Stacked susceptor structure

Abstract

An electrically heated aerosol-generating system is provided. The system comprises at least one inductor coil (66); a power supply device (72) connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil to generate an alternating magnetic field; a housing (36) of a reservoir (40) containing an aerosol-forming substrate (42); and a substantially planar susceptor assembly (12). The susceptor assembly (12) is configured to be heated by the alternating magnetic field and comprises a first susceptor element (16), a second susceptor element (18) and a wicking element (20) in fluid communication with the reservoir (40), the first susceptor element (16) and the second susceptor element (18) being integral with or fixed to the wicking element (20). A space is defined between the first susceptor element (16) and the second susceptor element (18), the wicking element (20) occupying the space and the reservoir (40) being positioned outside the space.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an electrically heated aerosol-generating system, a cartridge for an electrically heated aerosol-generating system, and a susceptor assembly for an electrically heated aerosol-generating system. BACKGROUND

[0002] In many known aerosol-generating systems, an aerosol-forming substrate is heated and vaporised to form a vapour. The vapour cools and condenses to form an aerosol. In some aerosol-generating systems, such as electrically heated smoking systems, this aerosol is then inhaled by a user. Such electrically heated smoking systems are typically hand-held and comprise a power supply, a storage portion for holding a supply of aerosol-forming substrate, and a heater element. The aerosol-forming substrate can be a liquid. In such cases, the aerosol-generating system can further comprise a wicking element configured to draw the liquid aerosol-forming substrate from the storage portion to the heater element for heating.

[0003] Some aerosol-generating systems comprise an aerosol-generating device and a cartridge configured for use with the device. In such systems, the aerosol-generating device is typically designed to be reusable and comprises a power supply. The cartridge is designed to be disposable and comprises or forms a storage portion holding an aerosol-forming substrate. The cartridge is replaced once the aerosol-forming substrate is depleted. The heater element can be located in the cartridge.

[0004] Hand-held aerosol-generating systems comprising an inductive heating system have been proposed. The inductive heating system typically comprises at least one inductor coil connected to a power supply and a susceptor element arranged in close proximity to the aerosol-forming substrate and within an alternating magnetic field. When the aerosol-generating system comprises an aerosol-generating device and a cartridge, the susceptor element can form part of the cartridge or the device.

[0005] The power supply is configured to supply an alternating current to the inductor coil, which generates an alternating magnetic field that induces a current to flow in the susceptor element. When the susceptor element is penetrated by the alternating magnetic field, the susceptor element heats up by at least one of Joule heating from the induced eddy currents in the susceptor and magnetic hysteresis losses. The heated susceptor element heats the aerosol-forming substrate such that volatile compounds are released from the aerosol-forming substrate, which cool to form an inhalable aerosol.

[0006] One advantage of inductive heating systems is that the electrical components of the system can be isolated from the aerosol-forming substrate and any generated aerosol. Another advantage is that the construction of the cartridge can be simplified, as there is no need to provide an electrical connection to the device. SUMMARY

[0007] It would be desirable to provide an efficient and robust inductive heating system for generating aerosols, and a system in which low frequency alternating current can be used.

[0008] According to the present disclosure, there is provided an electrically heated aerosol-generating system. The aerosol-generating system can comprise at least one inductor coil. The aerosol-generating system can comprise a power supply device. The power supply device can be connected to the at least one inductor coil. The power supply device can be configured to provide an alternating current to the at least one inductor coil to generate an alternating magnetic field. The aerosol-generating system can comprise a housing comprising a reservoir of aerosol-forming substrate. The aerosol-generating system can comprise a substantially planar susceptor assembly. The susceptor assembly can be configured to be heated by the alternating magnetic field. The susceptor assembly can comprise a first susceptor element. The susceptor assembly can comprise a second susceptor element. The susceptor assembly can comprise a wicking element. The wicking element can be in fluid communication with the reservoir. The first susceptor element and the second susceptor element can be integral with or fixed to the wicking element. A space can be defined between the first susceptor element and the second susceptor element. The wicking element can occupy the space.

[0009] The reservoir can be positioned outside the space between the first susceptor element and the second susceptor element. In other words, the susceptor assembly can be arranged substantially outside the reservoir. In particular, each susceptor element of the susceptor assembly can be arranged substantially outside the reservoir. Preferably, at least a portion of a major surface of the or each susceptor element is not in direct contact with the reservoir. Preferably, at least a portion of two opposing major surfaces of the susceptor assembly are in direct contact with air in an air flow path in the system.

[0010] In operation, the alternating current is passed through the at least one inductor coil to generate an alternating magnetic field that induces a voltage in the first susceptor element and the second susceptor element. The induced voltage causes a current to flow in each of the first susceptor element and the second susceptor element, and this current causes Joule heating of the first susceptor element and the second susceptor element, which in turn heats the aerosol-forming substrate that has been delivered by the wicking element. If the susceptor elements are ferromagnetic, then hysteresis losses in the susceptor elements can also generate a significant amount of heat.

[0011] The aerosol-forming substrate can be a liquid. The reservoir can be configured to hold a liquid aerosol-forming substrate. The reservoir can have any suitable shape and size, depending on the requirements of the aerosol-generating system.

[0012] In some embodiments, the reservoir comprises a retention material for retaining the liquid aerosol-forming substrate. Where the reservoir comprises a plurality of portions, the retention material can be positioned in one or more portions of the reservoir, or in all portions of the reservoir. The retention material can be a foam material, a sponge material, or a collection of fibres. The retention material can be formed from a polymer or a copolymer. In one embodiment, the retention material is a spun polymer. The retention material can be formed from any of the materials described below as being suitable for a wicking element.

[0013] When the reservoir comprises a retention material, the wicking element can be in fluid communication with the retention material. The retention material can contact the susceptor assembly. In particular, the retention material can be in contact with the wicking element of the susceptor assembly.

[0014] When the wicking element is in fluid communication with the reservoir, it can advantageously transport liquid aerosol-forming substrate from the reservoir. As such, a proportion of the aerosol-forming substrate can be transported towards the first and second susceptor elements. The transport of aerosol-forming substrate can be a result of capillary action in the wicking element. In particular, the wicking element can be arranged to transport aerosol-forming substrate from the reservoir across the major surfaces of the first and second susceptor elements that are fixed to or integral with the wicking element.

[0015] The provision of the wicking element improves wetting of the first and second susceptor elements, and therefore increases the aerosol generated by the system. It allows the susceptor elements to be made from materials that do not provide good wicking or wetting properties by themselves.

[0016] The provision of the wicking element between the first susceptor element and the second susceptor element that is integral with or fixed to the wicking element can advantageously cause, in operation, the aerosol-forming substrate proximate to the susceptor elements to evaporate at the outer surface of the wicking element. As such, the generated vapour can be generated primarily on the interface between the susceptor elements and the wicking element. Therefore, the generated vapour can not need to pass through the bulk of the wicking element to escape from the wicking element, which can cause cooling and possible condensation of the vapour. This arrangement can advantageously facilitate a more direct production of aerosol following the provision of an alternating current to the inductor coil, and can be more efficient and consume less power.

[0017] The wicking element occupying the space between the first susceptor element and the second susceptor element can advantageously mean that, in operation, the wicking element is heated from two opposite sides. This can increase the amount of aerosol-forming substrate that is evaporated in a given time compared to a susceptor assembly comprising only one susceptor element.

[0018] Advantageously, the susceptor assembly can be configured to hold only a small volume of liquid aerosol-forming substrate sufficient for a single user puff. This is advantageous because it allows for rapid evaporation of the small volume of liquid and minimal heat loss to other elements of the system or to the unevaporated liquid aerosol-forming substrate. Advantageously, the susceptor assembly or the heating region of the susceptor assembly can hold between 2 and 10 millilitres of liquid aerosol-forming substrate.

[0019] The reservoir can be configured to hold at least twice the aerosol-forming substrate of the susceptor assembly. Preferably, the reservoir can be configured to hold at least 5, 10, 15 or even 20 times the aerosol-forming substrate of the susceptor assembly.

[0020] The reservoir can be configured to hold sufficient aerosol-forming substrate for at least 10 puffs, preferably at least 20 puffs, even more preferably at least 30 puffs. The reservoir can be configured to hold sufficient aerosol-forming substrate for at least 2 smoking sessions, preferably at least 3, 4, 5 or 6 smoking sessions. Each smoking session can comprise at least 4 puffs, preferably at least 5 puffs, even more preferably at least 6 puffs. This contrasts with the susceptor assembly which can be configured to hold at any one time only a volume of liquid aerosol-forming substrate sufficient for a single user puff as described above.

[0021] The first susceptor element and the second susceptor element can be fluid permeable. As used herein, a "fluid permeable" element means an element that allows a liquid or gas to permeate therethrough. The fluid permeable susceptor element can advantageously allow the evaporated aerosol-forming substrate to escape through the susceptor element. Thus, the aerosol-forming substrate vapour generated in the region of the wicking element immediately adjacent to the susceptor element can escape through the susceptor element without having to pass through the wicking element.

[0022] As used herein, a "susceptor element" means an element that can be heated by penetration of an alternating magnetic field. The susceptor element can typically be heated by at least one of Joule heating by eddy currents induced in the susceptor element and magnetic hysteresis losses. Possible materials for the susceptor element include graphite, molybdenum, silicon carbide, stainless steel, niobium, aluminium and almost any other electrically conductive element. Advantageously, the first susceptor element and the second susceptor element can be ferritic elements. The material and geometry of the susceptor element can be selected to provide a desired electrical resistance and heat generation. Preferably, the first susceptor element and the second susceptor element comprise AISI 430 stainless steel.

[0023] Advantageously, the first susceptor element and the second susceptor element can have a relative magnetic permeability between 1 and 40000. When a large portion of the heating is desired to rely on eddy currents, a material with a lower magnetic permeability can be used, while when a hysteresis effect is needed, a material with a higher magnetic permeability can be used. Preferably, the material has a relative magnetic permeability between 500 and 40000. This can provide efficient heating.

[0024] As used herein, "alternating current" means an electric current that periodically reverses direction. Driving an alternating current through at least one inductor coil causes the at least one inductor coil to generate an alternating magnetic field. The alternating magnetic field can have any suitable frequency for heating a heating region of a susceptor element located in the alternating magnetic field. A suitable frequency of the alternating current can be between 100 kilohertz (kHz) and 30 megahertz (MHz). The alternating current can have a frequency between 100 kilohertz (kHz) and 1 megahertz (MHz).

