Patent Description:
Pharmaceutical medicament, physiologically active substances and flavourings for example may be delivered to the human body by inhalation through the mouth and/or nose. Such material or substances may be delivered directly to the mucosa or mucous membrane lining the nasal and oral passages and/or the pulmonary system. For example, nicotine is consumed for therapeutic or recreational purposes and may be delivered to the body in a number of ways. Nicotine replacement therapies are aimed at people who wish to stop smoking and overcome their dependence on nicotine. Nicotine is delivered to the body in the form of aerosol delivery devices and systems, also known as smoking-substitute devices or nicotine delivery devices. Such devices may be non-powered or powered.

Devices or systems that are non-powered may comprise nicotine replacement therapy devices such as "inhalators", e.g. Nicorette® Inhalator. These generally have the appearance of a plastic cigarette and are used by people who crave the behaviour associated with consumption of combustible tobacco - the so-called hand-to-mouth aspect - of smoking tobacco. Inhalators generally allow nicotine-containing aerosol to be inhaled through an elongate tube in which a container containing a nicotine carrier, for example, a substrate, is located. An air stream caused by suction through the tube by the user carries nicotine vapours into the lungs of the user to satisfy a nicotine craving. The container may comprise a replaceable cartridge, which includes a cartridge housing and a passageway in the housing in which a nicotine reservoir is located. The reservoir holds a measured amount of nicotine in the form of the nicotine carrier. The measured amount of nicotine is an amount suitable for delivering a specific number of "doses". The form of the nicotine carrier is such as to allow nicotine vapour to be released into a fluid stream passing around or through the reservoir. This process is known as aerosolization and or atomization. Aerosolization is the process or act of converting a physical substance into the form of particles small and light enough to be carried on the air i.e. into an aerosol. Atomization is the process or act of separating or reducing a physical substance into fine particles and may include the generation of aerosols. The passageway generally has an opening at each end for communication with the exterior of the housing and for allowing the fluid stream through the passageway. A nicotine-impermeable barrier seals the reservoir from atmosphere. The barrier includes passageway barrier portions for sealing the passageway on both sides of the reservoir. These barrier portions are frangible so as to be penetrable for opening the passageway to atmosphere.

A device or a system that is powered can fall into two sub-categories. In both subcategories, such devices or systems may comprise electronic devices or systems that permit a user to simulate the act of smoking by producing an aerosol mist or vapour that is drawn into the lungs through the mouth and then exhaled. The electronic devices or systems typically cause the vaporization of a liquid containing nicotine and entrainment of the vapour into an airstream. Vaporization of an element or compound is a phase transition from the liquid phase to vapour i.e. evaporation or boiling. In use, the user experiences a similar satisfaction and physical sensation to those experienced from a traditional smoking or tobacco product, and exhales an aerosol mist or vapour of similar appearance to the smoke exhaled when using such traditional smoking or tobacco products.

A person of ordinary skill in the art will appreciate that devices or systems of the second, powered category as used herein include, but are not limited to, electronic nicotine delivery systems, electronic cigarettes, e-cigarettes, e-cigs, vaping cigarettes, pipes, cigars, cigarillos, vaporizers and devices of a similar nature that function to produce an aerosol mist or vapour that is inhaled by a user. Such nicotine delivery devices or systems of the second category incorporate a liquid reservoir element generally including a vaporizer or misting element such as a heating element or other suitable element, and are known, inter alia, as atomizers, cartomizers, or clearomizers. Some electronic cigarettes are disposable; others are reusable, with replaceable and refillable parts.

Aerosol delivery devices or systems in a first sub-category of the second, powered category generally use heat and/or ultrasonic agitation to vaporize a solution comprising nicotine and/or other flavouring, propylene glycol and/or glycerine-based base into an aerosol mist of vapour for inhalation.

Aerosol delivery devices or systems in a second sub-category of the second, powered category may typically comprise devices or systems in which tobacco is heated rather than combusted. During use, volatile compounds may be released from the tobacco by heat transfer from the heat source and entrained in air drawn through the aerosol delivery device or system. Direct contact between a heat source of the aerosol delivery device or system and the tobacco heats the tobacco to form an aerosol. As the aerosol containing the released compounds passes through the device, it cools and condenses to form an aerosol for inhalation by the user. In such devices or systems, heating, as opposed to burning, the tobacco may reduce the odour that can arise through combustion and pyrolytic degradation of tobacco.

Aerosol delivery devices or systems falling into the first sub-category of powered devices or systems may typically comprise a powered unit, comprising a heater element, which is arranged to heat a portion of a carrier that holds an aerosol precursor. The carrier comprises a substrate formed of a "wicking" material, which can absorb aerosol precursor liquid from a reservoir and hold the aerosol precursor liquid. Upon activation of the heater element, aerosol precursor liquid in the portion of the carrier in the vicinity of the heater element is vaporised and released from the carrier into an airstream flowing around the heater and carrier. Released aerosol precursor is entrained into the airstream to be borne by the airstream to an outlet of the device or system, from where it can be inhaled by a user.

