AEROSOL DELIVERY SYSTEMS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application is a National Phase entry of PCT Application No. PCT/GB2023/052689, filed Oct. 17, 2023, which claims priority from Great Britian Application No. 2215358.9, filed Oct. 18, 2022, each of which are fully incorporated herein by reference in their entireties.

FIELD

[0002]The present disclosure relates to aerosol delivery systems such as, but not exclusively, nicotine delivery systems (e.g. e-cigarettes).

BACKGROUND

[0003]Aerosol delivery systems such as electronic cigarettes (e-cigarettes) generally contain an aerosol generating material, such as a chamber of a source solid or 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 delivery system will typically comprise an aerosol generation area containing an aerosol generator, e.g. a heating element, arranged to vaporise or aerosolise a portion of precursor material to generate a vapour or aerosol in the aerosol generation area. As a user inhales on the device and electrical power is supplied to the vaporiser, air is drawn into the device through an inlet hole and along an inlet air channel connecting to the aerosol generation area, where the air mixes with vaporised precursor material to form a condensation aerosol. There is an outlet channel connecting the aerosol generation area to an outlet in the mouthpiece and the air drawn into the aerosol generation area 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 electronic cigarettes 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 tobacco arranged in the air flow path between the aerosol generation area and the mouthpiece such that aerosol/condensation aerosol drawn through the device passes through the portion of tobacco before exiting the mouthpiece for user inhalation.

[0004]WO 2016/012774, incorporated herein by reference, discloses electronic vapour provision systems comprising a collar around a housing for a user to adjust alignment between one or more air inlet holes of the housing and the collar, to provide different levels of ventilation to the system.

[0005]WO 2017/046566, incorporated herein by reference, discloses an aerosol provision system with an airflow adjuster in the airflow path, downstream from the air inlet.

[0006]User experiences with electronic aerosol delivery systems are continually improving as such systems become more refined in respect of the nature of the vapour they provide for user inhalation, for example in terms of deep lung delivery, mouth feel and consistency in performance. Nonetheless, approaches for improving further still on these aspects of electronic vapour provision systems remain of interest. In particular, it is of interest to develop approaches in which an aerosol delivery system comprises functionality enabling operating characteristics of the system to be adjusted, preferably automatically, in order to target certain operating characteristics which may be desirable to a user.

[0007]Various approaches are described herein which seek to help address or mitigate at least some of the issues discussed above.

Terminology

Delivery System

Combustible Aerosol Provision System

[0012]According to the present disclosure, a “combustible” aerosol provision system is one where a constituent aerosol-generating material of the aerosol provision system (or component thereof) is combusted or burned during use in order to facilitate delivery of at least one substance to a user.

[0013]In some embodiments, the delivery system is a combustible aerosol provision system, such as a system selected from the group consisting of a cigarette, a cigarillo and a cigar.

[0014]In some embodiments, the disclosure relates to a component for use in a combustible aerosol provision system, such as a filter, a filter rod, a filter segment, a tobacco rod, a spill, an aerosol-modifying agent release component such as a capsule, a thread, or a bead, or a paper such as a plug wrap, a tipping paper or a cigarette paper.

Non-combustible Aerosol Provision System

[0015]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.

[0016]In some embodiments, the delivery system is a non-combustible aerosol provision system, such as a powered non-combustible aerosol provision system.

[0017]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.

[0018]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.

[0019]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.

[0020]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.

[0021]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.

[0022]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.

[0023]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.

[0024]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.

Aerosol-Free Delivery System

[0025]In some embodiments, the delivery system is an aerosol-free delivery system that delivers at least one substance to a user orally, nasally, transdermally or in another way without forming an aerosol, including but not limited to, lozenges, gums, patches, articles comprising inhalable powders, and oral products such as oral tobacco which includes snus or moist snuff, wherein the at least one substance may or may not comprise nicotine.

[0026]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.

Active Substance

[0027]In some embodiments, the substance to be delivered comprises an active substance. The active substance as used herein may be a physiologically active material, which is a material intended to achieve or enhance a physiological response. The active substance may for example be selected from nutraceuticals, nootropics, psychoactives. The active substance may be naturally occurring or synthetically obtained. The active substance may comprise for example nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or constituents, derivatives, or combinations thereof. The active substance may comprise one or more constituents, derivatives or extracts of tobacco, cannabis or another botanical.

[0028]In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance comprises caffeine, melatonin or vitamin B12.

[0029]As noted herein, the active substance may comprise one or more constituents, derivatives or extracts of cannabis, such as one or more cannabinoids or terpenes.

[0030]As noted herein, the active substance may comprise or be derived from one or more botanicals or constituents, derivatives or extracts thereof. As used herein, the term “botanical” includes any material derived from plants including, but not limited to, extracts, leaves, bark, fibres, stems, roots, seeds, flowers, fruits, pollen, husk, shells or the like. Alternatively, the material may comprise an active compound naturally existing in a botanical, obtained synthetically. The material may be in the form of liquid, gas, solid, powder, dust, crushed particles, granules, pellets, shreds, strips, sheets, or the like.

[0031]Example botanicals are tobacco, eucalyptus, star anise, hemp, cocoa, cannabis, fennel, lemongrass, peppermint, spearmint, rooibos, chamomile, flax, ginger, ginkgo biloba, hazel, hibiscus, laurel, licorice (liquorice), matcha, mate, orange skin, papaya, rose, sage, tea such as green tea or black tea, thyme, clove, cinnamon, coffee, aniseed (anise), basil, bay leaves, cardamom, coriander, cumin, nutmeg, oregano, paprika, rosemary, saffron, lavender, lemon peel, mint, juniper, elderflower, vanilla, wintergreen, beefsteak plant, curcuma, turmeric, sandalwood, cilantro, bergamot, orange blossom, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, geranium, mulberry, ginseng, theanine, theacrine, maca, ashwagandha, damiana, guarana, chlorophyll, baobab or any combination thereof. The mint may be chosen from the following mint varieties: Mentha Arventis, Mentha c.v., Mentha niliaca, Mentha piperita, Mentha piperita citrata c.v., Mentha piperita c.v, Mentha spicata crispa, Mentha cardifolia, Memtha longifolia, Mentha suaveolens variegata, Mentha pulegium, Mentha spicata c.v. and Mentha suaveolens.

[0032]In some embodiments, the active substance comprises or is derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is tobacco. In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from eucalyptus, star anise, cocoa and hemp.

