Aerosol-generating device and heater assembly

Abstract

An aerosol-generating device (500) for coupling to a cartridge, the aerosol-generating device5 (500) comprising a cartridge coupling portion for engaging a cartridge containing an aerosol- forming substrate. The aerosol-generating device (500) further comprising an air flow passage defined between an air inlet (510) and an air outlet (520); and a heater assembly. The heater assembly comprising a fluid permeable heating element (540) configured to heat an aerosol- forming substrate from the cartridge. The heater assembly comprising a first side and a second side, the first side opposing a second side, wherein the first side forms at least part of a surface of a wall of the air flow passage and wherein the second side forms part of the cartridge coupling portion and is configured to contact the cartridge to receive the aerosol-forming substrate.

Description

[0001] The present disclosure relates to an aerosol-generating device for coupling to a cartridge; a heater assembly for an aerosol-generating device; a cartridge; and an aerosol-generating system. The present invention relates to an aerosol-generating device for coupling to a cartridge, to a heater assembly for an aerosol-generating device and to an aerosol-generating system.

[0002] Aerosol-generating systems configured to generate inhalable aerosol from an aerosol-forming substrate are known in the art. Many prior aerosol-generating systems comprise an aerosol generating-device that is couplable to a cartridge. A typical cartridge for use with an aerosol-generating device comprises an aerosol-forming substrate and a heater assembly, where the heater assembly comprises a heating element. The cartridge may further comprise a wicking material adjacent to or in contact with the aerosol-forming substrate and the heating element. The wicking material is configured to transport aerosol-forming substrate to the heating element. In use, the heating element is configured to vaporise the aerosol-forming substrate. An airflow is provided past the heating element to entrain the generated vapour. In the airflow the vapour is condensed and an aerosol is formed. The aerosol may then be inhaled by a user. The cartridge is removably couplable to the aerosol-generating device. The aerosol-generating device typically comprises a power supply that is configured to supply power to the heating element, via electrical connectors.

[0003] In aerosol-generating systems of this type, it is desirable to minimise the amount of power required to heat the aerosol-forming substrate. This is particularly desirable in portable aerosol-generating systems where the system comprises a portable power supply such as a battery. To minimise power usage and efficiently heat the aerosol-forming substrate the heating element may be in direct contact with the wicking material and therefore the aerosol-forming substrate.

[0004] Repeated use of the aerosol-generating system, over many heating cycles, requires repeated heating of the wicking material. This may lead to degradation of the wicking material over a period of time. Degradation can be caused by heating of the wicking material. Degradation can also be caused by chemical interactions between the aerosol-forming substrate and the wicking material, mechanical stress on the wicking material and particle accumulations on the surface of the wicking element. The degradation of the wicking material may lead undesirable effects such as less efficient heat transfer between the heating element and the wicking material, less efficient transfer of aerosol-forming substrate from the wicking material to the heating element, or the generation of aerosols comprising unfavourable components. In addition, during use of an aerosol-generating system, hotspots may occur in the heating element. Hotspots are regions of the heating element that have a temperature higher than the average temperature of the heating element, during operation. These hotspots may lead to degradation of the wicking material.

[0005] As a result of degradation, the wicking material limits the lifetime of any cartridge.

[0006] US 2022 / 071289 A1 describes a smoking substitute system comprising a smoking substitute device and a consumable. The consumable includes a wick and a wick support element. A heater is configured to heat the wick. The heater is supported in the smoking substituted device. In an embodiment, the heater is mounted on a heater support element. The heater support element may have passages that open immediately adjacent to the heater and adjacent to an activation surface of the wick. The passages pass through the heater support element to enable air to pass towards the heater and the wick.

[0007] US 2014 / 109921 A1 describes an electronic cigarette that includes a cartridge and an atomizer assembly. The atomizer assembly comprises a heating element. The heating element includes a linear wick and a heating wire twined around the middle part of the wick. A power supply assembly is electrically connected to the heating wire to supply power to the heating wire. The power assembly includes an electrode slice and an electrode holder. The electrode slice and electrode holder are the positive and negative electrodes of the power supply, respectively. The electrical leads on the two ends of the heating wire are connected to the electrode slide and the electrode holder.

[0008] WO 2020 / 259961 A1 describes a vapour-generating system. The vapour-generating system can include a reservoir holding an aerosol-generating substrate, and a heating assembly. The heating assembly can include a heating element and a ceramic element. The ceramic element can include pores. In an embodiment, the ceramic element comprising pores abuts a heating element comprising a heating track and impermeable ceramic closure.

[0009] It would be desirable to provide an aerosol-generating system, and an aerosol-generating device for such a system, which requires less frequent disposal of the heater assembly.

[0010] According to a first aspect of the present disclosure, there is provided an aerosol-generating device for coupling to a cartridge. The aerosol-generating device comprises a cartridge coupling portion for engaging a cartridge containing an aerosol-forming substrate. The aerosol-generating device comprises an air flow passage defined between an air inlet and an air outlet. The aerosol-generating device further comprises a heater assembly, the heater assembly comprising a fluid permeable heating element configured to heat an aerosol-forming substrate from the cartridge, wherein the heater assembly comprises a first side and a second side, the first side opposing a second side, wherein the first side forms at least part of a surface of a wall of the air flow passage and wherein the second side forms part of the cartridge coupling portion and is configured to contact the cartridge to receive the aerosol-forming substrate.

[0011] The heater assembly may be arranged within the device to couple with a cartridge. The aerosol-generating device may be reusable. The cartridge may be disposable. Advantageously, when the cartridge needs to be disposed of, the cartridge may be uncoupled from the device, disposed of, and replaced. The heater assembly may be retained in the device, instead of being removed and disposed of. Therefore, the heater assembly may be reused. The heater assembly may be more costly to manufacture in comparison to elements of a cartridge, so it is advantageous to prevent unnecessary disposal of the heater assembly.

[0012] The air inlet may be defined in a side wall of the device. The air outlet may be defined in an end wall of the device. The side wall of the device may extend perpendicular to the end wall of the device. The configuration of the air inlet and air outlet may allow air to flow past the heater assembly and therefore entrain vapourised aerosol-forming substrate. The air outlet may be configured to align with an opening in the cartridge. Entrained vapourised aerosol-forming substrate may aerosolise in the in the air flow and pass through the air outlet into the cartridge.

[0013] The second side of the heater assembly may be situated outside of the airflow passage. The second side of the heater assembly may be configured so that at least a portion of the second side is contact with a wicking material of the cartridge.

[0014] The heating assembly may be a planar heater assembly. The heating element may be a planar heating element. The heating element may be perpendicular to a longitudinal axis of device.

[0015] The heating element may comprise at least one filament. The heating element may comprise a plurality of electrically conductive filaments. The term "filament" as used herein refers to an electrical path arranged between two electrical contacts. The at least one filament may have a round, square, flat or any other form of cross-section. The heating element may be an array of filaments, for example arranged parallel to each other. Preferably, the filaments may form a mesh.

[0016] The heating element may be a mesh heating element. The heating element may comprise a mesh. The heating element may allow vapour to flow from the second side of the heater assembly to the first side of the heater assembly. The heating element may not allow liquid to flow from the second side of the heating element to the first side of the heating element.

[0017] The electrically conductive filaments may define interstices between the filaments and the interstices may have a width of between 10 micrometres and 100 micrometres. Preferably, the filaments give rise to capillary action in the interstices, so that in use, liquid to be vaporized is drawn into the interstices, increasing the contact area between the heating element and the aerosol-forming substrate.

[0018] The electrically conductive filaments may form a mesh of size between 60 and 240 filaments per centimetre (+ / - 10 percent). Preferably, the mesh density is between 100 and 140 filaments per centimetres (+ / - 10 percent). More preferably, the mesh density is approximately 115 filaments per centimetre. The width of the interstices may be between 100 micrometres and 25 micrometres, preferably between 80 micrometres and 70 micrometres, more preferably approximately 74 micrometres. The percentage of open area of the mesh, which is the ratio of the area of the interstices to the total area of the mesh may be between 40 percent and 90 percent, preferably between 85 percent and 80 percent, more preferably approximately 82 percent. The electrically conductive filaments may have a diameter of between 8 micrometres and 100 micrometres, preferably between 10 micrometres and 50 micrometres, more preferably between 12 micrometres and 25 micrometres, and most preferably approximately 16 micrometres.

[0019] The area of the mesh of electrically conductive filaments may be small, for example less than or equal to 50 square millimetres, preferably less than or equal to 25 square millimetres, more preferably approximately 15 square millimetres. The size is chosen such to incorporate the heating element into a handheld system. Sizing of the mesh, array or fabric of electrically conductive filaments less or equal than 50 square millimetres reduces the amount of total power required to heat the mesh of electrically conductive filaments while still ensuring sufficient contact of the mesh of electrically conductive filaments to the aerosol-forming substrate. The mesh of electrically conductive filaments may, for example, be rectangular and have a length between 2 millimetres to 10 millimetres and a width between 2 millimetres and 10 millimetres. Preferably, the mesh has dimensions of approximately 5 millimetres by 3 millimetres.

