser 3 could be provided with indentations which engage with projections at the top end 21 of the main housing 2, so that a releasable connection is provided between the cartomiser and the main housing.

In any case, the cartomiser 3 is provided what may more generally be referred to as a device interface which is a part of the cartomiser 3 that interfaces with the main housing 2 (or aerosol-generating device). In the above example, the device interface may include the metal cap 8 including the bottom wall 81 and circumferential side wall 83 and I or the lower support unit 7 including the bottom surface 72. More generally, the device interface of the cartomiser 3 may encompass any part or parts of the cartomiser 3 that contact, abut, engage or otherwise couple to the main housing 2.

When the components of the cartomiser 3 have been assembled together, an overall air passage exists from the bottom end 32 to the top end 31 of the cartomiser 3 and it is formed by the air passage 73 leading to the air passage 58 which, in turn, leads to the mouthpiece orifice 41. Where the air passage 73 meets the air passage 58, the air flow bifurcates as it passes around the side edges of the heater assembly 6. It should be appreciated that sections of the heater assembly 6 that are provided below the wells 53 overlap the air passage 73 such that air may pass by or along these sections of the heater assembly 6 before bifurcating as it passes around the side edges of the heater assembly 6 and through the air passage 58.

With reference back to Figure 1, the top end 21 of the aerosol provision device 2 includes an air inlet hole 22 on each side of the aerosol provision device 2 (with one of the two air inlet holes 22 being visible in Fig. 1). Air can enter the air inlet holes 22 and flow transversely inwards to the longitudinal axis L1 so as to enter the bottom end of the air passage 73 of the lower support unit 7 and to start to flow in the direction of the longitudinal axis L1 towards the mouthpiece 33.

Figure 3 is a cross-sectional view through the cartomiser 3 of Figures 1 and 2 when the cartomiser 3 is in its assembled state.

As seen in Figure 3, the air passage 73 is provided through the lower support unit 7, extending from the lower, bottom surface 72 of the lower support unit 7 to an opposite, top surface 71. In this example, the air passage 73 is relatively wider than the air passage 58 formed in the upper clamping unit 5. As shown in Figure 3, this provides a region where the bottom of the wells 53 overlap a part of the heater assembly 6 that is directly above the air passage 73. The significance of this is explained in more detail below. However, it should be appreciated that this is optional, and in other implementations the part of the heater assembly 6 that overlaps the wells 53 is not provided above the air passage 73.

For completeness, Figure 3 also shows the engagement of the air tube 52 with the outer housing 4. More specifically, the outer housing 4 comprises an air tube 47 which surrounds the mouthpiece orifice 41. The air tube 47 is shown having a conical-shape (or at least a tube with tapered sides). From Figure 3, it may be seen that the top of the air tube 52 fits onto the bottom end 471 of the air tube 47 which extends downwards from the mouthpiece orifice 41 in the top face 43 of the outer housing 4. Thus, the air passage 58 is connected to an air passage 48 of the air tube 47. Also shown in Figure 3 is the reservoir 46 formed between the air tube 52, the inside of the circumferential side wall 44 of the outer housing 4 and the upper clamping unit 5, as described above.

Turning now to the heater assembly 6, the heater assembly 6 is a microfluidic heater assembly. Figure 4 illustrates the microfluidic heater assembly 6 in more detail. The microfluidic heater assembly of Figure 4 is not shown to scale and certain features are exaggerated for reasons of clarity.

The microfluidic heater assembly 6 comprises a substrate 62 and an electrically resistive layer 64 disposed on a surface of the substrate 62.

In this implementation, the substrate 62 is formed from a non-conductive material, such as quartz (silicon dioxide); however, it should be appreciated that other suitable non-conductive materials may be used, such as ceramics, for example. The substrate 62 may be formed from a bulk material (such as cultured quartz) or as a sintered material, e.g., from sintered powdered quartz. The electrically resistive layer 64 is formed from any suitable electrically conductive material, for example a metal or a metal alloy such as titanium or nickel chromium.

The heater assembly 6 is planar and in the form of a cuboidal block, elongate in the direction of a longitudinal axis L2. The heater assembly 6 has the shape of a strip and has parallel sides. The planar heater assembly 6 has parallel upper and lower major (planar) surfaces and parallel side surfaces and parallel end surfaces. In the shown implementation of Figure 4, the length of the heater assembly 6 is 10 mm, its width is 1 mm, and its thickness is 0.12 mm. The small size of the heater assembly 6 enables the overall size of the cartomiser to be reduced and the overall mass of the components of the cartomiser to be reduced. However, it should be appreciated that in other implementations, the heater assembly 6 may have different dimensions and/or shapes depending upon the application at hand. For example, in some implementations, the heater assembly 6 may be a 3 x 3 mm chip. Along the longitudinal axis L2, the heater assembly 6 has a central portion 67 and first and second end portions 68, 69. In Figure 4, the length of the central portion 67 (relative to the lengths of the end portions 68, 69) has been exaggerated for reasons of visual clarity. When the vaporizer is in situ in the cartomiser, the central portion 67 is positioned overlapping the air passage 73 and air passage 58. The central portion 67 extends across the top end of the air passage 73 of the lower support unit 7, and at least a part across the bottom end of the air passage 58 of the upper clamping unit 5. The end portions 68, 69 are clamped between the upper clamping unit 5 and the lower support unit 7.