[0033]In some embodiments, the active substance comprises or derived from one or more botanicals or constituents, derivatives or extracts thereof and the botanical is selected from rooibos and fennel.

Flavours

[0034]In some embodiments, the substance to be delivered comprises a flavour. As used herein, the terms “flavour” and “flavourant” refer to materials which, where local regulations permit, may be used to create a desired taste, aroma or other somatosensorial sensation in a product for adult consumers.

[0035]They may include naturally occurring flavour materials, botanicals, extracts of botanicals, synthetically obtained materials, or combinations thereof (e.g., tobacco, cannabis, licorice (liquorice), hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed (anise), cinnamon, turmeric, Indian spices, Asian spices, herb, wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange, mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape, durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits, Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint, peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honey essence, rose oil, vanilla, lemon oil, orange oil, orange blossom, cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil from any species of the genus Mentha, eucalyptus, star anise, cocoa, lemongrass, rooibos, flax, ginkgo biloba, hazel, hibiscus, laurel, mate, orange skin, rose, tea such as green tea or black tea, thyme, juniper, elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary, saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle, cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm, lemon basil, chive, carvi, verbena, tarragon, limonene, thymol, camphene), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, liquid such as an oil, solid such as a powder, or gas.

[0036]In some embodiments, the flavour comprises menthol, spearmint and/or peppermint. In some embodiments, the flavour comprises flavour components of cucumber, blueberry, citrus fruits and/or redberry. In some embodiments, the flavour comprises eugenol. In some embodiments, the flavour comprises flavour components extracted from tobacco. In some embodiments, the flavour comprises flavour components extracted from cannabis.

[0037]In some embodiments, the flavour may comprise a sensate, which is intended to achieve a somatosensorial sensation which are usually chemically induced and perceived by the stimulation of the fifth cranial nerve (trigeminal nerve), in addition to or in place of aroma or taste nerves, and these may include agents providing heating, cooling, tingling, numbing effect. A suitable heat effect agent may be, but is not limited to, vanillyl ethyl ether and a suitable cooling agent may be, but not limited to eucolyptol, WS-3.

Aerosol-Generating Material

[0038]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 50 wt %, 60 wt % or 70 wt % of amorphous solid, to about 90 wt %, 95 wt % or 100 wt % of amorphous solid.

[0039]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.

Aerosol-Former Material

[0040]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.

Functional Material

[0041]The one or more other functional materials may comprise one or more of pH regulators, colouring agents, preservatives, binders, fillers, stabilizers, and/or antioxidants.

Substrate

[0042]The material may be present on or in a support, to form a substrate. The support may, for example, be or comprise paper, card, paperboard, cardboard, reconstituted material, a plastics material, a ceramic material, a composite material, glass, a metal, or a metal alloy. In some embodiments, the support comprises a susceptor. In some embodiments, the susceptor is embedded within the material. In some alternative embodiments, the susceptor is on one or either side of the material.

Consumable

[0043]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.

Susceptor

[0044]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.

Aerosol-Modifying Agent

[0045]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.

Aerosol Generator

[0046]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.

[0047]The present disclosure relates to aerosol delivery systems (which may also be referred to as vapour delivery systems) such as nebulisers or e-cigarettes. Throughout the following description the term “e-cigarette” or “electronic cigarette” may sometimes be used, but it will be appreciated this term may be used interchangeably with aerosol delivery system/device and electronic aerosol delivery system/device. Furthermore, and as is common in the technical field, the terms “aerosol” and “vapour”, and related terms such as “vaporise”, “volatilise” and “aerosolise”, may generally be used interchangeably.

[0048]Aerosol delivery systems (e-cigarettes) often, though not always, comprise a modular assembly comprising a reusable device part and a replaceable (disposable/consumable) cartridge part. Often, the replaceable cartridge part will comprise the aerosol generating material and the vaporiser (which may collectively be called a ‘cartomizer’) and the reusable device part will comprise the power supply (e.g. rechargeable power source) and control circuitry. It will be appreciated these different parts may comprise further elements depending on functionality. For example, the reusable device part will often comprise a user interface for receiving user input and displaying operating status characteristics, and the replaceable cartridge device part in some cases comprises a temperature sensor for helping to control temperature. Cartridges are electrically and mechanically coupled to the control unit for use, for example using a screw thread, bayonet, or magnetic coupling with appropriately arranged electrical contacts. When the aerosol generating material in a cartridge is exhausted, or the user wishes to switch to a different cartridge having a different aerosol generating material, the cartridge may be removed from the reusable part and a replacement cartridge attached in its place. Systems and devices conforming to this type of two-part modular configuration may generally be referred to as two-part systems/devices.

[0049]It is common for electronic cigarettes to have a generally elongate shape. For the sake of providing a concrete example, certain embodiments of the disclosure will be taken to comprise this kind of generally elongate two-part system employing disposable cartridges. However, it will be appreciated that the underlying principles described herein may equally be adopted for different configurations, for example single-part systems or modular systems comprising more than two parts, refillable devices and single-use disposables, as well as other overall shapes, for example based on so-called box-mod high performance devices that typically have a boxier shape. More generally, it will be appreciated certain embodiments of the disclosure are based on aerosol delivery systems which are operationally configured to provide functionality in accordance with the principles described herein and the constructional aspects of systems configured to provide the functionality in accordance with certain embodiments of the disclosure is not of primary significance.

BRIEF SUMMARY OF THE INVENTION

[0050]The present invention provides an aerosol delivery subsystem for an aerosol delivery system, comprising: an inlet; an outlet; and a baffle configured to move and thereby modify fluid flow along a flow path between the inlet and the outlet in use, in response to fluid being drawn along the flow path. The present invention also provides an aerosol delivery subsystem comprising: an inlet means; an outlet means; and baffle means configured to move and thereby modify fluid flow along a flow path between the inlet and the outlet, in response to fluid being drawn along the flow path.

[0051]The present invention also provides a method of manufacturing an aerosol delivery subsystem, comprising providing: an inlet; an outlet; and a baffle configured to move and thereby modify fluid flow along a flow path between the inlet and the outlet in use, in response to fluid being drawn along the flow path.

[0052]The present invention also provides a method of modifying fluid flow along a flow path between an inlet and an outlet of an aerosol delivery subsystem, the method comprising: moving a baffle in response to fluid being drawn along the flow path.

[0053]The present invention also provides preferred embodiments as claimed in the dependent claims.

[0054]The claimed invention generally provides a sub-assembly or subsystem suitable for use in an aerosol delivery system, or configured for use in an aerosol delivery system. The subsystem may generally form part of an aerosol delivery system and in particular may form part of the reusable device and/or the consumable cartridge.