[0025] The thickness of each of the susceptor elements advantageously is of a similar order of magnitude as the skin depth of the material of the susceptor element at the operating frequency of the system. Advantageously, the susceptor assembly has a thickness that does not exceed ten times the skin depth of the material of the susceptor element at the operating frequency. This can ensure that each of the susceptor elements has a suitably low mass and, therefore, takes less time for the susceptor element to reach a temperature suitable for vaporizing the aerosol-forming substrate. When the susceptor elements are penetrated by the alternating magnetic field from opposite sides, each susceptor element can advantageously have a thickness that is at least twice the skin depth of the material of the susceptor element at the operating frequency. This can minimize the interaction of the skin effect on opposite sides of the susceptor element.

[0026] Each susceptor element can have a thickness of no more than two millimetres. Preferably, each susceptor element can have a thickness of one millimetre.

[0027] The first susceptor element and the second susceptor element can comprise or consist of electrically conductive filaments. The first susceptor element and the second susceptor element can comprise or consist of a web of electrically conductive filaments, a flat spiral coil of electrically conductive filaments, a fibre of electrically conductive filaments, or a fabric of electrically conductive filaments. As used herein, the term "web" encompasses a grid and an array of filaments with spaces therebetween. The term web also includes woven and non-woven fabrics. In operation, the vaporized aerosol-forming substrate can advantageously escape from the wicking element through the interstices between the electrically conductive filaments.

[0028] Although the wicking element transfers the aerosol-forming matrix from the reservoir to the first and second sensor elements via capillary action, the conductive filaments can also generate capillary action in the gaps between the filaments of the mesh to wet the first and second sensor elements. Wetting of the first and second sensor elements advantageously increases the contact area between the conductive filaments of the sensor elements and the aerosol-forming matrix.

[0029] The diameter of the conductive wire can be between 40 and 60 micrometers, preferably between 45 and 55 micrometers, and even more preferably 50 micrometers. The mesh size of the conductive wire mesh can be between 60 and 150 micrometers, preferably between 50 and 70 micrometers, even more preferably between 60 and 65 micrometers, and most preferably 63 micrometers. These dimensions are suitable for providing capillary action within the first and second sensor elements.

[0030] The percentage of the open area of ​​the net, which is the ratio of the area of ​​the gaps to the total area of ​​the net, is preferably between 25% and 56%. The net can be formed using different types of weaving or mesh structures. Alternatively, the filaments consist of an array of filaments arranged parallel to each other.

[0031] Wires can be formed by etching sheets such as foil. This can be particularly advantageous when the heater assembly includes an array of parallel wires. If the heating element comprises a web or fabric of wires, then the wires can be formed individually and woven together.

[0032] Preferably, the web is sintered. Advantageously, sintering the web creates an electrical bond between the filaments extending in different directions. In particular, when the web comprises one or more woven and nonwoven fabrics, it is advantageous to sinter the web to create an electrical bond between the overlapping filaments.

[0033] Alternatively, the first and second sensor elements may comprise or be constituted by a perforated foil. In operation, the evaporated aerosol-forming matrix can advantageously escape from the wicking element through the perforations in the perforated foil. The perforations can be uniformly distributed across the first and second sensor elements. Each sensor element can be perforated to allow vapor to escape from the sensor assembly or to allow the entry of the liquid aerosol-forming matrix.

[0034] Alternatively, each susceptor element can be printed on or otherwise deposited on the wicking element as a film or a plurality of tracks. Each susceptor element can comprise or consist of an electrically conductive material deposited directly onto the wicking element. The electrically conductive material of the first or second susceptor element can be deposited onto the wicking element as a plurality of tracks. In operation, the vaporised aerosol-forming substrate can advantageously escape from the wicking element through the gaps or spaces between the tracks. The plurality of tracks of each of the susceptor elements can advantageously be distributed over the surface of the wicking element to provide substantially uniform heating across the surface. For example, the width of each of the tracks and the spacing between the tracks can be substantially the same for each of the plurality of tracks. The plurality of tracks of each of the susceptor elements can comprise a first set of tracks parallel to each other. The plurality of tracks can further comprise a second set of tracks perpendicular to the first set of tracks and overlapping the first set of tracks. The first and second sets of tracks can together form a mesh-like structure.

[0035] The wicking element can comprise a capillary material. A capillary material is a material capable of transferring a liquid from one end of the material to the other end by means of capillary action. The capillary material can have a fibrous or sponge-like structure. The capillary material preferably comprises a bundle of capillaries. For example, the capillary material can comprise a plurality of fibres or wires or other fine bore tubes. The fibres or wires can be substantially aligned to transport the liquid aerosol-forming substrate across the major surface of each of the susceptor elements. In some embodiments, the capillary material can comprise a sponge-like or foam-like material. The structure of the capillary material can form a plurality of pores or tubes through which the liquid aerosol-forming substrate can be transported by capillary action. Where the susceptor element comprises voids or pores, the capillary material can extend into the voids or pores in the susceptor element. The susceptor element can draw the liquid aerosol-forming substrate into the voids or pores by capillary action. The wicking element can comprise or consist of an electrically insulating material. The wicking element can comprise a non-metallic material. The wicking element can comprise a hydrophilic material or a oleophilic material. This can advantageously facilitate the transport of the aerosol-forming substrate through the wicking element.

[0036] The wicking element can preferably comprise or consist of cotton, rayon or glass fibres.

[0037] Alternatively, the wicking element can comprise or consist of a porous ceramic material. A wicking element comprising a porous ceramic material can be particularly advantageous when one or both of the susceptor elements comprises an electrically conductive material printed on or otherwise deposited onto the wicking element. A wicking element comprising a porous ceramic material can be a suitable substrate for the manufacturing process associated with the printing or deposition of the electrically conductive material.

[0038] The first susceptor element of the susceptor assembly can be electrically isolated from the second susceptor element of the susceptor assembly.

[0039] The substantially planar susceptor assembly can extend parallel to a first plane. The aerosol-generating system can comprise a first inductor coil positioned on a first side of the susceptor assembly and extending parallel to the first plane and a second inductor coil positioned on a second side of the susceptor assembly opposite the first side and extending parallel to the first plane. The susceptor assembly can be positioned between the first inductor coil and the second inductor coil. The aerosol-generating system can comprise a control circuit connected to the first inductor coil and the second inductor coil and configured to provide an alternating current to the first inductor coil and the second inductor coil. Advantageously, the susceptor assembly can be substantially equidistant from the first inductor coil and the second inductor coil.

[0040] The arrangement can provide for efficient heating of the susceptor elements of the susceptor assembly and create conditions for a balance of forces exerted on the susceptor assembly by the magnetic fields generated by the first inductor coil and the second inductor coil. Advantageously, the control circuit is configured to provide a current to the inductor coils such that the first inductor coil provides an equal and opposite force on the susceptor assembly to the second inductor coil. The first inductor coil can generate a magnetic field opposite to the magnetic field generated by the second inductor coil.

[0041] In this context, a planar susceptor element is a susceptor element having a length and a width that are much larger than the thickness. The ratio of the length to the width can be between 0.4 and 1.6. Preferably, the ratio of the length to the width can be between 0.6 and 1.4. Even more preferably, the ratio of the length to the width can be between 0.8 and 1.2.

[0042] The length and width directions are orthogonal to each other and define a first plane. The thickness extends orthogonal to the first plane. The planar susceptor element can have two opposing major surfaces extending in a plane parallel to the first plane. One or both major surfaces are advantageously flat.

[0043] In this context, a susceptor assembly that is substantially equidistant from the first inductor coil and the second inductor coil means that the shortest distance between the first inductor coil and the susceptor assembly is between 0.8 and 1.2 times the shortest distance between the second inductor coil and the susceptor assembly. Preferably, the shortest distance between the first inductor coil and the susceptor assembly is between 0.85 and 1.15 times the shortest distance between the second inductor coil and the susceptor assembly. More preferably, the shortest distance between the first inductor coil and the susceptor assembly is between 0.9 and 1.1 times the shortest distance between the second inductor coil and the susceptor assembly. Even more preferably, the shortest distance between the first inductor coil and the susceptor assembly is substantially the same as the shortest distance between the second inductor coil and the susceptor assembly.

[0044] Advantageously, the first inductor coil and the second inductor coil are planar inductor coils. In this context, a planar inductor coil means a coil that lies in a plane that is perpendicular to the axis of winding of the coil. The planar inductor coils can be compact. The planar inductor coils can each lie in a plane that is parallel to the first plane.

[0045] The system can be configured such that at least one inductor coil provides a magnetic field at the susceptor assembly that is perpendicular to the first plane. The system can be configured such that the first inductor coil and the second inductor coil provide a magnetic field at the susceptor assembly that is perpendicular to the first plane. This allows for efficient heating of the susceptor element. The inventors have also found that this arrangement facilitates efficient heating of the first susceptor element and the second susceptor element, such that a lower current alternating frequency can be used. For example, an alternating current having a frequency of between 100 kHz and 1 MHz can be used. The lower frequency can allow for the use of simpler electronics to supply the alternating current.

[0046] The first planar inductor coil and the second planar inductor coil can have any shape, but in one advantageous embodiment, each of the planar inductor coils is rectangular. The planar inductor coils can advantageously have a size and shape that corresponds to the heating region of the susceptor element. The first inductor coil can have the same number of turns as the second inductor coil. The first inductor coil can have the same size and shape as the second inductor coil. The first inductor coil can be substantially identical to the second inductor coil. The first inductor coil can have the same resistance as the second inductor coil. The first inductor coil can have the same inductance as the second inductor coil.

[0047] In one embodiment, the inductor coils are electrically connected to form a single conductive path, and wherein the first inductor coil is wound in an opposite direction to the second inductor coil. The first inductor coil and the second inductor coil can then be supplied with the same alternating current.

[0048] In another embodiment, the first inductor coil is wound in the same direction as the second inductor coil. The control circuit is configured to provide a current to the first inductor coil that is directly out of phase with the current provided to the second inductor coil.

[0049] Advantageously, the aerosol-generating system can comprise one or more flux concentrators configured to contain the magnetic field generated by the inductor coil. The one or more flux concentrators can be configured to concentrate the magnetic field on the susceptor assembly, preferably perpendicular to the first plane.

[0050] Each susceptor element of the susceptor assembly can comprise a heating region and at least one mounting region. The first susceptor element and the second susceptor element can have the same shape as each other. The heating region and the at least one mounting region of the first susceptor element can correspond to the heating region and the at least one mounting region of the second susceptor element. Features of the heating region or the at least one mounting region described in relation to one of the first susceptor element and the second susceptor element can equally apply to the other of the first susceptor element and the second susceptor element.

[0051] The heating region can be a region of the susceptor element that is configured to heat to a temperature required to vaporise the aerosol-forming substrate upon penetration by a suitable alternating magnetic field.

