EP4304401A1

EP4304401A1 - Aerosol provision system

Info

Publication number: EP4304401A1
Application number: EP22706886.3A
Authority: EP
Inventors: David Rushforth; Charanjit Nandra
Original assignee: Nicoventures Trading Ltd
Current assignee: Nicoventures Trading Ltd
Priority date: 2021-03-11
Filing date: 2022-02-18
Publication date: 2024-01-17
Also published as: WO2022189765A1; KR20230144059A; CN116963627A; US20240138486A1; BR112023018326A2; CA3208833A1; JP2024510118A; GB202103375D0

Abstract

An aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, wherein the aerosol provision system comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator, in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

Description

AEROSOL PROVISION SYSTEM

Field

The present disclosure relates to aerosol provision systems such as nicotine delivery systems.

Background

Aerosol delivery systems generally contain a aerosol generating material, such as a portion of a solid, liquid or gel, or a reservoir of a source liquid which may contain an active substance and / or a flavour, from which an aerosol or vapour is generated for inhalation by a user, for example through heat vaporisation. Thus, an aerosol provision system / electrical smoking system will typically comprise a heating chamber or aerosol generation chamber containing an aerosol generator, e.g. a heating element, arranged to vaporise or aerosolise a portion of aerosolisable material (e.g. a solid material such as tobacco) to generate a vapour or aerosol in the aerosol generation chamber. As a user inhales on the device, and electrical power is supplied to the heating element, air is drawn into the device through an inlet hole and along an inlet air channel connecting to the aerosol generation chamber where the air mixes with vaporised precursor material to form a condensation aerosol. An outlet air channel connects from the aerosol generation chamber to an outlet in the mouthpiece, and the air drawn into the aerosol generation chamber as a user inhales on the mouthpiece continues along the outlet flow path to the mouthpiece outlet, carrying the aerosol with it, for inhalation by the user. Some aerosol delivery systems may also include a flavour element in the air flow path through the device to impart additional flavours. Such devices may sometimes be referred to as hybrid devices, and the flavour element may, for example, include a portion of solid aerosol-generating and / or flavourant material such as tobacco arranged in the air flow path between the aerosol generation chamber and the mouthpiece such that aerosol / condensation aerosol drawn through the device passes through the portion of solid material before exiting the mouthpiece for user inhalation. In some aerosol delivery systems, the aerosol generating material comprises a source liquid comprised in a cartridge or pod which also contains the heating element and aerosol generating chamber, and the cartridge is mechanically and electrically coupled to a control unit for use. The control unit comprises a battery and control circuitry which together supply power to the heating element via the cartridge.

As stated above, aerosol provision systems use an aerosol generator, such as a heater, to transfer energy to the aerosol forming material to generate an aerosol, e.g. through heat vaporisation. However, energy can dissipate or otherwise be transferred (i.e. through conduction, convention, or radiation) to components other than the heater and aerosol forming material (e.g. structural components supporting the heater or aerosol forming material) which can result in an increased temperature of the other components of the system. This can lead to undesirable consequences.

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

Summary

According to a first aspect of the present disclosure, there is provided an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, wherein the aerosol provision system comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator, in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

According to a second aspect of the present disclosure, there is provided a controller for use with an aerosol provision system for generating an aerosol for user inhalation from aerosol generating material using an aerosol generator.

According to a third aspect of the present disclosure, there is provided an aerosol provision device for an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, wherein the aerosol provision device comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator, in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

According to a fourth aspect of the present disclosure, there is provided a method for controlling an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, the method comprising: determining, after an end of a usage session, that an temperature of the aerosol provision system is below a predefined threshold temperature; and controlling an indicator in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature. According to a fifth aspect of the present disclosure, there is provided an aerosol provision means, for generating an aerosol for user inhalation from aerosol-generating means using an aerosol generator means, wherein the aerosol provision means comprises a control means and indicator means, wherein the control means is configured to: determine, after an end of a usage session, that an temperature of the aerosol provision means is below a predefined threshold temperature; and control the indicator means in response to determining the temperature of the aerosol provision means is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

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

Figure 1 is a schematic cross-sectional view through an example aerosol provision system 1 in accordance with certain embodiments of the disclosure.

Figure 2 schematically represents a method of controlling an aspect of the electronic aerosol provision device in accordance with certain embodiments of the disclosure.

Figure 3 is a schematic cross-sectional view through an example device part 2 in accordance with certain embodiments of the disclosure.

Figure 4 schematically represents a further method of controlling an aspect of the electronic aerosol provision device in accordance with certain embodiments of the disclosure.

Detailed Description

Aspects and features of certain examples and embodiments are discussed / described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not discussed / 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.

As will be explained below, an aerosol provision system having an aerosol generator, such as a heater, is configured to transfer energy to an aerosol forming material to generate an aerosol, e.g. through heat vaporisation. Excess or “loss” energy can dissipate or otherwise be transferred (i.e. through conduction, convention, or radiation) to components other than the heater and aerosol forming material (e.g. structural components supporting the heater or aerosol forming material, or housing components) which can result in an increased temperature of the other components of the system. In particular, dissipation of energy may result in an increase in temperature in the external surfaces of the system which might come into contact with the user’s skin, clothing and other objects.

In accordance with embodiments of the disclosure an aerosol provision device or system is provided having a control unit configured to determine (e.g. calculated, established), after usage of the device, that a temperature of the device is below a predefined threshold temperature, and to control an indicator (e.g. via audible, visual or haptic means) in response to determining that the temperature of the device has fallen below a predefined threshold temperature (e.g. a predefined level or value) , to indicate the temperature of the device is below the predefined threshold temperature.

The threshold temperature may be set so as to reduce the risk of adverse consequences, for example, a device that is still warm when stored in a rucksack or pocket may cause adverse effects to the user (e.g., an uncomfortable feeling) or adverse effects to the user’s other possessions (e.g., a mobile phone, cosmetic goods, food and drink, etc.). A user of the device, after becoming aware of the indication, will subsequently be informed that the device is able to be safely put away (e.g. in a bag or a pocket of their clothing) to minimise or alleviate such adverse effects. A device having a control unit in accordance with embodiments of the disclosure is advantageous in that a user may consider an increased surface temperature of the device to be undesirable, as it may be uncomfortable when in proximity to skin or may lead to marking or other damaging of possessions which are susceptible to damage by heating.

For example, when a device having a temperature above a predefined level is placed in an pocket, the presence of the device can become uncomfortable to the user because the device is held in relatively close proximity to a portion of user’s skin (e.g. a user’s thigh for a trouser pocket) whilst being shielded from ambient air flow and insulated by the pocket and clothing material layers. Additionally, or alternatively, when a device having a relatively high temperature is placed in close proximity to, or in a confined space with (e.g. in a pocket or a bag), an object that is susceptible to damage by heating, transfer of heat from the device to the object (i.e. through conduction, convention, or radiation, either directly or indirectly) may mark or otherwise damage the object. For example, an object comprising a delicate fabric, such as silk, could become damaged due to the transfer of energy from the device to the object causing the delicate fabric to discolour. For example, an object comprising a food stuff could become damaged due to the transfer of energy from the device to the object causing a property of the food stuff to change (e.g. chocolate of a chocolate bar or biscuit might melt and deform).

As discussed above, the present disclosure relates to aerosol provision / delivery systems (which may also be referred to as vapour delivery systems). As used herein, the term “delivery system” is intended to encompass systems that deliver at least one substance to a user, and includes non-combustible aerosol provision systems that release compounds from an aerosol-generating material without combusting the aerosol-generating material, such as electronic cigarettes, tobacco heating products, and hybrid systems to generate aerosol using a combination of aerosol-generating materials.

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 delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

In some embodiments, the non-combustible aerosol provision system is an electronic cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it is noted that the presence of nicotine in the aerosol-generating material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is an aerosol generating material heating system, also known as a heat-not-burn system. An example of such a system is a tobacco heating 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 aerosol generating material. The solid aerosol-generating 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 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 or an exothermic power source. In some embodiments, the exothermic power source comprises a carbon substrate which may be energised so as to distribute power in the form of heat to an aerosol-generating material or to a heat transfer material in proximity to the exothermic 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 wrapper, a filter, a mouthpiece, and/or an aerosol-modifying agent.

In some embodiments, the substance to be delivered may be an aerosol-generating material or a material that is not intended to be aerosolised. As appropriate, either 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.

Aerosol-generating material is a material that is capable of generating aerosol, for example when heated, irradiated or energized in any other way. Aerosol-generating material may, for example, be in the form of a solid, liquid or gel which may or may not contain an active substance and/or flavourants. In some embodiments, the aerosol-generating material may comprise an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous). In some embodiments, the amorphous solid may be a dried gel. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some embodiments, the aerosol-generating material may for example comprise from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid.

The aerosol-generating material may comprise one or more active substances and/or flavours, one or more aerosol-former materials, and optionally one or more other functional material. 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 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.

A consumable is an article comprising or consisting of aerosol-generating material, part or all of which is intended to be consumed during use by a user. A consumable may comprise one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol generation area, a housing, a wrapper, a mouthpiece, a filter and/or an aerosol-modifying agent. A consumable may also comprise an aerosol generator, such as a heater, that emits heat to cause the aerosol generating material to generate aerosol in use. The heater may, for example, comprise combustible material, a material heatable by electrical conduction, or a susceptor.

A susceptor is a material that is heatable by penetration with a varying magnetic field, such as an alternating magnetic field. The susceptor may be an electrically-conductive material, so that penetration thereof with a varying magnetic field causes induction heating of the heating material. The heating material may be magnetic material, so that penetration thereof with a varying magnetic field causes magnetic hysteresis heating of the heating material. The susceptor may be both electrically-conductive and magnetic, so that the susceptor is heatable by both heating mechanisms. The device that is configured to generate the varying magnetic field is referred to as a magnetic field generator, herein.

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 aerosol modifying 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.