[0055]The claimed invention may advantageously provide manually and/or automatically adjustable operating characteristics to target certain characteristics which may be desirable to a user.

BRIEF DESCRIPTION OF THE FIGURES

[0056]Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0057]FIG. 1 is a schematic cross-section view of an aerosol delivery system in accordance with some embodiments of the disclosure;

[0058]FIG. 2a is a schematic cross-section view of the air inlet region of the aerosol delivery system of FIG. 1 (shown dashed in FIG. 1), showing an aerosol delivery subsystem in accordance with some embodiments of the disclosure;

[0059]FIG. 2b is an enlarged schematic cross-section view of the baffle of FIG. 2a;

[0060]FIG. 2c is a schematic top-down view of the aperture in the baffle of FIGS. 2a-2b;

[0061]FIGS. 3a-3h are schematic cross-section views of the air inlet region of the aerosol delivery system of FIG. 1 (shown dashed in FIG. 1), showing various aerosol delivery subsystems in accordance with some embodiments of the disclosure; and

[0062]FIG. 3i is a schematic perspective view of the collar shown in FIG. 3h.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0063]Aspects and features of certain examples and embodiments are described herein. Some aspects and features of certain examples and embodiments may be implemented conventionally and these are not described in detail in the interest of brevity. It will thus be appreciated that aspects and features of apparatuses and methods discussed herein which are not described in detail may be implemented in accordance with any suitable conventional techniques.

[0064]FIG. 1 is a cross-sectional view through an example aerosol delivery system 1 in accordance with certain embodiments of the disclosure. The aerosol delivery system 1 comprises two main components, namely a reusable part 2 and a replaceable/disposable consumable cartridge part 4. In normal use, the reusable part 2 and the cartridge part 4 are releasably coupled together at an interface 6. When the cartridge part 4 is exhausted or the user simply wishes to switch to a different cartridge part 4, the cartridge part 4 may be removed from the reusable part 2 and a replacement cartridge part 4 attached to the reusable part 2 in its place. The interface 6 provides a structural, electrical and airflow path connection between the two parts 2, 4 and may be established in accordance with conventional techniques, for example based around a screw thread, magnetic or bayonet fixing with appropriately arranged electrical contacts and openings for establishing the electrical connection and airflow path between the two parts 2, 4 as appropriate. The specific manner by which the cartridge part 4 mechanically mounts to the reusable part 2 is not significant to the principles described herein, but for the sake of a concrete example is assumed here to comprise a magnetic coupling (not represented in FIG. 1). It will also be appreciated the interface 6 in some implementations may not support an electrical and/or airflow path connection between the respective parts 2, 4. For example, in some implementations an aerosol generator may be provided in the reusable part 2 rather than in the cartridge part 4, or the transfer of electrical power from the reusable part 2 to the cartridge part 4 may be wireless (e.g. based on electromagnetic induction), so that an electrical connection between the reusable part 2 and the cartridge part 4 is not needed. Furthermore, in some implementations the airflow through the electronic cigarette might not go through the reusable part 2, so that an airflow path connection between the reusable part 2 and the cartridge part 4 is not needed. In some instances, a portion of the airflow path may be defined at the interface between portions of the reusable part 2 and cartridge part 4 when these are coupled together for use. The cartridge/consumable part 4 may in accordance with certain embodiments of the disclosure be broadly conventional. In FIG. 1, the cartridge part 4 comprises a cartridge housing 42 formed of a plastics material. The cartridge housing 42 supports other components of the cartridge part 4 and provides the mechanical interface 6 with the reusable part 2. The cartridge housing 42 is generally circularly symmetric about a longitudinal axis along which the cartridge part 4 couples to the reusable part 2. In this example, the cartridge part 4 has a length of around 4 cm and a diameter of around 1.5 cm. However, it will be appreciated the specific geometry, and more generally the overall shapes and materials used, may be different in different implementations.

[0065]Within the cartridge housing 42 is a chamber or reservoir 44 that contains aerosol-generating material. In the example shown schematically in FIG. 1, the reservoir 44 stores a supply of liquid aerosol generating material. In this example, the liquid reservoir 44 has an annular shape with an outer wall defined by the cartridge housing 42 and an inner wall that defines an airflow path 52 through the cartridge part 4. The reservoir 44 is closed at each end with end walls to contain the aerosol generating material. The reservoir 44 may be formed in accordance with conventional techniques, for example it may comprise a plastics material and be integrally moulded with the cartridge housing 42.

[0066]The cartridge/consumable part 4 further comprises an aerosol generator 48 located towards an end of the reservoir 44 opposite to a mouthpiece outlet 50. It will be appreciated that in a two-part system such as shown in FIG. 1, the aerosol generator 48 may be in either of the reusable part 2 or the cartridge part 4. For example, in some embodiments, the aerosol generator 48 (e.g. a heater, which may be in the form of a wick and coil arrangement as shown, a distiller, which may be formed from a sintered metal fibre material or other porous conducting material, or any suitable alternative aerosol generator) may be comprised in the reusable part 2, and is brought into proximity with a portion of aerosol generating material in the cartridge part 4 when the cartridge part 4 is engaged with the reusable part 2. In such embodiments, the cartridge part 4 may comprise a portion of aerosol generating material, and an aerosol generator 48 comprising a heater is at least partially inserted into or at least partially surrounds the portion of aerosol generating material as the cartridge part 4 is engaged with the reusable part 2.

[0067]In the example of FIG. 1, a wick 46 in contact with the aerosol generator 48 extends transversely across the cartridge airflow path 52 with its ends extending into the reservoir 44 of the liquid aerosol generating material through openings in the inner wall of the reservoir 44. The openings in the inner wall of the reservoir 44 are sized to broadly match the dimensions of the wick 46 to provide a reasonable seal against leakage from the liquid reservoir 44 into the cartridge airflow path without unduly compressing the wick 46, which may be detrimental to its fluid transfer performance.