[0052] The heating region can comprise a first material that is a magnetic material that is heatable by penetration by an alternating magnetic field. The term "magnetic material" is used herein to describe a material that is capable of interacting with a magnetic field, including both paramagnetic and ferromagnetic materials. The first material can be any suitable magnetic material that is heatable by penetration by an alternating magnetic field. In some preferred embodiments, the first material comprises a ferritic stainless steel. Suitable ferritic stainless steels include AISI 400 series stainless steels, such as AISI 409, 410, 420 and 430 stainless steels.

[0053] In some preferred embodiments, the heating region is composed of the first material. However, in other embodiments, the heating region comprises the first material and one or more other materials. Where the heating region comprises the first material and one or more other materials, the heating region can comprise the first material in any suitable proportion. For example, the heating region can comprise at least 10% by weight of the first material, or at least 20% by weight of the first material, or at least 30% by weight of the first material, or at least 40% by weight of the first material, or at least 50% by weight of the first material, or at least 60% by weight of the first material, or at least 70% by weight of the first material, or at least 80% by weight of the first material, or at least 90% by weight of the first material.

[0054] The at least one mounting region of each of the susceptor elements is a region configured to contact the susceptor assembly holder. The at least one mounting region can be in contact with the susceptor assembly holder. As used herein, the term "contact" means both direct contact and indirect contact. The heating region can be configured to heat to substantially higher temperatures than the mounting region in the presence of an alternating magnetic field. This can be due to a material difference between the heating region and the mounting region, a geometric difference between the heating region and the mounting region, or both a material and geometric difference. The heating region can be located in the space directly between the first inductor coil and the second inductor coil, and the mounting region can be located outside the space directly between the first inductor coil and the second inductor coil. The mounting region can have a smaller width or length in the first plane than the heating region.

[0055] Preferably, the at least one mounting region is in direct contact with the susceptor assembly holder. As used herein, the term "direct contact" means contact between two components without any intervening material such that surfaces of the two components are in contact with each other.

[0056] The at least one mounting region of each susceptor element can be in indirect contact with the susceptor assembly holder. As used herein, the term 'indirect contact' is used to mean contact between two components via one or more intervening materials interposed between the two components such that surfaces of the two components are not in contact with each other. For example, the at least one mounting region of each susceptor element is in indirect contact with the susceptor assembly holder when an adhesive element is provided between a surface of the at least one mounting region and a surface of the susceptor assembly holder.

[0057] In some preferred embodiments, the at least one mounting region can extend into the reservoir. In some preferred embodiments, the heating region of each of the susceptor elements can be arranged outside the reservoir. Advantageously, arranging each of the susceptor elements substantially outside the reservoir, and in particular arranging the heating region of each of the susceptor elements outside the reservoir, can ensure that the aerosol-forming substrate is not sufficiently heated to release volatile compounds until after the aerosol-forming substrate has been transported outside the reservoir. This can facilitate release of volatile compounds from the aerosol-generating system.

[0058] The at least one mounting region of each of the susceptor elements can include a second material. The second material can be a non-magnetic material. The term "non-magnetic material" is used herein to describe a material that does not interact with a magnetic field and cannot be heated by penetration of an alternating magnetic field. The second material can be any suitable non-magnetic material. In some embodiments, the second material is a non-magnetic metal. For example, the second material can be a non-magnetic austenitic stainless steel. Suitable austenitic stainless steels include AISI 300 series stainless steels, such as AISI 304, 309, and 316 types of stainless steel.

[0059] The susceptor assembly retainer can be in contact with the second material at the at least one mounting region of each of the susceptor elements. The susceptor assembly retainer can contact each susceptor element only at the second material. Advantageously, providing contact between the susceptor assembly retainer and the susceptor elements at the second material can help to minimize heat transfer from the susceptor elements to the susceptor assembly retainer.

[0060] In some embodiments, the second material is non-metallic. For example, the second material can be a ceramic material.

[0061] In some embodiments, the second material is an electrically conductive material. As used herein, an "electrically conductive" material means a material having a volume resistivity less than about 1 x 10 -5 ohm-meters (Qm) at 20 degrees Celsius (°C), typically between about 1 x 10 -5 ohm-meters (Qm) and about 1 x 10 -9 ohm-meters (Qm). Suitable electrically conductive materials include metals, alloys, electrically conductive ceramics, and electrically conductive polymers. Suitable electrically conductive materials can include gold and platinum.

[0062] In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimize heat transfer from each of the susceptor elements to the susceptor assembly retainer. As used herein, an "electrically insulating" material means a material having a volume resistivity greater than about 1 x 10 6 ohm-meters (Qm) at 20 degrees Celsius (°C), typically between about 1 x 10 9 ohm-meters (Qm) and about 1 x 10 21 ohm-meters (Qm). Suitable electrically insulating materials include glasses, plastics, and certain ceramic materials.

[0063] In some embodiments, the second material is a thermally insulating material. Advantageously, a thermally insulating second material can help to minimise the transfer of heat from each of the susceptor elements to the susceptor assembly holder. As used herein, the term "thermally insulating" refers to a material having a volumetric thermal conductivity of less than about 5 Watts per meter Kelvin (mW / (m K)) at 23 °C and 50% relative humidity as measured using the Modified Transient Plane Source (MTPS) method.

[0064] In some embodiments, the second material is a thermally conductive material. As used herein, the term "thermally conductive" refers to a material having a volumetric thermal conductivity of at least about 10 Watts per meter Kelvin (mW / (m K)) at 23 °C and 50% relative humidity as measured using the Modified Transient Plane Source (MTPS) method.

[0065] In some embodiments, the second material can be a hydrophilic material. In some embodiments, the second material can be an oleophilic material. Advantageously, providing a hydrophilic second material or an oleophilic second material can facilitate the transport of aerosol-forming substrate through each of the susceptor elements.

[0066] In some embodiments, the second material comprises a cellulosic material. For example, the second material can comprise rayon.

[0067] In some preferred embodiments, the at least one mounting region of each of the susceptor elements is composed of the second material. However, in other embodiments, the at least one mounting region comprises the second material and one or more other materials. Where the at least one mounting region comprises the second material and one or more other materials, the at least one mounting region can comprise any suitable proportion of the second material. For example, the at least one mounting region of the susceptor element can comprise at least 10% by weight of the second material, or at least 20% by weight of the second material, or at least 30% by weight of the second material, or at least 40% by weight of the second material, or at least 50% by weight of the second material, or at least 60% by weight of the second material, or at least 70% by weight of the second material, or at least 80% by weight of the second material, or at least 90% by weight of the second material.

[0068] The at least one mounting region of each susceptor element can include the first material. However, the at least one mounting region includes a lower proportion of the first material than the heating region. The proportion by weight of the first material in the heating region can be greater than the proportion by weight of the first material in the at least one mounting region. For example: the heating region of the susceptor element can include at least 90% by weight of the first material, and the at least one mounting region of the susceptor element can include less than 10% by weight of the first material, or the heating region of the susceptor element can include at least 80% by weight of the first material, and the at least one mounting region of the susceptor element can include less than 20% by weight of the first material, or the heating region of the susceptor element can include at least 70% by weight of the first material, and the at least one mounting region of the susceptor element can include less than 30% by weight of the first material, or the heating region of the susceptor element can include at least 60% by weight of the first material, and the at least one mounting region of the susceptor element can include less than 40% by weight of the first material, or the heating region of the susceptor element can include at least 50% by weight of the first material, and the at least one mounting region of the susceptor element can include less than 50% by weight of the first material.

[0069] The at least one mounting region of each susceptor element can include: 90% or less by weight of the first material, or 80% or less by weight of the first material, or 70% or less by weight of the first material, or 60% or less by weight of the first material, or 50% or less by weight of the first material, or 40% or less by weight of the first material, or 30% or less by weight of the first material, or 20% or less by weight of the first material, or 10% or less by weight of the first material.

[0070] The at least one mounting region of each susceptor element can include: at least 10% by weight of the second material, and less than 90% by weight of the first material, or at least 20% by weight of the second material, and less than 80% by weight of the first material, or at least 30% by weight of the second material, and less than 70% by weight of the first material, or at least 40% by weight of the second material, and less than 60% by weight of the first material, or at least 50% by weight of the second material, and less than 50% by weight of the first material, or at least 60% by weight of the second material, and less than 40% by weight of the first material, or at least 70% by weight of the second material, and less than 30% by weight of the first material, or at least 80% by weight of the second material, and less than 20% by weight of the first material, or at least 90% by weight of the second material, and less than 10% by weight of the first material.

[0071] The heating region of each of the susceptor elements can comprise the second material. For example, the heating region can comprise: 90% or less by weight of the second material, or 80% or less by weight of the second material, or 70% or less by weight of the second material, or 60% or less by weight of the second material, or 50% or less by weight of the second material, or 40% or less by weight of the second material, or 30% or less by weight of the second material, or 20% or less by weight of the second material, or 10% or less by weight of the second material.

[0072] The heating region of each of the susceptor elements can comprise: at least 10% by weight of the first material, and less than 90% by weight of the second material, or at least 20% by weight of the first material, and less than 80% by weight of the second material, or at least 30% by weight of the first material, and less than 70% by weight of the second material, or at least 40% by weight of the first material, and less than 60% by weight of the second material, or at least 50% by weight of the first material, and less than 50% by weight of the second material, or at least 60% by weight of the first material, and less than 40% by weight of the second material, or at least 70% by weight of the first material, and less than 30% by weight of the second material, or at least 80% by weight of the first material, and less than 20% by weight of the second material, or at least 90% by weight of the first material, and less than 10% by weight of the second material.

[0073] The heating region can comprise any suitable proportion of the susceptor element. For example, the heating region can comprise at least 90% of the surface area of the susceptor element, at least 80% of the surface area of the susceptor element, or at least 70% of the surface area of the susceptor element. The heating region can have any suitable size and shape for heating the aerosol-forming substrate at the required rate to generate the desired amount of inhalable aerosol.

[0074] The at least one mounting region can comprise any suitable proportion of the susceptor element. Typically, the at least one mounting region comprises a smaller proportion of the susceptor element than the heating region. For example, the at least one mounting region can comprise 10% or less of the surface area of the susceptor element, or 20% or less of the surface area of the susceptor element, or 30% or less of the surface area of the susceptor element. The at least one mounting region can have any suitable size and shape for providing a robust connection between the susceptor element and the susceptor assembly holder.

[0075] In some embodiments, the at least one mounting region is located near a perimeter of the heating region, where the heating region has a length and a width, and the at least one mounting region has a length and a width. Preferably, the length of the at least one mounting region is less than the length of the heating region. In some embodiments, the length of the at least one mounting region is no more than half the length of the heating region. In some embodiments, the length of the at least one mounting region is no more than a quarter of the length of the heating region. Preferably, the width of the at least one mounting region is less than the width of the heating region. In some embodiments, the width of the at least one mounting region is no more than half the width of the heating region. In some embodiments, the width of the at least one mounting region is no more than a quarter of the width of the heating region.