In the central portion 67 of the heater assembly 6, a plurality of capillary tubes 66 are provided. Only the openings of the capillary tubes 66 are shown in Figure 4 (and in an exaggerated way for clarity), but the capillary tubes 66 extend from one side of the heater assembly 6 to the other. More specifically, the capillary tubes extend from the side of the heater assembly 6 opposite the electrically resistive layer 64 (the largest surface not shown in Figure 4), through the substrate 62 toward the face of the substrate 62 on which the electrically resistive layer 64 is disposed, and then through the electrically resistive layer 64. The plurality of capillary tubes 66 extend substantially linearly through the heater assembly 6 (that is, the capillary tubes 66 follow substantially linear paths). By substantially, it is meant that the capillary tubes 66 follow pathways that are within 5 %, within 2 % or within 1 % of a straight line. This measure may be obtained in any suitable way, e.g., by comparison of the length of the distance from a first point to a second point along the extent of the capillary tube 66 and the corresponding distance that the central axis of the capillary tube 66 extends between the same two points. The capillary tubes 66 are formed in the heater assembly 66 via a manufacturing process. That is to say, the capillary tubes 66 do not naturally exist in the substrate material 62 or electrically resistive layer 64, but rather, the capillary tubes 66 are formed in the substrate material 62 and electrically resistive layer 64 through a suitable process. A suitable process for forming the capillary tubes 66, particularly when forming capillary tubes that substantially follow a linear path, is laser drilling. However, any other suitable technique may be employed in order to generate the capillary tubes 66.

The capillary tubes 66 are configured so as to transport liquid from one surface of the heater assembly 6 (i.e. , the surface opposite the electrically resistive layer 64) to the electrically resistive layer 64. The exact dimensions of the capillary tubes 66, and in particular the diameter, may be set in accordance with the liquid to be stored in the reservoir 46 of the cartomiser 3 and subsequently used with the heater assembly 6. For example, the properties of the liquid aerosol-generating material (e.g., viscosity) in the reservoir 46 of the cartomiser 3 may dictate the diameter of the capillary tubes 66 to ensure that a suitable flow of liquid is provided to the electrically resistive layer 64. However, in some implementations, the capillary tubes 66 may have a diameter on the order to tens of microns, e.g., between 10 pm to 250 pm, between 10 pm to 150 pm, or between 10 pm to 100 pm. However, it should be appreciated that capillary tubes 66 in other implementations may be set differently based on the properties of the liquid to be vaporised and / or a desired supply of liquid to the electrically resistive layer 64. Moreover, it should be appreciated that to achieve a desired level of flow to the electrically resistive layer 64, not only the diameter of the capillary tubes 66 but also the number I number per unit area of the capillary tubes 66 may also influence the supply of liquid to the electrically resistive layer 64.

As described above, the central portion 67 of the heater assembly 6 (or rather a part thereof) is positioned below the wells 53 of the upper clamping unit 5, but such that it overlaps the air channel 73 of the lower support unit 7. In this way, it should be understood that liquid from the wells 531 reservoir is permitted to flow along the respective capillary tubes 66 to the electrically resistive layer 64 where the liquid is able to be subsequently vaporised. Although Figure 4 shows an arrangement of capillary tubes 66 provided uniformly over the area of the central portion 67, it should be understood that in some implementations, the capillary tubes 66 may be omitted from the part of the central portion 67 that overlaps the air passage 53.

With reference back to Figure 2, the heater assembly 6 is shown positioned between the upper clamping unit 5 and the lower support unit 7. In particular, the heater assembly 6 is oriented such that the electrically resistive layer 64 faces towards the lower support unit 7, while the substrate 62 faces towards the upper clamping unit 5.

It should be understood from Figure 2 that the end portions 68, 69 of the heater assembly 6 overlap the through holes 74 and the contact pads 75. More specifically, the electrically resistive layer 64 is provided in contact with the contact pads 75, and therefore the end portions 68, 69 act to form an electrical connection with the contact pads 75 (and thus any power source subsequently attached to the contact pads 75, such as from the aerosol provision device 2). For example, the aerosol provision device 2 may have two power supply pins (not shown) which make contact with the bottom ends of the contact pads 75. The top ends of the contact pads 75 are in electrical contact with the heater assembly 6, as above. In use, electrical power supplied by the power supply of the aerosol provision device 2 passes through the electrically resistive layer 64, by virtue of the electrical connection between the end portions 68, 69 and the contact pads 75, to cause heating of the electrically resistive layer 64. The amount of heating achieved (i.e. , the temperature of the electrically resistive layer 64 that is able to be reached) may depend on the power supplied by the aerosol provision device 2 and the electrical resistance of the electrically resistive layer 64. Equally, the amount of heating required (i.e., the temperature necessary to vaporise the liquid supplied to the resistive layer 64) will be dependent in part on the properties of the liquid supplied to the electrically resistive layer 64 and/or the configuration of heater assembly 6. Accordingly, the resistance of the electrically resistive layer 64 may be set based on the particular application at hand, whereby the resistance of the electrically resistive layer 64 may be dependent on the material of the electrically resistive layer 64 and the physical dimensions of the electrically resistive layer 64 (e.g., thickness). By way of example, the thickness of the electrically resistive layer 64 may be on the order of 5 pm or so, but it will be appreciated that this may vary from implementation to implementation.

In other implementations, the contact pads 75 may be omitted and the power supply pins (not shown) of the aerosol provision device 2 may alternatively pass through the through holes 74 of the lower support unit 7 to make direct electrical contact with the electrically resistive layer 64.