[0068]The wick 46 and aerosol generator 48 are arranged in the cartridge airflow path 52 such that a region of the cartridge airflow path 52 around the wick 46 and heater 48 in effect defines a vaporisation region for the cartridge part 4. Aerosol generating material in the reservoir 44 infiltrates the wick 46 through the ends of the wick extending into the reservoir 44 and is drawn along the wick by surface tension/capillary action (i.e. wicking). The aerosol generator 48 in this example comprises an electrically resistive wire coiled around the wick 46. In the example of FIG. 1, the heater 48 comprises a nickel chrome alloy (Cr20Ni80) wire and the wick 46 comprises a glass fibre bundle, but it will be appreciated the specific aerosol generator configuration is not significant to the principles described herein. In use, electrical power may be supplied to the aerosol generator 48 to vaporise an amount of aerosol generating material (aerosol generating material) drawn to the vicinity of the aerosol generator 48 by the wick 46. Vaporised aerosol generating material may then become entrained in air drawn along the cartridge airflow path from the vaporisation region towards the mouthpiece outlet 50 for user inhalation.

[0069]As noted above, the rate at which aerosol generating material is vaporised by the aerosol generator 48 will depend on the amount (level) 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 cartridge part 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.

[0070]The reusable part 2 comprises an outer housing 12 having with an opening that defines an air inlet 28 for the e-cigarette, a power source 26 (for example a battery) for providing operating power for the electronic cigarette, control circuitry/controller 22 for controlling and monitoring the operation of the electronic cigarette, a first user input button 14, a second user input button 16, and a visual display 24.

[0071]The aerosol delivery system 1 of FIG. 1 further comprises a subsystem used to vary the flow of fluid through the system in the form of the consumable part 4 comprising a baffle 60 across the air inlet 28. The baffle 60 is configured to move and thereby modify fluid flow along the flow path 52 between the inlet 28 and the outlet 50 in use, in response to fluid being drawn along the flow path 52. The baffle 60 is described in further detail with respect to FIG. 2 below.

[0072]The outer housing 12 may be formed, for example, from a plastics or metallic material and in this example has a circular cross section generally conforming to the shape and size of the cartridge part 4 so as to provide a smooth transition between the two parts 2, 4 at the interface 6. In this example, the reusable part 2 has a length of around 8 cm so the overall length of the e-cigarette when the cartridge part 4 and the reusable part 2 are coupled together is around 12 cm. However, and as already noted, it will be appreciated that the overall shape and scale of an electronic cigarette implementing an embodiment of the disclosure is not significant to the principles described herein.

[0073]The air inlet 28 connects to an airflow path 51 through the reusable part 2. The reusable part airflow path 51 in turn connects to the cartridge airflow path 52 across the interface 6 when the reusable part 2 and cartridge part 4 are connected together. Thus, when a user inhales on the mouthpiece opening 50, air is drawn in through the air inlet 28, along the reusable part airflow path 51, across the interface 6, through the aerosol generation area in the vicinity of the aerosol generator 48 (where vaporised aerosol generating material becomes entrained in the air flow), along the cartridge airflow path 52, and out through the mouthpiece opening 50 for user inhalation.

[0074]The power source 26 in this example is rechargeable and may be of a conventional type, for example of the kind normally used in electronic cigarettes and other applications requiring provision of relatively high currents over relatively short periods. The power source 26 may be recharged through a charging connector in the reusable part housing 12, for example a USB connector.

[0075]First and/or second user input buttons 14, 16 may be provided, which in this example are conventional mechanical buttons, for example comprising a spring mounted component which may be pressed by a user to establish an electrical contact. In this regard, the input buttons may be considered input devices for detecting user input and the specific manner in which the buttons are implemented is not significant. The buttons may be assigned to functions such as switching the aerosol delivery system 1 on and off, and adjusting user settings such as a power to be supplied from the power source 26 to the aerosol generator 48. However, the inclusion of user input buttons is optional, and in some embodiments buttons may not be included.

[0076]A display 24 may be provided to give a user with a visual indication of various characteristics associated with the aerosol delivery system, for example current power setting information, remaining power source power, and so forth. The display may be implemented in various ways. In this example the display 24 comprises a conventional pixilated LCD screen that may be driven to display the desired information in accordance with conventional techniques. In other implementations, the display may comprise one or more discrete indicators, for example LEDs, that are arranged to display the desired information, for example through particular colours and/or flash sequences. More generally, the manner in which the display 24 is provided and information is displayed to a user using the display is not significant to the principles described herein. For example, some embodiments may not include a visual display and/or may include other means for providing a user with information relating to operating characteristics of the aerosol delivery system, for example using audio signalling, or may not include any means for providing a user with information relating to operating characteristics of the aerosol delivery system.

[0077]A controller 22 is suitably configured/programmed to control the operation of the aerosol delivery system 1 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 delivery system 1 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 delivery 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 20 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 electronic cigarettes, such as display driving circuitry and user input detection circuitry. It will be appreciated that 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.

[0078]The functionality of the controller 22 is described further herein. For example, the controller 26 may comprise an application specific integrated circuit (ASIC) or microcontroller, for controlling the aerosol delivery device. The microcontroller or ASIC may include a CPU or micro-processor. The operations of a CPU and other electronic components are generally controlled at least in part by software programs running on the CPU (or other component). Such software programs may be stored in non-volatile memory, such as ROM, which can be integrated into the microcontroller itself, or provided as a separate component. The CPU may access the ROM to load and execute individual software programs as and when required.

[0079]The reusable part 2 comprises an airflow sensor 30 which is electrically connected to the controller 22. In most embodiments, the airflow sensor 30 comprises a so-called “puff sensor”, in that the airflow sensor 30 is used to detect when a user is puffing on the device. In some embodiments, the airflow sensor 30 comprises a switch in an electrical path providing electrical power from the power source 26 to the aerosol generator 48. In such embodiments, the airflow sensor 30 generally comprises a pressure sensor configured to close the switch when subjected to a particular range of pressures, enabling current to flow from the power source 26 to the aerosol generator 48 once the pressure in the vicinity of the airflow sensor 30 drops below a threshold value. The threshold value can be set to a value determined by experimentation to correspond to a characteristic value associated with the initiation of a user puff. In other embodiments, the airflow sensor 30 is connected to the controller 22, and the controller distributes electrical power from the power source 26 to the aerosol generator 48 in dependence of 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 carried out in accordance with any approach known to the skilled person.

[0080]In the example shown in FIG. 1, the airflow sensor 30 is mounted to a printed circuit board 31 as described further herein, but this is not essential. The airflow sensor 30 may comprise any sensor which is configured to determine a characteristic of airflow in an airflow path 51 disposed between air inlet 28 and mouthpiece opening 50, for example a pressure sensor or transducer (for example a membrane or solid-state pressure sensor), a combined temperature and pressure sensor, or a microphone (for example an electret-type microphone), which is sensitive to changes in air pressure, including acoustical signals. The airflow sensor 30 is situated within a sensor cavity 32, which comprises the interior space defined by one or more chamber walls 34. The sensor cavity 32 may also be referred to herein as a sensor chamber 32 (these terms may be used interchangeably), and comprises a region internal to one or more chamber walls 34 in which an airflow sensor 30 can be fully or partially situated. In some embodiments, the airflow sensor 30 is mounted to a printed circuit board (PCB) 31, which comprises one of the chamber walls of a sensor housing comprising the sensor chamber/cavity 32.