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. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator may be configured to subject the aerosol-generating material to one or more of vibration, increased pressure, or electrostatic energy.

Figure 1 is a cross-sectional view through an example aerosol provision system / heat-not- burn device 1 in accordance with certain embodiments of the disclosure. The aerosol provision system 1 comprises two main components, namely a reusable device part 2 and a replaceable consumable / cartridge / cartomiser part 4.

In normal use the reusable part 2 and the consumable part 4 are releasably coupled / attached together by partially or fully inserting the consumable part 4 into a chamber 50 of the reusable device part 2, comprising a heater chamber region / heating region 53. Figure 1 schematically shows the reusable device part 2 with a consumable part 4 partially received into a chamber 50. Chamber 50 comprises a cylindrical tube extending into the reusable device part 2 from an outer housing surface of the reusable device part. In this example, the chamber extends into the device from an outer surface of the mouthpiece end of the reusable device part 2, defined as the uppermost part of the reusable device part as a user holds it in their hand for use, the chamber 50 extending parallel to the long axis of the reusable device part 2. An aperture 51 communicates between the chamber 50 and the exterior of the device.

In broad outline, the reusable device part 2 is configured to generate an aerosol to be inhaled by a user, typically by heating one or more aerosol generating materials in the consumable part 4, either directly via one or more heating elements associated with the heating region 53 of the chamber 50, or by transmitting electrical energy or a magnetic field into the consumable part 4 to activate an aerosol generator such as a heating element in or on the consumable part 4. In use, a user inserts a consumable part 4 into the chamber 50 of the reusable device part via the aperture 51 , and then activates the reusable device part 2, e.g. using a button 14, to cause the reusable device part 2 to supply power from a power supply / battery 26 to an aerosol generating element to aerosolise the aerosol generating material(s) comprised in the consumable part 4 for inhalation by a user. The user subsequently draws on a mouthpiece 41 of the consumable part 4 which extends out of the aperture 51 at the mouthpiece end of reusable device part 2 to inhale an aerosol generated by the reusable device part 2. As a user draws on the mouthpiece 41 of consumable part 4, air is drawn into an air inlet 24 disposed on an outer surface of reusable part 2, down an air inlet channel 25, and into a heating region 53 of the chamber 50, wherein it enters at least one air inlet 42 of the consumable part 4, entraining vapour / aerosol generated via aerosolisation / heating of a portion of aerosol generating material 43 comprised in the consumable part 4. For the same of a concrete example, Figure 1 shows schematically a heating element 48 arranged around the heating region 53 of the chamber 50 as described further herein, which transmits heat into a portion of the consumable part 4 containing aerosol generating material 43. The entrained vapour / aerosol travels through the consumable part 4 towards a mouthpiece end of the reusable device part 2 (from which a mouthpiece 41 of consumable part 4 extends), wherein aerosol droplets condense out or further condense out of the vapour / aerosol, forming a condensation aerosol which exits the mouthpiece 41 of the consumable part 4 for inhalation by the user.

The reusable part 2 comprises an outer housing having with an opening that defines an air inlet 24, a power source 26 (for example a battery) for providing operating power for the aerosol provision system, control circuitry 22 for controlling and monitoring the operation of the aerosol provision system, an optional user input button 14, an optional display 16, and a visual display / visual feedback indicator 28. The outer housing of the reusable device part 2 may be formed, for example, from a plastics or metallic material, or any other material known to the skilled person. For the sake of providing a concrete example, the reusable device part 2 may in some embodiments have a length of around 80 mm, and the consumable part 4 extends from the mouthpiece end of the reusable device part by approximately 10 to 30 mm when fully inserted into the chamber 50, so the overall length of the aerosol provision system 1 when the consumable part and reusable device part are coupled together is around 90 to 110 mm. The consumable part 4 may have a diameter of approximately 80 mm. Flowever, and as already noted, it will be appreciated that the overall shape and scale of an aerosol provision system implementing an embodiment of the disclosure is not significant to the principles described herein.

The power source 26 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in aerosol provision systems such as heat-not-burn devices, tobacco heating devices, electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods (for example, a lithium ion battery). The power source 26 may be recharged through a charging connector in the reusable part housing, comprising for example a micro-USB or USB-C connector, which may also provide an interface for data transfer between a controller 22 and an external processing device such as a smartphone or a personal computer.

A user input button 14 may optionally be provided, which in this example is a conventional mechanical button, for example comprising a spring mounted component which may be pressed by a user to establish an electrical contact. In this regard, the input button 14 may be considered an input devices for detecting user input and the specific manner in which the button is implemented is not significant (e.g. it may comprise a capacitive touch sensor and / or a touch-sensitive display element). A plurality of such buttons may be provided, with one or more buttons being assigned to functions such as switching the aerosol provision system 1 on and off, and adjusting user settings such as a power to be supplied from the power source 26 to an aerosol generator 48, and / or selecting one or more device modes. However, the inclusion of user input buttons is optional, and in some embodiments such buttons may not be included.

An optional display unit 16 may in some instanced be provided on an outer surface of the housing of reusable device part 2. The display unit 16, where included, may comprises a pixilated or non-pixilated display unit (for example, comprising a single LED, an array of LEDs, a liquid crystal display (LCD), light-emitting diode (LED) display, organic light emitting- diode (OLED) display, active-matrix organic light-emitting diode (AMOLED) display, electroluminescent display (ELD), plasma display panel (PDP), e-ink display), connected to controller 22. The skilled person may implement such a display in accordance with any approaches known in the art. Such a display may be used for displaying to a user usage information about the use of the aerosol provision system 1. Exemplary forms of usage information which may be displayed to a user via an optional display unit 16 are described further herein.

At least one visual feedback indicator 28 is provided, with a display region visible on an outer surface of the housing of the reusable device part 2, the visual feedback indicator 28 being configured to provide visual feedback to a user about one or more aspects of the operation or status of the device. Such visual feedback may comprise information about, for example, whether the system is on or off, a selected operating mode, how much charge or aerosol generating material remains in the aerosol provision system, the temperature of a heating element, or a strength with which a user is inhaling on the device (e.g. derived from an airflow sensor as described further herein). Such information may be shown before, during and / or after a puff or session on the aerosol provision device. The visual feedback indicator used to display such information may comprise a display panel comprising a plurality of pixels, comprising for example an LCD, LED, OLED, AMOLED, ELD, PDP, e-ink display, or any other form of pixilated display panel known to the skilled person. Additionally or alternatively, the visual feedback indicator 28 may comprise one or more non-pixilated display elements, such as one or more LEDs. As set out further herein, the at least one visual feedback indicator 28 may further comprise one or more light guiding elements, such as one or more light pipe, fibre optic or otherwise transparent or translucent light-transmitting elements, configured to guide a visual feedback signal from one or more light-emitting visual feedback elements situated within the housing of the reusable device part 2 to one or more display regions visible on, in or through a housing surface of the reusable device part 2.

A controller 22 is suitably configured / programmed to control the operation of the aerosol provision system to provide functionality in accordance with embodiments of the disclosure as described further herein, as well as for providing conventional operating functions of the aerosol provision system in line with the established techniques for controlling such devices. The controller (processor circuitry) 22 may be considered to logically comprise various sub units / circuitry elements associated with different aspects of the operation of the aerosol provision system 1. In this example the controller 22 comprises power supply control circuitry for controlling the supply of power from the power source 26 to the aerosol generator 48 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 / circuitry associated functionality in accordance with the principles described herein and conventional operating aspects of aerosol provision systems, such as display driving circuitry and user input detection circuitry. It will be appreciated the functionality of the controller 22 can be provided in various different ways, for example using one or more suitably programmed programmable computer(s) and / or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s) configured to provide the desired functionality. The controller 22 may comprise a wireless transceiver and associated control circuitry enabling transfer of data between the reusable device part 2 and an external computing device such as a smartphone or personal computer (not shown), via a wireless transfer protocol such as Bluetooth, near-field communication (NFC) or Zigbee. The controller 22 also comprises one or more data storage elements (e.g. a memory element such as a ROM or RAM element) which can be used to store data associated with usage of the aerosol provision system, according to established techniques for data storage and transfer.