The configuration of the cartomiser 3 shown in Figures 2 and 3 is one where the vaporisation of liquid occurs in a certain region of the heater assembly 6; namely, the central portion 67 of the heater assembly 6. The end portions 68, 69 of the heater assembly 6 are not especially suited for vaporising liquid, firstly because these end portions 68, 69 are not provided with capillary tubes 66 extending through to the electrically resistive layer 64 in these portions, and secondly because the contact pads 75 contact a part of the surface of the electrically resistive layer 64 at the end portions 68, 69. As described above, the central portion 67 of the heater assembly 6 (or rather a part thereof) is positioned below the wells 53 of the upper clamping unit 5, but such that it overlaps the air passage 73 of the lower support unit 7. In this way, it should be understood that liquid from the wells 531 reservoir 46 is permitted to flow along the respective capillary tubes 66 overlapping the wells 53 to the electrically resistive layer 64 where the liquid is able to be subsequently vaporised when the electrically resistive layer 64 is energised. With reference to Figure 3, it can be seen that in the regions where the heater assembly 6 overlaps the wells 53, liquid is supplied to the capillary tubes 66 in these areas and subsequently to the electrically resistive layer 64 where it is vaporised. The vapour is released from the heater assembly 6 below the electrically resistive layer 64 and into the portion of the air passage 73 below the heater assembly 6. Subsequently, air that is drawn through the air passage 73 passes by the heater assembly 6 and vaporised liquid aerosol generating material is able to be entrained in the drawn air before passing through the air passage 58.

Figures 5a to 5b each schematically show a cross-sectional view of a capillary tube 66 extending through the substrate 62, from a first side of the substrate 60 to a second side of the substrate 62 and through the electrically resistive layer 64. Put another way, the capillary tubes 66 extend from one side of the heater assembly 6 to a side of the heater assembly 6 comprising the electrically resistive layer 64. Each of Figures 5a to 5b shows only a part of the heater assembly 6 depicting a single capillary tube 66 for the purposes of explaining the principles of the present disclosure. However, it should be understood that for any given heater assembly 6, one or more of the capillary tubes 66 may be configured as described in accordance with Figures 5a to 5b.

In accordance with aspects of the present disclosure, the capillary tubes 66 are provided with a flared end 61. More specifically, the end of capillary tube 66 at the electrically resistive layer is configured to provide the flared end 61, which has an opening at the surface of the electrically resistive layer 64 (which is at the surface of the electrically resistive layer 64 opposite the adjacent surface of the substrate 62, i.e., the uppermost surface of the electrically resistive layer 64 in Figures 5a to 5b). The flared end 61 has an increasing characteristic dimension of extent (e.g., a width W, as shown in Figure 5a) along the direction from the surface of the substrate 62 to the opening formed in the electrically resistive layer 64 (i.e., the vertical direction in Figure 5a to 5b). That is to say, the characteristic dimension of extent, e.g., the width W, of the flared end 61 of the capillary tube 66 increases the closer to the opening in the electrically resistive layer 64 the capillary tube 66 gets.

The characteristic dimension of extent represents a dimension of the cross-sectional area of the flared end 61 when viewed along the direction of extent of the flared end 61 or capillary tube 66. The characteristic dimension of extent may therefore be a width or length (or some combination thereof) of the cross-sectional area (or cross-section). In the above example of Figure 4, the capillary tube 66 has a broadly cylindrical shape. The cross-section of the capillary tube 66 is correspondingly circular or substantially circular. Accordingly, the flared end 61 has a characteristic dimension of extent which is a diameter in this example, and as above, the diameter of the flared end 61 increases in a direction from the substrate 62 (more specifically from the surface of the substrate opposite the surface comprising the electrically resistive layer 64) to the opening in the electrically resistive layer 64. The flared end 61 in this regard can be considered to define a truncated cone shape with the base of the truncated cone shape corresponding to the opening in the electrically resistive layer 64.

However, it should be understood that the flared end 61 may be configured with a crosssection taking any suitable shape, for example a square. The cross-sectional shape of the flared end 61 of the capillary tube 66 may correspond to the cross-sectional shape of the capillary tube 66 (that is, be the same cross-sectional shape) or it may be a different cross- sectional shape.

The flared end 61 may be formed in the heater assembly 6 using any suitable technique. As described above, the capillary tubes 66 may be formed by laser drilling. Correspondingly, the flared end 61 may also be formed using a suitable laser drilling or laser ablation techniques, by increasing the size or movement range of the laser beam. However, other ways of forming the flared end 61 may also be used, such as chemical etching.

The flared end 61 of the capillary tube 66 is provided to aid in the generation and release of aerosol from the heater assembly 6. As described above, the capillary tubes 66 are configured to facilitate the flow of liquid aerosol-generating material from the reservoir to the electrically resistive layer 64 which is subsequently heated (through application of an electric current). Liquid aerosol-generating material which is brought close to the electrically resistive layer 64 is subsequently heated by the electrically resistive layer 64 and forms an aerosol. The amount of energy (i.e., heat) required to generate aerosol from a mass of liquid will depend on several factors, one of which is the vapour pressure. The vapour pressure is an indicator of the tendency of particles to escape the bulk material (e.g., a liquid) to form an aerosol. Without wishing to be bound by theory, it is thought that by providing the flared end 61 of the capillary tube 66 at the electrically resistive layer 64, the vapour pressure is altered and, more specifically, facilitates the release of particles from the bulk liquid aerosolgenerating material to subsequently form a vapour I aerosol for delivery to a user. More simply, the flared end 61 is provided to facilitate the release of liquid aerosol-generating material when vaporised (e.g., by the electrically resistive layer 64 when heated).