The heater element is typically a resistive coil heater, which is wrapped around a portion of the carrier and is usually located in the liquid reservoir of the device or system. Consequently, the surface of the heater may always be in contact with the aerosol precursor liquid, and long-term exposure may result in the degradation of either or both of the liquid and heater. Furthermore, residues may build up upon the surface of the heater element, which may result in undesirable toxicants being inhaled by the user. Furthermore, as the level of liquid in the reservoir diminishes through use, regions of the heater element may become exposed and overheat. <CIT> discloses an aerosol-generation apparatus comprising a heater having a planar heating surface, and is configured to receive an aerosol precursor carrier for thermal interaction the heating surface. The heater comprises a heating element at said heating surface and said heating surface comprises a fluid transport region adjacent said heating element. The fluid transport region is configured to move liquid across the heating surface towards the heating element.

The present technology has been devised in light of the above considerations.

An invention is set out in the claims. At its most general, the present technology proposes that an aerosol-generation apparatus has a heater and a fluid-transfer article for holding an aerosol precursor. A heating surface of the heater has at least one channel therein which opposes the fluid-transfer article. Normally, the fluid-transfer article will be arranged to transfer the aerosol precursor to an activation surface, and it is that activation surface of the fluid-transfer article which interacts with the heating surface. The channel may thus be open towards the activation surface.

Thus, the channel may define a spacing between part of the heating surface and the activation surface, through which spacing air can flow. It may thus form an air-flow pathway. Aerosol precursor which reaches the activation surface may then be heated by the heater, to form a vapour or a vapour/aerosol mixture. That vapour or mixture may then mix with air in the air-flow pathway to pass to the user.

Optionally, there may be a plurality of such channels, which plurality of channels forms the air-flow pathway.

Thus, according to a first aspect of the present disclosure, there may be provided an aerosol-generation apparatus comprising a heater and a fluid-transfer article, the fluid-transfer article having a first region for holding an aerosol precursor and for transferring said aerosol precursor to an activation surface of a second region of said article, said activation surface being configured for thermal interaction with a heating surface of said heater; said heating surface including at least one discontinuity therein forming a corresponding at least one channel, the or each said channel being configured for providing a fluid-flow pathway across said activation surface, said heater being configured such that, when the fluid transfer article is arranged with respect to said heating surface for thermal interaction therebetween, the or each said channel opposes said activation surface and opens towards said activation surface.

The activation surface may be disposed at an end of the fluid-transfer article.

Optionally, said heating surface is configured such that, when the fluid transfer article is arranged with respect to said heating surface for thermal interaction therebetween, the or each discontinuity is spaced apart from said activation surface.

Advantageously, the or each said channel may be at least partly defined by a pair of spaced apart side walls and an arcuate surface portion extending between said wall portions to form a ceiling portion of said channel.

Optionally, said arcuate surface portion blends smoothly with each of said side walls, thereby eliminating a sharp corner therebetween.

Alternatively, the or each channel may be at least partially defined by a pair of spaced apart side walls and a flat surface portion, said flat surface portion extending between said wall portions to form a ceiling portion of said channel. A further possibility is that the or each channel is at least partially defined by a pair of side walls, said side walls being inclined relative to each other to meet an apex portion of said channel.

Conveniently, said side walls are substantially planar.

Conveniently, at least said second region is formed from a polymeric wicking material.

Advantageously, said first and second regions are both formed from said polymeric wicking material.

Optionally, said polymeric wicking material is porous.

Conveniently, said polymeric wicking material is configured such that pore diameter in said first region is greater than pore diameter in said second region.

Advantageously, said polymeric wicking material is heat resistant.

Optionally, said polymeric wicking material is a hydrophilic material that is configured to transfer fluid from said first region to said second region.

Conveniently, said polymeric wicking material is of greater hydrophilicity in said second region than said first region.

According to another aspect of the present disclosure, there may be provided an aerosol delivery system having an aerosol-generation apparatus as discussed above and a carrier, the carrier having a housing containing said heater and said fluid-transfer article.

Preferably, said housing has an inlet and an outlet. The air-flow pathway may then extend to said inlet and said outlet, said air-flow pathway passing said arcuate surface portion of said heating surface.

So that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:.

In general outline, one or more embodiments in accordance with the present disclosure may provide a system for aerosol delivery in which an aerosol carrier may be inserted into a receptacle (e.g. a "heating chamber") of an apparatus for initiating and maintaining release of an aerosol from the aerosol carrier. Another end, or another end portion, of the aerosol carrier may protrude from the apparatus and can be inserted into the mouth of a user for the inhalation of aerosol released from the aerosol carrier cartridge during operation of the apparatus.

Hereinafter, and for convenience only, "system for aerosol delivery" shall be referred to as "aerosol delivery system".