In some embodiments of the present disclosure, reusable device part 2 may comprise an airflow sensor 30 such as a pressure sensor or flow-rate sensor (for example a hot-wire anemometer) which is electrically connected to the controller 22, and in fluid communication with a portion of the airflow path between air inlet 24 and mouthpiece 41. The airflow sensor 30 may, for example, be disposed in a wall of the air inlet channel 25 or the chamber 50, and / or extend at least partially into or across a portion of an air flow pathway defined by air inlet channel 25 or the chamber 50). In some embodiments, a combined airflow and temperature sensor is used which allows the temperature of airflow in a portion of the airflow path in the device to be determined. In some embodiments, the airflow sensor comprises a so-called “puff sensor”, in that a signal from the airflow sensor 30 is used by the controller 22 to detect when a user is puffing on the device. In some embodiments, detection of a user puff (for example, by the controller 22 detecting a signal from the airflow sensor 30 indicative of pressure and / or flow rate in the airflow path between air inlet 24 and the mouthpiece 41 , and determining it is above or below a predefined threshold) is used by the controller 22 to control the supply of power to the aerosol generator / heater 48. Accordingly, the controller 22 may distribute electrical power from the power source 26 to the aerosol generator 48 in dependence on at least a signal received from the airflow sensor 30 by the controller 22. The specific manner in which the signal output from the airflow sensor 30 (which may comprise a measure of capacitance, resistance or other characteristic of the airflow sensor, made by the controller 22) is used by the controller 22 to control the supply of power from the power source 26 to the aerosol generator 48 can be implemented in accordance with any approach known to the skilled person (for example, by providing an amount of power to the aerosol generator 48 which is proportional to the characteristics of airflow (e.g. pressure, flow-rate and / or speed) through the aerosol provision system as determined on the basis of the signal output by the airflow sensor 30). In some instances, signal received from the pressure sensor (i.e. the aerosol generator 48 is ‘puff activated’) is used by the controller 22 to switch on and / or off the supply of power to the aerosol generator 48 (e.g. by supplying power when an airflow parameter value determined on the basis of a signal received from the airflow sensor 30 is one side of a predefined threshold, and not supplying power when the airflow parameter value is the other side of the predefined threshold). In other embodiments, the supply of power to the aerosol generator 48 is controlled via other means (e.g. by button 14), with the delivery of power being modified based on the signal received by the controller 22 from the airflow sensor (e.g. modulated in proportion to an airflow parameter determined based on a signal received from the airflow sensor 30). However, it will be appreciated that the inclusion of an airflow sensor is optional, and in some embodiments no airflow sensor is included. In such embodiments, the supply of power to the aerosol generator 48 may be switched on and off by a button 14, or may be switched on by a button 14, with the supply of power to the aerosol generator 48 being switched off by the controller 22 after a predetermined or predefined period of time has elapsed. For example, when the controller 22 detects a predetermined or predefined input signal (for example, supplied via a button 14, or comprising detecting via a suitable sensor that a user has inserted a consumable part 4 into the chamber 50), the controller may begin to supply power from battery 26 to the aerosol generator 48 and begin a timer. When the elapsed time / activation duration on the timer reaches a predefined threshold (for example, 210 seconds), the controller 22 may stop supplying power to the aerosol generator 48. The activation duration of the aerosol generator 48 at a given power level may be set based on the time taken for the aerosol generator 48 to aerosolise / volatilise a predefined amount of the aerosol generating material 48 in the consumable part 4. A suitable activation duration (i.e. the time from aerosol generator 48 activation after which the controller 22 automatically turns off the supply of power to the aerosol generator 48) may be determined for a given consumable part 4 using experimentation or modelling.

In some embodiments, the aperture 51 of the reusable part 2 via which the consumable part 4 is inserted into the chamber 50 may be opened and closed by a door (not shown), which is movable between a closed position and an open position to allow for insertion of the consumable part 4 into the reusable device part 2 when in the open position. The door may be co-planar with a mouthpiece-end surface of the reusable device part, being configured slide along an axis between open and closed positions or rotate between open and closed positions. A spring or magnet may bias the door the open and closed positions to retain it in either of the open or closed position once the user has slid or rotated the door into either position.

The reusable part 2 typically comprises an aerosol generator 48 located in the vicinity of the heating region 53 of the consumable chamber 50. An aerosol generator is an element or apparatus configured to cause aerosol to be generated from the aerosol-generating material in the consumable part 4, for example, by heating. Accordingly, in some embodiments, the aerosol generator 48 comprises a heater configured to subject the aerosol-generating material in the consumable part 4 to heat energy, so as to release one or more volatiles from the aerosol-generating material to form an aerosol. In some embodiments, the aerosol generator is configured to cause an aerosol to be generated from the aerosol-generating material without heating. For example, the aerosol generator 48 may be configured to subject the aerosol-generating material in the consumable part 4 to one or more of vibration, increased pressure, or electrostatic energy to volatilise the aerosol generating material. It will be appreciated that in a two-part device such as shown in Figure 1 , portions of the aerosol generator 48 may be in either of the reusable device part 2 and / or the consumable part 4. It will further be appreciated that in some instances the consumable part 4 may comprise a cartridge containing an electrically operated aerosol generator (e.g. a heater), and that in addition to or in place of aerosol generator 48 in the reusable device part 2, the reusable device part 2 may comprise an electrical interface comprising electrical contacts disposed in chamber 50 which electrically connect the aerosol generator in the consumable part 4 with the power source 26 and controller 22 in the reusable device part 4 when the consumable part 4 is fully received within the chamber 50.

In some embodiments of the disclosure, an aerosol generator 48 comprising at least one heating element is formed as a cylindrical tube, having a hollow interior heating chamber, configured in use to provide heat energy to a heating region 53 of the chamber / receiving recess 50, into which the consumable part 4 comprising aerosol generating material 43 is inserted for heating. As set out further herein, a heating element may directly form a portion of a tube comprising chamber 50, or may be disposed around or proximate a heating region 53 of a tube comprising chamber 50. Different arrangements for the aerosol generator / heater 48 are possible. In some embodiments, a heater 48 may comprise a single heating element (e.g. a resistive trace, track and / or winding) or may be formed of plural heating elements aligned longitudinally or transversely (e.g. radially) to the longitudinal axis of the chamber 50. Each of one or more heating elements comprised in the heater 48 may be annular or tubular, or at least part-annular or part-tubular around its circumference. The one or more heating elements may comprise one or more thin-film heaters comprising one or more resistive tracks on a heat-resistant substrate comprising, for example, polyimide film. The one or more heating elements may comprise a ceramics material, comprising for example aluminium nitride or silicon nitride ceramics, which may be laminated and sintered with one or more heat-generating layers to form a heater according to approaches known in the art. Other heater arrangements are possible, including for example inductive heating elements, infrared heater elements, which heat by emitting infrared radiation, or resistive heating elements formed by for example a resistive electrical winding. In the latter case, the resistive winding may be disposed around a ceramic, metallic or heat-resistant polymer tube, or embedded within such a tube, the tube either comprising heating region 53 of the chamber 50, or arranged around it, to emit heat into a cavity within heating region 53. The battery 26 is electrically coupled to the heating element to supply electrical power when required, and under control of the control circuitry 22 to heat the aerosolisable material in the consumable 4 (as discussed further herein, to volatilise the aerosolisable material without causing the aerosolisable material to burn).

The rate at which aerosol generating material in the consumable part is vaporised by the aerosol generator / heater 48 will depend on the amount of power supplied to the aerosol generator 48. Thus electrical power can be applied to the aerosol generator 48 to selectively generate aerosol from the aerosol generating material in the consumable 4, and furthermore, the rate of aerosol generation can be changed by changing the amount of power supplied to the aerosol generator 48, for example through pulse width and/or frequency modulation techniques, under the control of controller 22.

In some embodiments, at least one heating element comprised in aerosol generator 48 is supported by and surrounds a thermally conductive tube, formed for example of stainless steel, comprising part of the wall of the chamber 50 which receives the consumable part 4. At least the portion of the tube proximate to the heating element(s) may be considered to comprise the heating region 53 of the chamber 50. The internal diameter of the tube comprising the chamber 50 is sized relative to the diameter of the consumable part 4 to be inserted into the tube. The tube may taper slightly (not shown) from a wider diameter at the aperture 51 to a narrower diameter at the base of the chamber distal to the aperture 51 , such that as the consumable part 4 is slid into the chamber 50, the end distal to the mouthpiece 41 is slightly radially compressed as the consumable part 4 reaches the end of its travel into the chamber 50, causing the consumable part 4 to be gently retained in the chamber 50. This arrangement can prevent the consumable 4 accidentally sliding out of the reusable device part 4 if, for example, the reusable device part 4 is inverted during use. The chamber 50 may also be slightly flared or chamfered at the aperture end to allow the consumable part to be easily guided into the chamber 50. Accordingly, the chamber 50 may act as an elongate support for supporting, in use, the consumable part 4 comprising aerosol generating material. The diameter of the chamber 50 in the heating region 53 will in general be selected to closely match that of the consumable part 4, ensuring contact between the exterior surface of the consumable part 4 and a substantial portion of the interior surface of the heating region 53 of the chamber 50, allowing for efficient heat transfer of heat from one or more heating elements comprised in the aerosol generator 48 into the consumable part 4.

In embodiments where the aerosol generator 48 comprises a heater, the tube comprising the heating region 53 of the chamber 50 comprises a material which transfers heat from the heater 48, to the consumable part 4, and generally comprises a metal or a metal alloy, such as one or more materials selected from the group consisting of: aluminium, gold, iron, nickel, cobalt, conductive carbon, graphite, steel, plain-carbon steel, mild steel, ferritic stainless steel, molybdenum, copper, and bronze. In other embodiments, the section of tube comprising the heating region 53 of the chamber 50 may be made from a different material, as long as it is thermally conductive. Other heating elements 48 may be used in other embodiments. For example, the heating element 48 may comprise a susceptor (for instance a portion of a tube comprising chamber 50) that is heated via induction when exposed to a magnetic field generated by one or more magnetic field generators such as drive coils (not shown) disposed within the reusable part 2.

Typically, where the aerosol generator 48 comprises one or more heating elements, the aerosol generator 48 is dimensioned relative to the distribution of aerosol generating material in the consumable part 4 so that when the consumable 4 is inserted in the reusable device part 2, substantially all of aerosol generating material in the consumable part can be heated in use (for example, a longitudinal extent of the heating region 53 down the axis of the chamber 50 may match the longitudinal extent of the distribution of aerosol generating material 43 in the consumable part 4, when the consumable part 4 is fully received into the chamber 50). In some embodiments, one or more heating elements comprised in the aerosol generator 48 may be arranged so that selected zones of the aerosol generating material in the consumable part 4 can be independently heated, for example in turn (over time) or together (simultaneously) as desired (for example by distributing independently controllable heating elements along a length of the chamber 50 comprising the heating region 53).

As mentioned further herein, in some embodiments, the aerosol generator 48 is in the form of a hollow cylindrical tube which comprises, is embedded in, or surrounds the heating region 53 of the chamber 50. The chamber formed by the internal portion of the tube comprising the heating region 53 is typically in fluid communication with the aperture 51 at the mouthpiece end of the reusable device part 2 via a non-heating region 52 of the chamber 50 (which may also be referred to as an expansions region / chamber. In such embodiments, the non-heating region 52 comprises a tubular body that has a first open end adjacent to or comprising the aperture 51 and a second open end adjacent the heating chamber region 53 of the chamber 50. In this manner, the non-heating region 52 and heating region 53 can be considered tubular portions of chamber 50 which are arranged end to end. In general, the diameter of the expansion region 52 and heating region 53 will be matched at the interface between them to ensure smooth passage of the non-mouthpiece end of the consumable part 4 through the non-heating region 52 and into the heating region 53. The non-heating / expansion region 52 and heating region 53 of a tube comprising chamber 50 may be separately formed and connected via mechanical joining processes, or integrally formed. In some embodiments, the non-heating region 52 comprises a flared section (not shown) which widens as it opens out onto the aperture 51 , and a section of substantially constant internal diameter proximate to the interface with the heating region 53.