[0081]A deformable membrane is disposed across an opening communicating between the sensor cavity 32 containing the sensor 30, and a portion of the airflow path disposed between air inlet 28 and mouthpiece opening 50. The deformable membrane covers the opening, and is attached to one or more of the chamber walls according to approaches described further herein.

[0082]As described further herein, the aerosol delivery system 1 comprises communication circuitry configured to enable a connection to be established with one or more further electronic devices (for example, a storage/charging case, and/or a refill/charging dock) to enable data transfer between the aerosol delivery system 1 and further electronic device(s). In some embodiments, the communication circuitry is integrated into controller 22, and in other embodiments it is implemented separately (comprising, for example, separate application-specific integrated circuit(s)/circuitry/chip(s)/chipset(s)). For example, the communication circuitry may comprise a separate module to the controller 22 which, while connected to controller 22, provides dedicated data transfer functionality for the aerosol delivery device. In some embodiments, the communication circuitry is configured to support communication between the aerosol delivery system 1 and one or more further electronic devices over a wireless interface. The communication circuitry may be configured to support wireless communications between the aerosol delivery system 1 and other electronic devices such as a case, a dock, a computing device such as a smartphone or PC, a base station supporting cellular communications, a relay node providing an onward connection to a base station, a wearable device, or any other portable or fixed device which supports wireless communications.

[0083]Wireless communications between the aerosol delivery system 1 and a further electronic device may be configured according to known data transfer protocols such as Bluetooth®, ZigBee, WiFi®, Wifi Direct, GSM, 2G, 3G, 4G, 5G, LTE, NFC, RFID. More generally, it will be appreciated that any wireless network protocol can in principle be used to support wireless communication between the aerosol delivery system 1 and further electronic devices. In some embodiments, the communication circuitry is configured to support communication between the aerosol delivery system 1 and one or more further electronic devices over a wired interface. This may be instead of or in addition to the configuration for wireless communications set out above. The communication circuitry may comprise any suitable interface for wired data connection, such as USB-C, micro-USB or Thunderbolt interfaces. More generally, it will be appreciated the communication circuitry may comprise any wired communication interface which enables the transfer of data, according to, for example, a packet data transfer protocol, and may comprise pin or contact pad arrangements configured to engage cooperating pins or contact pads on a dock, case, cable, or other external device which can be connected to the aerosol delivery system 1.

[0084]FIG. 2a is a schematic cross-section view of the air inlet region of the aerosol delivery system 1 of FIG. 1 (shown dashed in FIG. 1), illustrating the features of the aerosol delivery subsystem comprising the baffle 60 across the inlet 28 in FIG. 1 in more detail. FIG. 2b is an enlarged schematic cross-section view of the baffle 60 of FIG. 2a.

[0085]In FIGS. 1-2b, the baffle 60 on the consumable part 4 comprises a flexible resilient membrane 60 having an aperture 61. The baffle 60 is within and spans the air inlet 28 whilst the aperture 61 provides an opening to the flow path 52 for fluid flowing from the air inlet 28 to the outlet 50, via the aerosol generator 48. Said fluid typically contains incoming air from the air inlet 28 and aerosol entrained therein from the aerosol generator 48, and is drawn along the flow path in use, e.g. when a user inhales (or exhales) on the outlet 50. The remainder of the baffle 60 effectively restricts or obstructs air flow through the air inlet 28 and thus along the flow path 52. Although only one air inlet 28 and aperture 61 are shown here, multiple air inlets 28 and/or apertures 61 may be provided, to provide greater air flow in use and/or to provide air flow even if a user inadvertently covers one of the air inlets 28 and/or apertures 61, e.g. with a finger.

[0086]In FIGS. 1-2b, the baffle 60 is shown to be internal, within the inlet 28, flush with the reusable part 2 and consumable part 4, but in other embodiments the baffle 60 may be more generally positioned anywhere suitable for modifying the fluid flow, such as proximal to the air inlet 28, including external to and upstream of the air inlet 28, or alternatively generally within or proximal to the flow path 52, i.e. downstream from the air inlet 28 in the flow path 52. The proximity to the air inlet 28 or flow path 52 must be such that the baffle 60 impacts the air flow therethrough and includes, but is not limited to being, adjacent thereto. Various such other arrangements are described later with reference to FIGS. 3a-3h.

[0087]The flexible, resilient nature of the membrane 60 allows the baffle 60 to move by temporarily deflecting and/or deforming, altering the size of the aperture 61 when fluid is drawn along the flow path 52, e.g. when the user inhales (or exhales) on the outlet 50. When inhaling occurs, this reduces the fluid pressure in the flow path 52 and thus draws air in through the air inlet 28 via the aperture 61 in the baffle 60 and draws aerosol to the user. When the baffle 60 comprises a flexible membrane 60 as here, then when the user inhales, the drop in pressure in the flow path 52 creates a pressure differential from ambient pressure across the flow path 52 and causes the baffle 60 to be sucked into the air inlet 28, stretching the membrane and thereby opening the aperture 61 further, increasing the effective cross-sectional area of the flow path 52 and reducing the restriction/obstruction of air flow into the air inlet 28, thus altering the ventilation and hence fluid flow through the air inlet 28 and along the flow path 52 to the outlet 50. The resilient nature of the membrane 60 means that it returns to its original, non-deformed shape when the pressure differential is removed.

[0088]Typically, operating pressure differentials range between about 98-1471 Pa (10-150 mm H₂O), and an ideal operating pressure is around 686-785 Pa (70-80 mm H₂O). Maximum operating pressure differentials could be >1961 Pa (200 mm H₂O), such as between about 2942 Pa-3923 Pa (300-400 mm H₂O), although such high pressure differentials would in practice be difficult for users to draw a puff. Accordingly, in some embodiments, the baffle 60 may be configured to modify a fluid pressure differential between a fluid pressure in the flow path 52 and ambient, the differential being about 98-1961 Pa (10-200 mm H₂O), preferably about 294-981 Pa (30-100 mm H₂O), more preferably about 294-686 Pa (30-70 mm H₂O), 588-785 Pa (60-80 mm H₂O), 588-883 Pa (60-90 mm H₂O), 686-883 Pa (70-90 mm H₂O), 785-981 Pa (80-100 mm H₂O) or 686-785 Pa (70-80 mm H₂O). The membrane material may be chosen to provide desirable movement/fluid pressure differential by deflection and/or deformation and said movement may be proportional to the fluid pressure differential caused by the user inhaling or exhaling on the outlet. In some embodiments, the material may be sufficiently stiff to move only when the pressure differential exceeds a threshold.