Referring now to <FIG>, there is illustrated a perspective view of an aerosol delivery system <NUM> comprising an aerosol generation apparatus <NUM> operative to initiate and maintain release of aerosol from a fluid-transfer article in an aerosol carrier <NUM>. In the arrangement of <FIG>, the aerosol carrier <NUM> is shown with a first end <NUM> thereof and a portion of the length of the aerosol carrier <NUM> located within a receptacle of the apparatus <NUM>. A remaining portion of the aerosol carrier <NUM> extends out of the receptacle. This remaining portion of the aerosol carrier <NUM>, terminating at a second end <NUM> of the aerosol carrier, is configured for insertion into a user's mouth. A vapour and/or aerosol is produced when a heater (not shown in <FIG>) of the apparatus <NUM> heats a fluid-transfer article in the aerosol carrier <NUM> to release a vapour and/or an aerosol, and this can be delivered to the user, when the user sucks or inhales, via a fluid passage in communication with an outlet of the aerosol carrier <NUM> from the fluid-transfer article to the second end <NUM>.

The device <NUM> also comprises air-intake apertures <NUM> in the housing of the apparatus <NUM> to provide a passage for air to be drawn into the interior of the apparatus <NUM> (when the user sucks or inhales) for delivery to the first end <NUM> of the aerosol carrier <NUM>, so that the air can be drawn across an activation surface of a fluid-transfer article located within a housing of the aerosol carrier cartridge <NUM> during use. Optionally, these apertures may be perforations in the housing of the apparatus <NUM>.

A fluid-transfer article (not shown in <FIG>, but described hereinafter with reference to <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <NUM>) is located within a housing of the aerosol carrier <NUM>. The fluid-transfer article contains an aerosol precursor material, which may include at least one of: nicotine; a nicotine precursor material; a nicotine compound; and one or more flavourings. The fluid-transfer article is located within the housing of the aerosol carrier <NUM> to allow air drawn into the aerosol carrier <NUM> at, or proximal, the first end <NUM> to flow across an activation surface of the fluid-transfer article. As air passes across the activation surface of the fluid-transfer article, an aerosol may be entrained in the air stream from a substrate forming the fluid-transfer article, e.g. via diffusion from the substrate to the air stream and/or via vaporisation of the aerosol precursor material and release from the fluid-transfer article under heating.

The substrate forming the fluid-transfer article <NUM> comprises a porous material where pores of the porous material hold, contain, carry, or bear the aerosol precursor material. In particular, the porous material of the fluid-transfer article may be a polymeric wicking material such as, for example, a sintered material. Particular examples of material suitable for the fluid-transfer article include: Polyetherimide (PEI); Polytetrafluoroethylene (PTFE); Polyether ether ketone (PEEK); Polyimide (PI); Polyethersulphone (PES); and Ultra-High Molecular Weight Polyethylene. Other suitable materials may comprise, for example, BioVyonTM (by Porvair Filtration Group Ltd) and materials available from Porex®. Further optionally, a substrate forming the fluid-transfer article may comprise Polypropylene (PP) or Polyethylene Terephthalate (PET). All such materials may be described as heat resistant polymeric wicking material in the context of the present technology.

The aerosol carrier <NUM> is removable from the apparatus <NUM> so that it may be disposed of when expired. After removal of a used aerosol carrier <NUM>, a replacement aerosol carrier <NUM> can be inserted into the apparatus <NUM> to replace the used aerosol carrier <NUM>.

<FIG> is a cross-sectional side view illustration of a part of apparatus <NUM> of the aerosol delivery system <NUM>. The apparatus <NUM> comprises a receptacle <NUM> in which is located a portion of the aerosol carrier <NUM>. In one or more optional arrangements, the receptacle <NUM> may enclose the aerosol carrier <NUM>. The apparatus <NUM> also comprise a heater <NUM>, which opposes an activation surface of the fluid-transfer article (not shown in <FIG>) of the aerosol carrier <NUM> when an aerosol carrier <NUM> is located within the receptacle <NUM>.

Air flows into the apparatus <NUM> (in particular, into a closed end of the receptacle <NUM>) via air-intake apertures <NUM>. From the closed end of the receptacle <NUM>, the air is drawn into the aerosol carrier <NUM> (under the action of the user inhaling or sucking on the second end <NUM>) and expelled at the second end <NUM>. As the air flows into the aerosol carrier <NUM>, it passes across the activation surface of the fluid-transfer article. Heat from the heater <NUM>, which opposes the activation surface of the fluid-transfer article, causes vaporisation of aerosol precursor material at the activation surface of the fluid-transfer article and an aerosol is created in the air flowing over the activation surface. Thus, through the application of heat in the region of the activation surface of the fluid-transfer article, an aerosol is released, or liberated, from the fluid-transfer article, and is drawn from the material of the aerosol carrier unit by the air flowing across the activation surface and is transported in the air flow to via outlet conduits (not shown in <FIG>) in the housing of the aerosol carrier <NUM> to the second end <NUM>. The direction of air flow is illustrated by arrows in <FIG>.

To achieve release of the captive aerosol from the fluid-transfer article, the fluid-transfer article of the aerosol carrier <NUM> is heated by the heater <NUM>. As a user sucks or inhales on second end <NUM> of the aerosol carrier <NUM>, the aerosol released from the fluid-transfer article and entrained in the air flowing across the activation surface of the fluid-transfer article is drawn through the outlet conduits (not shown) in the housing of the aerosol carrier <NUM> towards the second end <NUM> and onwards into the user's mouth.