In some embodiments, the consumable part 4 is in the form of a cylindrical rod which has or contains aerosol generating material 43 at an end distal to the mouthpiece 41 , in a section of the consumable part 4 that is within the heating region 53 of the chamber 50 when the consumable part 4 is fully inserted in the reusable device part 2. For the sake of providing a concrete example, in one embodiment the consumable part 4 has a diameter of around 8 mm and a length of around 84 mm. The depth of the chamber 50 of the reusable device portion is sized relative to the length of the consumable part 4 such that a mouthpiece end 41 of the consumable part 4 typically extends from the aperture (for example, by 10 mm, 20 mm, 30 mm or more than 30 mm) when the consumable part 4 is fully inserted into the chamber 50. Accordingly, a mouthpiece end of the consumable part 4 typically extends from the reusable device part 2, out of aperture 51. The consumable part 4 may include a filter / cooling element 44 for filtering / cooling aerosol, disposed between the mouthpiece 41 and a region of aerosol generating material 43. The consumable part 4 is typically circumferentially wrapped in a wrapper / outer layer (not shown) which may comprise a paper material, and / or a metallic foil, and / or a polymer film such as Natureflex (TM). The outer layer of the consumable part 4 may be permeable to allow some heated volatilised components from the aerosol generating material 43 to escape the consumable part 2 prior to reaching the mouthpiece 41. In some embodiments, the wrapper may comprise a metallic material in the vicinity of the aerosol generating material 43, which is configured to act as a susceptor, which is heated by induction via one or more magnetic field generators / drive coils (not shown) in the reusable device part 2, so as to heat the aerosol generating material 43 via inductive heating. For example, in such embodiments, the aerosol generator 48 may comprise one or more magnetic field generators / drive coils configured to induce inductive heating of a metallic wrapper of consumable 4, and / or one or more susceptor elements embedded within the aerosol generating material 43 within the consumable part 4, to induce heating of aerosol generating material 43 in the consumable part 4. It will be appreciated the configuration of the consumable part 4 set out above is illustrative, and the skilled person may modify the overall structure of the consumable part according to approaches known in the art.

In some embodiments, the aerosol generator 48 comprises at least one heating element configured to transfer heat into the consumable part 4 (according to approaches for heating set out further herein), and at least one magnetic field generator / drive coil configured to inductively heat at least one susceptor element comprised in consumable part 4 (according to approaches set out further herein). In such embodiments, the aerosol generating material 43 may comprise a plurality of aerosol generating materials, at least a first of which is heated by heat transferred into the consumable part 4 from the aerosol generator 48, and at least a second of which is heated by one or more susceptors comprised in or on consumable 4.

Where the aerosol generator 48 is configured to heat the consumable part 4, the temperature of part of the aerosol generator 48, and / or the heating region 53 of the chamber 50, or the consumable part 4, or any part of the reusable device part 2, may be detected by the controller 22 using one or more temperature sensors. For example, a heating element comprised in aerosol generator 48 may comprise a material with a temperature coefficient of resistance property such that its resistance varies with temperature. The controller 22 may determine the resistance of the heating element via known approaches and compare this result with a look-up table derived via experimentation or modelling linking heating element resistance to temperature, in order to estimate a temperature of the aerosol generator 48 based on the measured resistance. Alternatively or in addition, one or more temperature sensing elements such as thermistors may be positioned in the vicinity of the heating region 53 (for example, attached to or embedded in a tube comprising the heating region 53 of the chamber 50), said thermistors being connected to the controller 22 to enable the controller to monitor the temperature of the consumable part 4 and / or the heating region 53. The temperature of air in the air inlet channel 25 may also be monitored by one or more temperature sensors (for example a combined temperature and pressure sensor or thermistor) in a similar manner.

Typically, the primary flow path for heated volatilised components produced by heating of the aerosol generating material 43 by the heater 48 is axially through the consumable part 4, through the filter / cooling element 44 (where included), and into a user’s mouth through the open end of the mouthpiece 41. However, some of the volatilised components may escape from the consumable part 4 through its permeable outer wrapper and into a space surrounding the consumable part 4 in the non-heated chamber region 52 (e.g. a space formed by an optional gap (not shown) between the outer surface of the consumable 4 and the inner surface of the chamber 50 in the flared portion of the non-heating / expansion chamber region 53).

As used herein, the term “aerosol generating material” 43 typically includes materials that provide volatilised components upon heating, typically in the form of vapour or an aerosol. “Aerosol generating material” may be a non-tobacco-containing material or a tobacco- containing material. “Aerosol generating material” may, for example, include one or more of tobacco per se, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenised tobacco or tobacco substitutes. The aerosol generating material can be in the form of ground tobacco, cut rag tobacco, extruded tobacco, reconstituted tobacco, reconstituted aerosol generating material, liquid, gel, amorphous solid, gelled sheet, powder, or agglomerates, or the like. “Aerosol generating material” also may include other, non tobacco, products, which, depending on the product, may or may not contain nicotine. “Aerosol generating material” may comprise one or more humectants, such as glycerol, propylene glycol, triacetin, or diethylene glycol.

As noted above, the aerosol generating material 43 may comprise an “amorphous solid”, which may alternatively be referred to as a “monolithic solid” (i.e. non-fibrous), or as a “dried gel”. The amorphous solid is a solid material that may retain some fluid, such as liquid, within it. In some cases, the aerosol generating material comprises from about 50wt%, 60wt% or 70wt% of amorphous solid, to about 90wt%, 95wt% or 100wt% of amorphous solid. In some cases, the aerosol generating material consists of amorphous solid.

In some embodiments, the aerosol generating material is non-liquid aerosol generating material, and the reusable device part is for heating non-liquid aerosol generating material to volatilise at least one component of the aerosol generating material. Once all, or substantially all, of the volatilisable component(s) of the aerosol generating material in the consumable part 4 have / have been exhausted, the user may remove the consumable part 4 from the reusable device part 1 and dispose of the consumable part 4. The user may subsequently re-use the reusable device part 2 with another consumable part 4. However, in other respective embodiments, the consumable part 4 and the reusable device part 2 may be disposed of together once the volatilisable component(s) of the aerosol generating material has/have been spent. The consumable part 4 may be configured with a quantity of aerosol generating material 43 which is configured to be heated and exhausted over a single heating cycle (for example, an activation duration of 210 seconds), or may be configured with quantity of aerosol generating material 43 which is configured to be exhausted over a plurality of heating cycles. In the latter case, the consumable part 4 may be considered to be a reusable consumable part 4.

In some embodiments, the consumable part 4 may be sold, supplied or otherwise provided separately from the reusable device part 2 with which the consumable part 4 is usable. However, in some embodiments, the reusable device part 2 and one or more of the consumable parts 4 may be provided together as a system such as a kit or an assembly, possibly with additional components, such as cleaning utensils.

As described further herein, the controller 22 may indicate to a user via one or more feedback mechanisms / indicators comprised in the reusable device 1 . Such information may be termed ‘feedback’ or ‘usage information’, and may be indicated to a user using one or more of a visual feedback indicator 28 (as described further herein), a display unit 16, an audio feedback mechanism (such as a speaker), or a haptic feedback mechanism (such as an eccentric-rotating-mass actuator).

In accordance with certain embodiments of the disclosure there is described an aerosol provision system for generating an aerosol for user inhalation, wherein the aerosol provision system comprises a controller 22 and an indicator (for example display 16, visual feedback indicator 28, or an audio or tactile feedback device), and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol delivery system is below the predefined threshold temperature. By controlling the indicator, the control unit is configured to cause a change to the operation of the indicator. In some examples, the control unit can cause the indicator to activate (e.g. turn on/ emit an indication) in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature. In some examples, the control unit can cause the indicator to deactivate (e.g. turn off / cease indicating) in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature. In some examples, the control unit can cause the indicator to change or adjust an indication being emitted by the indicator (e.g. change a mode of indication) in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature. A device part 2 having a controller 22 in accordance with embodiments of the disclosure is advantageous given that a user may consider an increased surface temperature of the device to be undesirable, as it may be uncomfortable when in proximity to skin and / or may lead to marking or other damage to possessions which are susceptible to damage by heating.

By “a usage session” it is meant a period of time in which a user uses or is able to use the aerosol provision device 1 (i.e. a session of use). In some examples, a usage session may be a continuous period of time from a start of the usage session to an end of the usage session. In some examples, a usage session is a period in which the controller 22 controls the aerosol provision system 1 to generate an aerosol for inhalation by a user from the consumable 4 (in some examples, a pre-heat phase may also be considered part of the usage session). In some examples, a usage session is a cumulative period of time in which the user is drawing on the device (e.g. as measured by an airflow sensor 30). In some examples, a usage session is a moving window of time (i.e. period) in which the cumulative usage of the device 1 is monitored (e.g. the cumulative usage within a 1 minute moving window is monitored).

By “predefined” it is meant that the controller 22 obtains or determines relevant values or parameters (e.g. predefined levels or thresholds) prior to the start of a usage session, at the start or during the usage session, or at the end of a usage session. In some examples, the controller 22 is provided with the relevant values or parameters during manufacture (e.g. as part of installation of software) or during a software update. Thus, the controller 22 may obtain the relevant values from a memory or the like storing the relevant values. In some examples, the controller 22 determines (e.g., calculates or estimates) the relevant values or parameters prior to, at the start or during, or at the end of a usage session (e.g. during a start up process or initialisation process, taking account of ambient conditions such as ambient temperature). In either case, the values are predetermined or preselected prior to comparing the temperature of the aerosol provision system to the relevant values (e.g., levels or thresholds).