[0076] In some embodiments, the at least one mounting region of each of the susceptor elements is secured to the susceptor assembly holder. The at least one mounting region can be secured to the susceptor assembly holder by an adhesive.

[0077] The at least one mounting region of each of the susceptor elements can be arranged at any suitable location relative to the heating region of each of the susceptor elements. In some preferred embodiments, the at least one mounting region of each of the susceptor elements is at a perimeter of the respective susceptor element. For example, the at least one mounting region can be at a side of the susceptor element.

[0078] In some preferred embodiments, the at least one mounting region comprises a plurality of mounting regions. Each susceptor element can comprise any suitable number of mounting regions. For example, each susceptor element can comprise one, two, three, four, five, or six mounting regions. Advantageously, providing a susceptor element with a plurality of mounting regions can enable the susceptor assembly holder to provide a more robust support for the susceptor assembly compared to a susceptor element with a single mounting region.

[0079] In some embodiments, the plurality of mounting regions can comprise a first mounting region and a second mounting region, the first mounting region being positioned at a side of the respective susceptor element, and the second mounting region being positioned at the same side of the susceptor element as the first mounting region. In some of these embodiments, the first mounting region is positioned at a first end of the susceptor element, and the second mounting region is positioned at a second end of the susceptor element opposite the first end.

[0080] In some embodiments, the plurality of mounting regions includes a first mounting region and a second mounting region, the first mounting region is positioned at a first side of the susceptor element, and the second mounting region is positioned at a second side of the susceptor element opposite the first side. In some of these embodiments, the heating region has a length, and the first mounting region and the second mounting region are positioned at the same location along the length of the heating region. In some of these embodiments, the first mounting region and the second mounting region are positioned at one end of the susceptor element. In some of these embodiments, the heating region has a length, and the first mounting region and the second mounting region are positioned centrally along the length of the heating region. In some of these embodiments, the heating region has a length, and the first mounting region and the second mounting region are positioned at different locations along the length of the heating region. In some of these embodiments, the first mounting region is positioned at a first end of the susceptor element, and the second mounting region is positioned at a second end of the susceptor element opposite the first end.

[0081] In some preferred embodiments, the plurality of mounting regions includes a first mounting region and a second mounting region, the second mounting region is positioned opposite the first mounting region.

[0082] In some preferred embodiments, the plurality of mounting regions includes a first pair of mounting regions positioned at a first end of the susceptor element at opposite sides of the susceptor element, and a second pair of mounting regions positioned at a second end of the susceptor element at opposite sides of the susceptor element, the second end of the susceptor element being opposite the first end.

[0083] In some embodiments, the plurality of mounting regions includes a plurality of pairs of mounting regions, each pair of mounting regions including a first mounting region positioned at a first side of the susceptor element, and a second mounting region positioned at a second side of the susceptor element opposite the first side of the susceptor element.

[0084] In some embodiments, the plurality of mounting regions includes a plurality of pairs of mounting regions, each pair of mounting regions including a first mounting region and a second mounting region, the second mounting region being positioned opposite the first mounting region.

[0085] In cases where the susceptor element includes a mesh, the heating region can include filaments of a first material. In some embodiments, the heating region can include filaments of a first material and filaments of a second material. The heating region can include filaments of a first material in a first direction, and filaments of a second material in a second direction different from the first direction.

[0086] In cases where the susceptor element includes a mesh, the at least one mounting region can include filaments of the second material. In some embodiments, the at least one mounting region can include filaments of the first material and filaments of the second material. The at least one mounting region can include filaments of the first material in a first direction, and filaments of the second material in a second direction different from the first direction.

[0087] In cases where the susceptor element includes a mesh, the mesh can be woven. A woven mesh includes filaments in a weft direction and filaments in a warp direction.

[0088] In cases where the susceptor element includes a woven mesh, the at least one mounting region can include filaments of the second material in the weft direction. The susceptor assembly holder can contact the susceptor element at the at least one mounting region only at the filaments in the weft direction, and not at the filaments in the warp direction. Advantageously, the filaments in the weft direction formed of the second material at the at least one mounting region can reduce heat transfer from the susceptor element to the susceptor assembly holder compared to a susceptor element having filaments in the weft direction formed of the first material at the at least one mounting region.

[0089] In cases where the susceptor element includes a woven mesh, the at least one mounting region can include filaments of the first material in the weft direction, and filaments of the second material in the warp direction, and the at least one mounting region can include filaments of the second material in the weft direction, and filaments of the second material in the warp direction.

[0090] In cases where the susceptor element includes a woven mesh, the at least one mounting region can be composed of filaments of the first material in the weft direction, and filaments of the second material in the warp direction, and the at least one mounting region can be composed of filaments of the second material in the weft direction, and filaments of the second material in the warp direction.

[0091] In cases where the susceptor elements each include a woven mesh, the at least one mounting region can include filaments of the first material in the warp direction, and filaments of the second material in the weft direction, and the at least one mounting region can include filaments of the second material in the warp direction, and filaments of the second material in the weft direction.

[0092] In cases where the susceptor elements each include a woven mesh, the at least one mounting region can be composed of filaments of the first material in the warp direction, and filaments of the second material in the weft direction, and the at least one mounting region can be composed of filaments of the second material in the warp direction, and filaments of the second material in the weft direction.

[0093] In the case where the susceptor elements each comprise a woven mesh, the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the first material along the warp direction, and the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the second material along the warp direction.

[0094] In the case where the susceptor elements each comprise a woven mesh, the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the first material along the warp direction, and the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the second material along the warp direction.

[0095] In the case where the susceptor elements each comprise a woven mesh, the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the first material along the warp direction, and the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the second material along the warp direction.

[0096] In the case where the susceptor elements each comprise a woven mesh, the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the first material along the warp direction, and the at least one mounting region can comprise filaments of the first material along the weft direction, and filaments of the second material along the warp direction.

[0097] Advantageously, the aerosol-generating system can further comprise an airflow pathway extending between the air inlet and the air outlet. The air outlet can be defined in a mouthpiece of the system. In operation, a user of the system can draw air through the mouthpiece.

[0098] A portion of the susceptor assembly can be within the airflow pathway. Airflow in the airflow pathway can pass over the surface of the first susceptor element and the surface of the second susceptor element. Airflow in the airflow pathway can pass over the heating region of the first susceptor element and the second susceptor element. Thus, in operation, aerosol-forming substrate that has been vaporised at the interface between the first susceptor element and the second susceptor element and the wicking element can advantageously pass directly into the airflow pathway through the first susceptor element and the second susceptor element. The vapour can condense to form an aerosol within the airflow pathway. The aerosol can be drawn out of the aerosol-generating system through the air outlet. The air outlet can be provided in a mouth end of the aerosol-generating system through which a user can draw generated aerosol.

[0099] The wicking element can be in fluid communication with the reservoir as a portion of the wicking element protrudes into the reservoir. The reservoir can comprise a fluid passageway extending towards the susceptor assembly. Liquid aerosol-forming substrate can flow in the passageway to the susceptor assembly. At least a portion of the wicking element can protrude into the passageway. As described above, the at least one mounting region of each of the susceptor elements can extend into the reservoir.

[0100] The housing can comprise an inner wall and an outer wall, such that the internal passageway is defined by the inner wall. The internal passageway can be surrounded by a space defined between the inner wall and the outer wall. The space surrounding the internal passageway can be an annular space.

[0101] The airflow passage can be at least partially defined by the internal passageway. The reservoir can be at least partially defined by the space surrounding the internal passageway. In this arrangement, at least a portion of the airflow passage can pass through the reservoir.

[0102] Alternatively, the reservoir can be at least partially defined by the internal passageway, and the airflow passage can be at least partially defined by the space surrounding the internal passageway.

[0103] Having the internal passageway at least partially define one of the airflow passage or the reservoir, and having the space surrounding the internal passageway at least partially define the other, advantageously provides a compact aerosol-generating system. It also allows the system to be manufactured to be symmetrical and balanced, which is advantageous when the system is a hand-held system. Furthermore, these arrangements result in the airflow passage being in close proximity to the reservoir, such that the reservoir can advantageously have a cooling effect on the air in the airflow passage, which can promote the formation of aerosol in the airflow passage.

[0104] As described above, the aerosol-generating system can comprise a susceptor assembly holder, the susceptor assembly being mounted on the susceptor assembly holder. At least one mounting region of the first susceptor element and the second susceptor element can contact the holder. The susceptor assembly holder can be tubular having at least one side wall. The susceptor assembly can be mounted through at least one opening through the side wall. The susceptor assembly can be mounted through at least two openings through the side wall.

[0105] The susceptor assembly holder can be configured to withstand the susceptor assembly being raised to a temperature for heating an aerosol-forming substrate.

[0106] The susceptor assembly holder can be formed of any suitable material capable of withstanding the susceptor being raised to a temperature for heating an aerosol-forming substrate. Preferably, the susceptor assembly holder comprises a thermally insulating material. Advantageously, forming the susceptor assembly holder from a thermally insulating material can minimise heat transfer from the susceptor elements to the susceptor assembly holder. Preferably, the susceptor assembly holder comprises an electrically insulating material. The susceptor assembly holder can be formed of a durable material. The susceptor assembly holder can be formed of a liquid-impermeable material. The susceptor holder can be formed of a mouldable plastics material, such as polypropylene (PP) or polyethylene terephthalate (PET).

[0107] The susceptor holder can have any suitable shape and size.

[0108] At least one side wall of the susceptor assembly holder can form at least a portion of an inner wall of the housing. In such cases, at least one side wall of the housing can define a portion of the internal passageway. The space between the inner wall and the outer wall can be at least partially defined between the at least one side wall and the outer wall of the housing. In some preferred embodiments, the susceptor assembly holder is tubular.

[0109] In some embodiments, the susceptor assembly extends into the internal passageway of the susceptor holder. In some preferred embodiments, the first susceptor element and the second susceptor element extend into the internal passageway of the susceptor holder. The first susceptor element and the second susceptor element can extend across the internal passageway of the susceptor assembly holder. Where the first susceptor element and the second susceptor element extend across the internal passageway of the susceptor holder, the first susceptor element and the second susceptor element can include a first mounting region at a first side of each of the susceptor elements in contact with the susceptor holder, and a second mounting region at a second side of each of the susceptor elements opposite the first side in contact with the susceptor holder. Advantageously, arranging the susceptor elements to contact the susceptor holder at opposite sides can enable the susceptor holder to robustly secure the susceptor elements in place in the cartridge.