[0020] The heating element may comprise a porous material. Advantageously, a mesh heating element, a heating element comprising a mesh, or a heating element comprising a porous material may provide a large surface area in contact with the liquid aerosol-forming substrate. This large surface area may provide efficient vaporisation of the liquid aerosol-forming substrate.

[0021] Preferably, the heating element comprises a single filament. A heating element comprising a single filament may also be referred to as a heating wire. The single filament may have a diameter of 0.1 millimetres to 0.5 millimetres. The single filament may have a diameter of 0.02 millimetres to 0.2 millimetres.

[0022] The heating element, or portions thereof, may comprise an electrically resistive material. The heating element may be configured to be resistively heated. In other words, the heating element may be configured to generate heat when an electrical current is passed though the heating element. The heating element, or portions thereof, may comprise or be formed from any material with suitable electrical and mechanical properties, for example a suitable, electrically resistive material. Suitable materials may include but are not limited to: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable metal alloys include Constantan, nickel-, cobalt-, chromium-, aluminium-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, Timetal ®< , iron-aluminium based alloys and iron manganese-aluminium based alloys. Timetal ®< is a registered trade mark of Titanium Metals Corporation, 1999 Broadway Suite 4300, Denver Colorado. In composite materials, the electrically resistive material may optionally be embedded in, encapsulated or coated with an insulating material or vice-versa, depending on the kinetics of energy transfer and the external physicochemical properties required. The heating element, or portions thereof, may comprise a metallic etched foil insulated between two layers of an inert material. In that case, the inert material may comprise Kapton ®< , all-polyimide or mica foil. Kapton ®< is a registered trade mark of E.I. du Pont de Nemours and Company, 1007 Market Street, Wilmington, Delaware 19898, United States of America.

[0023] Preferably, the heating element comprises stainless steel. Stainless steel may provide a heating element with desirable mechanical properties, corrosion resistance and high electrical resistance.

[0024] The heating element may comprise a ferrimagnetic material. The heating element may comprise a ferromagnetic material. The heating element may be formed of a ferrimagnetic or ferromagnetic material. At least a portion of the heating element may be formed of a ferrimagnetic or ferromagnetic material. The electrical resistance of the heating element may increase as the frequency of an alternating current applied to the heating element is increased. The use of a heating element comprising ferrimagnetic or ferromagnetic material may advantageously increase the electrical resistance of the heating element, and therefore locally generating more heat, without the need to reduce the diameter of the heating element. Reducing the diameter may compromise the mechanical strength of the heating element.

[0025] The electrical resistance of the heating element may be between 0.1 Ohms and 5 Ohms. Preferably the electrical resistance of the heating element may be between 0.4 Ohms to 2 Ohms.

[0026] The heating element may be coated with a corrosion resistant material. A corrosion resistant coating may increase the life span of the heating element. The heating element may be coated with a ceramic material.

[0027] The heater assembly may be configured to contact a wicking portion of the cartridge. The heating element may be configured to contact a wicking portion of the cartridge.

[0028] The heater assembly comprises a support element. The support element provides mechanical support to the heating element. The support element may laterally support the heating element. The support element comprises a thermal conduction material in thermal contact with the heating element. The support element may be configured to absorb heat produced by the heating element. Advantageously, the presence of a support element comprising a thermal conduction material may reduce the temperature of the heating element in regions where the heating element is not in contact with a wicking material or aerosol-forming substrate. This may reduce overheating of the heating element, preferably prolonging the life of the heating element. In addition, this may reduce or slow down degradation of a wicking material in contact with the heating element.

[0029] The support element may comprise at least one of aluminium, copper, brass, gold, silver or thermally conductive ceramic. Advantageously these materials are highly thermally conductive.

[0030] The thermal conductivity of the support element may be at least 10 W / mK. The thermal conductivity of the support element may be at least 50 W / mK. The thermal conductivity of the support element may be at least 200 W / mK.

[0031] The support element may comprise at least one supporting pin. The support element may comprise at least 4, at least 6, at least 8, at least 10 or at least 12 supporting pins. The heating element may be engaged with the at least one supporting pin. The heating element may be figured to be wound or wrapped around the at least one supporting pin. The heating element may be a heating wire wherein the heating wire passes around each of the supporting pins.

[0032] The at least one supporting pin may be cylindrical. The cross-section of the at least one supporting pin may have a diameter of 0.5 millimetres to 5 millimetres, preferably 1 millimetres to 2 millimetres.

[0033] The heater assembly may further comprise a heater holder. The heater holder may provide mechanical support to the support element. The heater holder may comprise an upper plate and a lower plate. The heating element may be situated between the upper plate and the lower plate. Advantageously, a heater holder comprising an upper plate and a lower plate with a heating element situated therebetween may be straightforward to manufacture.

[0034] The heater holder may have an aperture defined therethrough. The aperture may be defined through the upper plate and the lower plate. The heating element may span at least part of the aperture. The aperture may be configured to allow aerosol-forming substrate to flow between the second side of the heater assembly and the first side of the heater assembly. The aperture may be configured to allow gases, such as air and vapour generated from the aerosol-forming substrate, to flow between the second side of the heater assembly and the first side of the heater assembly.

[0035] The aerosol-generating device may further comprise a first electrical connector and a second electrical connector. The first and second electrical connectors may be configured to supply power to the heating element. The electrical connectors may be situated in electrical contact with the heating element. The first electrical connector may comprise a first contact pad and the second electrical connector may comprise a second electrical contact pad, wherein the first and second electrical contact pads are configured to be in electrical contact with the heating element. The electrical connectors may extend outside of the heater assembly to allow for the provision of electrical energy to the electrical connectors and thus the heating element, from a power supply. In operation, the heating element may be heated as a result of electrical current passing through the heating element. The first electrical connector and the second electrical connect may be positioned on opposite sides of the heating element. An electrical current passing from the first electrical connector to the second electrical connector may pass through the heating element.

[0036] The support element may be situated adjacent to the aperture. The support element may be situated as close as possible to the aperture. The distance between the support element and the aperture may be less than 2mm, preferably less than 1 mm. Advantageously, this may minimise the total length of the heating element. The length of the heating element that is not spanning the aperture may also be reduced. The percentage of the heating element that is spanning the aperture may be increased. Increasing the percentage of the heating element that is spanning the aperture may increase the percentage of the second side of the heating element that is configured to contact the cartridge to receive the aerosol-forming substrate. Advantageously, less material may be needed to manufacture the heating element while not reducing performance of the heating element. The electrical connectors may be in electrical contact with the heating element at distance further from the aperture than the distance of the support element from the aperture. The first electrical connector may be in electrical contact with a first end of the heating element. The second electrical connector may be in contact with a second end of the heating element. The electrical connectors may be connected with the heating element in series. Preferably, the heating element may have a diameter of 0.1 millimetres to 0.5 millimetres.

[0037] The first and second electrical connectors may be situated adjacent to the aperture. The support element may be in contact with the heating element at a distance further from the aperture than the distance of the first and second electrical connectors from the aperture. The first and second electrical connectors may be situated as close as possible to the aperture. The distance between first electrical connector and the aperture may be less than 2 millimetres, preferably less than 1 millimetre. The distance between second electrical connector and the aperture may be less than 2 millimetres, preferably less than 1 millimetres. In this configuration, the length of the heating element between the first electrical connector and the second electrical connector is shorter than in the previous configuration. As a result, a small diameter of the heating element is selected. The first and second electrical connectors, preferably the first and second electrical contact pads, may be configured to absorb some of the heat produced by the heating element in operation. Advantageously, this may reduce the temperature of a portion of the heating element that is not in contact with, or configured to be in contact with, aerosol-forming substrate. The first and second electrical connectors, preferably the first and second electrical contact pads, may be in contact with the heating element at more than two positions on the heating element. The first and second electrical connectors, preferably the first and second electrical contact pads, may be connected with the heating element in parallel. Preferably, the heating element may have a diameter of 0.02 millimetres to 0.2 millimetres.

[0038] The cross-sectional area of the aperture may be from 4 square millimetres to 1000 square millimetres. Preferably, the cross-sectional area of the aperture may be from 9 square millimetres to 400 square millimetres. Most preferably, the cross-sectional area of the aperture may be from 16 square millimetres to 100 square millimetres. Any shape may be selected for the cross-section of the aperture. Preferably, the cross-section of the aperture may be circular, square, or rectangular. Advantageously, these cross-sectional shapes for the aperture may be simple to manufacture.

[0039] The heater holder may be electrically insulating. The heater holder may have a thermal conductivity of 1 W / mk or less. The heater holder may comprise a heat resistant polymer. The heater holder may comprise polyether ether ketone (PEEK). The heater holder may comprise liquid crystal polymer (LCP). The heater holder may comprise a ceramic. The heater holder may comprise alumina. The heater holder may comprise zirconia. Advantageously, these materials are able to withstand high temperatures.