In some examples, the controller 22 is configured to identify the start of a usage session (e.g. an initiation time for the usage session, when the usage session is considered to have started or have begun). For example, the start of the usage session can be the time that a command is first received by the controller 22 indicating that a user intends to use the device, or the first activation of the aerosol generator after a period of non-use. In some examples, the user interacts with a user interface, such as a button 14, to indicate they desire to use the aerosol provision device 1 , and the controller 22 identifies the start of the usage session based on the user interaction. In some examples, the user draws on the device (i.e. takes a puff), the airflow sensor 30 indicates to the controller 22 that the user has started puffing, and the controller 22 identifies the start of the usage session based on the indication from the airflow sensor 30 (e.g. identifying the start of the usage session as a time at which a signal from the airflow sensor 30 crosses a predefined threshold). In some examples, the user inserts a new consumable part 4 into reusable device part 2, and the controller 22 identifies the start of the usage session based on a determination that a new consumable part 4 has been inserted.

In some examples, the controller 22 is configured to identify an end of a usage session (e.g. the time at which aerosol generator stops generating aerosol and / or the time at which power ceases to be supplied to the aerosol generator 48). By identifying the end of the usage session, an indication provided by an indicator can be provided at a more accurate time corresponding to time from the end of usage session (e.g. the end of a cooldown period after the end of the usage session). In some examples, the controller 22 can start a cooldown timer after identifying the end of the usage session. In some examples, the cooldown timer is a period of time which is predefined based on the length of the usage session, and /or is predefined based on a usage amount (e.g. a determined or estimated amount of aerosol generated by the aerosol provision system). In some examples, after identifying the end of the usage session, the controller 22 can start analysing sensor readings (e.g. one or more temperature sensor readings as described further herein) to determine when a temperature of the system 1 reduces below a predefined threshold temperature. In some examples, a predefined cooldown period following the end of a usage session is greater than a duration selected from the group comprising 15 seconds, 30 seconds, 60 seconds, 120 seconds, and 180 seconds. In some examples, the predefined cooldown period is less than a duration selected from the group comprising 180 seconds, 120 seconds, 60 seconds, 30 seconds, and 20 seconds.

For example, the controller 22 can be configured to identify a start of the usage session and measure a time (i.e. by counting) from the identified start of the usage session. The predefined duration may be termed a session length and can, in some examples, correspond to the time in which a user is expected, or is allowed, to generate aerosol using the device. In some examples, the duration is between 30 seconds and 360 seconds, preferably between 1 minute and 4 minutes and more preferably between 2 minutes and 3 minutes. It will be appreciated that the appropriate length of a usage session will depend upon the consumable 4 (e.g. the type, quantity and distribution of aerosol generating material) and the process of generating an aerosol from the consumable (e.g. type of aerosol generator 48 and the settings used to control the aerosol generator 48, such as a level of power supplied to the aerosol generator 48). Advantageously, in these examples, the method is simplified (therefore using less processing resources of controller 22) in that the controller 22 need only establish one parameter (the time corresponding to the start of the session) before counting. The time period that is counted is selected to be long enough that the device will heat up (i.e. to aerosolise aerosol generating material) and then cool to the required temperature within the counted time period (e.g. it is a total time period including heating and cooling phases). As will be appreciated, a particular time period can be chosen for counting from the start of the usage session, dependent on the expected session length. For example, where a controller has one or more predefined session heating schemes for respective usage sessions, a suitable total time period can be pre-selected or predefined for each of the predefined heating schemes.

In some examples, the predefined duration or period (session length) is based on an average usage session length. The controller 22 may compare a time since a start of a current usage session to an average usage session length accessible by the controller 22. In some examples, the average usage session length is stored in a memory of the controller 22. In some examples, the average usage session length is a predefined value provided upon manufacture of the aerosol provision system 1 , or provided via a software update, and may correspond to an expected average usage length for a consumable, determined via experimentation or modelling. Such an average usage session length may be termed a global usage session length in that similar devices manufactured at the same time will have the same predefined value. In some examples, the controller 22 is configured to calculate or otherwise establish an average usage session length based on prior uses of the device 1 by a user (such an average usage session may be termed a local usage session as it is unique to the device). It will be appreciated that in some cases the controller 22 may overwrite a predefined value (e.g. a global value) of the average usage session length, after a set number of uses of the device 1 (i.e. after a learning period).

In some examples, the controller 22 is configured to identify the end of the usage session as occurring after a predefined duration from the start of a usage session. In some examples, the controller 22 is configured to identify the end of the usage session based on a user input to the aerosol provision system 1 (e.g. a user interaction with the aerosol provision system). In some examples, the controller 22 can be configured to identify that the usage session has ended based on a last activation of the aerosol provision system by a user, the last activation corresponding to a user interaction or input on the aerosol provision system 1 . In some examples, a last activation is determined based on a user interacting with a user interface of the device (e.g. button 14) and / or interacting with the airflow sensor 30. In some examples, the controller 22 is configured to assume any detected activation is a last activation (i.e. an activation taken to mark the end of a usage session). As such, if the device 1 is activated again before a trigger condition is met (e.g. device temperature reduces below a level or threshold and / or a cooldown time period expires), the controller 22 will consider the new activation to be the last activation. The controller 22 can continue to monitor for new activations until a trigger condition is met (e.g. device temperature reduces below a level or threshold and / or a cooldown time period expires).

In some examples, the controller is configured to establish an end of a usage session based on a user indicating the end of the usage session by interacting with the aerosol provision system 1. In some examples, a user interaction with a user interface (such as button 14) is taken by controller 22 to indicate that the usage session has ended. For example the user may transition the device to a sleep, inactive or off mode by interacting with a user interface. In some examples, the user interacts with the aerosol provision system 1 by removing or detaching the consumable part 4 from the reusable device part 2, the controller 22 being configured to identify when the consumable part 2 has been disconnected from the reusable device part 2. In some examples, the user interacts with the aerosol provision system 1 by closing a door or similar which is configured to cover an aperture 51 through which the consumable part 2 is at least partially inserted into the reusable device part 2.

In some examples, the controller 22 is configured to identify the end of a usage session based on the last activation of an aerosol generator 48 of the aerosol provision system. In some examples, the activation of the aerosol generator 48 is controlled by the controller 22 in accordance with a predefined heating profile, such that last activation occurs at a predefined time (for example, an elapsed time since a start of the predefined heating profile). In some examples, the aerosol generator 48 is activated in accordance with a user interacting with a user interface of the device (e.g. button 14) and / or interacting with the airflow sensor 30; the last activation of the aerosol generator 48 substantially corresponding to the last activation of the user interface and / or airflow sensor 30.

In some examples, the controller 22 is configured to identify the end of the usage session based on an estimated usage amount, by monitoring or estimating an amount of aerosol that has been generated from the aerosol generating material 43 in consumable part 4. In some examples, the controller 22 is configured to calculate or estimate an amount of aerosol generated based on one or more of heater power, airflow rate, consumable type, and session time. In some examples, the controller 22 is configured to implement a cut-off after a certain amount of usage (e.g. a certain amount of aerosol determined or estimated to have been generated from the aerosol generating material 43); and wherein the cut-off comprises the controller 22 ceasing the supply of power to and / or preventing the further supply of power to the aerosol generator 48.

In some examples, the controller 22 is configured to identify or determine the end of the usage session based on a combination of the above approaches for identifying the end of a usage session. In some examples, the controller 22 determines the end of the usage session when multiple criteria are satisfied (e.g. an estimated usage amount is satisfied, and a last activation of the aerosol generator is satisfied). In some examples, the controller 22 determines the end of a usage session has occurred when one or more criteria from a set comprising a plurality of criteria are satisfied (exemplary criteria may comprise a user interacting with the device to indicate they are ending the session, and / or predefined thresholds being met for an estimated usage amount, and / or a total time since the start of a session). It will be appreciated that there are a large number of potential combinations of criteria which can be used to identify the end of a usage session, based on the above examples.

Figure 2 schematically represents a method of controlling an aspect of the electronic aerosol provision system / device 1 for generating aerosol in accordance with certain embodiments of the disclosure.

At a first step 220 of Figure 2, the controller 22 is configured to determine (e.g. after an end of a usage session) that a temperature of the aerosol provision system is below a predefined threshold temperature. In some examples, a temperature of the aerosol provision system 1 or reusable device part 2 comprises a temperature of a predefined location within the aerosol provision system 1 or reusable device part 2 (e.g. the location of a temperature sensor within the device). In some examples the predefined location in / on the aerosol provision device / system 1 comprises a location on an outer housing of the reusable device part 2 of the aerosol provision system 1 . In some examples, a temperature of the aerosol provision device 1 comprises an average temperature of the aerosol provision device 1 or device part 2. In some examples, the temperature of the device at one or more locations (e.g. adjacent one or more sensors, respectively) is used to infer a temperature at a separate location (e.g. a surface of the device).

In some examples, the controller is configured to determine / estimate that a temperature of the system is below a predefined threshold temperature after a predefined period (e.g. a duration of time) from the identified start of a usage session. The predefined period expires or ends after the end of the usage session, such that the device 1 will be estimated to be cooling down or have cooled down after use (e.g. after a heating period / cycle operational during the usage session), when the predefined period ends. The predefined period may be termed a total period because it comprises both the period in which the device is being used, or able to be used, (i.e. a usage session) and a cooldown period. In other words the controller 22 determines that the temperature of the reusable device part 2 is estimated to be below a predefined threshold temperature based on the elapsed period of time since the start of a usage session. In some examples, the controller 22 is configured to estimate that the temperature of the system is below a predefined threshold temperature after a predefined total period from the identified start of a usage session, the first predefined total period ending after the end of the usage session. In some examples, the first predefined total period is one selected from the group comprising a period of at least one minute, a period of at least two minutes, and a period of at least five minutes. It will be appreciated that the predefined total period can be selected based on a predetermined aerosolisation profile which defines the duration and scale of power supplied to the aerosol generator 48 (and as such the amount of energy supplied to the aerosol generator). The total period encompasses the length of time in which the predetermined aerosolisation profile is active, and also a cooldown period selected for that predetermined aerosolisation profile taking into account the amount of energy that may have dissipated into the surrounding components during the predetermined aerosolisation profile.