The specific shape and I or dimensions of the flared end 61 may be dictated by the properties of the liquid aerosol-generating material and I or the heater assembly 6. For example, the size of the opening in the resistive layer 64, the height (or depth) of the flared end 61 and I or the angle and shape of the side walls defining the flared end 61 may be set based on the liquid aerosol-generating material to be vaporised (or rather, the properties thereof such as the viscosity, specific heat capacity, latent heat of vaporisation, etc.). The specific configuration of the flared end 61 may be determined through empirical testing or through simulation. However, it is generally thought that any such configuration that provides a relative increase in the exposed surface area of the liquid aerosol-generating material at the opening of the electrically resistive layer 64 will help facilitate the generation of aerosol. This may contribute to aerosol provision systems 1 which have improved battery life as the energy required to vaporise the same mass of liquid aerosol-generating material is less, or that provide better user sensory experiences e.g., by generating relative more aerosol or by generating aerosol relatively quicker.

Turning to Figures 5a to 5c individually, each of these Figures represents different implementations of the flared end 61. In Figure 5a, the characteristic dimension of extent of the flared end 61 (e.g., the diameter) increases linearly along the direction from the surface of the substrate 62 to the opening in the electrically resistive layer 64. That is, for example, with each step in the direction towards the opening in the electrically resistive layer 64, the characteristic dimension of extent (e.g., diameter or width W) increases by the same amount. As seen in Figure 5a, the side walls of the flared end 61 generally follow a linear path.

However, in other implementations, such as in Figure 5b which shows a second implementation of the flared end 6T, the characteristic dimension of extent of the flared end 6T (e.g., the diameter) increases non-linearly along the direction from the surface of the substrate 62 to the opening in the electrically resistive layer 64. That is, for example, with each step in the direction towards the opening in the electrically resistive layer 64, the characteristic dimension of extent (e.g., diameter or width W) increases by a different or varying amount. As shown in Figure 5b, in such implementations, the side walls of the flared end 61 may generally follow a curved path. In the example of Figure 5b, the rate of increase in the diameter of the flared end 61 increases as the capillary tube 66 approaches the opening in the electrically resistive layer 64. The flared end 6T in this example may generally be trumpet-shaped. However, in other implementations, the rate of increase in the diameter of the flared end decreases as the capillary tube 66 approaches the opening in the electrically resistive layer 64. In such implementations, the flared end may approximate a bowl or hemisphere shape.

Further, Figure 5c shows a characteristic dimension of extent of the flared end 61” (e.g., the diameter) according to a third implementation whereby the characteristic dimension of extent of the flared end 61” increases in a stepwise manner along the direction from the surface of the substrate 62 to the opening in the electrically resistive layer 64. That is, the characteristic dimension of extent (e.g., diameter or width W) increases sharply at a certain distance from the electrically resistive layer 64. As with Figure 5a, the side walls of the flared end 61” generally follow a linear path; however, the stepped portion of the side walls of the flared end 61” follow a linear path which is at, or substantially at, 90° to the linear path of the remaining side walls of the flared end 61”. It should also be understood that although Figure 5c shows the side walls of the flared end 61” forming 90° angles with respect to one another, the angle may be greater than 90° (i.e., thereby providing a tapered or angled sidewall extending from the stepped portion to the electrically resistive layer 64) and/or the intersection between the stepped portion and the remaining side wall of the flared end 61” may be rounded or curved (i.e., there may be a gradual transition between the stepped portion and the remaining side walls of the flared end 61”). Additionally, it should be appreciated that the flared end 61” may alternatively be described as providing a portion of the capillary tube 66 at an end thereof as having a greater characteristic dimension of extent than the remaining portion of the capillary tube 66.

Figures 5a to 5c show the flared end 61 , 61’, 61” extending from (i.e., starting from) a region or point within the substrate 62 (i.e., below the lower surface of the electrically resistive layer 64) to (ending at) the upper surface of the electrically resistive layer 64. Note that the terms “upper” and “lower” are used only to differentiate between the two surfaces shown in the upper and lower parts of Figures 5a to 5c. The use of upper and lower is not intended to infer any particular orientation of the heater assembly 6. As seen in Figures 5a to 5c, the flared end 61, 6T, 61” is formed partly within the electrically resistive layer 64 and partly within the substrate 62. That is, the flared end 61, 6T, 61” is formed both in the electrically resistive layer 64 and the substrate 62.

However, it should be understood that the flared end 61 , 6T, 61” is not limited to such configurations. In some implementations, the flared end 61 , 6T, 61” may extend from (i.e., start from) the lower surface of the electrically resistive layer 64. In such implementations, the flared end 61 , 6T, 61” is formed entirely in the electrically resistive layer 64 and extends from one surface to the other surface of the electrically resistive layer 64 . In other implementations, the flared end 61 , 6T, 61” may extend from (i.e., start from) a region within the electrically resistive layer 64 (i.e., between the upper and lower surfaces of the electrically resistive layer 64). In such implementations, the flared end 61 , 6T, 61” is formed entirely within the electrically resistive layer 64 but extends only partway into the electrically resistive layer 64. The precise arrangement of the flared end 61, 6T, 61”, and in particular the depth to which it extends into the heater assembly from the opening at the electrically resistive layer 64, may depend on the properties of the liquid aerosol-generating material (such as described above) and the thickness of the electrically resistive layer 64. That is to say, the shape and configuration of the flared end 61 , 6T, 61” may not be limited by the thickness of the electrically resistive layer 64 and may extend into the substrate 62 or only partway into the electrically resistive layer 64 in order to provide improved release of aerosol-generating material.

In the implementations of Figures 5a to 5c, the capillary tube 66 comprises side walls formed in the substrate 62 having a distance therebetween which is the same, or substantially the same, along the direction from the lower surface of the substrate 62 to the flared end 61, 6T, 61” of the capillary tube 66. Broadly, the part of the capillary tube 66 not including the flared end 61, 6T, 61” is provided with a constant distance between the sides of the capillary tube 66 and / or a constant cross-sectional area along the longitudinal extent of the capillary tube 66. However, in other implementations, the distance between the side walls of the capillary tube 66 is different along the direction from the surface of the substrate 62 to the flared end 61, 6T, 61 ” of the capillary tube 66. That is, the part of the capillary tube 66 not including the flared end 61, 6T, 61” is provided with a varying distance between the sides of the capillary tube 66 and / or a varying cross-sectional area along the longitudinal extent of the capillary tube 66. More particularly, the side walls of the capillary tube 66 are tapered from a larger opening at the lower surface of the substrate 62.