[0089]Various fluid properties such as fluid pressure, temperature, density, viscosity, velocity and/or degree of turbulence (Reynolds number) may be altered by the configuration of the baffle 60 and the movement thereof, varying ventilation through the system. Many of these fluid properties are related to one another—for example, under the conservation of energy (Bernoulli effect), fluid pressure reduces where flow velocity is increased; and the viscosity of air principally depends on temperature. In any case, these properties of fluid in the flow path 52 can differ to ambient air and impact the entrainment of aerosol and/or the delivery of aerosol to the user, altering the sensory experience.

[0090]The variable ventilation can also be used to adjust the draw resistance of the e-cigarette. Thus as a user inhales, the lungs in effect work against the draw resistance, i.e. the work required to pull air into and then through the e-cigarette into the lungs. For most users, there is a range of draw resistance that helps them to perform a steady inhalation. However, if the draw resistance is too low, the inhalation may become too rapid and unsteady, while if the draw resistance is too high, the inhalation may become unduly burdensome. The most suitable level of draw resistance varies from one user to another user, based e.g. on physiological factors. Accordingly, providing variable ventilation and fluid flow as described herein can help a user to configure the draw resistance of e-cigarette to an appropriate value for their own personal preferences and characteristics.

[0091]The baffle 60 can be configured to provide particular desirable effects dependent on user preferences. For example, the baffle 60 can have a particular shape, location or mode of operation/movement to modify one or more of the fluid properties of fluid flowing in the flow path 52 in use and the baffle 60 may be further configurable (e.g. further movable and/or adjustable) by the user to allow a greater range of adjustment. Generally, when the baffle 60 is external to (upstream from) the air inlet 28, this makes further user adjustment by the user easier as the baffle 60 is more readily accessible. In some embodiments, the user can actuate an input such as a dial or button 14, 16 on the device for adjustment of the fluid flow. Alternatively, the subsystem may modify the fluid flow dependent on the user's draw strength automatically, e.g. actuating the baffle 60 based on the draw, such as providing a unique adjustment for that particular user based on their typical (average) puff, or even based on the particular draw.

[0092]In some embodiments, the baffle 60 has multiple preconfigured starting positions selectable by a user, allowing adjustment of the range of movement of the baffle 60 from the starting position chosen. For example, the baffle 60 may have a length extending into the flow path 52 corresponding to half the width of the air inlet 28, and have a first starting position enabling the baffle 60 to cover between 0-50% of the width of the air inlet 28, and a second position enabling the baffle 60 to cover only between 0-25% of the width of the air inlet 28, with the remaining portion of the baffle 60 being recessed in the consumable part 4, or equally the reusable part 2.

[0093]Although the consumable part 4 comprises the baffle in FIG. 1, in other embodiments, the reusable part 2 may instead comprise the baffle 60, or the baffle 60 may be an integral component of a single-part non-modular ‘throwaway’ system.

[0094]FIG. 2c is a schematic top-down view of the aperture 61 in the flexible membrane baffle 60 in FIGS. 2a-2b and illustrates how the aperture 61 may deform, enlarging as pressure in the flow path 52 decreases (or increases) when the user inhales (or exhales) on the outlet 50. As shown in FIG. 2c, the aperture 61 is variable in size due to the flexible nature of the membrane baffle 60.

[0095]In some embodiments, the nominal diameter do of the flow path through the aperture 61 (at ambient pressure/zero differential across the aperture 61) is within the ranges 0.1-2.0 mm, 0.25-1.5 mm or 0.5-1.0 mm in diameter. The membrane baffle 60 may be suitably flexible to move by deflecting or deforming to provide a design maximum enlarged aperture diameter ds (e.g. when a pressure differential across the aperture 61 is equal to ambient pressure) within the ranges 0.5-5.0 mm, 0.75-2.5 mm, 1.0-2.0 mm or 1.5-2.0 mm. In one embodiment, the nominal to enlarged diameter range (d₀-d₃) is 0.5-2.0 mm. For a variation between 0.5 mm nominal diameter to 2 mm enlarged diameter, this equates to modifying an effective cross-sectional area of the aperture 61 (and thus the effective inlet 28 in FIG. 1) of between about 2×10⁻⁷ and 3×10⁻⁶ m². Generally applicable ranges of suitable cross sectional areas of the flow path/inet are 1×10⁻⁷ to 5×10⁻⁶ m², 1.5×10⁻⁷ to 4×10⁻⁶ m² and 2×10⁻⁷ to 3×10⁻⁶ m².

[0096]In some embodiments, the baffle 60 may comprise one or more slits 62 instead of, or in addition to, one or more apertures 61. A slit beneficially allows greater deformation under pressure than an aperture, thus allowing more cross-sectional area variation for the same pressure differential range, and greater air flow therethrough when under pressure. A slit may also be used to substantially seal the inlet at ambient pressure, e.g. when the device is not in use, preventing debris entering, but still allow deformation and hence air flow when under pressure. FIG. 2c illustrates two perpendicular, horizontal and vertical ‘crosshair’ slits 62 across the aperture 61, to aid deformation. In other embodiments, any other slit arrangements may be used.

[0097]FIGS. 3a-3h are schematic cross-section views of the air inlet region of the aerosol delivery system 1 of FIG. 1 (shown dashed in FIG. 1), showing various baffles 60 in different forms to the flexible membrane baffle 60 of FIGS. 1-2b, with the other details of the subsystem (and optional wider system) not shown for clarity. The baffle 60 may generally comprise a resilient element, a flexible membrane, a flap, an adjustable diaphragm of overlapping flaps (akin to a camera aperture opening), a valve, a biasing element, telescoping elements, a slider and/or a collar. The baffle 60 may comprise a biasing element 63 to bias the baffle 60 into a predetermined configuration such as open, closed or anything in between.