In some examples, the controller 22 is configured to determine that a temperature of the system is estimated to be below a predefined threshold temperature after a predefined period from the identified end of a usage session. The predefined period can be termed a cooldown period or duration because it comprises a period of time in which the device is considered to be cooling down from an operating temperature to a lower temperature after use (e.g. after a session / puff). In some examples the cooldown period is one selected from the group comprising a period of at least 15 seconds, a period of at least 30 seconds, a period of at 60 seconds, and a period of at least 180 seconds. It will be appreciated that the device may continue to cool after the end of the cooldown period, and that the cooldown period is therefore an estimate of an amount of time required from the device to cool from an operating temperature to a lower / lesser temperature. The lesser temperature may be a “safe” or “comfortable” temperature, for example a temperature determined from user trials to be an appropriately low temperature for the aerosol provision system 1 (or one or more of reusable device part 2 and consumable 4) to be handled or stored safely and / or comfortably.

In some examples, the cooldown period determined by the controller 22 varies dependent on the duration of a usage session, wherein the cooldown period is longer when the duration of a usage session is longer. In some examples, the cooldown period is determined upon the controller 22 identifying that the session has ended with the controller identifying the length of the session and calculating or determining a suitable cooldown period for the identified session length. As such, the cooldown period is predetermined at the end of the session. In these examples, if the user uses the device for less than an average or expected time, the aerosol provision system 1 will not need to cool as much to reach or fall below a given temperature, because heat from the aerosol generator 48 will not have dissipated into the device components to the same extent, and in these examples, the cooldown period duration can be reduced. Conversely, if the user has used the device over a longer than average, or expected time period, then a greater amount of heat will have dissipated into the device components, and in these examples, the cooldown period duration can be increased.

In some examples, as described in more detail in relation to Figure 3, the controller 22 is configured to determine, after the end of a usage session, that a temperature of the aerosol provision system 1 is estimated to be below a predefined threshold temperature based on at least one signal from a temperature sensor, or of one or more temperature sensors comprised in the aerosol provision system 1 . In some examples, the controller 22 receives a measurement or signal indicative of a temperature that is less than the predefined threshold temperature. In some examples, the controller 22 receives a measurement that indicative of a temperature that is higher than the predefined threshold temperature, and the controller calculates, estimates or otherwise establishes based on the measurement that a temperature of the device at a location different to the sensor location is below the predefined threshold temperature based on a relationship between the sensor location and the different location (e.g. a surface location). For example, the controller 22 can be configured to calculate the temperature of the different location as the temperature of the sensor minus an absolute value (e.g. 5°C) or a relative value (e.g. sensor temperature minus an ambient temperature measured prior to usage session multiplied by a factor such as 0.2).

In some examples, the value of the predefined threshold temperature is one selected from the group comprising a temperature less than 45^eC, a temperature less than 40^eC, and a temperature less than 35^eC. In some examples, the temperature of the predefined threshold temperature is a level or value at which the device is considered comfortable to the user and / or such that risk of damage to any materials contacting the aerosol provision system 1 is reduced. In some examples, the temperature of the predefined threshold temperature corresponds to a temperature of the sensor at which a surface region of the device (separate to the temperature sensor) is considered comfortable to the user and / or such that risk of damage is reduced. For example, a relationship between temperature measurements of one or more sensors internal to the device, and a temperature of the external surface of the device, may be established through testing or simulation, wherein a threshold temperature can be set to a value such that when the temperature of the sensor falls below the threshold temperature, the temperature of the surface region is estimated to be a temperature less than 45^eC, a temperature less than 40^eC, or a temperature less than 35^eC. For example, a relationship may identify that after use of the device, the temperature of an external surface of the device is less than 35^eC when the temperature of the sensor falls below 70^eC, and therefore in this particular example, the threshold temperature may be set at 70^eC to provide an indication when the temperature of the external surface of the device is estimated to be a temperature of 35^eC (e.g. a “safe” and / or “comfortable” temperature). As such the value of the predefined threshold temperature does not have to be a “safe” temperature itself (i.e. a temperature a would consider safe / comfortable to touch), but instead can be selected based on prior testing and / or simulations in relation to an expected temperature of an external surface of the device.

In some examples the controller 22 is configured to implement multiple control schemes for determining, after the end of the usage session, that a temperature of the system is estimated to be below a predefined / predetermined threshold temperature. The use of multiple control schemes provides redundancy in the case of failure or malfunction of any one of the approaches described above for determining when a temperature of the system is estimated to be below a predefined threshold temperature. In some examples, the controller 22 is configured to determine, after the end of a usage session, that a temperature of the system is estimated to be below a predefined threshold temperature based on at least one signal received from one or more temperature sensors of the aerosol provision system 1 ; and also the controller is configured to determine that a temperature of the system is estimated to be below a predefined threshold temperature after a predefined period has elapsed from the identified end of a usage session. In some of the examples described herein, the predefined period can be set to have a duration in which it is expected that the temperature (e.g. a temperature of one or more regions / components of the aerosol provision system 1) will have reduced by a necessary amount (e.g. to a “safe” and / or “comfortable” temperature as described further herein), and hence that the controller 22 will have identified before the predefined period elapses that a temperature of the system is estimated to be below a predefined threshold temperature based on at least one signal received from one or more temperature sensors of the aerosol provision system 1. Hence, in these examples, the timer using the predefined duration acts as a backup to determining that the temperature has fallen to a particular level based on a sensor.

At a second step 230 of Figure 2, the controller 22 is configured to control an indicator in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol delivery system is below the predefined threshold temperature. In some examples, an indicator is configured to provide at least one indication selected from the group comprising a visual indication, a haptic indication, and an audio indication. In other words, once the controller 22 determines or estimates that the temperature has fallen below the predefined threshold temperature, the controller causes the indicator to behave or operate in a different manner such that it indicate to the user that the temperature of the aerosol delivery system is below the predefined threshold temperature.

In some examples, the indicator emits an indication (e.g. activates) to indicate to the user that the temperature of the aerosol delivery system is below the predefined threshold temperature. For example, the controller 22 controls the indicator to cause it to indicate that the system is “cool” or “safe” once the controller 22 has determined or estimated that the system has cooled beneath the predefined threshold temperature.

In some examples, the indicator ceases or stops emitting an indication (e.g. deactivates) to indicate to the user that the temperature of the aerosol delivery system is below the predefined threshold temperature. For example, the controller 22 firstly controls the indicator to cause it to indicate that the system is “hot”, and then the controller controls (e.g. switches off) the indicator to stop indicating that the system is “hot”, once the controller 22 has determined or estimated that the system has cooled beneath the predefined threshold temperature.

In some examples, the indicator emits a first indication when the temperature of the aerosol delivery system is determined or estimated to be above the predefined threshold temperature, and a second, different indication when the temperature of the aerosol delivery system is determined or estimated to be below the predefined threshold temperature to indicate to the user that the temperature of the aerosol delivery system is below the predefined threshold temperature. For example, the controller 22 firstly controls the indicator to cause it to indicate that the system is “hot”, and then the controller 22 controls the indicator to cause it to indicate that the system is “cool” or “safe” once the controller 22 has determined or estimated that the system has cooled beneath the predefined threshold temperature.

The indication may comprise a visual, audio, and / or a haptic or tactile indication. For example, visual feedback mechanism 28 or display 16 (or a different display provided by the device part 2) may be used to provide the indication to the user. In some examples, the indication is provided to the user via a separate device (e.g. a smartphone) which is in wired or wireless communication with the controller 22 (e.g. via a Bluetooth link provided by wireless transceiver circuitry comprised in controller 22). The user, observing the change in indication (e.g. on to off, off to on, or first mode to second mode), may identify that the device is safe to be put away (for example, in a bag, pocket or case) as the temperature of the device (or one or more regions of the device) has reduced to a “safe” temperature. In some examples where the controller 22 causes the indicator to indicate that the system is “cool” or “safe”, the controller 22 continues to cause the indicator to indicate that the system is “cool” or “safe” until the device is switched off manually and / or until a period of non use has expired (e.g. a time out period). Figure 3 is a cross-sectional view through an example device part 2 in accordance with certain embodiments of the disclosure. In contrast to example aerosol provision system 1 of Figure 1 , the replaceable / disposable consumable 4 of Figure 1 is omitted for simplicity. Features of Figure 3 provided with the same reference number as in Figure 1 operate as described above in accordance with Figure 1 and will not be described again.

In accordance with some embodiments of the present disclosure the device part 2 of Figure 3 differs from that of Figure 1 , in that it further comprises a temperature sensor 61 , for sensing a temperature of the device (or at least a part of the device), the temperature sensor 61 being electrically connected to the controller 22. The electrical connections allow the temperature sensor 61 to communicate with the controller 22. For example, electrical connections allow the temperature sensor 61 to provide signals corresponding to temperature measurements to the controller 22. In other examples, the temperature sensor 61 is instead configured to be in wireless communication with the controller 22.