Figures 6a and 6b schematically illustrate two implementations comprising tapered side walls of the capillary tube 66. Figures 6a and 6b will be understood from Figure 5a and like reference signs depict like components. Only a discussion of the differences is presented herein. In much the same way as Figures 5a to 5c, Figures 6a and 6b show only a part of the heater assembly 6 depicting a single capillary tube 66 for the purposes of explaining the principles of the present disclosure. However, it should be understood that for any given heater assembly 6, one or more of the capillary tubes 66 may be configured as described in accordance with Figures 6a to 6b.

Figure 6a depicts a first implementation comprising tapered side walls of the capillary tube 66. In Figure 6a, a part of the capillary tube 66 not including the flared end 61 is provided with tapered side walls 63. The tapered side walls 63 are provided at an end of the capillary tube 66 opposite the flared end 61 of the capillary tube 66. However, there exists a region between the flared end 61 and the tapered side walls 63 where the side walls of the capillary tube 66 are not tapered; that is, the distance between the side walls in this region of the capillary tube 66 is approximately constant.

Figure 6b depicts an implementation in which this is not the case. The tapered side walls 63’ of Figure 6b extend to the flared end 61 of the capillary tube 66. In other words, the tapered side walls 63’ extend from the lower surface of the substrate 62 to the start of the flared end 61 , where, as can be seen in Figure 6b, the side walls of the capillary tube 66 flare out as described above.

In either implementation of Figure 6a or 6b, the tapered side walls 63, 63’ provide a wider I larger opening at the lower surface of the substrate 62 that subsequently narrows as the capillary tube 66 extends along the longitudinal direction of the capillary tube 66. In Figure 6a this narrowing is achieved prior to reaching the flared end 61 , while in Figure 6b this narrowing is achieved upon reaching the flared end 61.

The lower surface of the substrate 62 is the surface of the substrate 62 that contacts the reservoir I the wells 53. Accordingly, the tapered side walls 63, 63’ provide a relatively larger opening at the surface of the substrate 62 that is in contact with the reservoir and thereby help facilitate liquid absorption from the reservoir into the capillary tubes 66. That is to say, the tapered side walls 63, 63’ improve the uptake or absorption of liquid to the heater assembly 6. Additionally or alternatively, the narrowing of the capillary tube 66 (that is, as the tapered side walls 63, 63’ narrow and I or the part of the capillary tube 66 having an approximately constant separation distance between the side walls) may be provided to control the flow of liquid through the capillary tube 66 and to the electrically resistive layer 64. For example, as liquid passes along the capillary tube 66 towards the electrically resistive layer 64, the electrically resistive layer 64 when energised causes heating of the liquid. The thermal energy will likely travel at least some way into the substrate 62 and subsequently to the liquid in the capillary tube 66. Therefore, even if the liquid in the capillary tube 66 is not close enough to the electrically resistive layer 66 to be vaporised, it may still experience some warming due to the heat generated by the electrically resistive layer 64. This warming will likely affect the viscosity of the liquid as it approaches the electrically resistive layer 64. Therefore, providing the tapered side walls 63, 63’ helps improved liquid uptake into the heater assembly 6 (at the wider end thereof) and control or regulate the flow of liquid to the electrically resistive layer 64 (at or towards the narrower end thereof).

Regardless of whether or not the tapered side walls 63, 63’ are provided, the flared end 61, 6T, 61” is arranged to have its largest characteristic dimension of extent (i.e. , width or diameter) at the opening at the surface of the electrically resistive layer 64 and its smallest characteristic dimension of extent (i.e., width or diameter) at the portion of the flared end 61, 6T, 61” furthest from the opening. The narrowest characteristic dimension of extent of the flared end 61, 6T, 61” may act to provide some degree of regulation I control of the flow of liquid to the remaining part of the flared end 61, 6T, 61” where it is likely that the majority of vaporisation will occur.

In the examples of Figures 5a to 6b, the smallest or narrowest characteristic dimension of extent of the flared end 61, 6T, 61” is the narrowest characteristic dimension of extent of the flared end 61, 6T, 61” and the corresponding capillary tube 66. As this is likely to be the region where liquid is at its highest temperature without experiencing vaporisation, providing the narrowest restriction in the capillary tube 66 at the region closest to the flared end 61 , 6T, 61” may help to regulate the flow of liquid into the flared end 61 , 6T, 61”.

In the example of Figures 5a and 5b, the largest characteristic dimension of extent of the flared end 61, 6T, 61” (i.e., the opening at the electrically resistive layer 64) is the widest characteristic dimension of extent of the flared end 61, 6T, 61” and the corresponding capillary tube 66. Providing the largest characteristic dimension of extent at the flared end 61 , 6T, 61” helps to facilitate the release of aerosol from the heater assembly 6. Such an arrangement also minimises the number of machining / manufacturing steps. However, this need not necessarily be the case as demonstrated by Figures 6a and 6b where the tapered side walls 63, 63’ provide a larger characteristic dimension of extent than the flared ends 61 , 6T, 61”. As discussed above, this may be provided for the purposes of increasing uptake of the liquid aerosol-generating material into the heater assembly 6.