[0110] The internal passageway can extend substantially along a longitudinal axis. In some embodiments, the susceptor assembly is substantially planar, and the susceptor assembly extends parallel to the longitudinal axis. In some embodiments, the susceptor assembly is substantially planar, and the susceptor assembly extends perpendicular to the longitudinal axis.

[0111] In some embodiments, the internal passageway of the susceptor assembly holder can form a portion of an air passageway of the cartridge, and the space surrounding the internal passageway defined between the susceptor assembly holder and an outer housing of the system can form a portion of a reservoir. In these embodiments, the heating region of the susceptor element can be arranged in the internal passageway of the susceptor holder, and the at least one mounting region can be arranged in the space.

[0112] In some embodiments, the internal passageway of the susceptor assembly holder can form a portion of a reservoir of the cartridge, and the space surrounding the internal passageway defined between the susceptor assembly holder and an outer housing of the system can form a portion of an air passageway. In these embodiments, the at least one mounting region of the susceptor element can extend into the internal passageway of the susceptor holder, and the heating region can extend into the space.

[0113] The tubular susceptor assembly holder can have an open end such that the internal passageway of the susceptor holder is open at at least one end. At least one side wall of the tubular susceptor holder can define an opening between the ends of the tubular susceptor holder. At least one mounting region of the susceptor element can extend into the opening of the tubular susceptor holder. In some embodiments in which the susceptor element comprises a plurality of mounting regions, at least one side wall of the tubular susceptor holder defines a plurality of openings between the ends of the tubular susceptor holder. In these embodiments, each mounting region of the susceptor element can extend into one of the plurality of openings of the at least one side wall of the tubular susceptor holder.

[0114] The susceptor assembly holder can comprise an electrically insulating material. Suitable electrically insulating materials include glass, plastics and certain ceramic materials.

[0115] The susceptor assembly holder can comprise a thermally insulating material.

[0116] The susceptor assembly holder can be moulded onto the susceptor assembly. The moulded holder can hold the first susceptor element and the second susceptor element and the wicking element together such that the elements are fixed together. The holder can be formed from a heat resistant plastics material or a ceramic material. The holder can therefore support the susceptor assembly and provide strength to the susceptor assembly.

[0117] The susceptor assembly can be surrounded by a permeable electrically insulating coating. The coating can comprise or consist of a permeable ceramic material. The coating can be a ceramic coating. When the susceptor assembly comprises a coating, it can be a coating that holds the first susceptor element and the second susceptor element and the wicking element together such that the elements are fixed together. The coating can advantageously improve the robustness and strength of the susceptor assembly. The provision of the coating can be instead of or in addition to the holder as described above. The coating can comprise AI2O3 or a silicon-based ceramic material. The coating can have a porosity of about 30%.

[0118] At least a portion of the susceptor assembly holder can comprise a porous or permeable material, such as a ceramic material. The portion can be a region of the susceptor assembly on which the mounting region of the susceptor assembly is mounted. Aerosol-forming substrate from the reservoir can pass through the portion of the susceptor assembly holder to the mounting region of the susceptor assembly. This advantageously provides a route for aerosol-forming substrate from the reservoir to the susceptor assembly and can increase the amount of aerosol-forming substrate supplied to the susceptor assembly.

[0119] The portion of the susceptor assembly holder comprising a porous or permeable material can comprise AI2O3 or a silicon-based ceramic material. The portion can have a porosity of about 30%.

[0120] The susceptor assembly can further include a third susceptor element and a second wicking element positioned between the first susceptor element and the third susceptor element or the second susceptor element and the third susceptor element. There can be other wicking elements between other susceptor elements.

[0121] The aerosol-generating system can include a second susceptor assembly. The second susceptor assembly can be substantially similar in structure to the first susceptor assembly. The second susceptor assembly can also be mounted on the susceptor assembly holder. The second susceptor assembly can be mounted on the same susceptor assembly holder as the first susceptor assembly. When the susceptor assembly holder is tubular, the second susceptor assembly can be mounted on the side of the susceptor assembly holder opposite the first susceptor assembly. This arrangement can be particularly advantageous when the internal passageway of the susceptor assembly holder forms part of the reservoir of the cartridge and the annular space defined between the susceptor assembly and the outer housing forms at least part of the airflow passage. At least one mounting region of the susceptor elements of each of the susceptor assemblies can protrude into the internal passageway and the heating region can extend into the annular space. Thus, the heating regions of the first and second susceptor assemblies can be evenly spaced around the airflow passage, resulting in more even aerosol production.

[0122] The aerosol-generating system can include other susceptor assemblies. Each of these susceptor assemblies can be mounted on the susceptor assembly holder. The susceptor assemblies can be mounted on the susceptor assembly holder so that they are evenly distributed around the airflow passage.

[0123] The aerosol-forming substrate is a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating the aerosol-forming substrate.

[0124] The aerosol-forming substrate can comprise plant-based material. The aerosol-forming substrate can comprise tobacco. The aerosol-forming substrate can comprise tobacco-containing material comprising volatile tobacco flavour compounds which are released from the aerosol-forming substrate on heating. Alternatively, the aerosol-forming substrate can comprise tobacco-free material. The aerosol-forming substrate can comprise homogenised plant-based material. The aerosol-forming substrate can comprise homogenised tobacco material. The aerosol-forming substrate can comprise at least one aerosol-former. An aerosol-former is any suitable known compound or mixture of compounds which in use is beneficial in forming a dense and stable aerosol and which is substantially resistant to thermal degradation at the operating temperature 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 glycerol; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or poly-carboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate. A preferred aerosol-former is a polyhydric alcohol or mixture thereof, for example triethylene glycol, 1,3-butanediol and most preferably glycerol. The aerosol-forming substrate can comprise other additives and ingredients such as flavourings.

[0125] The system can further comprise a circuit connected to the at least one inductor coil and the power source. The circuit can comprise a microprocessor, which can be a programmable microprocessor, a microcontroller or an application specific integrated chip (ASIC) or other electronic circuit capable of providing control. The circuit can comprise further electronic components. The circuit can be configured to regulate the supply of current to the inductor coil. The current can be supplied to the inductor coil continuously after the system is activated or can be supplied intermittently on a puff-by-puff basis. The circuit can advantageously comprise a DC / AC converter, which can comprise a class D or class E power amplifier. The control circuit can comprise other electronic components. For example, in some embodiments the control circuit can comprise any of sensors, switches, display elements.

[0126] The aerosol-generating system can comprise a power source. The power source can be contained in the device of the system. The power source can be a DC power source. The power source can be a battery. The battery can be a lithium-based battery, for example a lithium cobalt, lithium iron phosphate, lithium titanate or lithium polymer battery. The battery can be a nickel metal hydride battery or a nickel cadmium battery. The power source can be another form of charge storage device, for example a capacitor. The power source can be rechargeable and configured for a number of charge-discharge cycles. The power source can have a capacity that allows for the storage of sufficient energy for one or more user experiences of the aerosol-generating system; for example, the power source can have sufficient capacity to allow for the continuous generation of aerosol for a period of about six minutes, corresponding to the typical time taken to smoke a conventional cigarette, or for a period that is a multiple of six minutes. In another example, the power source can have sufficient capacity to allow for a predetermined number of puffs or discrete activations of the atomiser assembly.

[0127] An aerosol-generating system can comprise an aerosol-generating device and a cartridge configured to be used with the device. The aerosol-generating device can comprise at least one inductor coil, a power supply, and a device housing. The device housing can be configured to engage at least a portion of the cartridge when the cartridge is used with the aerosol-generating device. The cartridge can comprise a susceptor assembly. The cartridge can further comprise a cartridge housing. The at least one inductor coil can be positioned around or adjacent to the susceptor assembly when the cartridge is engaged with the aerosol-generating device. When the aerosol-generating system comprises a first inductor coil and a second inductor coil, the first inductor coil can be positioned on a first side of the cartridge and the second inductor coil can be positioned on a second side of the cartridge when the cartridge is engaged with the aerosol-generating device. A portion of the cartridge comprising the susceptor assembly of the cartridge can be located between the first inductor coil and the second inductor coil when the cartridge is engaged with the aerosol-generating device.

[0128] The cartridge housing can comprise a housing defining a reservoir. The cartridge can comprise a holder for the susceptor assembly.

[0129] According to the present disclosure, there is also provided a cartridge for use in an electrically heated aerosol-generating system comprising an aerosol-generating device. The cartridge can be configured to be used with the device. The device can comprise a device housing which can be configured to engage at least a portion of the cartridge when the cartridge is used with the aerosol-generating device. The aerosol-generating device can comprise at least one inductor coil. The aerosol-generating device can comprise a power supply connected to the at least one inductor coil. The power supply can be configured to provide an alternating current to the at least one inductor coil such that the inductor coil generates an alternating magnetic field within the cartridge. The cartridge can comprise a cartridge housing. The cartridge housing can define a reservoir containing an aerosol-forming substrate. The cartridge can comprise a substantially planar susceptor assembly. The substantially planar susceptor assembly can extend parallel to a first plane. The susceptor assembly can be configured to be heated by the alternating magnetic field. The susceptor assembly can comprise a first susceptor element. The susceptor assembly can comprise a second susceptor element. The susceptor assembly can comprise a wicking element in fluid communication with the reservoir. The first susceptor element and the second susceptor element can be integral with or fixed to the wicking element. A space can be defined between the first susceptor element and the second susceptor element. The wicking element can occupy the space. The reservoir can be located outside the space.

[0130] The housing of the aerosol-generating device can be elongate. The housing of the aerosol-generating device can comprise any suitable material or combination of materials. Examples of suitable materials include a metal, an alloy, a plastic or a composite material comprising one or more of those materials, or a thermoplastic material suitable for food or pharmaceutical applications, such as polypropylene, polyether ether ketone (PEEK) and polyethylene. Preferably, the material is lightweight and non-brittle.

[0131] The aerosol-generating device housing can define a cavity for receiving the cartridge. The aerosol-generating device can comprise one or more air inlets. The one or more air inlets can enable ambient air to be drawn into the cavity.

[0132] The aerosol-generating device can have a connection end configured to connect the aerosol-generating device to the cartridge. The connection end can comprise a cavity for receiving the cartridge.

[0133] The aerosol-generating device can have a distal end opposite the connection end. The distal end can comprise an electrical connector configured to connect to an electrical connector of an external power source for charging a power source of the aerosol-generating device.

[0134] The cartridge can comprise an outer housing. The outer housing can be formed from a durable material. The outer housing can be formed from a liquid-impermeable material. The outer housing can be formed from a mouldable plastics material such as polypropylene (PP) or polyethylene terephthalate (PET). The outer housing can be formed from the same material as the susceptor holder, or can be formed from a different material.