[0040] The heating element may be, or may comprise, a susceptor material. The susceptor material may be configured to be inductively heated. In operation, the susceptor material may be heated by eddy currents induced in the susceptor material. Hysteresis losses may also contribute to the inductive heating.

[0041] The device may comprise no wicking element. After repeated heating of an aerosol-forming substrate in an aerosol-generating system, wicking elements may degrade more quickly compared to other components such as the heating element. The degraded wicking material may need replacing before other components of the system such as the heater assembly. Therefore, the device not having a wicking element may increase the lifetime of the device.

[0042] The heater assembly may comprise a compressible element. The compressible element may be configured to be compressed by the cartridge when the cartridge is received by the aerosol-generating device.

[0043] The compressible element may be a spring. The spring may be situated adjacent to or in contact with the lower plate of the heater holder. The compressible element may allow the heater assembly to move along a longitudinal axis of the device. In use, when a cartridge is attached to the device, the cartridge may provide a force to the heater assembly which moves the heater assembly. When the cartridge is coupled to the device, the spring may compress. When the cartridge is uncoupled from the device, the spring may expand. The spring may be positioned to act against the force provided by insertion of the cartridge. Advantageously, a close fit between the cartridge and the heater assembly may be achieved, reducing the likelihood of leakage of aerosol-forming substrate. A close fit may provide more efficient heating of the aerosol-forming substrate.

[0044] The aerosol-generating device may further comprise a power supply. The power supply may be a DC power supply. The power supply may be a battery. The battery may be a Lithium based battery, for example a Lithium-Cobalt, a Lithium-Iron- Phosphate, a Lithium Titanate or a Lithium-Polymer battery. The battery may be a Nickel metal hydride battery or a Nickel cadmium battery. The power supply may be another form of charge storage device such as a capacitor. The power supply may be configured to supply power to the heating element. This may heat the heating element.

[0045] The power supply may be configured to supply an alternating current. The power supply may comprise a direct current to alternating current (DC / AC) inverter for converting a DC current supplied by the DC power supply to an alternating current.

[0046] The power supply may be configured to supply power to the heating element to resistively heat the heating element. The power supply may be configured to supply power to the heating element to inductively heat the heating element.

[0047] The power supply may be electrically connected to the first and second electrical connectors. The power supply may be configured to supply power to the heating element via the electrical connectors. The power supply may be configured to supply power to the heating element by passing an electrical current through the heating element.

[0048] The aerosol-generating device may further comprise a control circuitry. The control circuitry may comprise a controller. The controller may be a microprocessor, which may be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC) or other electronic control circuitry. The controller may be configured to control supply of power from the power supply. The controller may be configured to regulate the supply of power from the power supply to the heater assembly. Thus, the controller may control heating of the heating element.

[0049] The heating element may be airflow actuated. The heating element may be puff actuated. The aerosol-generating device may comprise a puff detector. The puff detector may be in communication with the control circuitry. The puff detector may be configured to detect when there is an airflow through the air flow passage. The control circuitry may be configured to activate the heating element when an airflow is detected.

[0050] The aerosol-generating device may be a handheld aerosol-generating device.

[0051] It would be desirable to provide a heater assembly where the likelihood of hotspots occurring is reduced in comparison to prior art systems.

[0052] According to a second aspect of the present disclosure, there is provided a heater assembly for an aerosol-generating device, the heater assembly comprises a heater holder comprising an aperture, a heating element spanning at least part of the aperture, first and second electrical connectors in electrical contact with the heating element, and a support element comprising a thermal conduction material in thermal contact with the heating element. The heater assembly of the second aspect may comprise any of the features of the heater assembly described in relation to the first aspect of the disclosure. In addition, any of the features of the heater assembly of the second aspect may be equally applied to the heater assembly of the first aspect.

[0053] Advantageously, a support element comprising a thermal conduction material will conduct heat away from hotspots of the heating element. Thus, leading to a more uniform temperature along the heating element. This may reduce degradation of a wicking material that is adjacent to or in contact with the heating element during use of the heater assembly.

[0054] The heating assembly may be a planar heater assembly. The heating element may be a planar heating element. The heating element may be a mesh heating element. The heating element may comprise a mesh. The heating element may comprise a porous material. Advantageously, a mesh heating element, a heating element comprising a mesh, or a heating element comprising a porous material may provide a large surface area in contact with the liquid aerosol-forming substrate. This large surface area may provide efficient vaporisation of the liquid aerosol-forming substrate.

[0055] The heating element may comprise at least one filament. The heating element may comprise a plurality of electrically conductive filaments. The term "filament" as used herein refers to an electrical path arranged between two electrical contacts. The at least one filament may have a round, square, flat or any other form of cross-section. Preferably the heating element comprises a single filament. A heating element comprising a single filament may also be referred to as a heating wire. The heating element may have a diameter of 0.1 millimetres to 0.5 millimetres. The heating element may have a diameter of 0.02 millimetres to 0.2 millimetres.

[0056] The heating element, or portions thereof, may comprise an electrically resistive material. The heating element may be configured to be resistively heated. The heating element, or portions thereof, may comprise or be formed from any material with suitable electrical and mechanical properties, for example a suitable, electrically resistive material.

[0057] The heating element may comprise stainless steel. Stainless steel may provide a heating element with desirable mechanical properties, corrosion resistance and high electrical resistance.

[0058] The heating element may comprise a ferrimagnetic material. The heating element may comprise a ferromagnetic material. The heating element may be formed of a ferrimagnetic or ferromagnetic material. At least a portion of the heating element may be formed of a ferrimagnetic or ferromagnetic material. The electrical resistance of the heating element may increase as the frequency of an alternating current applied to the heating element is increased. The use of a heating element comprising ferrimagnetic or ferromagnetic material may advantageously increase the electrical resistance of the heating element, and therefore locally generating more heat, without the need to reduce the diameter of the heating element. Reducing the diameter may compromise the mechanical strength of the heating element.

[0059] The total electrical resistance of the heating element may be from 0.1 Ohms to 5 Ohms, preferably from 0.4 Ohms to 2 Ohms. Advantageously, electrical resistance within this range allows the heating element to reach temperatures suitable for vaporisation of an aerosol-forming substrate.

[0060] The heating element may be coated with a corrosion resistant material. A corrosion resistant coating may increase the life span of the heating element. The heating element may be coated with a ceramic material.

[0061] The support element may be configured to absorb heat produced by the heating element. The support element provides mechanical support to the heating element. The support element may laterally support the heating element. The support element comprises a thermal conduction material in thermal contact with the heating element. The support element may be configured to absorb heat produced by the heating element. Advantageously, the presence of a support element comprising a thermal conduction material may reduce the temperature of the heating element in regions where the heating element is not in contact with a wicking material or aerosol-forming substrate. This may reduce overheating of the heating element, preferably prolonging the life of the heating element. In addition, this may reduce or slow down degradation of a wicking material in contact with the heating element. Advantageously, the support element will conduct heat away from hotspots of the heating element, leading to a more uniform temperature along the heating element. This may reduce degradation of a wicking material that is adjacent to or in contact with the heating element during use of the heater assembly.

[0062] The support element may comprise at least one of aluminium, copper, brass, gold, silver or thermally conductive ceramic. Advantageously these materials are highly thermally conductive.

[0063] The thermal conductivity of the support element may be at least 10 W / mK. Preferably, the thermal conductivity of the support element may be at least 50 W / mK. Preferably, the thermal conductivity of the support element may be at least 200 W / mK.

[0064] The support element may comprise at least one supporting pin. The heating element may be engaged with at the least one supporting pin. The support element may comprise at least 4, at least 6, at least 8, at least 10 or at least 12 supporting pins. The heating element may be engaged with the at least one supporting pin. The heating element may be figured to be wound or wrapped around the at least one supporting pin. The heating element may be a single filament wherein the filament passes around each of the supporting pins.

[0065] The at least one supporting pin may be cylindrical. The at least one supporting pin may have a diameter of 0.5 millimetres to 5 millimetres, preferably 1 millimetres to 2 millimetres.

[0066] The heater holder may provide mechanical support to the support element. The heater holder may comprise an upper plate and a lower plate. The heating element may be situated between the upper plate and the lower plate. Advantageously, a heater holder comprising an upper plate and a lower plate with a heating element situated therebetween may be straightforward to manufacture. The support element may be attached to the heater holder. The support element may be mechanically fixed to the heater holder. The support element may be pressed into the heater holder. The support element may be fixed to the heater holder with adhesive, such as glue. The support element may be mechanically fixed to the lower plate. The support element may be mechanically fixed to the upper plate. An interference fit may exist between the support element and the heater holder.

[0067] The upper plate may be mechanically fixed to the lower plate. The upper plate may be fixed to the lower plate with fasteners. Suitable fasteners may be screws or rivets. The upper plate may be fixed to the lower plate with adhesive. The upper plate may be fixed to the lower plate by plastic welding of the upper and lower plate. The upper plate may be fixed to the lower plate by overmoulding.