[0098]In the embodiments of FIGS. 3a-3h, the baffle 60 moves by translating or rotating to alter the obstruction to the flow path and the effective diameter/cross-sectional area of the air inlet 28 or the flow path 52, rather than by deflection/deformation as in FIGS. 1-2c. The same ranges for the effective diameter/cross-sectional area of the air inlet 28 or the flow path 52 outlined above for the flexible membrane baffle 60 may also apply here.

[0099]FIG. 3a illustrates the baffle 60 comprising a rigid slider 60 that is external to and upstream from the air inlet 28, whilst FIG. 3b illustrates the baffle 60 comprising a rigid slider 60 which is downstream in the flow path 52 and at least partially receivable in the consumable part 4. Here, the baffle 60 can slide to alter the effective diameter/cross-sectional area of the air inlet 28 as per the flexible membrane embodiment of FIG. 1-2c, but as the baffle 60 is solid, its movement is not predetermined by its material properties and so a drop in the fluid pressure in the flow path 52 does not necessarily cause notable deflection/deformation. Nevertheless, the rigid baffle 60 can be configured to move to increase the effective cross-sectional area of the flow path 52 and reduce the restriction/obstruction of air flow into the air inlet 28 when the user inhales, as per the flexible membrane embodiment, or conversely to decrease the effective cross-sectional area of the flow path 52.

[0100]In some embodiments, the system 1 may be configured to trigger activation of the aerosol generator 48 and/or movement of the baffle 60 in response to fluid being drawn along the flow path 52, which may be detected by the flow sensor 30. Furthermore, if desired, the rigid baffle 60 can be configured to continually adjust the effective cross-sectional area in accordance with a user profile or preferences, or a temporal profile. Such automation and granularity of the fluid flow adjustment provides an enhanced user experience.

[0101]FIG. 3c illustrates a rigid slider baffle 60 external to, upstream and offset from the air inlet 28 by a static mount 65, the baffle 60 thereby always permitting air flow even when the baffle 60 is fully deployed across (spanning) the air inlet 28. In some embodiments, the baffle 60 may increase or decrease the effective length of the flow path 52. As shown in FIG. 3c, movement of the baffle 60 toward the reusable part 2 effectively lengthens the air flow path 52, whilst movement of the baffle 60 toward the consumable part 4 and away from the reusable part 2 effectively shortens the air flow path. FIG. 3d illustrates two baffles 60a, 60b, one on each of the reusable part 2 and the consumable part 4. In this arrangement, the baffles 60 may be configured to move independently or collectively and this provides greater freedom of movement. For example, in this arrangement, the baffles 60 may be moved to alter the flow path towards the reusable part 2 and away from the consumable part 4, or vice versa, or moved cooperatively to reduce or enlarge a central aperture formed between the baffles 60.

[0102]FIG. 3e illustrates the baffle 60 comprising a hinged flap, with a biasing element 63. Here, the baffle 60 moves by pivoting (rotating) to modify the fluid flow, and the baffle 60 is biased into a partially open configuration by the biasing element 63, to allow air flow into the inlet 28 and down the flow path 52 even when there is lower than ambient pressure in the flow path 52 (which might otherwise force the baffle 60 to close and fully obstruct the air inlet 28). In further embodiments, other or additional biasing elements 63 may be provided, for example to limit opening of the baffle 60, or to bias the baffle 60 into a closed position. The cross-sectional area of the flow path can be modified similarly to the preceding ‘slider’ examples.

[0103]FIG. 3f illustrates the baffle 60 comprising multiple telescoping elements 60. This arrangement provides a compact baffle 60 that can be readily extended/contracted to adjust fluid flow along the flow path 52. Although not shown, in some embodiments these elements 60 may comprise one or more apertures 61 to permit air flow therethrough even when the elements span the inlet 28.

[0104]FIG. 3g illustrates the baffle 60 comprising a simple valve, having a ‘T’ flow path therethrough, where the horizontal path of the ‘T’ effectively provides two inlet apertures 28 which are adjustable in size (vertical height) as the baffle 60 moves vertically as shown. An actuator 64 is shown for opening and closing the baffle 60 in response to fluid being drawn along the flow path 52.

[0105]FIG. 3h illustrates the baffle 60 comprising a collar 60 located around a portion of the housing 12 in which two air inlets 28 are provided. The collar 60 is shown in insolation in a perspective view in FIG. 3i and is movable with respect to the housing 12. In this embodiment, the collar 60 moves with respect to the housing 12 in response to fluid being drawn along the flow path and the system comprises a mechanism such as an actuator 64 for positioning the collar 60 with respect to the housing 12 at any position or a plurality of predetermined positions as the collar 60 moves with respect to the housing 12, wherein different positions result in different degrees of alignment between the collar and the one or more air inlets 28, varying the air flow into the system. In some embodiments, the collar 60 positively engages with the housing 12, e.g. with a mechanical interlock using protrusions and/or recesses on the collar 60 and/or the housing 12, to secure the collar 60 in the predetermined position. The collar 60 is shown to be external to the housing 12, but may instead be internal.

[0106]In the embodiment shown, the collar 60 comprises multiple apertures 61 which are azimuthally spaced around the circumference of the collar 60. Each aperture 61 allows air to flow through the collar in a radial direction, i.e. from outside the collar 60 to inside the collar 60, and the collar 60 is rotatable to vary alignment between the apertures 61 in the collar 60 and the air inlets 28. The multiple apertures 61 can be arranged on the collar 60 so that in various predetermined positions of the collar 60 with respect to the housing 12, none, any subset of or all air inlets 28 are blocked or open. A similar arrangement is detailed further in WO 2016/012774, which is incorporated herein by reference. Furthermore, the apertures 61 may vary in size or taper, so that more granular variation and modification of air flow can be provided. Similar such arrangements are detailed further in WO 2017/046566, which is incorporated herein by reference. Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure.

[0107]In a further embodiment (not shown), the collar 60 is movable axially and radially, and is axially locatable in multiple substantially circumferential tracks around the housing 12, providing different degrees of overlap (e.g. 25%, 50%, 75%, 100%) between the apertures 61 and the inlets 28 as the collar 60 rotates about the housing 12 in the track. This arrangement provides multiple, user-selectable positions for the collar 60 to vary the air flow range. In one particular arrangement, the housing 12 and/or collar 60 comprise complementary helical threads to provides said substantially circumferential tracks, permitting movement of the collar 60 axially and radially with respect to the housing 12 to vary the air flow. The user may optionally be able to further manually adjust the position of the collar with respect to the housing 12.