Furthermore, the above disclosure has focused on examples of the heater assembly 6 whereby liquid is fed generally in a vertical direction from the wells 53 of the cartomiser to the capillary tubes 66 (and subsequently to the electrically resistive layer 64). However, in some implementations, the heater assembly 6 may be provided with a transport element, such as a porous material, which permits horizontal transport of liquid across the length of the heater assembly (e.g., in the direction parallel to the longitudinal axis L2). For example, the transport element may be a separate porous element, such as a fibrous pad or the like which is positioned between the heater assembly 6 and the wells 53 of the cartomsier 3. Alternatively, the substrate 62 of the heater assembly 6 may be formed of a sintered material (such as sintered quartz) or other fibrous material which is suitably configured to allow for horizontal movement of the liquid. In such examples, the wells 53 may be positioned above regions of the heater assembly which do not comprise capillary tubes 66 (e.g., the end regions 68, 69) and liquid is permitted to flow horizontally towards the regions that do comprise capillary tubes 66 (e.g., the central region 67) before passing along the capillary tubes 66 to the electrically resistive layer 64.

The heater assembly 6 as described above is generally provided as a relatively small component having a relatively small footprint (as compared to more traditional heater assemblies, such as a wick and coil). However, owing in part to the fact the capillary tubes 66 are formed via a manufacturing process in the heater assembly 6 (i.e. , the capillary tubes are engineered through a laser drilling process), the heater assembly 6 can provide similar liquid delivery characteristics (and thus comparable aerosol formation characteristics) despite its relatively small size. That is to say, the heater assembly 6 may provide more efficient wicking of liquid given that that diameter of the capillary tubes 66 can be selected I optimised for a given liquid to be vaporised and that the capillary tubes 66 are formed to follow substantially linear paths that directly deliver the liquid to the electrically resistive layer 64. By providing a smaller component, material wastage (e.g., when the cartomiser 3 is disposed of) can be reduced.

Not only can the liquid be provided more efficiently to the electrically resistive layer 64, but by manufacturing the capillary tubes 66, more control is given over the supply of liquid to the electrically resistive layer 64 (that is, the more capillary tubes of a certain diameter, the more liquid per unit time (ml/s) can be delivered to the electrically resistive layer 64). It should be appreciated that the configuration of the cartomiser 3 accommodating the heater assembly 6 is provided as an example configuration of such a cartomiser 3. The principles of the present disclosure apply equally to other configurations of the cartomiser 3 (for example, comprising similar or different components to those as shown in Figures 1 and 2, and a similar or different layout to that shown in Figure 2). That is, the cartomiser 3 and the relative position of the heater assembly 6 in the cartomiser 3 is not significant to the principles of the present disclosure. Broadly speaking, a cartomiser is likely to comprise a top end (having the mouthpiece orifice 41) and a bottom end. In the examples shown above, the heater assembly 6 is arranged to be below the reservoir, substantially horizontal to the longitudinal axis of the cartomiser 3, and arranged in an airflow path that is substantially perpendicular to longitudinal axis of the heater assembly. However, this need not be case, and in other implementations the cartomiser 3 may be configured differently depending on the particular design and application at hand.

For example, the heater assembly 6 may be arranged such that airflow is substantially parallel to the longitudinal axis of the heater assembly 6, e.g., along the exposed surface of the electrically resistive layer 64. For example, the upper clamping unit 5 may not be provided with the central air passage 58 and instead the air passage may be provided to one side of the upper clamping unit 5. Air may enter the cartomiser 3 by a suitable inlet and flow along the longitudinal surface of the heater assembly 6 (and along the electrically resistive layer 64) before passing in a substantially vertical direction through the air passage 58 positioned at one end of the upper clamping unit 5 (e.g., the end opposite the air inlet). The outer housing 4 and mouthpiece orifice 41 may be suitably configured. In such an example, the wells 53 of the upper clamping unit 5 may supply the entire central portion 67 of the heater assembly 6 with liquid aerosol-generating material from the reservoir. In the example shown in Figure 2, the contact pads 75 directly contact the electrically resistive layer 64 of the heater assembly 6. However, the cartomiser 3 may be provided with any suitable arrangement that facilitates the electrical contact between the aerosol provision device 2 and the heater assembly 6. For example, in some implementations, electrical wiring or other electrically conductive elements may extend between the electrically resistive layer 64 and the contact pads 75 of the cartomiser 3. This may particularly be the case when the heater assembly 6 has its largest dimension (e.g., its length) less than a minimum distance between the contact pads 75. The distance between the contact pads 75 may be dictated by the electrical contacts on the aerosol provision device 2.

It should also be appreciated that while the above has described a cartomiser 3 which includes the heater assembly 6, in some implementations the heater assembly 6, may be provided in the aerosol provision device 2 itself. For example, the aerosol provision device 2 may comprise the heater assembly 6 and a removable cartridge (containing a reservoir of liquid aerosol-generating material). The heater assembly 6 is provided in fluid contact with the liquid in the cartridge (e.g., via a suitable wicking element or via another fluid transport mechanism). Alternatively, the aerosol provision device 2 may include an integrated liquid storage area in addition to the heater assembly 6, which may be refillable with liquid. More broadly, the aerosol provision system (which encompasses a separable aerosol provision device and cartomiser / cartridge or an integrated aerosol provision device and cartridge) includes the heater assembly.