Turning now to <FIG>, a cross-sectional side view of the aerosol delivery system <NUM> is schematically illustrated showing the features described above in relation to <FIG> and <FIG> in more detail. As can be seen, apparatus <NUM> comprises a housing <NUM>, in which are located the receptacle <NUM> and heater <NUM>. The housing <NUM> also contains control circuitry (not shown) operative by a user, or upon detection of air and/or vapour being drawn into the device <NUM> through air-intake apertures <NUM>, i.e. when the user sucks or inhales. Additionally, the housing <NUM> comprises an electrical energy supply <NUM>, for example a battery. Optionally, the battery comprises a rechargeable lithium ion battery. The housing <NUM> also comprises a coupling <NUM> for electrically (and optionally mechanically) coupling the electrical energy supply <NUM> to control circuitry (not shown) for powering and controlling operation of the heater <NUM>.

Responsive to activation of the control circuitry of apparatus <NUM>, the heater <NUM> heats the fluid-transfer article (not shown in <FIG>) of aerosol carrier <NUM>. This heating process initiates (and, through continued operation, maintains) release of vapour and/or an aerosol from the activation surface of the fluid-transfer article. The vapour and/or aerosol formed as a result of the heating process is entrained into a stream of air being drawn across the activation surface of the fluid-transfer article (as the user sucks or inhales). The stream of air with the entrained vapour and/or aerosol passes through the aerosol carrier <NUM> via outlet conduits (not shown) and exits the aerosol carrier <NUM> at second end <NUM> for delivery to the user. This process is briefly described above in relation to <FIG>, where arrows schematically denote the flow of the air stream into the device <NUM> and through the aerosol carrier <NUM>, and the flow of the air stream with the entrained vapour and/or aerosol through the aerosol carrier cartridge <NUM>.

<FIG> schematically illustrate the aerosol carrier <NUM> in more detail (and, in <FIG> and <FIG>, features within the receptacle in more detail). <FIG> illustrates an exterior of the aerosol carrier <NUM>, <FIG> illustrates internal components of the aerosol carrier <NUM> in an optional arrangement, and <FIG> illustrates internal components of the aerosol carrier <NUM> in another optional arrangement.

<FIG> illustrates the exterior of the aerosol carrier <NUM>, which comprises housing <NUM> for housing said fluid-transfer article (not shown) and at least one other internal component. The particular housing <NUM> illustrated in <FIG> comprises a tubular member, which may be generally cylindrical in form, and which is configured to be received within the receptacle of the apparatus. First end <NUM> of the aerosol carrier <NUM> is for location to oppose the heater of the apparatus, and second end <NUM> (and the region adjacent the second end <NUM>) is configured for insertion into a user's mouth.

<FIG> illustrates some internal components of the aerosol carrier <NUM> and of the heater <NUM> of apparatus <NUM>.

As described above, the aerosol carrier <NUM> comprises a fluid-transfer article <NUM>. The aerosol carrier <NUM> optionally may comprise a conduction element <NUM> (as shown in <FIG>) being part of the heater <NUM>. In one or more arrangements, the aerosol carrier <NUM> is located within the receptacle of the apparatus such that the activation surface of the fluid-transfer article opposes the heater of the apparatus and receives heat directly from the heater of the apparatus. In an optional arrangement, such as illustrated in <FIG> for example, the aerosol carrier <NUM> comprises a conduction element <NUM>. When aerosol carrier <NUM> is located within the receptacle of the apparatus such that an activation surface <NUM> of the fluid-transfer article <NUM> is located to oppose the heater <NUM> of the apparatus, the conduction element <NUM> is disposed between the rest of the heater <NUM> and the activation surface <NUM> of the fluid-transfer article <NUM>. Heat may be transferred to the activation surface via conduction through conduction element <NUM> (i.e. application of heat to the activation surface is indirect).

Further components not shown in <FIG> and <FIG> (see <FIG> and <FIG>) comprise: an inlet conduit, via which air can be drawn into the aerosol carrier <NUM>; an outlet conduit, via which an air stream entrained with aerosol can be drawn from the aerosol carrier <NUM>; a filter element; and a reservoir for storing aerosol precursor material and for providing the aerosol precursor material to the fluid-transfer article <NUM>.

In <FIG> and <FIG>, aerosol carrier is shown as comprising the fluid-transfer article <NUM> located within housing <NUM>. The material forming the fluid transfer article <NUM> comprises a porous structure, where pore diameter size varies between one end of the fluid-transfer article <NUM> and another end of the fluid-transfer article. In the illustrative examples of <FIG> and <FIG>, the pore diameter size gradually decreases from a first end remote from heater <NUM> (the upper end as shown in the figure) to a second end proximal heater <NUM> (the lower end as shown in the figure). Although the figure illustrates the pore diameter size changing in a step-wise manner from the first to the second end (i.e. a first region with pores having a diameter of a first size, a second region with pores having a diameter of a second, smaller size, and a third region with pores having a diameter of a third, yet smaller size), the change in pore size from the first end to the second end may be gradual rather than step-wise. This configuration of pores having a decreasing diameter size from the first end and second end can provide a wicking effect, which can serve to draw fluid from the first end to the second end of the fluid-transfer article <NUM>.