[0068] The heater holder may have an aperture defined therethrough. The aperture may be defined through the upper plate and the lower plate. The heating element may span at least part of the aperture. The aperture may be configured to allow aerosol-forming substrate to flow between the second side of the heater assembly and the first side of the heater assembly. The aperture may be configured to allow gases, such as air and vapour generated from the aerosol-forming substrate, to flow between the second side of the heater assembly and the first side of the heater assembly.

[0069] The first and second electrical connectors may be configured to supply power to the heating element. The electrical connectors may be situated in electrical contact with the heating element. The first electrical connector may comprise a first contact pad and the second electrical connector may comprise a second electrical contact pad, wherein the first and second electrical contact pads are configured to be in electrical contact with the heating element. The electrical connectors may extend outside of the heater assembly to allow for the provision of electrical energy to the electrical connectors and thus the heating element, from a power supply. In operation, the heating element may be heated as a result of electrical current passing through the heating element. The first electrical connector and the second electrical connect may be positioned on opposite sides of the heating element. An electrical current passing from the first electrical connector to the second electrical connector may pass through the heating element.

[0070] The support element may be situated adjacent to the aperture. The support element may be situated as close as possible to the aperture. The distance between the support element and the aperture may be less than 2mm, preferably less than 1 mm. Advantageously, this may minimise the total length of the heating element. The length of the heating element that is not spanning the aperture may also be reduced. The percentage of the heating element that is spanning the aperture may be increased. Increasing the percentage of the heating element that is spanning the aperture may increase the percentage of the second side of the heating element that is configured to contact the cartridge to receive the aerosol-forming substrate. Advantageously, less material may be needed to manufacture the heating element while not reducing performance of the heating element. Hotspots in the heating element may be more likely to occur at portions of the heating element that are in contact with the heater holder. Therefore, the support elements may be situated adjacent to the aperture where the heating element would come into contact with the heater holder. This may reduce the occurrence of hotspots in the heating element, during sue of the heater assembly.

[0071] The electrical connectors may be in electrical contact with the heating element at distance further from the aperture than the distance of the support element from the aperture. The first electrical connector may be in electrical contact with a first end of the heating element. The second electrical connector may be in contact with a second end of the heating element. The electrical connectors may be connected with the heating element in series. Preferably, the heating element may have a diameter of 0.1 millimetres to 0.5 millimetres.

[0072] The first and second electrical connectors may be situated adjacent to the aperture. The support element may be in contact with the heating element at a distance further from the aperture than the distance of the first and second electrical connectors from the aperture. The first and second electrical connectors may be situated as close as possible to the aperture. The distance between first electrical connector and the aperture may be less than 2 millimetres, preferably less than 1 millimetre. The distance between second electrical connector and the aperture may be less than 2 millimetres, preferably less than 1 millimetres. In this configuration, the length of the heating element between the first electrical connector and the second electrical connector is shorter than in the previous configuration. As a result, a small diameter of the heating element is selected. The first and second electrical connectors, preferably the first and second electrical contact pads, may be configured to absorb some of the heat produced by the heating element in operation. Advantageously, this may reduce the temperature of a portion of the heating element that is not in contact with, or configured to be in contact with, aerosol-forming substrate. The first and second electrical connectors, preferably the first and second electrical contact pads, may be in contact with the heating element at more than two positions on the heating element. The first and second electrical connectors, preferably the first and second electrical contact pads, may be connected with the heating element in parallel. Preferably, the heating element may have a diameter of 0.02 millimetres to 0.2 millimetres.

[0073] The cross-sectional area of the aperture may be from 4 square millimetres to 1000 square millimetres. Preferably, the cross-sectional area of the aperture may be from 9 square millimetres to 400 square millimetres. Most preferably, the cross-sectional area of the aperture may be from 16 square millimetres to 100 square millimetres. Any shape may be selected for the cross-section of the aperture. Preferably, the cross-section of the aperture may be circular, square, or rectangular. Advantageously, these cross-sectional shapes for the aperture may be simple to manufacture.

[0074] The heater holder may be electrically insulating. The heater holder may be thermally insulating. The heater holder may have a thermal conductivity of 1 W / mk or less. The heater holder may comprise a heat resistant polymer. The heater holder may comprise polyether ether ketone (PEEK). The heater holder may comprise liquid crystal polymer (LCP). The heater holder may comprise a ceramic. The heater holder may comprise alumina. The heater holder may comprise zirconia. Advantageously, these materials are able to withstand the high temperatures, preferably temperatures higher than those that may be reached during normal operation of the heating element.

[0075] The heater assembly may comprise a compressible element. The compressible element may be configured to be compressed by the cartridge when the cartridge is received by the aerosol-generating device.

[0076] The compressible element may be a compressible wicking element. The compressible wicking element may be situated on the second side of the heater assembly.

[0077] The compressible element may be a spring. The spring may be situated adjacent to or in contact with the lower plate of the heater holder. The compressible element may allow the heater assembly to move along a longitudinal axis of the device. In use, when a cartridge is attached to the device, the cartridge may provide a force to the heater assembly which moves the heater assembly. When the cartridge is coupled to the device, the spring may compress. When the cartridge is uncoupled from the device, the spring may expand. The spring may be positioned to act against the force provided by insertion of the cartridge. Advantageously, a close fit between the cartridge and the heater assembly may be achieved, reducing the likelihood of leakage of aerosol-forming substrate. A close fit may provide more efficient heating of the aerosol-forming substrate.

[0078] According to a third aspect of the disclosure, there is provided a cartridge configured to couple with an aerosol-generating device as described in the first aspect of the disclosure. The cartridge may comprise an aerosol-forming substrate and a wicking material in fluid communication with the aerosol-forming substrate. The wicking material may form part of an external surface of the cartridge and may be configured to contact the aerosol-generating device.

[0079] The cartridge may not comprise a heater assembly. The cartridge may not comprise a heating element. Advantageously, the cost and complexity of manufacturing the cartridge may be reduced compared to cartridges of the prior art, for example cartridges that comprise a wicking material and a heating element in contact with the wicking material. The cartridge may be disposed of when the wicking material becomes degraded, usually after many heating cycles. Advantageously, the cartridge may be uncoupled from an aerosol-generating device and the cartridge disposed of. The aerosol-generating device and the components contained in the aerosol-generating device may be reused.

[0080] The cartridge may comprise a cartridge air flow passage defined between a cartridge air inlet and a cartridge air outlet. When a negative pressure is applied to the cartridge air outlet, air is drawn into the cartridge air inlet and an airflow is formed in the airflow passage, from the cartridge air inlet to the cartridge air outlet.

[0081] The cartridge may comprise a mouthpiece. The mouthpiece may be a removable mouthpiece. The mouthpiece may comprise the cartridge air outlet. In use, when the cartridge is engaged with an aerosol-generating device, a user may puff on the mouthpiece of the cartridge.

[0082] The aerosol-forming substrate may be a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may be solid or liquid or comprise both solid and liquid components. The aerosol-forming substrate may be a fluid. The aerosol-forming substrate may be a gel. The gel may be a solid at room temperature. "Solid" in this context means that the gel has a stable size and shape and does not flow. Room temperature in this context means 25 degrees Celsius. Preferably, the aerosol-forming substrate is a liquid.

[0083] The aerosol-forming substrate may comprise plant-based material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise a non-tobacco-containing material.

[0084] The aerosol-forming substrate may comprise at least one aerosol-former. An aerosol-former is any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the temperature of operation of the system. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, 1,3-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Preferred aerosol formers are polyhydric alcohols or mixtures thereof, such as triethylene glycol, 1,3-butanediol and, most preferred, glycerine. The aerosol-forming substrate may comprise other additives and ingredients, such as flavourants.

[0085] The cartridge may comprise a reservoir for containing the aerosol-forming substrate. The reservoir may have any size of shape suitable for containing the aerosol-forming substrate within the cartridge. The wicking material may be in fluid communication with the aerosol-forming substrate contained in the reservoir.

[0086] The reservoir may comprise at least one opening. The at least one opening may be in contact with the wicking material. The wicking material may be in fluid communication with the reservoir via the at least one opening. The at least one opening may be configured to allow aerosol-forming substrate to flow from the reservoir to the wicking material. The at least one opening may be configured to allow gas or gases to flow from the wicking material to the reservoir. During use of the cartridge, aerosol-forming substrate may flow from the reservoir to the wicking material and gases such as air may flow through the wicking material to the reservoir. This may allow pressure to be balanced within the cartridge.

[0087] The cartridge may comprise a wicking portion. The wicking portion may comprise the wicking material. The wicking material may form part of an external surface of the cartridge and may be configured to contact a heating element of the aerosol-generating device.