In some examples, signals communicated from the temperature sensor 61 to the controller 22 correspond to a measurement of temperature by the temperature sensor 61. For example, the sensor 61 may be configured to calculate or otherwise determine a temperature for communication to the controller 22. Accordingly, in some examples signals communicated from a temperature sensor 61 to the controller 22 comprise a parameter indicative of a temperature. For example an electrical characteristic such as voltage or resistance associated with temperature sensor 61 may be indicative of a temperature obtained by or of the temperature sensor 61. In some of these examples, the controller 22 is configured to calculate or otherwise determine a temperature based on the parameter indicative of a temperature. For example, the controller 22 can obtain a measurement of temperature, or a measurement indicative of temperature, from the temperature sensor 61 (e.g. a measurement of voltage or resistance which is dependent on temperature, for instance, where temperature sensor 61 comprises a material with a non-zero temperature coefficient of resistance).

In some of these examples, the temperature sensor 61 comprises a thermistor. By thermistor it is meant that the resistance of the thermistor changes with temperature such that a temperature can be established based on the change in resistance (e.g. based on a measurement of an electrical characteristic that varies dependent on resistance). In some of these examples, a temperature sensor 61 is a component from which the controller 22 can obtain a temperature reading by passing a current through the temperature sensor 61 , without the need for any processing capability at the sensor itself. In some examples, the temperature of the aerosol provision system is an estimated temperature of a predefined location in or on the outer housing of the reusable device part 2 or aerosol provision system 1.

In some examples, the controller 22 is configured to measure, or otherwise establish, a temperature of the device via the temperature sensor 61 to determine whether the temperature of the device (as obtained by the temperature sensor) is below a predefined threshold temperature. In some examples, by temperature of the device, it is meant the temperature of the whole of the device (e.g. an average temperature of the reusable device part 2, consumable part 4, or the whole aerosol provision system 1), the temperature of a portion of the aerosol provision system 1 in the vicinity of the temperature sensor 61 (e.g. adjacent to the sensor, proximally located to the sensor), or the temperature of a portion of the aerosol provision system 1 away from the temperature sensor 61 , the temperature of which can be inferred from the temperature measured by the one or more temperature sensors 61 (e.g. a measurement of temperature inside the device can be used to infer that a surface of the device is below a certain temperature).

In some examples, the controller 22 is configured to control an aspect of the operation of device part 2 operation based on the temperature of temperature sensor(s) 61. In some examples, the controller 22 is configured to distribute or cease distributing electrical power from the power source 26 to the aerosol generator 48 in response to a temperature measurement. In some examples, the controller 22 is configured to display or otherwise communicate a temperature to a user (e.g. by a display 16, visual feedback mechanism 28 of the device part 2, an audio or haptic feedback mechanism, or via a separate device, such as a mobile computing device in communication with the controller 22).

In some examples, the controller 22 is configured to indicate when the temperature of the system is estimated to have fallen below a predefined threshold temperature, after the end of the usage session, based on sensor readings from the sensor. In some examples, an indication to a user comprises a visual, audio, and / or a tactile indication. For example, visual feedback mechanism 28, or a different display provided by the device part 2, may be used to provide the indication to the user. In some examples, the temperature sensor 61 is provided substantially in a region separating the aerosol generator 48 from a housing of the device part 2. In some examples, the temperature sensor 61 is located closer to an external surface of the device part 2 than to the aerosol generator 48. As a result, a temperature of the temperature sensor 61 , or recorded by the temperature sensor 61 , is more indicative of the temperature of the external surface of the device and less indicative of the temperature of the aerosol generator 48 and the receiving recess / chamber 50.

In some examples, a first temperature sensor 61 is provided adjacent the external housing of the reusable device part 2 (for example adjacent an internal surface of a wall provided the external housing). In some examples, the temperature of the aerosol provision system 1 is an estimated temperature of the outer housing (e.g. an average temperature of the whole housing, or the local temperature of a region of the housing). In some examples, the predefined threshold temperature is one selected from the group comprising a temperature less than 45^eC, a temperature less than 40^eC, and a temperature less than 35^eC.

In some examples, where the aerosol generator 48 is positioned asymmetrically in the device part 2, the temperature sensor 61 is provided in the region of the shortest separation between the aerosol generator 48 (and / or the heating region 53 of the receiving recess / chamber 50) and the housing of the device part 2. For such an asymmetric arrangement, it is expected that the housing closest to the aerosol generator 48 will be heated more than the housing further from the heater, by heat dissipation from the heater. As such, placing the first temperature sensor 61 in this location can be used to measure or otherwise establish a temperature of the expected “hottest” external surface region of the device part 2.

In some examples, the controller 22 is configured to receive measurements from the temperature sensor 61 , and to estimate (e.g. receive, calculate, or infer) a temperature of the device based on the received measurements. In some examples, the determined temperature is a temperature of the temperature sensor 61. In some other examples, the temperature of the device is a temperature of an external surface of the device. For example, the controller 22 may be configured to infer a temperature of an external surface by establishing a temperature measured at the temperature sensor 61 positioned at a first location in or on the aerosol provision system 1 , and calculating a corresponding temperature of the external surface (i.e. a second location on the aerosol provision system 1 ) based on a pre-determined relationship between the temperature at the first location and the temperature at the second location (said relationship being established, for instance, via experimentation or modelling). It will be appreciated that in some examples, the reusable device part 2 and / or the consumable part 4 may comprise further or alternate temperature sensors, in addition to or as an alternative to temperature sensor 61 for use in estimating a temperature of the device. In some examples, the controller 22 is configured to use temperature measurements from two or more temperature sensors to determine the temperature of the reusable device part 2 (or multiple device parts) is / are below a predefined threshold temperature, and to provide an indication to a user based on the measurements from the two or more temperature sensors.

In some examples, the airflow sensor 30 is a combined pressure and temperature sensor, and provides an alternative temperature sensor to, or an additional temperature sensor with, temperature sensor 61. In these examples, the controller 22 is configured to receive signals from the airflow sensor 30 indicative of temperature.

In some examples, the controller 22 is configured to obtain an indication of temperature from the aerosol generator 48. In these examples, the aerosol generator 48 can provide an alternative temperature sensor to, or an additional temperature sensor with, temperature sensor 61. In some examples, the temperature of the aerosol provision system 1 is an estimated temperature of the aerosol generator 48. In some examples, the controller 22 is configured to determine a temperature of the aerosol generator 48 based on the resistance of the aerosol generator 48 or a portion of the aerosol generator 48 and / or one or more components associated with the aerosol generator 48 (e.g. the aerosol generator 48 can comprise an integrated temperature sensor). The controller 22 can measure temperature by supplying power to the aerosol generator 48, or may otherwise obtain signals indicative of the temperature, to determine a temperature of the aerosol generator 48 and / or a heater comprised in or comprising aerosol generator 48.

In examples where the aerosol generator 48 is used to estimate a temperature of the aerosol provision system 1 , a relationship between temperature measurements of the aerosol generator 48 and a temperature of the external surface of the device (for example, of reusable device part 2 and / or consumable part 4) may be established through testing, wherein a threshold temperature can be set such that when the temperature of the aerosol generator 48 is determined to be at or below the threshold temperature, the temperature of the external surface is estimated to be a temperature less than 45^eC, a temperature less than 40^eC, or a temperature less than 35^eC. For example, a heating element may have an operating temperature (e.g. a temperature at which aerosol is generated) of between 150^eC and 300 ^eC. In some examples, a relationship may identify that after use of the device, the temperature of an external surface of the device is less than 35^eC when the temperature of the heating element falls below a temperature of between 80^eC and 120^eC. In some particular examples, the threshold temperature may be set at a value between 80^eC and 120^eC to provide an indication to a user when the temperature of the external surface of the device is estimated to be at a temperature of 35^eC or below (e.g. an exemplary “safe” or “comfortable” temperature). As such the temperature of the predefined threshold temperature does not itself have to be a “safe” temperature (i.e., a user would not be expected to or allowed to handle the heater directly), but instead can be selected based on prior testing and / or simulation used to derive a relationship between the heater temperature and an expected temperature of an external surface of the device.

In some examples, the reusable device part 2 comprises a battery temperature sensor which can be used as an alternative temperature sensor to, or as an additional temperature sensor with, the temperature sensor 61. For example, the battery temperature sensor can be a sensor integrated with the battery 26. In these examples, the controller 22 is configured to receive signals from the battery temperature sensor indicative of a temperature of the battery.

Figure 4 schematically represents a method of controlling an aspect of the electronic aerosol provision device for generating aerosol in accordance with certain embodiments of the disclosure. In examples in accordance with figure 4, the controller 22 is configured to provide a first indication to a user when the temperature of the device is established to be below a predefined threshold temperature and to provide a second indication to a user when the temperature of the device is established to be below a second or further predefined threshold temperature. The method of Figure 4 can advantageously be used to firstly inform a user of a “cautionary” state, where care should be taken due to the residual heat in the device, and secondly to inform a user of a “safe” or “comfortable” state, where the device is considered to have cooled to at least a particular predefined temperature.

At a first step 225 of Figure 4, the controller 22 determines, after an end of a usage session, that an temperature of the aerosol provision system is below a (first) predefined threshold temperature. The first step 225 of Figure 4 differs from that of the first step 220 of the Figure 2, in that the predefined threshold temperature may be considered a first predefined threshold temperature.

At a second step 235 of Figure 4, the controller 22 is configured to control the indicator (e.g. display 16 or visual feedback indicator 28, and / or an audio or haptic feedback indicator) in response to determining the temperature of the aerosol provision system 1 is below the first predefined threshold temperature to indicate the temperature of the aerosol provision system is below the first predefined threshold temperature. The second step 235 of Figure 4 is substantially similar to that of the second step 230 of the Figure 2. At a third step 240 of Figure 4, the controller 22 determines, after an end of a usage session, that an temperature of the aerosol provision system is below a further predefined threshold temperature. The third step 240 of Figure 4 differs from that of the first step 220 of the Figure 2 in that the predefined threshold temperature is a further or second predefined threshold temperature, wherein the second predefined threshold temperature is a lower temperature than the first predefined threshold temperature as per step 225.