The fluid-transfer article <NUM> comprises a first region 34a for holding an aerosol precursor. In one or more arrangements, the first region 34a of the fluid-transfer article <NUM> comprises a reservoir for holding the aerosol precursor. The first region 34a can be the sole reservoir of the aerosol carrier <NUM>, or it can be arranged in fluid communication with a separate reservoir, where aerosol precursor is stored for supply to the first region 34a.

The fluid-transfer article <NUM> also comprises a second region 34b. Aerosol precursor is drawn from the first region 34a to the second region 34b by the wicking effect of the substrate material forming the fluid transfer article. Thus, the first region 34a is configured to transfer the aerosol precursor to the second region 34b of the article <NUM>.

At the second end of fluid-transfer article <NUM>, the surface of the second region 34b defines the activation surface <NUM>, which is disposed opposite a surface for conveying heat to the activation surface <NUM>. In the illustrative examples of <FIG> and <FIG>, the opposing surface for conveying heat to the activation surface <NUM> comprises a conduction element <NUM> which is a part of the heater <NUM>. The conduction element <NUM> is located for thermal interaction with the rest of the heater <NUM> and is arranged to transfer heat from the rest of the heater <NUM> to the activation surface <NUM>. As noted above, however, the conduction element <NUM> may be absent in some arrangements, in which case the activation surface <NUM> is disposed to receive heat directly from heater <NUM>.

The conduction element <NUM>, if present, may comprise a thin film of thermally conductive material, such as, for example, a metal foil (for example, aluminium, brass, copper, gold, steel, silver, or an alloy comprising anyone of the foregoing together with thermally conductive plastics and/or ceramics).

The surface of the conduction element <NUM> is discontinuous such that at least one channel <NUM> is formed between the activation surface <NUM> and the conduction element <NUM> (or the upper surface of the heater <NUM> is discontinuous in the case of arrangements in which the conduction element <NUM> is absent). In some arrangements, the discontinuities may be such that the surface of the conduction element <NUM> or heater <NUM> itself is undulating.

In the illustrative examples of <FIG> and <FIG>, the conduction element <NUM> has a plurality of grooves or valleys therein to form an undulating surface, the grooves or valleys being disposed in a parallel arrangement in the conduction element <NUM>. Since it is the surface of the conduction element <NUM> closest to the activation surface <NUM> which acts as the heating surface for the aerosol precursor, those grooves or valleys can be said to be in the heating surface. The grooves or valleys define a plurality of channels <NUM>, between the activation surface <NUM> and the conduction element <NUM>.

In the illustrative example of <FIG>, the grooves or valleys in the conduction element <NUM> provide alternating peaks and troughs that give rise to a "saw-tooth" type profile. In one or more optional arrangements, the surface of the conduction element <NUM> may comprise a "castellated" type profile (i.e. a "square wave" type profile), for example, such as illustrated in the example of <FIG>. In one or more optional arrangements, the surface of the conduction element <NUM> may comprise a "sinusoidal" type profile. The profile may comprise a mixture of two or more of the above profiles given as illustrative examples.

In the illustrative examples of <FIG> and <FIG>, the first region 34a of the fluid-transfer article <NUM> is located at an "upstream" end of the fluid-transfer article <NUM> and the second region 34b is located at a downstream" end of the fluid-transfer article <NUM>. That is, aerosol precursor is wicked, or is drawn, from the "upstream" end of the fluid-transfer article <NUM> to the "downstream" end of the fluid-transfer article <NUM> (as denoted by arrow A in <FIG>).

The aerosol precursor is configured to release an aerosol and/or vapour upon heating. Thus, when the activation surface <NUM> receives heat conveyed from heater <NUM>, the aerosol precursor held at the activation surface <NUM> is heated. The aerosol precursor, which is captively held in material of the fluid-transfer article at the activation surface <NUM> is released into an air stream flowing through the channels <NUM> between the conduction element <NUM> and activation surface <NUM> (or between the heater <NUM> and the activation surface <NUM>) as an aerosol and/or vapour.

The shape and/or configuration of the conduction element <NUM> (or the upper surface of the heater <NUM> if no conduction element is present) and the associated shape(s) and/or configuration(s) of the one or more channels <NUM> formed between the activation surface <NUM> and conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>) permit air to flow across the activation surface <NUM> (through the one or more channels <NUM>) and also increase the surface area of the activation surface <NUM> of the fluid-transfer article <NUM> that is available for contact with a flow of air across the activation surface <NUM>.