[0135] The susceptor assembly can be arranged in the outer housing. The susceptor assembly holder can be arranged in the outer housing. In some embodiments, the susceptor assembly holder can be integrally formed with the outer housing.

[0136] The outer housing of the cartridge can define part of the reservoir. The outer housing can define the reservoir. The outer housing and the reservoir can be integrally formed. Alternatively, the reservoir can be formed separately from the outer housing and arranged in the outer housing.

[0137] In some preferred embodiments in which the cartridge comprises an outer housing, the susceptor assembly holder can secure the susceptor assembly to the outer housing. Advantageously, providing the cartridge with a susceptor assembly holder that secures the susceptor assembly to the housing can decouple the susceptor assembly from the outer housing, such that the outer housing does not need to be configured to withstand the temperature to which the susceptor assembly is raised for heating the aerosol-forming substrate. This can enable the cartridge to be made from less durable and cheaper materials.

[0138] The cartridge can comprise two parts: a first part and a second part. The second part can be movable relative to the first part. The first part and the second part of the cartridge can be movable relative to each other between a storage configuration and a use configuration. In the storage configuration, the susceptor assembly can be isolated from the aerosol-forming substrate. In the use configuration, the susceptor assembly can be in fluid communication with the aerosol-forming substrate.

[0139] The reservoir can comprise two portions: a first portion and a second portion. A seal can be provided between the first portion and the second portion. The seal can be arranged to prevent fluid communication between the first portion of the reservoir and the second portion of the reservoir. In other words, the seal can fluidically isolate the first portion of the reservoir from the second portion of the reservoir. In the storage configuration, the liquid aerosol-forming substrate can be held in the first portion of the reservoir. In the storage configuration, the seal can prevent the aerosol-forming substrate from flowing from the first portion of the reservoir to the second portion of the reservoir.

[0140] The first portion of the cartridge can comprise the first portion of the reservoir and the seal. The second portion of the cartridge can comprise the susceptor holder and the susceptor assembly. The susceptor holder can comprise one or more perforating elements. The one or more perforating elements can be arranged to pierce or penetrate the seal of the second portion of the cartridge when the first and second portions of the cartridge are moved from the storage configuration to the use configuration.

[0141] The one or more perforating elements of the susceptor holder can pierce the seal and enable the aerosol-forming substrate to flow from the first portion of the reservoir to the second portion of the reservoir when the first and second portions of the cartridge are moved from the storage configuration to the use configuration.

[0142] The susceptor assembly can extend into the second portion of the reservoir. Where the susceptor assembly comprises a wicking element, a portion of the wicking element can extend into the second portion of the reservoir. Thus, the susceptor assembly is isolated from the aerosol-forming substrate when the cartridge is in the storage configuration and the susceptor assembly is supplied with aerosol-forming substrate from the second portion of the reservoir when the cartridge is in the use configuration.

[0143] The seal can be any suitable type of seal for preventing fluid flow between the first portion of the reservoir and the second portion of the reservoir. For example, the seal can comprise a metal foil, a plastic foil, or an elastomeric seal.

[0144] The first and second portions of the cartridge can be moved relative to one another in any suitable manner. In some embodiments, the first and second portions of the cartridge can be slidable relative to one another. In some embodiments, the first and second portions of the cartridge can be rotatable relative to one another.

[0145] The aerosol-generating system can be a hand-held aerosol-generating system configured to allow a user to draw air through the mouth end opening to draw aerosol through the mouthpiece by inhaling. The aerosol-generating system can have dimensions comparable to a conventional cigar or cigarette. The aerosol-generating system can have an overall length of between about 30 mm and about 150 mm. The aerosol-generating system can have an outer diameter of between about 5 mm and about 30 mm.

[0146] The aerosol-generating system can be configured to deliver nicotine to a user. The aerosol-generating system can be an electrically operated smoking system.

[0147] There is also provided according to the application of the present disclosure, a susceptor assembly for an electrically heated aerosol-generating system comprising: a housing defining a reservoir containing an aerosol-forming substrate; at least one inductor coil; and a power supply connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil such that the inductor coil generates an alternating magnetic field. The susceptor assembly can comprise a first susceptor element configured to be heated by the alternating magnetic field. The susceptor assembly can comprise a second susceptor element configured to be heated by the alternating magnetic field. The susceptor assembly can comprise a wicking element configured to be in fluid communication with the reservoir of the aerosol-generating system. The first susceptor element and the second susceptor element are integral with or fixed to the wicking element. A space can be defined between the first susceptor element and the second susceptor element, the space being occupied by the wicking element.

[0148] A non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples can be combined with any one or more features of another example, embodiment, or aspect described herein.

[0149] EX1. An electrically heated aerosol-generating system comprising:

[0150] at least one inductor coil;

[0151] a power supply connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil to generate an alternating magnetic field;

[0152] a housing containing a reservoir of aerosol-forming substrate; and

[0153] a substantially planar susceptor assembly configured to be heated by the alternating magnetic field and comprising a first susceptor element, a second susceptor element, and a wicking element in fluid communication with the reservoir, the first susceptor element and the second susceptor element being integral with or fixed to the wicking element;

[0154] wherein a space is defined between the first susceptor element and the second susceptor element, the space being occupied by the wicking element and the reservoir being positioned outside the space.

[0155] EX2. The electrically heated aerosol-generating system according to example EX1, wherein the first susceptor element and the second susceptor element are fluid permeable.

[0156] EX3. An electrically heated aerosol-generating system according to example EX1 or EX2, wherein the aerosol-forming substrate is a liquid.

[0157] EX4. An aerosol-generating system according to any one of examples EX1 to EX3, wherein the wicking element is arranged to transport aerosol-forming substrate from the liquid reservoir across a major surface of the susceptor element.

[0158] EX5. An electrically heated aerosol-generating system according to example EX3 or EX4, wherein the susceptor assembly or a heating region of the susceptor assembly holds between 2 and 10 millilitres of liquid aerosol-forming substrate.

[0159] EX6. An aerosol-generating system according to any one of the preceding examples, wherein at least a portion of each of the two opposing major surfaces of the susceptor assembly is in direct contact with air in an air flow passage in the system.

[0160] EX7. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the first susceptor element and the second susceptor element have a relative magnetic permeability of between 1 and 40000, preferably between 500 and 40000.

[0161] EX8. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the alternating current has a frequency of between 100 kHz and 30 MHz, preferably between 500 kHz and 30 MHz.

[0162] EX9. An electrically heated aerosol-generating system according to any one of examples EX1 to EX7, wherein the alternating current has a frequency of between 100 kHz and 1000 MHz.

[0163] EX10. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the thickness of each susceptor element and the skin depth of the material of the susceptor element at the operating frequency of the system are of the same order of magnitude or less than the skin depth.

[0164] EX11. An aerosol-generating system according to any one of the preceding examples, wherein each susceptor element has a thickness of no more than two millimetres.

[0165] EX12. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the first susceptor element and the second susceptor element comprise electrically conductive filaments.

[0166] EX13. An electrically heated aerosol-generating system according to example EX12, wherein the first susceptor element and the second susceptor element comprise a mesh of the electrically conductive filament, a flat spiral coil of the electrically conductive filament, a fibre of the electrically conductive filament or a fabric of the electrically conductive filament.

[0167] EX14. An electrically heated aerosol-generating system according to example EX12 or EX13, wherein the diameter of the electrically conductive filament is between 40 and 60 micrometres, preferably between 45 and 55 micrometres, and even more preferably 50 micrometres.

[0168] EX15. An electrically heated aerosol-generating system according to any one of examples EX12 to EX14, wherein the mesh opening of the mesh of the electrically conductive filament is between 60 and 150 micrometres, preferably between 50 and 70 micrometres, even more preferably between 60 and 65 micrometres, and most preferably 63 micrometres.

[0169] EX16. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the first susceptor element and the second susceptor element comprise an electrically conductive material printed on or otherwise deposited onto the wicking element.

[0170] EX17. An electrically heated aerosol-generating system according to example EX16, wherein the electrically conductive material of the first susceptor element or the second susceptor element is printed on or otherwise deposited onto the wicking element as a film or a plurality of tracks.

[0171] EX18. An electrically heated aerosol-generating system according to example EX17, wherein the plurality of tracks of each of the susceptor elements are distributed across the surface of the wicking element.

[0172] EX19. An electrically heated aerosol-generating system according to example EX17 or EX18, wherein the plurality of tracks of each of the susceptor elements form a mesh structure.

[0173] EX20. An electrically heated aerosol-generating system according to any one of examples EX1 to EX11, wherein the first susceptor element and the second susceptor element comprise a perforated foil.

[0174] EX21. An electrically heated aerosol-generating system according to example EX20, wherein the perforations are evenly distributed across the first susceptor element and the second susceptor element.

[0175] EX22. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the wicking element comprises an electrically insulating material.

[0176] EX23. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the wicking element comprises a non-metallic material.

[0177] EX24. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the wicking element comprises a hydrophilic material or a lipophilic material.

[0178] EX25. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the wicking element comprises cotton, rayon or glass fibre.

[0179] EX26. An electrically heated aerosol-generating system according to any one of Examples EX1 to EX24, wherein the wicking element comprises a porous ceramic material.

[0180] EX27. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the at least one inductor coil comprises a first inductor coil and a second inductor coil.

[0181] EX28. An electrically heated aerosol-generating system according to Example EX27, wherein the first inductor coil is positioned on a first side of the susceptor assembly and the second inductor coil is positioned on a second side of the susceptor assembly and extends parallel to the first plane.

[0182] EX30. An electrically heated aerosol-generating system according to claim 28 or 29, wherein the susceptor assembly is substantially equidistant from the first inductor coil and the second inductor coil.

[0183] EX31. An aerosol-generating system according to any one of Examples EX27 to EX30, wherein the system is configured such that the first inductor coil and the second inductor coil produce magnetic fields that are equal to and opposite to each other.

[0184] EX32. An aerosol-generating system according to any one of Examples EX28 to EX31, wherein the system is configured such that the first inductor coil and the second inductor coil provide magnetic fields at the susceptor assembly that are perpendicular to the first plane.

[0185] EX33. An aerosol-generating system according to any one of Examples EX27 to EX32, wherein each of the planar inductor coils is rectangular.

[0186] EX34. An aerosol-generating system according to any one of Examples EX27 to EX33, wherein the first inductor coil has the same number of turns as the second inductor coil.

[0187] EX35. An aerosol-generating system according to any one of Examples EX27 to EX34, wherein the first inductor coil has the same size and shape as the second inductor coil.

[0188] EX36. An aerosol-generating system according to any one of Examples EX27 to EX35, wherein the first inductor coil is substantially identical to the second inductor coil.