[0088] The wicking material may comprise, or may be, a material soaked with, or a material configured to be soaked with, aerosol-forming substrate. The wicking material may have a fibrous or spongy structure. The wicking material may be a capillary material. A capillary material is a material that actively conveys liquid from one end of the material to another. The capillary material may have a fibrous or spongy structure. The capillary material preferably comprises a bundle of capillaries. For example, the capillary material may comprise a plurality of fibres or threads or other fine bore tubes. The fibres or threads may be generally aligned to convey aerosol-forming substrate. Alternatively, the capillary material may comprise sponge-like or foam-like material. The structure of the capillary material forms a plurality of small bores or tubes, through which the aerosol-forming substrate can be transported by capillary action. The capillary material may comprise any suitable material or combination of materials. Examples of suitable materials are a sponge or foam material, ceramic- or graphite-based materials in the form of fibres or sintered powders, foamed metal or plastics material, a fibrous material, for example made of spun or extruded fibres, such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, terylene or polypropylene fibres, nylon fibres or ceramic. The capillary material may have any suitable capillarity and porosity so as to be used with different aerosol-forming substrate physical properties. The aerosol-forming substrate has physical properties, including but not limited to viscosity, surface tension, density, thermal conductivity, boiling point and vapour pressure, which allow the aerosol-forming substrate to be transported through the capillary material by capillary action.

[0089] Preferably, the wicking material may be a ceramic wick. The ceramic wick may comprise, or preferably consist of, a ceramic material. Preferably, when the wicking element is a ceramic wick, the wicking element may comprise a porous ceramic. The porous ceramic wick may comprise an open-porous ceramic. A ceramic wick may be rigid. A ceramic wick may not deform when the cartridge is coupled to the aerosol-generating device.

[0090] The cartridge may further comprise a compressible element. The cartridge compressible element may be a compressible wicking element. The compressible wicking element may be the wicking material. The compressible wicking element may be situated adjacent to the wicking material.

[0091] The compressible wicking element may comprise, or preferably consist of, a compressible material. For example, the compressible wicking element preferably comprises a spongy or foam material. The compressible wicking element may form part of the device coupling portion and be configured to contact the aerosol-generating device. The compressible wicking element may be compressed when the cartridge is coupled to the aerosol-generating device. This may advantageously ensure that the contact area between the compressible wicking element and the device is maximised and therefore improve transport of aerosol-forming substrate to a heating element, improving heating efficiency. Preferably, the compressible wicking element may comprise or consist of a resilient material. Such a wicking element may advantageously return to its original shape after being compressed. Therefore, when the cartridge is uncoupled from the aerosol-generating device the compressible wicking element may return to its original shape.

[0092] The wicking material may have any suitable cross-sectional shape. The wicking material may have a square, rectangular or circular cross-section. Wicking material of this shape may be simple to manufacture. Preferably, the wicking material is cylindrical.

[0093] The wicking material may have a width of between 2 millimetres and 32 millimetres, preferably between 3 millimetres and 20 millimetres, more preferably between 4 millimetres and 10 millimetres. If the wicking element is cylindrical, the values for the width correspond to values for the diameter of the cylindrical wicking element.

[0094] The cartridge may comprise a device coupling portion. The device coupling portion may be configured to couple with an aerosol-generating device. The device coupling portion may comprise the cartridge air inlet. The device coupling portion may be provide on an end of the cartridge that is opposite to the cartridge air outlet. The device coupling portion may comprise the wicking material. The wicking material may protrude from a surface of the device coupling portion. This may allow the wicking material to readily contact a cartridge coupling portion of a device. In particular, this may allow the wicking material to readily contact a heating element of the device. The wicking material may protrude from a surface of the device coupling portion by at least 1 millimetre, preferably by at least 2 millimetres, more preferably by at least 3 millimetres.

[0095] The cartridge may further comprise a removable seal. The removable seal may be configured to cover the wicking material before use of the cartridge. Advantageously, the removable seal may protect the wicking material from damage or contamination prior to use of the cartridge. The removable seal may also prevent exposure of the wicking material, and therefore aerosol-forming substrate, to air prior to use of the cartridge. Advantageously, the removable seal may reduce evaporation of the aerosol-forming substrate from the wicking material before the cartridge is coupled to an aerosol-generating device. The removable seal may advantageously prevent loss or leakage of aerosol-forming substrate from the cartridge prior to use of the cartridge, in particular during storage or transit. The removable seal may be configured to be removed by a user prior to use of the cartridge. The removable seal may be configured to be removed by a user prior to coupling of the cartridge with an aerosol-generating device.

[0096] The cartridge may further comprise a protruding wall. The protruding wall may protrude from the surface of the device coupling portion. The protruding wall may protrude from the surface of the device coupling portion by at least 1 millimetre, preferably by at least 2 millimetres, more preferably by at least 3 millimetres. The protruding wall may surround a perimeter of the device coupling portion. The protruding wall may be configured to contact or be received by an aerosol-generating device. The protruding wall may be configured to contact or be received by a cartridge coupling portion of the aerosol-generating device.

[0097] The protruding wall may be configured to protrude from the surface of the device coupling portion by at least the same amount as the wicking material. The protruding wall may be configured to protrude from the surface of the device coupling portion by more than wicking material. Advantageously, the protruding wall may protect the wicking material from shocks or damage. The protruding wall may be configured to engage with an aerosol-generating device. The removable seal may be attached to the protruding wall. The removable seal may be attached to the protruding wall by adhesive. The removable seal may not be in contact with the wicking material.

[0098] The cartridge air inlet may comprise a separation wall that protrudes from the surface of the device coupling portion. The separation wall may protrude from the surface of the device coupling portion by at least 1 millimetre, preferably at least 2 millimetres, more preferably by at least 3 millimetres. The separation wall may protrude from the surface of the device coupling portion by at least the same amount as the wicking material. The separation wall may protrude from the surface of the device coupling portion by more than the wicking material. The separation wall may protrude from the surface of the device coupling portion by less than the protruding wall. The separation wall may protrude from the surface of the device coupling portion by the same amount as the protruding wall. The removable seal may cover the cartridge air inlet. Advantageously this may protect the cartridge air inlet from contaminants prior to a user removing the removable seal, in particular during storage and transit of the cartridge. The separation wall may be configured to engage with an aerosol-generating device.

[0099] It would be desirable to provide an aerosol-generating system with reduced degradation of a wicking material in comparison to prior art systems, and which would require less frequent disposal of a cartridge and heater assembly.

[0100] According to a fourth aspect of the present disclosure, there is provided an aerosol generating system. The aerosol-generating system may comprise any of the features of the aerosol-generating device, the heater assembly or the cartridge described in relation to the first, second or third aspects of the present disclosure.

[0101] The aerosol-generating system comprises a cartridge. The cartridge comprises an aerosol-forming substrate in fluid communication with a wicking material wherein the wicking material forms part of an external surface of the cartridge. The aerosol-generating system further comprises an aerosol-generating device. The aerosol-generating device comprises a cartridge coupling portion for engaging a cartridge comprising an aerosol-forming substrate, an air flow passage defined between a device air inlet and a device air outlet, and a heater assembly. The heater assembly comprises a fluid permeable heating element configured to heat an aerosol-forming substrate from the cartridge. The heater assembly comprises a first side and a second side, the first side opposing the second side, wherein the first side forms at least part of a surface of a wall of the air flow passage and wherein the second side forms part of the cartridge coupling portion and is configured to contact the wicking material of the cartridge to receive the aerosol-forming substrate.

[0102] Advantageously, when the cartridge needs replacing the heater assembly may be retained in the device, instead of being removed and disposed of. The heater assembly may be more costly to manufacture in comparison to other elements of a cartridge, so it may be advantageous to prevent unnecessary disposal of the heater assembly. Situating the heater assembly in the device may mean the cartridge does not comprise a heater assembly. The cartridge may therefore be less costly and simpler to manufacture compared to cartridges containing a heater assembly.

[0103] The aerosol-forming substrate may be a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may be solid or liquid or comprise both solid and liquid components. The aerosol-forming substrate may be a fluid. The aerosol-forming substrate may be a gel. The gel may be a solid at room temperature. "Solid" in this context means that the gel has a stable size and shape and does not flow. Room temperature in this context means 20 degrees Celsius. Preferably, the aerosol-forming substrate is a liquid.

[0104] The cartridge may comprise a reservoir for containing the aerosol-forming substrate. The reservoir may have any size of shape suitable for containing the aerosol-forming substrate within the cartridge. The wicking material may be in fluid communication with the aerosol-forming substrate contained in the reservoir.

[0105] The reservoir may comprise at least one opening. The at least one opening may be in contact with the wicking material. The wicking material may be in fluid communication with the reservoir via the at least one opening. The at least one opening may be configured to allow aerosol-forming substrate to flow from the reservoir to the wicking material. The at least one opening may be configured to allow gas or gases to flow from the wicking material to the reservoir. During use of the cartridge, aerosol-forming substrate may flow from the reservoir to the wicking material and gases such as air may flow through the wicking material to the reservoir. This may allow pressure to be balanced within the cartridge.

[0106] The cartridge may comprise a wicking portion. The wicking portion may comprise the wicking material. The wicking material may form part of an external surface of the cartridge and may be configured to contact a heating element of the aerosol-generating device.