<FIG> and <FIG> show perspective view illustrations of the fluid-transfer article <NUM> of the aerosol carrier and a heater <NUM> of the apparatus of the system for aerosol delivery. In particular, these figures illustrate air flows across the activation surface <NUM> when the apparatus is in use in a first arrangement of the fluid-transfer article <NUM> (see <FIG>), and in a second arrangement of the fluid-transfer article <NUM> (see <FIG>).

In the illustrated example of use of the apparatus schematically illustrated in <FIG>, when a user sucks on a mouthpiece of the apparatus, air is drawn into the carrier through inlet apertures (not shown) provided in a housing of the carrier. An incoming air stream <NUM> is directed to the activation surface <NUM> of the fluid-transfer article <NUM> (e.g. via a fluid communication pathway within the housing of the carrier). When the incoming air stream <NUM> reaches a first side of the activation surface <NUM>, the incoming air stream <NUM> flows across the activation surface <NUM> via the one or more channels <NUM> formed between the activation surface <NUM> and the conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>). The air stream flowing through the one or more channels <NUM> is denoted by dashed line <NUM> in <FIG>. As the air stream <NUM> flows through the one or more channels <NUM>, aerosol precursor at activation surface <NUM>, across which the air stream <NUM> flows, is released from the activation surface <NUM> by heat conveyed to the activation surface from the heater <NUM>. Aerosol precursor released from the activation surface <NUM> in this manner is then entrained in the air stream <NUM> flowing through the one or more channels <NUM>.

In use, the heater <NUM> of the apparatus <NUM> conveys heat to the fluid transfer article <NUM> to raise the temperature of the activation surface <NUM> to a sufficient temperature to release, or liberate, captive substances (i.e. the aerosol precursor) held at the activation surface <NUM> of the fluid-transfer article <NUM> to form a vapour and/or aerosol, which is drawn downstream across the activation surface <NUM> of the fluid-transfer article. As the air stream <NUM> continues its passage in the one or more channels <NUM>, more released aerosol precursor is entrained within the air stream <NUM>. When the air stream <NUM> entrained with aerosol precursor exits the one or more channels <NUM> at a second side of the activation surface <NUM>, it is directed to an outlet, from where it can be inhaled by the user via a mouthpiece. An outgoing air stream <NUM> entrained with aerosol precursor is directed to the outlet (e.g. via a fluid communication pathway within the housing of the carrier).

Therefore, operation of the apparatus will cause heat from the heater <NUM> to be conveyed to the activation surface <NUM> of the fluid-transfer article. At a sufficiently high temperature, captive substances held at the activation surface <NUM> of the fluid-transfer article <NUM> are released, or liberated, to form a vapour and/or aerosol. Thus, when a user draws on a mouthpiece of the apparatus, the released substances from the fluid-transfer article are drawn away from the activation surface <NUM> (entrained in a stream of air) and condense to form an aerosol that is drawn through the a gas communication pathway for delivery to an outlet, which is in fluid communication with the mouthpiece.

As the aerosol precursor is released from the activation surface <NUM>, a wicking effect of the fluid-transfer article <NUM> causes aerosol precursor within the body of the fluid-transfer article to migrate to the activation surface <NUM> to replace the aerosol precursor released from the activation surface <NUM> into air stream <NUM>.

Operation of the heater <NUM> is controlled by control circuitry (not shown), which is operable to actuate the heater <NUM> responsive to an actuation signal from a switch operable by a user or configured to detect when the user draws air through a mouthpiece of the apparatus by sucking or inhaling. In an optional arrangement, the control circuitry operates to actuate the heater <NUM> with as little delay as possible from receipt of the actuation signal from the switch, or detection of the user drawing air through the mouthpiece. This may effect near instantaneous heating of the activation surface <NUM> of the fluid-transfer article <NUM>.

In the illustrated example of use of the apparatus schematically illustrated in <FIG>, rather than the case of <FIG> where air is drawn toward the activation surface <NUM> from one side only (and exits from the one or more channels <NUM> at an opposite side), a gas communication pathway for an incoming air stream is configured to deliver the incoming air stream to the activation surface <NUM> from both sides of the fluid-transfer article, and thus from both ends of the channels <NUM> formed therein. In such an arrangement, a gas communication pathway for an outlet airstream may be provided through the body of the fluid-transfer article <NUM>. An outlet fluid communication pathway for an outlet airstream in the illustrative example of <FIG> is denoted by reference number <NUM>.

Thus, in the illustrative example of <FIG>, when a user draws on a mouthpiece of the apparatus, air is drawn into the carrier <NUM> through inlet apertures (not shown) provided in a housing of the carrier. An incoming air stream 42a from a first side is directed to a first side of the activation surface <NUM> of the fluid-transfer article <NUM> (e.g. via a gas communication pathway within the housing of the carrier <NUM>). An incoming air stream 42b from a second side is directed to a second side of the activation surface <NUM> of the fluid-transfer article <NUM> (e.g. via a gas communication pathway within the housing of the carrier <NUM>). When the incoming air stream 42a from the first side reaches the first side of the activation surface <NUM>, the incoming air stream 42a flows across the activation surface <NUM> via the one or more channels <NUM> formed between the activation surface <NUM> and the conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>). Likewise, when the incoming air stream 42b from the second side reaches the second side of the activation surface <NUM>, the incoming air stream 42b flows across the activation surface <NUM> via the one or more channels <NUM> formed between the activation surface <NUM> and the conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>). The air streams 42a, 42b from each side flowing through the one or more channels <NUM> are denoted by dashed lines 44a and 44b in <FIG>.