[0189] EX37. An aerosol-generating system according to any one of Examples EX27 to EX36, wherein the first inductor coil has the same electrical resistance as the second inductor coil.

[0190] EX38. An aerosol-generating system according to any one of Examples EX27 to EX37, wherein the inductor coils are electrically connected to form a single conductive path, and wherein the first inductor coil is wound in an opposite direction to the second inductor coil.

[0191] EX39. An aerosol-generating system according to any one of Examples EX27 to EX38, wherein the first inductor coil and the second inductor coil are provided with the same alternating current.

[0192] EX40. An aerosol-generating system according to any one of Examples EX27 to EX39, wherein the first inductor coil is wound in the same direction as the second inductor coil, and wherein the control circuitry is configured to provide the first inductor coil with a current that is directly out of phase with the current provided to the second inductor coil.

[0193] EX41. An aerosol-generating system according to any one of Examples EX27 to EX40, comprising one or more flux concentrators configured to contain the magnetic field generated by the inductor coils.

[0194] EX42. An aerosol-generating system according to any one of the preceding examples, further comprising a susceptor assembly holder, and wherein each of the susceptor elements comprises a heating region and at least one mounting region, wherein the heating region is a region of the susceptor element configured to heat to a temperature required to vaporise a liquid aerosol-forming substrate from the liquid reservoir upon penetration by a suitable alternating magnetic field, and wherein the at least one mounting region of the susceptor element is a region of the susceptor element configured to contact the susceptor holder.

[0195] EX43. An aerosol-generating system according to Example EX42, wherein the heating region is configured to heat to a substantially higher temperature than the mounting region in the presence of an alternating magnetic field.

[0196] EX44. An aerosol-generating system according to example EX42 or EX43, wherein the heating region is located in a space directly between the first inductor coil and the second inductor coil, and the mounting region can be located outside the space directly between the first inductor coil and the second inductor coil.

[0197] EX45. An aerosol-generating system according to any one of examples EX42 to EX44, wherein the heating region of each of the susceptor elements is arranged outside the liquid reservoir.

[0198] EX46. An electrically heated aerosol-generating system according to any one of the preceding examples, further comprising an airflow passage extending between an air inlet and an air outlet.

[0199] EX47. An electrically heated aerosol-generating system according to example EX46, wherein the air outlet is defined in a mouthpiece of the system.

[0200] EX48. An electrically heated aerosol-generating system according to example EX46 or EX47, wherein airflow in the airflow passage passes over a surface of the first susceptor element and a surface of the second susceptor element.

[0201] EX49. An electrically heated aerosol-generating system according to any one of examples EX46 to EX48, wherein the wicking element is in fluid communication with the reservoir because the wicking element protrudes into the reservoir.

[0202] EX50. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the housing comprises an inner wall and an outer wall, such that an inner passage is defined by the inner wall.

[0203] EX51. An electrically heated aerosol-generating system according to example EX50, wherein the inner passage is surrounded by a space defined between the inner wall and the outer wall.

[0204] EX52. An electrically heated aerosol-generating system according to example EX51, wherein the space surrounding the inner passage is an annular space.

[0205] EX53. An electrically heated aerosol-generating system according to example EX51 or EX52, wherein the airflow passage can be at least partially defined by the inner passage, and the reservoir is at least partially defined by the space surrounding the inner passage.

[0206] EX54. An electrically heated aerosol-generating system according to example EX51 or EX52, wherein the reservoir is at least partially defined by the inner passage, and the airflow passage is at least partially defined by the annular space.

[0207] EX55. An electrically heated aerosol-generating system according to any one of the preceding Examples, wherein the aerosol-generating system comprises a susceptor assembly holder, the susceptor assembly being mounted on the susceptor assembly holder.

[0208] EX56. An electrically heated aerosol-generating system according to Example EX55, wherein the susceptor elements of the susceptor assembly each comprise at least one mounting region which contacts the holder.

[0209] EX57. An electrically heated aerosol-generating system according to Example EX55 or EX56, wherein the susceptor assembly holder is tubular and has at least one side wall.

[0210] EX58. An electrically heated aerosol-generating system according to Example EX57, wherein the susceptor assembly is mounted through at least one opening through the side wall.

[0211] EX59. An electrically heated aerosol-generating system according to Example EX57 or EX58, wherein the susceptor assembly is mounted through at least two openings through the side wall.

[0212] EX60. An electrically heated aerosol-generating system according to any one of Examples EX55 to EX59, wherein the susceptor assembly holder is configured to withstand the susceptor assembly being raised to a temperature for heating the aerosol-forming substrate.

[0213] EX61. An electrically heated aerosol-generating system according to any one of Examples EX55 to EX60, wherein the susceptor assembly holder is formed from a liquid-impermeable material.

[0214] EX62. An electrically heated aerosol-generating system according to any one of Examples EX55 to EX61, wherein the susceptor holder is formed from a mouldable plastics material such as polypropylene (PP) or polyethylene terephthalate (PET).

[0215] EX63. An electrically heated aerosol-generating system according to any one of Examples EX57 to EX62, wherein the at least one side wall of the susceptor assembly holder forms at least part of an inner wall of the housing.

[0216] EX64. An electrically heated aerosol-generating system according to Example EX63, wherein the housing comprises an inner wall and an outer wall, such that an internal passageway is defined by the inner wall, and wherein the at least one side wall of the housing defines a portion of the internal passageway.

[0217] EX65. An electrically heated aerosol-generating system according to example EX64, wherein the space between the inner wall and the outer wall is at least partially defined between the at least one side wall and the outer wall of the housing.

[0218] EX66. An electrically heated aerosol-generating system according to example EX65, wherein the susceptor assembly extends into the internal passageway of the susceptor holder.

[0219] EX67. An electrically heated aerosol-generating system according to any one of examples EX55 to EX66, wherein the holder is moulded onto the susceptor assembly.

[0220] EX68. An electrically heated aerosol-generating system according to example EX67, wherein the moulded holder holds the first susceptor element and the second susceptor element and the wicking element together such that the elements are fixed together.

[0221] EX69. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the susceptor assembly is surrounded by a permeable electrically insulating coating.

[0222] EX70. An electrically heated aerosol-generating system according to example EX69, wherein the coating comprises a permeable ceramic material.

[0223] EX71. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the susceptor assembly further comprises a third susceptor element and a second wicking element, the second wicking element being positioned between the first susceptor element and the third susceptor element or the second susceptor element and the third susceptor element.

[0224] EX72. An electrically heated aerosol-generating system according to any one of the preceding examples, further comprising a second susceptor assembly substantially similar to the first susceptor assembly.

[0225] EX73. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the system further comprises an electrical circuit connected to the at least one inductor coil and to a power supply.

[0226] EX74. An electrically heated aerosol-generating system according to any one of the preceding examples, wherein the aerosol-generating system comprises an aerosol-generating device and a cartridge configured to be used with the device, the device comprising the at least one inductor coil, the power supply and a device housing configured to engage at least a portion of the cartridge when the cartridge is used with the aerosol-generating device.

[0227] EX75. An electrically heated aerosol-generating system according to example EX74, wherein the cartridge comprises a susceptor assembly and a cartridge housing.

[0228] EX76. An electrically heated aerosol-generating system according to example EX74 or EX75, wherein the at least one inductor coil is positioned around or adjacent to the susceptor assembly when the cartridge is engaged with the aerosol-generating device.

[0229] EX77. An electrically heated aerosol-generating system according to any one of examples EX74 to EX76, wherein the aerosol-generating system comprises a first inductor coil and a second inductor coil, the first inductor coil is positioned on a first side of the cartridge and the second inductor coil is positioned on a second side of the cartridge when the cartridge is engaged with the aerosol-generating device.

[0230] EX78. An electrically heated aerosol-generating system according to example EX77, wherein the portion of the cartridge comprising the susceptor assembly of the cartridge is positioned between the first inductor coil and the second inductor coil when the cartridge is engaged with the aerosol-generating device.

[0231] EX79. A cartridge for use in an electrically heated aerosol-generating system comprising an aerosol-generating device, the cartridge being configured for use with the device, wherein the device comprises: a device housing configured to engage at least a portion of the cartridge when the cartridge is in use with the aerosol-generating device; at least one inductor coil; and a power supply connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil such that the inductor coil generates an alternating magnetic field within the cartridge; the cartridge comprising:

[0232] a cartridge housing defining a reservoir containing an aerosol-forming substrate; and

[0233] a substantially planar susceptor assembly configured to be heated by the alternating magnetic field and comprising a first susceptor element, a second susceptor element and a wicking element in fluid communication with the reservoir, the first susceptor element and the second susceptor element being integral with or fixed to the wicking element;

[0234] wherein a space is defined between the first susceptor element and the second susceptor element, the wicking element occupies the space and the reservoir is positioned outside the space.

[0235] occupies the space and the reservoir is positioned outside the space.

[0236] EX80. A cartridge according to example EX79, wherein the first susceptor element and the second susceptor element are fluid permeable.

[0237] EX81. A cartridge according to example EX79 or EX80, wherein the aerosol forming substrate is a liquid.

[0238] EX82. A cartridge according to any of examples EX79 to EX81, wherein the wicking element is arranged to transport aerosol forming substrate from the liquid reservoir across a major surface of the susceptor element.

[0239] EX83. A cartridge according to example EX81 or EX82, wherein the susceptor assembly or a heating region of the susceptor assembly holds between 2 and 10 millilitres of liquid aerosol forming substrate.

[0240] EX84. A cartridge according to any of examples EX79 to EX83, wherein at least a portion of each of the two opposing major surfaces of the susceptor assembly is in direct contact with air in an air flow passage in the system.

[0241] EX85. A cartridge according to any of examples EX79 to EX84, wherein the first susceptor element and the second susceptor element have a relative magnetic permeability of between 1 and 40000, preferably between 500 and 40000.

[0242] EX86. A cartridge according to any of examples EX79 to EX85, wherein the thickness of each susceptor element is of the same order of magnitude or less than the skin depth of the material of the susceptor element at the operating frequency of the system.

[0243] EX87. A cartridge according to any of examples EX79 to EX86, wherein the susceptor assembly has a thickness of no more than two millimetres.

[0244] EX88. A cartridge according to any of examples EX79 to EX87, wherein the first susceptor element and the second susceptor element comprise electrically conductive filaments.

[0245] EX89. A cartridge according to example EX88, wherein the first susceptor element and the second susceptor element comprise a mesh of the electrically conductive filaments, a flat spiral coil of the electrically conductive filaments, fibres of the electrically conductive filaments or a weave of the electrically conductive filaments.