Additionally, the above has described a heater assembly 6 in which an electrically resistive layer 64 is provided on a surface of the respective substrate. In the aerosol provision system 1 of Figure 2, electrical power is supplied to the electrically resistive layer 64 via the contact pads 75. Accordingly, an electrical current is able to flow through the electrically resistive layer 64 from one end to the other to cause heating of the electrically resistive layer 64. However, it should be understood that electrical power for the purposes of causing the electrically resistive layer 64 to heat may be provided via an alternative means, and in particular, via induction. In such implementations, the aerosol provision system 1 is provided with a coil (known as a drive coil) to which an alternating electrical current is applied. This subsequently generates an alternating magnetic field. When the electrically resistive layer 64 is exposed to the alternating magnetic field (and it is of sufficient strength), the alternating magnetic field causes electrical current (Eddy currents) to be generated in the electrically resistive layer 64. These currents can cause Joule heating of the electrically resistive layer 64 owing to the electrical resistance of this layer 64. Depending on the material which the electrically resistive layer 64 is formed, heating may additionally be generated through magnetic hysteresis (if the material is ferro- or ferrimagnetic). More generally, the electrically resistive layer 64 is an example of a heater layer of the heater assembly 6 which is configured to generate heat when supplied with energy (e.g., electrical energy), which, for example, may be provided through direct contact or via induction. Additional ways of causing the heater layer to generate heat are also considered within the principles of the present disclosure.

Moreover, it should be understood that in some implementations, an additional layer or layers, e.g., serving as a protective layer, may be disposed on top of the electrically resistive layer 64. In such implementations, the capillary tubes 66 (and more particularly the flared ends 61, 6T, 61” of the capillary tubes 66) still extend to an opening on the electrically resistive layer 64 but may additionally extend through the additional layer(s). More broadly, the capillary tubes 66 (and more particularly the flared ends 61, 6T, 61” thereof) extend through the heater assembly 6 to an opening at a surface of a side of the heater assembly 6 comprising the electrically resistive layer 64, which includes an opening in the electrically resistive layer 64 itself as well as an opening in any additional layer(s) positioned above the electrically resistive layer 64.

Figure 7 depicts an example method for manufacturing the heater assembly 6.

The method begins at step S1 by providing a substrate 62 comprising an electrically resistive layer 64 provided on a first surface of the substrate. The way in which the substrate 62 is formed is not significant to the principles of the present disclosure. For example, the substrate 62 may be cut from a portion of cultured quartz or formed via a sintering process by sintering quartz powders I fibres, for example. The way in which the electrically resistive layer 64 is formed on the surface of the substrate 62 is not significant to the principles of the present disclosure. For example, the electrically resistive layer 64 may be a sheet of metal (e.g., titanium) adhered, welded, or the like to the substrate 62. Alternatively, the electrically resistive layer 64 may be formed through a vapour or chemical deposition technique using the substrate 62 as a base. Yet a further alternative is to grow or culture the substrate 62 using the electrically resistive layer 64 as a base.

Once the substrate 62 including an electrically resistive layer 64 is provided, the method proceeds to step S2 where one or more capillary tubes 66 are formed in the substrate 621 electrically resistive layer 64. As noted above, the capillary tubes 66 extend from a surface (another surface) of the substrate 62 through the electrically resistive layer 64 provided on the first surface of the substrate 62. That is, as shown in Figures 5a to 6b, the capillary tubes 66 extend all the way through the heater assembly 6. The capillary tubes 66 may be formed by laser drilling, as noted above, or any other suitable technique.

After or during step S2, the method proceeds to step S3. At step S3, flared ends 61 , 6T, 61” of the one or more capillary tubes 66 are formed. The flared ends 61 , 6T, 61” may be formed using any suitable manufacturing technique (including laser drilling) and may be formed in accordance with any suitable shape as described above. The flared end 61 , 6T, 61” has an opening at the surface of the electrically resistive layer 64 opposite the first surface of the substrate 62. As described previously, the flared end 61 , 6T, 61” is formed so as to have an increasing characteristic dimension of extent (e.g., width or diameter) along the direction from the (lower) surface of the substrate 62 to the opening in the electrically resistive layer 64.

Thereafter, once the heater assembly 6 is formed, the heater assembly 6 may be positioned in a cartomiser 3 or more generally an aerosol provision system 1.

It should be appreciated that although steps S1 to S3 are shown in a certain order in Figure 7, in some implementations the method steps may be performed in an alternative sequence. For example, in some implementations, capillary tubes 66 may be formed in the substrate 62 prior to providing the electrically resistive layer 64 (e.g., via a deposition technique). In such implementations, step S2 and optionally step S3 may precede step S1 , noting that the provision of a substrate 62 is required for step S2 and optionally step S3 to be performed. Additionally, step S3 may be performed prior to step S2; that is, the flared ends 61 of the capillary tube 66 may be formed prior to the formation of the remaining part of the capillary tube 66. Thus, it should be understood that the method of Figure 7 is an example method only, and adaptations to the steps or ordering of the steps of this method are contemplated within this disclosure.

Thus, there has been described a heater assembly for an aerosol provision system, the heater assembly including: a substrate; a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; and one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate. The ends of the one or more capillary tubes at the heater layer are configured to provide a flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer. Also described is a cartomiser including the heater assembly, an aerosol provision system including the heater assembly, and a method for manufacturing the heater assembly.

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 are not directly relevant to the principles underlying the examples described herein.

It should also be appreciated that while the above has described the provision of capillary tubes 66 through a substrate 62 and electrically resistive layer 64 (or more broadly a heater layer), with said capillary tubes 66 including flared ends 61, 6T, 61”, the principles of the present disclosure are not limited to implementations in which vaporisation occurs by heating. For example, alternative means of aerosolising a liquid or other aerosol-generating material, such as vibrating plates or meshes or pressurised systems may also employ the principles of the present disclosure to help facilitate the generation of aerosol through use of the flared ends of capillary tubes designed to feed liquid to a surface of the aerosolisation assembly. That is, the principles of the present disclosure may be extended to an aerosolisation assembly (e.g., a heater assembly, a vibrating mesh assembly, a pressurised fluid assembly) for an aerosol provision system, the aerosolsiation assembly comprising a substrate; and one or more capillary tubes extending from a first surface of the substrate through the substrate to a second surface of the substrate. The ends of the one or more capillary tubes are configured to provide a flared end having an opening at the second surface of the aerosolisation assembly, wherein the flared end has an increasing characteristic dimension of extent along the direction from the first surface of the substrate to the opening at the second surface.