As air streams 44a and 44b flow through the one or more channels <NUM>, aerosol precursor in the activation surface <NUM>, across which the air streams 44a and 44b flow, is released from the activation surface <NUM> by heat conveyed to the activation surface from the heater <NUM>. Aerosol precursor released from the activation surface <NUM> is entrained in air streams 44a and 44b flowing through the one or more channels <NUM>. In use, the heater <NUM> of the apparatus <NUM> conveys heat to the fluid-transfer article <NUM> to raise a temperature of the activation surface <NUM> to a sufficient temperature to release, or liberate, captive substances (i.e. the aerosol precursor) held at the activation surface <NUM> of the fluid-transfer article <NUM> to form a vapour and/or aerosol, which is drawn downstream across the activation surface <NUM> of the fluid-transfer article.

As the air streams 44a and 44b continue their passages in the one or more channels <NUM>, more released aerosol precursor is entrained within the air streams 44a and 44b. When the air streams 44a and 44b entrained with aerosol precursor meet at a mouth of the outlet fluid communication pathway <NUM>, they enter the outlet fluid communication pathway <NUM> and continue until they exit outlet fluid communication pathway <NUM>, either as a single outgoing air stream <NUM> (as shown), or as separate outgoing air streams. The outgoing air stream <NUM> is directed to an outlet, from where it can be inhaled by the user via a mouthpiece. The outgoing air stream <NUM> entrained with aerosol precursor is directed to the outlet (e.g. via a gas communication pathway within the housing of the carrier <NUM>).

<FIG> and <FIG> illustrate an aerosol carrier <NUM> according to one or more possible arrangements in more detail. <FIG> is a cross-section side view illustration of the aerosol carrier <NUM> and <FIG> is a perspective cross-section side view illustration of the aerosol carrier <NUM> of <FIG>.

As can be seen from <FIG> and <FIG>, the aerosol carrier <NUM> is generally tubular in form. The aerosol carrier <NUM> comprises housing <NUM>, which defines the external walls of the aerosol carrier <NUM> and which defines therein a chamber in which are disposed the fluid-transfer article <NUM> (adjacent the first end <NUM> of the aerosol carrier <NUM>) and internal walls defining the fluid communication pathway <NUM>. Fluid communication pathway <NUM> defines a fluid pathway for an outgoing air stream from the channels <NUM> to the second end <NUM> of the aerosol carrier <NUM>. In the examples illustrated in <FIG> and <FIG>, the fluid-transfer article <NUM> is an annular shaped element located around the fluid communication pathway <NUM>. Note that, in <FIG> and <FIG>, the channels <NUM> in the conduction element <NUM> extend radially and the sectional views of <FIG> and <FIG> are along the length of two channels on opposite radial positions relative to the fluid communication pathway <NUM> in the fluid-transfer article.

In walls of the housing <NUM>, there are provided inlet apertures <NUM> to provide a fluid communication pathway for an incoming air stream to reach the fluid-transfer article <NUM>, and particularly the one or more channels <NUM> defined between the activation surface of the fluid-transfer article <NUM> and the conduction element <NUM> (or between the activation surface and the <NUM> heater).

In the illustrated example of <FIG> and <FIG>, the aerosol carrier <NUM> further comprises a filter element <NUM>. The filter element <NUM> is located across the fluid communication pathway <NUM> such that an outgoing air stream passing through the fluid communication pathway <NUM> passes through the filter element <NUM>.

With reference to <FIG>, when a user sucks on a mouthpiece of the apparatus (or on the second end <NUM> of the aerosol carrier <NUM>, if configured as a mouthpiece), air is drawn into the carrier through inlet apertures <NUM> extending through walls in the housing <NUM> of the aerosol carrier <NUM>. An incoming air stream 42a from a first side of the aerosol carrier <NUM> is directed to a first side of the activation surface <NUM> of the fluid-transfer article <NUM> (e.g. via a gas communication pathway within the housing of the carrier). An incoming air stream 42b from a second side of the aerosol carrier <NUM> is directed to a second side of the activation surface <NUM> of the fluid-transfer article <NUM> (e.g. via a gas communication pathway within the housing of the carrier). When the incoming air stream 42a from the first side of the aerosol carrier <NUM> reaches the first side of the activation surface <NUM>, the incoming air stream 42a from the first side of the aerosol carrier <NUM> flows across the activation surface <NUM> via the one or more channels <NUM> formed between the activation surface <NUM> and the conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>). Likewise, when the incoming air stream 42b from the second side of the aerosol carrier <NUM> reaches the second side of the activation surface <NUM>, the incoming air stream 42b from the second side of the aerosol carrier <NUM> flows across the activation surface <NUM> via the one or more channels <NUM> formed between the activation surface <NUM> and the conduction element <NUM> (or between the activation surface <NUM> and heater <NUM>). The air streams from each side flowing through the one or more channels <NUM> are denoted by dashed lines 44a and 44b in Figure <NUM>. As air streams 44a and 44b flow through the one or more channels <NUM>, aerosol precursor in the activation surface <NUM>, across which the air streams 44a and 44b flow, is released from the activation surface <NUM> by heat conveyed to the activation surface from the heater <NUM>. Aerosol precursor released from the activation surface <NUM> is entrained in air streams 44a and 44b flowing through the one or more channels <NUM>.