[0108]In another embodiment (not shown), the collar 60 itself has no apertures 61 and moves only axially to vary coverage of the air inlet(s) 28.

[0109]In some embodiments, the system 1 is configured to move the baffle 60 automatically in response to the sensor 30 detecting fluid being drawn along the flow path 52. As noted above, the sensor 30 may comprise a pressure sensor configured to detect a threshold pressure change, or measure the pressure of the fluid being drawn along the fluid flow path. The sensor 30 may comprise a sensor configured to sense (measure) a property or characteristic of fluid being drawn along the flow path 52. The system 1 may further comprise an actuator 64 (such as a motor, solenoid etc.) configured to move the baffle 60 in response to the sensor data (sensed property). Such a configuration can provide more granular control of movement of the baffle 60 and thus the user experience, since the characteristics of the movement can be tailored to a user's preference. For example, the system can be configured to operate in a similar fashion to the FIG. 1 embodiment, in which when the user inhales, the baffle 60 moves to increase the effective cross-sectional area of the flow path 52 and reduce the restriction/obstruction of air flow into the air inlet 28, thus altering the air flow through the air inlet 28 and along the flow path 52. Alternatively, the baffle 60 may instead be configured to move to decrease the effective cross-sectional area of the flow path 52 and increase the restriction/obstruction of air flow into the air inlet 28, thus altering the air flow through the air inlet 28 and along the flow path 52 in the opposite manner to the membrane arrangement of FIG. 1, which may be desirable for some users.

[0110]Advantageously, the system may be configurable to operate in either manner, or any manner in between, such as providing a first effective cross-sectional area of the flow path 52 for a first predetermined period of time after detecting fluid flow or whilst a first property of the fluid flow (e.g. pressure) is below (or above) a first threshold, and thereafter increasing or decreasing the effective cross-sectional area, optionally for a second predetermined period of time or whilst the first or another property of the fluid is above (or below) a second threshold, to suit individual user preferences. Any combination of these parameters, i.e. the fluid properties (the same or differing for each stage), thresholds (first and second being the same or differing), predetermined periods of time (first and second being the same or differing), ‘above’/‘below’ and ‘increasing’/‘decreasing’ conditions may be used, and may be configurable on the system by the user.

[0111]In one embodiment, when the airflow sensor 30 detects a user puffing on the system, the baffle 60 provides or moves to provide a first effective cross-sectional area of the flow path 52 for a predetermined time (or whilst a first property of the fluid (e.g. pressure) is below (or above) a first threshold), and subsequently the baffle 60 moves to provide a second effective cross-sectional area of the flow path 52 thereafter, which may optionally be for a predetermined time or until the first or another property of the fluid is above (or below) the first or a second threshold.

[0112]In one embodiment, when the sensor 30 detects fluid being drawn along the flow path 52, the baffle 60 is configured to: move to increase or decrease an effective cross-sectional area of the flow path 52; or provide a first effective cross-sectional area of the flow path 52 for a predetermined period of time; and then move to increase or decrease the effective cross-sectional area of the flow path 52.

[0113]In one embodiment, the system may be configured to increase an effective cross-sectional area of the flow path 52 when a sensed property of fluid flowing in the flow path 52 is above or below a threshold; and/or decrease an effective cross-sectional area of the flow path 52 when a sensed property of fluid flowing in the flow path 52 is above or below a threshold.

[0114]In one embodiment, the baffle 60 may be configured to provide a first effective cross-sectional area of the flow path 52 when a first sensed property of fluid flowing in the flow path 52 is above or below a first threshold; and increase or decrease the effective cross-sectional area of the flow path 52 when the first or a second sensed property of fluid flowing in the flow path 52 is above or below the first or a second threshold.

[0115]In embodiments, any type of movement (including deformation, deflection, axial, radial, rotational), any number of apertures 61, or no apertures 61, and any number of air inlets 28 may be used, in any combination. Also, the relative sizes of the inlets 28 and apertures 61 can be modified as required; they need not be the same as in the Figures. The examples show the inlets 28 and apertures 61 have a diameter which is substantially constant. This is not essential; the inlets 28 and/or apertures 61 may be otherwise shaped to achieve particular effects of flow control.

[0116]In the figures, the baffle 60 is schematically represented as a solid rectangular element. In embodiments of the disclosure, the baffle 60 and any associated aperture(s) 61 or slit(s) 62 may be of any shape. In particular, the baffle 60 may comprise a curved or square rib, an edge feature such as a chamfered or bevelled edge and/or protrusions/recesses to further modify fluid flow.

[0117]In some embodiments, the baffle 60 comprises one or more apertures 61 and/or the subsystem comprises one or more fluid (air) inlets 28, and different degrees of alignment between the apertures 61 in the baffle 60 and the one or more inlets 28 provide different degrees of overlap between the one or more inlets 28 and the one or more apertures 61. It may be desired that complete blockage of the airflow path is unachievable, at least in use, such as for safety reasons, so the system may be configured to ensure that the air inlet flow path is always at least partly open when the device is on, e.g. by using a biasing element 63 such as in FIG. 3e, or e.g. by limiting the amount of movement of the baffle 60 to be within a range where some overlap between the aperture(s) 61 and the inlet(s) 28 is always maintained. In some embodiments, the baffle 60 is configured to move to substantially cover the air inlet 28 to prevent airflow therethrough. The system may be configured to move the baffle to substantially cover the air inlet 28 e.g. when the user switches off the device, the aerosol-generating material is substantially depleted and/or the power source is substantially depleted.

[0118]In some embodiments, the baffle 60 is interchangeable and/or replaceable by the user, for example to allow switching between different baffles 60 having different features such as materials with different properties (e.g. stiffness, porosity), geometries (e.g. length, width, edge features, aperture size, aperture number, aperture shape or aperture arrangement) etc. to alter the user experience.

[0119]In some embodiments, flow path diameter/cross-sectional area adjustments may be configured to be practically instantaneous, or configured to be steadily increasing/decreasing over a short period of time, such as the time for a user to take a partial puff, a single puff or a few puffs (e.g. 0.1-0.5 seconds, 0.1-1 second, 0.5-3 seconds, 0.5-5 seconds, 1-3 seconds, 1-30 seconds).

[0120]In some embodiments, the baffle 60 may be configured to provide periodic (e.g. every 0.5 s, 1 s, 2 s, effectively for each puff) or continuous temporal adjustment, e.g. dependent on sensed parameters (fluid properties), and/or may provide continuously variable position adjustment or position adjustment between two or more predetermined positions only.

[0121]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.