It should be appreciated that the hater assembly 6 has been described as being planar and in the form of a cuboidal block, elongate in the direction of a longitudinal axis L2, and having parallel upper and lower major (planar) surfaces and parallel side surfaces and parallel end surfaces. However, as described above, the heater assembly 6 may take different shapes in other implementations. For example, in some implementations, the upper and/or lower major surfaces may be curved (that is, be in a curved plane). For example, when viewing the heater assembly 6 in cross-section, the longer edges of the major surface(s) follow a curve or an arc (or put another way, may have a curved profile). In particular, the curve or an arc that the edges of the major surface(s) follow may be an open curve or an arc. Accordingly, in some implementations, there is provided: A heater assembly for an aerosol provision system, the heater assembly comprising: a substrate; a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; and one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate, wherein at least one surface of the substrate is curved in at least one direction. In some implementations, the curved substrate follows a path that is an open curve. In some implementations, the at least one surface of the substrate that is curved is the first surface. In some implementations, the at least one surface of the substrate that is curved is a surface of the substrate arranged to receive liquid from a liquid reservoir.

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 may be combined with features of the independent claims in combinations other than those explicitly set out in the claims. The disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

1. A heater assembly for an aerosol provision system, the heater assembly comprising: a substrate; a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; and one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate, wherein the ends of the one or more capillary tubes at the heater layer are configured to provide a flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer.

2. The heater assembly of claim 1 , wherein the flared end is configured so as to facilitate the release of liquid aerosol-generating material.

3. The heater assembly of any of the preceding claims, wherein the one or more capillary tubes have a circular cross-section, and wherein the flared end has an increasing diameter, as the characteristic dimension of extent, along the direction from the another surface of the substrate to the opening in the heater layer.

4. The heater assembly of any of the preceding claims, wherein the characteristic dimension of extent of the flared end increases linearly along the direction from the another surface of the substrate to the opening in the heater layer.

5. The heater assembly of any of claims 1 to 3, wherein the characteristic dimension of extent of the flared end increases non-linearly along the direction from the another surface of the substrate to the opening in the heater layer.

6. The heater assembly of any of claims 1 to 5, wherein the characteristic dimension of extent of the flared end increases in a stepwise manner along the direction from the another surface of the substrate to the opening in the heater layer.

7. The heater assembly of any of the preceding claims, wherein the one or more capillary tubes comprise side walls formed in the substrate, and wherein the distance between the side walls is the same, or substantially the same, along the direction from the another surface of the substrate to the flared end of the one or more capillary tubes.

8. The heater assembly of any of claims 1 to 6, wherein the one or more capillary tubes comprise side walls formed in the substrate, and wherein the distance between the side walls is different along the direction from the another surface of the substrate to the flared end of the one or more capillary tubes.

9. The heater assembly of any of the preceding claims, wherein the flared end has its largest characteristic dimension of extent at the opening at the surface of the heater layer, and its smallest characteristic dimension of extent at the portion of the flared end furthest from the opening.

10. The heater assembly of claim 9, wherein the smallest characteristic dimension of extent of the flared end is the narrowest characteristic dimension of extent of the flared end and the corresponding capillary tube.

11. The heater assembly of claim 9 or 10, wherein the largest characteristic dimension of extent of the flared end is the widest characteristic dimension of extent of the flared end and the corresponding capillary tube.

12. The heater assembly of any of the preceding claims, wherein the substrate is formed from quartz.

13. The heater assembly of any one of the preceding claims, wherein the one or more capillary tubes have a diameter in the range of 10 to 250pm.

14. The heater assembly of any one of the preceding claims, wherein the one or more capillary tubes are formed by laser drilling.

15. A cartomiser for use with an aerosol-generating device for generating aerosol from an aerosol-generating material, the cartomiser comprising: a reservoir for storing aerosol-generating material, and a heater assembly according to any one of the preceding claims, wherein the heater assembly is provided in fluid communication with the reservoir.

16. An aerosol provision system for generating aerosol from an aerosol-generating material, the aerosol provision system comprising the heater assembly of any one of claims 1 to 14.

17. The aerosol provision system of claim 16, the system comprising an aerosol provision device and the cartomiser according to claim 15, wherein the cartomiser is releasably connectable to the aerosol provision device.

18. A method of manufacturing a heater assembly for an aerosol provision system, the method comprising: providing a substrate comprising a heater layer configured to generate heat when supplied with energy, the heater layer provided on a first surface of the substrate; forming one or more capillary tubes extending from another surface of the substrate through the heater layer provided on the first surface of the substrate; and forming flared ends of the one or more capillary tubes at the ends of the one or more capillary tubes at the heater layer, the flared end having an opening at the surface of the heater layer opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer.

19. Heater means for an aerosol provision system, the heater means comprising: a substrate; heater layer means configured to generate heat when supplied with energy, the heater layer means provided on a first surface of the substrate; and capillary means extending from another surface of the substrate through the heater layer means provided on the first surface of the substrate, wherein ends of the capillary means at the heater layer means are configured to provide a flared end having an opening at the surface of the heater layer means opposite the first surface of the substrate, wherein the flared end has an increasing characteristic dimension of extent along the direction from the another surface of the substrate to the opening in the heater layer means.