In some examples, the second predefined threshold temperature is an absolute value which is lower than the first predefined threshold temperature. For example, the second predefined threshold temperature can be a value at least 15^eC lower than that first predefined threshold temperature, the second predefined threshold temperature can be a value at least 10^eC lower than that first predefined threshold temperature, or the second predefined threshold temperature can be a value at least 5^eC lower than that first predefined threshold temperature. For example, the first predefined threshold temperature may be a value between 40-45^eC and the second predefined threshold temperature may be a value between 30-35^eC. In some examples, the second predefined threshold temperature is a relative value in comparison to the first predefined threshold temperature. For example, the second predefined threshold temperature may be a value of less than 30% of the first predefined threshold temperature, the second predefined threshold temperature may be a value of less than 20% of the first predefined threshold temperature, the second predefined threshold temperature may be a value of less than 10% of the first predefined threshold temperature.

At a fourth step 250 of Figure 4, the controller 22 is configured to control the indicator in response to determining the temperature of the aerosol provision system 1 is below the further predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the further predefined threshold temperature. The fourth step 250 of Figure 4 is substantially similar to that of the second step 230 of the Figure 2, except that the step 250 occurs in response to the temperature falling below or being estimated to have fallen below a second or further predefined threshold temperature.

In some examples, the controller controls the indicator to emit an indication to indicate to the user that the temperature of the aerosol provision system is below the first predefined threshold temperature, and then controls the indicator to cause the indicator to indicate to the user that the temperature of the aerosol provision system is below the further predefined threshold temperature, or alternatively to stop indicating to the user that the aerosol provision system is below the first predefined threshold temperature once the controller determines or estimates that the aerosol provision system is below the further predefined threshold temperature. For example, the controller 22 controls the indicator to cause it to indicate that the system is “cool” or “safe” once the controller 22 has determined or estimated that the system has cooled beneath the first predefined threshold temperature and then the controller controls (e.g. switches off) the indicator to stop indicating that the system is “cool” or “safe”, once the controller 22 has determined or estimated that the system has cooled beneath the further predefined threshold temperature. In some examples, the controller may also cause the indicator to indicate to the user that the system is “hot” when the controller determines or estimates that the aerosol provision system is above the predefined threshold temperature.

In some examples, an indication to a user comprises a visual, audio, and / or a tactile / haptic indication. For example, visual feedback mechanism 28, or a different display provided by the device part 2, may be used to provide the indication to the user. In some examples, the indication is provided to the user via a separate device (e.g. a smartphone) in communication with the controller 22,. The user observing the second indication identifies that the device is safe to be put away as it has further reduced to or is beneath a second predefined “safe” temperature.

In some examples, the second indication is a repeat of the first indication (e.g. it may be provided to the user in the same way as the first indication). In some examples, the second indication is different to the first indication (e.g. it can be a deactivation of the indicator or a different mode of operation of the indicator). In some examples, the first activation of the indicator may include one of an audio, visual and haptic indication, whilst the second activation may include two of an audio, visual and haptic indication or an alternate one of an audio, visual and haptic indication. The second indication is selected to convey to the user that a lower temperature is estimated to have been reached.

While Figure 4 describes a process in which the controller 22 is configured to provide two indications for when the temperature of the aerosol provision system 1 is established to be below two different predefined threshold temperatures respectively; it will be appreciated that in other examples, there may be more than two predefined threshold temperatures. For example in these examples, there may be more than 3, more than 5 or more than 10 predefined threshold temperatures, each triggering a respective indication. In some examples, the indication may differ for each of the predefined threshold temperatures such that the user is presented with a sequence of indications as the aerosol provision system 1 (or a reusable device part 2 or consumable part 4) cools. In some of these examples, when the temperature is determine or estimated to have dropped below the lowest temperature threshold, the controller can cause the indicator to stop or deactivate.

Thus, there has been described an aerosol provision system for generating an aerosol for user inhalation, wherein the aerosol provision system comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that an temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

The various embodiments described herein are presented only to assist in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only, and are not exhaustive and/or exclusive. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects described herein are not to be considered limitations on the scope of the invention 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 claimed invention. Various embodiments of the invention may suitably comprise, consist of, or consist essentially of, appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc, other than those specifically described herein. In addition, this disclosure may include other inventions not presently claimed, but which may be claimed in future.

Claims

1 . An aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, wherein the aerosol provision system comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator, in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

2. The aerosol provision system according to claim 1 , wherein the controller is configured to determine that the temperature of the aerosol provision system is below the predefined threshold temperature by determining that a predefined cooldown period has elapsed since the end of the usage session.

3. The aerosol provision system according to claim 2, wherein the predefined cooldown period is greater than a duration selected from the group comprising 15 seconds, 30 seconds, 60 seconds, 120 seconds, and 180 seconds.

4. The aerosol provision system according to claim 2 or 3, wherein the predefined cooldown period is less than a duration selected from the group comprising 180 seconds, 120 seconds, 60 seconds, 30 seconds, and 20 seconds.

5. The aerosol provision system according to any of claims 2 to 4, wherein the predefined cooldown period is dependent on a length of the usage session, wherein the length of the predefined cooldown period is longer when the length of the usage session is longer.

6. The aerosol provision system according to any of claims 1 to 5, wherein the aerosol provision system comprises a temperature sensor for sensing a temperature at a sensing location of the aerosol provision system; and the controller is configured to determine, after the end of the usage session, that the temperature of the system is below the predefined threshold temperature using measurements from the temperature sensor.

7. The aerosol provision system according to claim 6, wherein the aerosol provision system comprises an external surface and an aerosol generator, and wherein the sensing location is closer to the external surface of the aerosol provision system than to the aerosol generator of the aerosol provision system.

8. The aerosol provision system according to claim 6, wherein the aerosol generating system comprises an aerosol generator, wherein the sensing location is at the aerosol generator.

9. The aerosol provision system according to any of claims 6 to 8, wherein the temperature sensor forms part of a combined pressure and temperature sensor for detecting user inhalation.

10. The aerosol provision system according to claims 1 to 9, wherein the controller is configured to identify that the usage session has ended, and to determine, after identifying that the usage session has ended, that the temperature of the aerosol provision system is below the predefined threshold temperature.

11. The aerosol provision system according to claim 10, wherein the controller is configured to identify that the usage session has started and to identify that the usage session has ended by determining that a predefined time period for the usage session has elapsed since the start of the usage session.

12. The aerosol provision system according to claim 10 or 11 , wherein the controller is configured to identify that the usage session has ended based on a user input.

13. The aerosol provision system according to any of claims 10 to 12, wherein the aerosol provision system comprises an aerosol generator, and wherein the controller is configured to identify the end of the usage session by determining a time of the last activation of the aerosol generator.

14. The aerosol provision system according to any of claims 1 to 13, wherein the controller is configured to identify that the usage session has started, and to determine that the temperature of the aerosol provision system is below the predefined threshold temperature by determining that both a predefined time period for the usage session and a predefined cooldown period have elapsed since the start of the usage session.

15. The aerosol provision system according to any of claims 1 to 14, wherein the indicator is configured to provide at least one indication selected from the group comprising a visual indication, a haptic indication, and an audio indication.

16. The aerosol provision system according to any of claims 1 to 15, wherein the aerosol provision system further comprises a consumable comprising aerosol-generating material.

17. The aerosol provision system according to claim 16, wherein the aerosol-generating material comprises a solid aerosol-generating material.

18. The aerosol provision system according to any of claims 15 to 16, wherein the aerosol-generating material comprises a liquid aerosol-generating material.

19. The aerosol provision system according to any of claims 1 to 18, wherein the aerosol provision system comprises an outer housing, and wherein the temperature of the aerosol provision system is an estimated temperature of the outer housing.

20. The aerosol provision system according to claim 19, wherein the predefined threshold temperature is one selected from the group comprising a temperature less than 45^eC, a temperature less than 40^eC, and a temperature less than 35^eC.

21. The aerosol provision system according to any of claims 1 to 18, wherein the aerosol provision system comprises an aerosol generator, and wherein the temperature of the aerosol provision system is an estimated temperature of the aerosol generator.

22. The aerosol provision system according to any of claims 1 to 18, wherein the aerosol provision system comprises an outer housing, wherein the temperature of the aerosol provision system is an estimated temperature of a predefined location within the outer housing.

23. The aerosol provision system according to any of claims 1 to 22, wherein the controller is further configured to: determine, after the end of the usage session, that the temperature of the aerosol provision system is below a further predefined threshold temperature; and control the indicator in response to determining the temperature of the aerosol provision system is below the further predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the further predefined threshold temperature; wherein the further predefined threshold temperature is a temperature lower than the predefined threshold temperature.

24. The aerosol provision system according to any of claims 1 to 23, wherein the aerosol provision system comprises an aerosol generator, and wherein the aerosol generator is configured to generate heat during operation of the aerosol generator to generate aerosol from aerosol-generating material.

25. A controller for use with an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator according to any of claims 1 to 24.

26. An aerosol provision device for an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, wherein the aerosol provision device comprises a controller and an indicator, and the controller is configured to: determine, after an end of a usage session, that a temperature of the aerosol provision system is below a predefined threshold temperature; and control the indicator, in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

27. A method for controlling an aerosol provision system for generating an aerosol for user inhalation from aerosol-generating material using an aerosol generator, the method comprising: determining, after an end of a usage session, that an temperature of the aerosol provision system is below a predefined threshold temperature; and controlling an indicator in response to determining the temperature of the aerosol provision system is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.

28. Aerosol provision means, for generating an aerosol for user inhalation from aerosol generating means using an aerosol generator means, wherein the aerosol provision means comprises a control means and indicator means, wherein the control means is configured to: determine, after an end of a usage session, that an temperature of the aerosol provision means is below a predefined threshold temperature; and control the indicator means in response to determining the temperature of the aerosol provision means is below the predefined threshold temperature, to indicate the temperature of the aerosol provision system is below the predefined threshold temperature.