In use, the heater <NUM> of the apparatus <NUM> conveys heat to the activation surface <NUM> of the fluid-transfer article <NUM> to raise a temperature of the activation surface <NUM> to a sufficient temperature to release, or liberate, captive substances (i.e. the aerosol precursor) held at the activation surface <NUM> of the fluid-transfer article <NUM> to form a vapour and/or aerosol, which is drawn downstream across the activation surface <NUM> of the fluid-transfer article <NUM>.

As the air streams 44a and 44b continue their passages in the one or more channels <NUM>, more released aerosol precursor is entrained within the air streams 44a and 44b. When the air streams 44a and 44b entrained with aerosol precursor meet at a mouth of the outlet fluid communication pathway <NUM>, they enter the outlet fluid communication pathway <NUM> and continue until they pass through filter element <NUM> and exit outlet fluid communication pathway <NUM>, either as a single outgoing air stream, or as separate outgoing air streams <NUM> (as shown). The outgoing air streams <NUM> are directed to an outlet, from where it can be inhaled by the user directly (if the second end <NUM> of the aerosol capsule <NUM> is configured as a mouthpiece), or via a mouthpiece. The outgoing air streams <NUM> entrained with aerosol precursor are directed to the outlet (e.g. via a gas communication pathway within the housing of the carrier).

When the user initially draws on a mouthpiece of the apparatus (or one the second end <NUM> of the aerosol carrier <NUM>, if configured as a mouthpiece), this will cause an air column located in the fluid communication pathway <NUM> to move towards the outlet. In tum, this will draw air into the fluid communication pathway from the one or more channels <NUM>. This will cause a pressure drop in the channels <NUM>. To equalise the pressure in the channels <NUM>, air will be drawn into the aerosol carrier <NUM>, and thus into the channels <NUM> via the inlet apertures <NUM>. During the period of lower pressure in the one or more channels <NUM> when the user begins to draw, aerosol precursor in the fluid-transfer medium will be released into the channels from the activation surface <NUM>, because the aerosol precursor is drawn into the one or more channels by way of the lower pressure. This effect is in addition to the effect of releasing the aerosol precursor from the activation surface <NUM> by way of heat conveyed from the heater. The drawing of the aerosol precursor from the activation surface <NUM> by way of the user sucking on the mouthpiece of the apparatus (or one the second end <NUM> of the aerosol carrier <NUM>, if configured as a mouthpiece) may produce a dragging effect on the volumetric rate of flow experienced by the user during a suction action, i.e. the user may have to suck harder to achieve a same volumetric rate of flow. This effect may manifest itself as a similar physical sensation experienced by the user as those experienced from a traditional smoking or tobacco product.

<FIG> is an exploded perspective view illustration of a kit-of-parts for assembling an aerosol delivery system <NUM>.

As will be appreciated, in the arrangements described above, the fluid-transfer article <NUM> is provided within a housing <NUM> of the aerosol carrier <NUM>. In such arrangements, the housing of the carrier <NUM> serves to protect the aerosol precursor-containing fluid-transfer article <NUM>, whilst also allowing the carrier <NUM> to be handled by a user without his/her fingers coming into contact with the aerosol precursor liquid retained therein. In such arrangements, it will be appreciated that the carrier <NUM> has a multi-part construction. The second region 34b of the fluid-transfer article may have a thickness of less than <NUM>. In other embodiments it may have a thickness of: less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM>.

There has been described in the foregoing one or more proposals for an aerosol delivery system, and parts thereof, that avoids or at least ameliorates problems of the prior art.

Claim 1:
An aerosol-generation apparatus (<NUM>) comprising a heater (<NUM>) and a fluid-transfer article (<NUM>), the fluid-transfer article (<NUM>) having a first region (34a) for holding an aerosol precursor and for transferring said aerosol precursor to an activation surface (<NUM>) of a second region (34b) of said article (<NUM>), said activation surface (<NUM>) configured for thermal interaction with a heating surface of said heater (<NUM>); characterised in that said heating surface includes at least one discontinuity therein forming a corresponding at least one channel (<NUM>), the or each said channel being configured for providing a fluid-flow pathway across said activation surface, said heating surface being configured such that, when the fluid transfer article (<NUM>) is arranged with respect to said heating surface for thermal interaction therebetween, the or each said channel (<NUM>) opposes said activation surface (<NUM>) and opens towards said activation surface (<NUM>).