[0107] The wicking material may comprise, or may be, a material soaked with, or a material configured to be soaked with, aerosol-forming substrate. The wicking material may have a fibrous or spongy structure. The wicking material may be a capillary material.

[0108] The wicking material may be a ceramic wick. The ceramic wick may comprise, or preferably consist of, a ceramic material. Preferably, when the wicking element is a ceramic wick, the wicking element may comprise a porous ceramic. The porous ceramic wick may comprise an open-porous ceramic. A ceramic wick may be rigid. A ceramic wick may not deform when the cartridge is coupled to the aerosol-generating device.

[0109] The cartridge may comprise a cartridge air inlet and a cartridge air outlet, wherein the cartridge air inlet is aligned with the device air outlet. The cartridge air outlet may comprise a mouthpiece.

[0110] The device air inlet may be defined in a side wall of the aerosol-generating device. The device air outlet may be defined in an end wall of the aerosol-generating device. The side wall of the aerosol-generating device may extend perpendicular to the end wall of the aerosol-generating device. The device air outlet may be configured to align with an opening in the cartridge.

[0111] When the cartridge is coupled to the device an air flow passage may be formed from the device air inlet to the cartridge air outlet. During use of the aerosol-generating system, a user may suck on the cartridge air outlet. This may draw air into the device air inlet, past the heating element, through the device air outlet, through the cartridge air inlet and out of the cartridge air outlet, to the user.

[0112] The second side of the heater assembly may be situated outside of the airflow passage. The second side of the heater assembly may be configured to contact the wicking material of the cartridge. The heater assembly may be a planar heater assembly.

[0113] The heater assembly may comprise a heater holder. The heater holder may have an aperture defined therethrough. The heater holder may comprise an upper plate and a lower plate. The aperture may be defined through the upper plate and the lower plate. The heating element may span at least part of the aperture. The aperture may be configured to allow aerosol-forming substrate to flow between the second side of the heater assembly and the first side of the heater assembly. The aperture may be configured to allow gases, such as air and vapour generated from the aerosol-forming substrate, to flow between the second side of the heater assembly and the first side of the heater assembly.

[0114] The wicking material may have a shape that corresponds to the shape of the aperture of a heater assembly. The wicking material may have a cross-sectional area that corresponds to a cross-sectional area of an aperture of a heater assembly for an aerosol-generating device. Wicking material cross-section corresponding to the cross section of an aperture of a heater assembly may advantageously allow good contact between the wicking material a heating element of the heater assembly. The wicking material may have a cross-sectional area that is at least 2, 3, 4, or 5 percent smaller than the cross-sectional area of an aperture of a heater assembly for an aerosol-generating device. This may allow the wicking material to be easily received by the aperture of the heater assembly. The wicking material may have any suitable cross-sectional shape. The wicking material may have a square, rectangular or circular cross-section. Wicking material of this shape may be simple to manufacture. Preferably, the wicking material is cylindrical.

[0115] The wicking material may have a width of between 2 millimetres and 32 millimetres, preferably between 3 millimetres and 20 millimetres, more preferably between 4 millimetres and 10 millimetres. If the wicking element is cylindrical, the values for the width correspond to values for the diameter of the cylindrical wicking element.

[0116] The heater assembly may be configured to contact a wicking portion of the cartridge. The heating element may be configured to contact a wicking portion of the cartridge.

[0117] The heating element may be a mesh heating element. The heating element may comprise a mesh. The heating element may comprise a porous material. Advantageously, a mesh heating element, a heating element comprising a mesh, or a heating element comprising a porous material may provide a large surface area in contact with the liquid aerosol-forming substrate. This large surface area may provide efficient vaporisation of the liquid aerosol-forming substrate.

[0118] The heating element may comprise at least one filament. The heating element may comprise a plurality of electrically conductive filaments. The term "filament" as used herein refers to an electrical path arranged between two electrical contacts. The at least one filament may have a round, square, flat or any other form of cross-section. Preferably the heating element comprises a single filament. A heating element comprising a single filament may also be referred to as a heating wire. The heating element may have a diameter of 0.1 millimetres to 0.5 millimetres. The heating element may have a diameter of 0.02 millimetres to 0.2 millimetres.

[0119] The heating element, or portions thereof, may comprise an electrically resistive material. The heating element may be configured to be resistively heated. In other words, the heating element may be configured to generate heat when an electrical current is passed though the heating element.

[0120] Preferably, the heating element comprises stainless steel. Stainless steel may provide a heating element with desirable mechanical properties, corrosion resistance and high electrical resistance.

[0121] The heater assembly comprises a support element. The support element provides mechanical support to the heating element. The support element may laterally support the heating element. The support element comprises a thermal conduction material in thermal contact with the heating element. The support element may be configured to absorb heat produced by the heating element. The support element comprising a thermal conduction material may conduct heat away from the heating element at areas where the heating element is in contact with the support element. Advantageously, the presence of a support element comprising a thermal conduction material may reduce the temperature of the heating element in regions where the heating element is not in contact with a wicking material or aerosol-forming substrate. This may reduce overheating of the heating element, preferably prolonging the life of the heating element. In addition, this may reduce or slow down degradation of a wicking material in contact with the heating element. Advantageously, the support element comprising a thermally conductive material may reduce the likelihood of hotspots forming in the heating element. Reducing hotspots may increase the lifetime of the heating element. Reducing hotspots may also increase the lifetime of the wicking material of the cartridge.

[0122] The heater assembly may comprise a compressible element. The compressible element may be configured to be compressed by the cartridge when the cartridge is received by the aerosol-generating device.

[0123] The compressible element may be a spring.

[0124] The compressible element may be a compressible wicking element.

[0125] The cartridge may comprise a cartridge housing. The device may comprise a device housing. The cartridge housing and the device housing may be rigid. The cartridge housing may engage with the device housing. When the device housing engages with the cartridge housing, the compressible element may be compressed.

[0126] The aerosol-generating system may further comprise a first electrical connector and a second electrical connector. The first and second electrical connectors may be configured to supply power to the heating element. The electrical connectors may be situated in electrical contact with the heating element. The first electrical connector may comprise a first contact pad and the second electrical connector may comprise a second electrical contact pad, wherein the first and second electrical contact pads are configured to be in electrical contact with the heating element. The electrical connectors may extend outside of the heater assembly to allow for the provision of electrical energy to the electrical connectors and thus the heating element, from a power supply. In operation, the heating element may be heated as a result of electrical current passing through the heating element. The first electrical connector and the second electrical connect may be positioned on opposite sides of the heating element. An electrical current passing from the first electrical connector to the second electrical connector may pass through the heating element.

[0127] The aerosol-generating system may further comprise a power supply. The power supply may be a DC power supply. The power supply may be a battery. The battery may be a Lithium based battery, for example a Lithium-Cobalt, a Lithium-Iron- Phosphate, a Lithium Titanate or a Lithium-Polymer battery. The battery may be a Nickel metal hydride battery or a Nickel cadmium battery. The power supply may be another form of charge storage device such as a capacitor. The power supply may be configured to supply power to the heating element. This may heat the heating element.

[0128] The power supply may be configured to supply power to the heating element to resistively heat the heating element.

[0129] The power supply may be electrically connected to the first and second electrical connectors. The power supply may be configured to supply power to the heating element via the electrical connectors. The power supply may be configured to supply power to the heating element by passing an electrical current through the heating element.

[0130] The aerosol-generating system may further comprise a control circuitry. The control circuitry may comprise a controller. The controller may be a microprocessor, which may be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC) or other electronic control circuitry. The controller may be configured to control supply of power from the power supply. The controller may be configured to regulate the supply of power from the power supply to the heater assembly. Thus, the controller may control heating of the heating element.

[0131] The aerosol-generating system may be puff actuated. The heating element may be airflow actuated. The heating element may be puff actuated. The aerosol-generating system may comprise a puff detector. The puff detector may be in communication with the control circuitry. The puff detector may be configured to detect when there is an airflow through the air flow passage. The control circuitry may be configured to activate the heating element when an airflow is detected.

[0132] The aerosol-generating system may be a handheld aerosol-generating system. The aerosol-generating system may have a size comparable to a conventional cigar or cigarette. The aerosol-generating system may have a total length between about 30 mm and about 150 mm. The aerosol-generating system may have an external diameter between about 5 mm and about 30mm.

[0133] As used herein, the term "heating element" refers to an element of a heater assembly, the element being configured to be heated. For example, the term "heating element" may refer to an element configured to be heated to at least 50, 100, 150, 200, 250, or 300 degrees Celsius.

[0134] As used herein, the term 'coupled or coupleable' is used to mean that the cartridge and device can be coupled and uncoupled from one another and without significantly damaging either the device or cartridge.

[0135] The invention is defined in the claims.

[0136] Features of one aspect of the invention may be applied to the other aspects of the invention.

[0137] Examples will now be further described with reference to the figures in which: Figure 1 shows a simplified cross-section of an aerosol-generating system; Figure 2A shows an exploded perspective view of part of an aerosol-generating system; Figure 2B shows a cross-sectional perspective view of part of an aerosol-generating system; Figure 3A shows an exploded perspective view of a heater assembly according to a first embodiment; Figure 3B shows a perspective view of the heater assembly of Figure 3A; Figure 4A shows an exploded perspective view of a heater assembly according to a second embodiment; Figure 4B shows a perspective view of the heater assembly of Figure 4A; Figure 5 shows a cross-sectional perspective view of a cartridge according to a first embodiment; Figure 6A shows a cross-sectional perspective view of a cartridge according to a second embodiment; and Figure 6B shows a perspective view of the cartridge of Figure 6A.

[0138] Figure 1 shows a cross-sectional diagram of an aerosol generation system 700 comprising an aerosol generating device 500 and a cartridge 600. In this example, the aerosol-generating system 700 is an electrically operated smoking system, often referred to as an e-cigarette system. The aerosol-generating system 700 is a handheld, portable system and has a size comparable to a conventional cigar or cigarette.

[0139] The device 500 comprises a battery 560, such as a lithium iron phosphate battery, and a controller 570 electrically connected to the battery 560.

[0140] The device 500 comprises an air inlet 510, an air outlet 520, and a heater assembly 530. An airflow passage is defined between the air inlet 510 and the air outlet 520. The heater assembly 530 is positioned downstream of the air inlet 510 and upstream of the air outlet 520. The heater assembly 530 comprises a fluid permeable heating element 540, first and second electrical connectors (not shown in Figure 1), a heater holder 550, and a support element (not shown in Figure 1). The heating element 540 is a heating wire that spans an aperture in the heater holder 550. The first and second electrical connectors are electrically connected with the heating element 540, the battery 560 and the controller 570. The device 500 also comprises a compressible element 580, such as a spring.

[0141] The device 500 comprises a cartridge coupling portion 502 for engaging the cartridge 600.

[0142] The cartridge 600 comprises a liquid aerosol-forming substrate in a reservoir 610. In this system, the reservoir 610 is in fluid communication with a ceramic wicking material 620, so that liquid aerosol-forming substrate can flow from the reservoir 610 to the wicking material 620.

[0143] The cartridge 600 is coupled to the device 500 by the cartridge coupling portion.

[0144] The device air outlet 520 is configured to align with a cartridge air inlet 630. When the device 500 is coupled to the cartridge 600 the device air flow passage is connected to a cartridge air flow passage, defining an air flow passage from the device air inlet 510 to the cartridge air outlet 640. The cartridge comprises a mouthpiece, the cartridge air outlet 640 is defined in the mouthpiece.

[0145] The wicking material 620 is configured to align with an aperture of the heater holder 550. The aperture is circular with a cross-sectional area of 4 millimetre 2< to 1000 millimetre 2< . The wicking material 620 also has a circular cross-section, so that the wicking material 620 may be easily received by the aperture of the heater holder 550.

[0146] In use, a user puffs on the mouthpiece of the cartridge 600 drawing air into the device air inlet 510. The system is puff actuated meaning that puff sensor (not shown), which may be a pressure sensor or an air flow sensor, is located in the system 700. The puff sensor will detect the user puff and send a signal to the controller 570, which results in power being supplied from the battery 560 to the heating element 540, via the first and second electrical connectors. This causes a current to flow through the heating element 540, thereby resistively heating the heating element 540. In other examples, the aerosol-generating system may comprise a button that a user pressure to send a signal to the controller to supply power from the battery to the heating element 540.

[0147] As the heating element 540 is resistively heated the support element will conduct heat away from the heating element 540, where the heating element 540 is in contact with the supporting element. This will minimise the number of hotspots occurring across the heating element 540 leading to a relatively even temperature across the heating element. As the heating element 540 is heated, it heats the wicking material 620 and therefore any aerosol-forming substrate contained in the wicking material 620. The heating of the wicking material 620 causes the aerosol-forming substrate to be vaporised.

[0148] As the user puffs on the cartridge air outlet 640, air is drawn into the device air inlet 510. The air will pass across the heater assembly 530 as it is drawn through the air passage. The air will flow across the first side of heating element 540, across the surface of the wicking material and towards the cartridge air outlet. The vaporised aerosol-forming substrate is entrained in this flowing air. This entrained vapour then cools and condenses to form an aerosol. The aerosol leaves the device air flow passage through the air outlet 520. Then the aerosol enters the cartridge 600 through the cartridge air inlet 630, exits the cartridge through the cartridge air outlet 640, and is delivered to the user's mouth.

[0149] As liquid aerosol-forming substrate in the wicking material 620 is heated, vaporised, and entrained in the air flow, liquid aerosol-forming substrate from the reservoir 610 travels into the wicking material 620. This aerosol-forming substrate from the reservoir 610 effectively replaces the vaporised aerosol-forming substrate. The liquid aerosol-forming substrate from the reservoir 610 may be drawn into the wicking material 620, at least partly, by capillary action. This is because the wicking material 620 is a capillary material having a fibrous or spongy structure.

[0150] After many uses of the aerosol-generating system 700, the wicking material may start to degrade. The user can then uncouple the cartridge 600 from the device 500. The cartridge 500 can be removed and disposed of. The aerosol-generating device 500 can then be re-used with a new cartridge.

[0151] Figure 2A shows a perspective view of part of an aerosol-generating system 800. The system 800 comprises a cartridge 1000 and an aerosol-generating device 900. The aerosol-generating device 900 comprises a heater assembly. The heater assembly comprises a heater holder comprising an upper plate 952 and a lower plate 954, a heating element 940, and supporting pins 962. A device air inlet 910 is defined in a side wall of the aerosol-generating device. A device air outlet 920 is formed in a cartridge coupling portion of the device.

[0152] Figure 2B shows a cross-sectional view of the aerosol-generating system 800 of Figure 2A, when the aerosol-generating device 900 is coupled to the cartridge 1000. The cartridge 1000 is received by the cartridge coupling portion of the device 900.

[0153] Figure 3A shows an exploded view of heater assembly 130 according to a first embodiment. The heater assembly 130 comprises a fluid permeable heating element 140, a heater holder 150 and a support element 160. The heater assembly 130 comprises a first side 132 and a second side 134, the first side 132 opposing a second side 134.

[0154] The heater holder 150 comprises an upper plate 152 and a lower plate 154, with the heating element 140 situated therebetween. Both the upper plate 152 and the lower plate 154 comprise an aperture. When assembled, the aperture of the upper plate 152 and the aperture of the lower plate 154 are aligned, thereby forming an aperture through the heater assembly 130. The cross-sectional area of the aperture is from 9 millimetres 2< to 400 millimetres 2< , preferably from 16 millimetres 2< to 100 millimetres 2< . The heater holder 150 comprises a heat resistant polymer, specifically PEEK or LCP. In other examples, the heater holder may comprise a ceramic such as alumina or zirconia.

[0155] The heating element 140 spans at least a portion of the aperture. The heating element is a stainless steel filament (heating wire) configured to be resistively heated. In other examples, the heating element may comprise a mesh. The mesh may comprise a plurality of filaments. The heating element may be coated with a corrosion resistant material, for example a ceramic material. In the example shown in Figure 3A, the heating wire 140 has a diameter of 0.1 millimetres to 0.5 millimetres. The heating element has a total electrical resistance of 0.1 to 5 Ohms, preferably 0.4 to 2 Ohms.

[0156] The supporting element 160 comprises six supporting pins 162. The supporting pins comprise thermally conductive material such as aluminium, copper, brass, gold coated metal, silver coated metal or thermally conductive ceramic. The thermal conductivity of the supporting pins is at least 10 W / mK, preferably at least 50 W / mK and more preferably at least 200 W / mK. The supporting pins 162 provide mechanical support to the heating element 140. The supporting pins 162 also function as thermal conductors to conduct heat from the heating element 140, in particular to conduct heat away from hotspots in the heating element 140. The supporting pins 162 are situated adjacent to the aperture in the upper plate 152 and the lower plate 154.

[0157] The heating assembly further comprises a first electrical connector 170 and a second electrical connector 180. The first electrical connector is in electrical contact with a first end of the heating element. The second electrical connector is in electrical contact with a second end of the heating element. The first and second electrical connectors are configured to supply power to the heating element 140.

[0158] Figure 3B shows the heater assembly of Figure 3A when assembled. As shown in Figure 3B, the upper plate 152 and the lower plate 154 are attached, forming a planar heating assembly.

[0159] The heater assembly 130 is configured so that in use, electrical power is supplied to the heating element 140 via the first 170 and second 180 electrical connectors. The electrical power resistively heats the heating element 140. Where the heating element 140 is in physical contact with the supporting pins 162, the supporting pins 162 conduct heat from the heating element. Therefore, temperature peaks or hotspots in the heating element are reduced. Substantially uniform temperature is achieved across the heating element.

[0160] The heater assembly 130 is manufactured by pressing or gluing the supporting pins 162 over the lower plate 154. The heating element (wire) 140 is wound around the supporting pins 162 and held in tension, forming the heating net shown in Figures 1A and 1B. The first electrical connector 170 is applied over a first end of the heating element 140 and the second electrical connector 180 is applied over a second end of the heating element 140. The upper plate 152 is then applied over the top of the other elements. The upper plate 152 and lower plate 154 may be attached by plastic welding the upper plate 152 and lower plate 154. Alternatively, they may be joined by applying an adhesive between the upper plate 152 and lower plate 154. Alternatively, or in addition, by adding fasteners, such as screws or rivets, between the upper 152 and lower plate 154.

[0161] Figure 4A and Figure 4B show a heater assembly 230 according to a second embodiment of the present disclosure. The heater assembly 230 comprises a fluid permeable heating element 240, a heater holder 250 and a support element 260. The heater assembly 230 comprises a first side 232 and a second side 234, the first side 232 opposing a second side 234.

[0162] The embodiment shown in Figure 4A shows the first 270 and second 280 electrical connectors adjacent to the aperture in the upper plate and the aperture in the lower plate. The supporting element 260 comprises support pins 262. In this embodiment, the support pins 262 are situated at greater distance from the aperture than the distance of the electrical connectors from the aperture. The first 270 and second 280 electrical connectors are situated adjacent to the aperture and the heating element 240 spans the aperture. The heating element is a heating wire that has a diameter of 0.02 millimetres to 0.2 millimetres, and is wound around support pins 262. The first 270 and a second 280 electrical connectors are applied over the heating wire, and connected in parallel.

[0163] Figure 4B shows the heater assembly of Figure 4A, when assembled. In use of the heater assembly 230, an electrical power is supplied to the heating element 240 via the first 270 and second 280 electrical connectors. The electrical power delivers an electrical current to the heating element 240, which is configured to be resistively heated. Where the heating element 240 is in physical contact with the supporting pins 262, the supporting pins 262 conduct heat from the heating element. Therefore, temperature peaks or hotspots in the heating element are reduced. In this configuration, the electrical current flows along the portions of the heating wire between the first electrical connector 270 and second electrical connector 280. Due to the position of the first 270 and second 280 electrical connectors, current does not flow in the portions of the heating element that are in contact with the supporting pins 262. In this embodiment, the first 270 and second 280 electrical connectors conduct heat away from the heating element 240 and act to reduce hotspots in the heating element 240. In particular, they conduct heat away from the portion of the heating element 230 with which they are in physical contact, in this case that is the portion that also comes into contact with the heater holder 250, and therefore is an area where hotspots would be likely to occur.

[0164] Figure 5 shows a cartridge 300. The cartridge 300 comprises an aerosol-forming substrate stored in a reservoir 310 and a wicking material 320 that is in fluid communication with the aerosol-forming substrate. The reservoir 310 may be any size or shape suitable for containing an aerosol-forming substrate within the cartridge 300. In this example, the aerosol-forming substrate is a liquid. A portion of the reservoir 310 is in contact with the wicking material 320. This portion is configured to allow fluid to pass between the reservoir 310 and the wicking material 320. This portion of the reservoir 310 has openings 350 defined therethrough, to allow fluid to pass through. During use of the system, fluid aerosol-forming substrate can flow from the reservoir to the wicking material and gases such as air can flow through the wicking material to the reservoir, to allow pressure to be balanced within the system.

[0165] The wicking material 320 is a porous ceramic and forms part of an external surface of the cartridge 300 and is configured to contact an aerosol-generating device. The wicking material is configured to absorb and transport fluid aerosol-forming substrate through the wicking material.

[0166] The cartridge 300 also comprises a cartridge air inlet 330 and a cartridge air outlet 340. A cartridge airflow passage is defined between the cartridge air inlet 330 and the cartridge air outlet 340. The cartridge further comprises a mouthpiece 360. The mouthpiece comprises the cartridge air outlet. In use, when the cartridge is engaged with an aerosol-generating device, a user may puff on the mouthpiece of the cartridge, to draw air through the system and out of the cartridge air outlet.

[0167] Figure 6A and Figure 6B show a second embodiment of a cartridge 400, comprising a removable seal. The wicking material 420 forms part of an external surface of the cartridge 400 and is configured to contact an aerosol-generating device. The cartridge 400 comprises a protruding wall 470 that surround a perimeter of the device coupling portion of the cartridge 400. The protruding wall 470 protrudes further from the cartridge than the wicking material 420. The cartridge air inlet 430 comprises a separation wall 480 that protrudes from the surface of the device coupling portion.

[0168] The cartridge 400 comprises a removable seal 460 that is attached to the separation wall 480 and the protruding wall 470 of the cartridge.

[0169] The removable seal is configured to be removed by a user prior to coupling of the cartridge 400 with a device.

[0170] Figure 6B shows the cartridge of Figure 6A with the removable seal 460 peeled back from the cartridge 400. The removable seal 460 shown in Figure 6B has been partially removed from the cartridge.

[0171] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1. An aerosol-generating device (500, 900) for coupling to a cartridge (300, 400, 600, 1000), the aerosol-generating device comprising: a cartridge coupling portion (502) for engaging a cartridge containing an aerosol-forming substrate; an air flow passage defined between an air inlet (510, 910) and an air outlet (520, 920); and a heater assembly (130, 230, 530), the heater assembly comprising a fluid permeable heating element (140, 240, 540, 940) configured to heat an aerosol-forming substrate from the cartridge, wherein the heater assembly comprises a first side (132, 232) and a second side (134, 234), the first side opposing the second side, wherein the first side forms at least part of a surface of a wall of the air flow passage and wherein the second side forms part of the cartridge coupling portion and is configured to contact the cartridge to receive the aerosol-forming substrate, wherein the heater assembly comprises a support element (160, 260), wherein the support element provides mechanical support to the heating element and comprises a thermal conduction material in thermal contact with the heating element.

2. An aerosol-generating device (500, 900) according to claim 1 wherein the support element (160, 260) comprises at least one of aluminium, copper, brass, gold, silver or thermally conductive ceramic.

3. An aerosol-generating device (500, 900) according to claim any preceding claim wherein the heater assembly (130, 230, 530) further comprises a heater holder (150, 250, 550) comprising a heat resistant polymer.

4. An aerosol-generating device (500, 900) according to claim 3 wherein the heater holder (150, 250, 550) has an aperture defined therethrough.

5. An aerosol-generating device (500, 900) according to claim 4, wherein the heater holder (150, 250, 550) comprises an upper plate (152, 952) and a lower plate (154, 954) and the aperture is defined through the upper plate and the lower plate.

6. An aerosol-generating device (500, 900) according to claim 4 or 5 wherein the heating element (140, 240, 540, 940) spans at least part of the aperture.

7. An aerosol-generating device (500, 900) according to any preceding claim wherein the heating element (140, 240, 540, 940) is a heating wire, with a diameter of 0.1 millimetres to 0.5 millimetres, or a diameter of 0.02 millimetres to 0.2 millimetres.

8. An aerosol-generating device (500, 900) according to any preceding claim further comprising a first electrical connector (170, 270) and a second electrical connector (180, 280), wherein the first and second electrical connectors are configured to supply power to the heating element (140, 240) and the heating element (140, 240) is configured to be resistively heated.

9. An aerosol-generating device (500, 900) according to claim 8 wherein the first (170, 270) and second (180, 280) electrical connectors are situated adjacent to the aperture.

10. An aerosol-generating device (500, 900) according to any of claims 1 to 8 wherein the support element (160, 260) is situated adjacent to the aperture.

11. A heater assembly (130, 230, 530) for an aerosol-generating device (500, 900), the heater assembly (130, 230, 530) comprising: a heater holder (150, 250, 550) comprising an aperture; a heating element (140, 240, 540) spanning at least part of the aperture; first (170, 270) and second (270, 280) electrical connectors in electrical contact with the heating element; and a support element (160, 260) providing mechanical support to the heating element and comprising a thermal conduction material in thermal contact with the heating element.

12. An aerosol-generating system (700, 800) comprising: an aerosol-generating device (500, 900) according to any one of claims 1 to 10; and a cartridge (300, 400, 600, 1000), the cartridge comprising: an aerosol-forming substrate in fluid communication with a wicking material (320, 420, 620) wherein the wicking material forms part of an external surface of the cartridge.

13. An aerosol-generating system (700, 800) according to claim 12, further comprising a compressible element (580), wherein the compressible element is configured to be compressed by the cartridge (300, 400, 600, 1000) when the cartridge is received by the aerosol-generating device (500, 900).

14. An aerosol-generating system (700, 800) according to claim 12 or 13, further comprising a mouthpiece and a cartridge air flow passage defined between a cartridge air inlet (330, 630) and a cartridge air outlet (340, 640), wherein the cartridge air inlet is aligned with the device air outlet (520, 920) and the mouthpiece comprises the cartridge air outlet.

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