[0246] EX90. A cartridge according to example EX88 or EX89, wherein the electrically conductive filaments have a diameter of between 40 micrometres and 60 micrometres, preferably between 45 micrometres and 55 micrometres, and even more preferably 50 micrometres.

[0247] EX91. The cartridge according to any one of Examples EX88 to EX90, wherein the mesh of the web of electrically conductive filaments is between 60 to 150 microns, preferably between 50 to 70 microns, even more preferably between 60 to 65 microns, and most preferably 63 microns.

[0248] EX92. The cartridge according to any one of Examples EX79 to EX91, wherein the first susceptor element and the second susceptor element comprise an electrically conductive material printed on or otherwise deposited onto the wicking element.

[0249] EX93. The cartridge according to Example EX92, wherein the electrically conductive material of the first susceptor element or the second susceptor element is printed on or otherwise deposited onto the wicking element as a film or a plurality of tracks.

[0250] EX94. The cartridge according to Example EX93, wherein the plurality of tracks of each of the susceptor elements are distributed over the surface of the wicking element.

[0251] EX95. The cartridge according to Example EX93 or EX94, wherein the plurality of tracks of each of the susceptor elements form a mesh-like structure.

[0252] EX96. The cartridge according to any one of Examples EX79 to EX91, wherein the first susceptor element and the second susceptor element comprise a perforated foil.

[0253] EX97. The cartridge according to Example EX96, wherein the perforations are evenly distributed across the first susceptor element and the second susceptor element.

[0254] EX98. The cartridge according to any one of Examples EX79 to EX97, wherein the wicking element comprises an electrically insulating material.

[0255] EX99. The cartridge according to any one of Examples EX79 to EX98, wherein the wicking element comprises a non-metallic material.

[0256] EX100. The cartridge according to any one of Examples EX79 to EX99, wherein the wicking element comprises a hydrophilic material or a oleophilic material.

[0257] EX101. The cartridge according to any one of Examples EX79 to EX100, wherein the wicking element comprises cotton or rayon.

[0258] EX102. The cartridge according to any one of Examples EX79 to EX101, wherein the wicking element comprises a porous ceramic material.

[0259] The features described with respect to one embodiment or implementation can also be applied to other embodiments and implementations. Attached Figure Description

[0260] Several examples will now be described further with reference to the accompanying drawings, in which:

[0261] Figure 1a This is a schematic diagram of an aerosol generation system according to an example of this disclosure;

[0262] Figure 1b yes Figure 1a A schematic diagram of an aerosol generation system rotated 90 degrees around the central longitudinal axis of the aerosol generation system.

[0263] Figure 2a -c is from Figure 1a and 1b A schematic diagram of the system's cylinder;

[0264] Figure 3 It is a perspective view of the receptor assembly and receptor assembly holder according to this disclosure, separate from the rest of the aerosol generation system;

[0265] Figure 4 The sensor assembly in Figures 1 and 2 is a plan view of the sensor assembly, separate from the rest of the aerosol generation system.

[0266] Figure 5 This is an exploded perspective view of an embodiment of the receptor assembly according to the present disclosure;

[0267] Figure 6a is Figure 1b A diagram of the system, showing the magnetic field lines during one operational phase;

[0268] Figure 6b is Figure 1b The system diagram shows the magnetic field lines for subsequent operational phases;

[0269] Figure 7 This is an exploded perspective view of another embodiment of the receptor assembly according to the present disclosure;

[0270] Figure 8 This is a perspective view of another embodiment of the receptor assembly according to the present disclosure;

[0271] Figure 9 This is a perspective view of a receptor assembly including a coating, according to the present disclosure;

[0272] Figure 10a It has the same Figure 4 Perspective views of different shapes of receptor components according to embodiments of receptor components disclosed herein;

[0273] Figure 10b yesFigure 10a A plan view of the receptor components;

[0274] Figure 11 ad is a plan view of an exemplary receptor element according to this disclosure;

[0275] Figure 12 ai is a plan view of another exemplary sensor element according to this disclosure;

[0276] Figure 13a This is a schematic diagram of an aerosol generation system according to another embodiment of the present disclosure;

[0277] Figure 13b is... Figure 13a A schematic diagram of the device portion rotated 90 degrees around the central longitudinal axis of the aerosol generation system;

[0278] Figure 13c is an end view of the device in Figure 13b;

[0279] Figure 14 This is a schematic diagram of the arrangement of coils and sensors in one embodiment;

[0280] Figure 15a This is a schematic diagram of a cylinder for an aerosol generation system prior to use, according to another embodiment of this disclosure;

[0281] Figure 15b It is in the configuration process. Figure 9 A schematic diagram of tube a;

[0282] Figure 16a It includes Figure 15b The system of tubes;

[0283] Figure 16b It is a 90-degree rotation around the central longitudinal axis of the aerosol generation system. Figure 16a The system;

[0284] Figure 17a This is a cross-sectional view of a planar receptor element according to another embodiment of the present disclosure, the cross-section being taken in a plane perpendicular to the plane of the receptor element; and

[0285] Figure 17b yes Figure 17a A plan view of the receptor element. Detailed Implementation

[0286] Figure 1a A schematic diagram of an aerosol generation system according to an example of this disclosure is shown. Figure 1b It shows Figure 1aFigure 1 is a schematic view of an aerosol-generating system of the application. The aerosol-generating system is portable and has a size comparable to a conventional cigar or cigarette.

[0287] The cartridge 10 comprises a susceptor assembly 12 mounted in a susceptor holder 14. Figure 2a - c shows the cartridge 10 separate from the aerosol-generating system. Figure 3 Figure 2 shows a perspective view of the susceptor assembly 12 and holder 14 separate from the rest of the aerosol-generating system. Figure 4 and Figure 5 The structure of the susceptor assembly 12 is shown more clearly. Figure 4 is a cross-sectional schematic view of the susceptor assembly 12. Figure 5 is an exploded schematic view of the susceptor assembly 12.

[0288] The susceptor assembly 12 is planar and thin, having a thickness dimension substantially smaller than the length and width dimensions. The susceptor assembly 12 comprises three elements: a first susceptor element 16, a second susceptor element 18, and a wicking element 20 arranged between the first and second susceptor elements 16, 18. Each of the first and second susceptor elements 16, 18 and the wicking element 20 has the same length and width dimensions. As described in more detail below, the first and second susceptor elements 16, 18 are substantially identical and comprise a sintered mesh formed of ferritic stainless steel wires and austenitic stainless steel wires. The wicking element 20 comprises a porous body of rayon. The wicking element 20 is configured to deliver liquid from an externally exposed surface of the wicking element 20 to the first and second susceptor elements 16, 18.

[0289] Each of the first and second susceptor elements 16, 18 comprises a mesh having wires extending in a first direction, and wires extending in a second direction substantially perpendicular to the first direction. The electrically conductive wires comprise wires formed of AISI 430 stainless steel. The mesh has a porosity of 63 microns, and the electrically conductive wires have a diameter of 50 microns.

[0290] Each of the first susceptor element 16 and the second susceptor element 18 includes a pair of mounting regions 22 and a heating region 24. The heating region 24 is a substantially rectangular region centrally located on the susceptor element 16, 18. The pair of mounting regions 22 are also substantially rectangular regions located at the periphery of the heating region 24 at opposite sides of the heating region 24. The heating region 24 is configured to be heated by penetration of an alternating magnetic field for vaporizing an aerosol-forming substrate. The pair of mounting regions 22 are configured to contact the susceptor holder 14 so that the susceptor holder 14 can support the susceptor assembly 12 in place in the cartridge 10.

[0291] In addition to the wire of AISI 430 stainless steel extending in the first direction, and the wire of austenitic stainless steel extending in the second direction, the pair of mounting regions 22 also includes wire of AISI 316 stainless steel. Thus, the heating region 24 is composed of magnetic material, and the pair of mounting regions 22 is partially composed of magnetic material, and partially composed of non-magnetic material. The proportion by weight of AISI 430 stainless steel in the heating region 24 is greater than the proportion by weight of AISI 430 in each of the pair of mounting regions 22.

[0292] Thus, the heating region 24 is composed of magnetic material, and the pair of mounting regions 22 is partially composed of magnetic material, and partially composed of non-magnetic material. The proportion by weight of AISI 430 stainless steel in the heating region 24 is greater than the proportion by weight of AISI 430 stainless steel in each of the pair of mounting regions 22. This helps to reduce heating of the mounting regions 22 when the susceptor element is penetrated by an alternating magnetic field. This configuration also helps to reduce heat transfer from the susceptor assembly 12 to the susceptor holder 14.

[0293] It will be appreciated that in other embodiments, the heating region 24 and the pair of mounting regions 22 can be formed of other combinations of magnetic and non-magnetic material. For example, in some embodiments, the heating region 24 includes wire of AISI 430 stainless steel (ferritic stainless steel) extending in the first direction, and wire of AISI 316 stainless steel (austenitic stainless steel) extending in the second direction. In these embodiments, the pair of mounting regions 22 can include wire of AISI 316 stainless steel extending in both the first direction and the second direction. Thus, in these embodiments, the heating region 24 is partially composed of magnetic material, and partially composed of non-magnetic material, and the pair of mounting regions 22 is composed of non-magnetic material.

[0294] The susceptor holder 14 includes a tubular body formed of a moldable plastic material such as polypropylene. The tubular body of the susceptor holder 14 includes a sidewall that defines an interior passage 26 having an open end. A pair of openings 28 extend through the sidewall at opposite sides of the tubular susceptor holder 14. The openings 28 are centrally disposed along the length of the susceptor holder 14.

[0295] The susceptor assembly 12 is disposed within the interior passage 26 of the tubular susceptor holder 14 and extends in a plane that is parallel to the central longitudinal axis of the susceptor holder 14. The heating regions 24 of the first and second susceptor elements 16, 18 are entirely disposed within the interior passage 26 of the susceptor holder 14, and each of the mounting regions 22 extends through one of the openings 28 in the sidewall of the susceptor holder 14. The openings 28 in the sidewall of the susceptor holder 14 are sized to accommodate the susceptor assembly 12 in a friction fit, such that the susceptor assembly is secured in the susceptor holder 14. The friction fit between the susceptor assembly 12 and the susceptor holder 14 results in the mounting regions 22 directly contacting the susceptor holder 14 at the openings 28. The susceptor assembly 12 and the susceptor holder 14 are secured together such that movement of the susceptor holder 14 also moves the susceptor assembly 12.

[0296] It should be appreciated that the susceptor assembly 12 and the susceptor holder 14 can be secured together by other means. For example, in some embodiments, the susceptor assembly 12 is secured to the susceptor holder 14 by an adhesive at the mounting regions 22 of the susceptor assembly 12, such that the mounting regions 22 indirectly contact the susceptor holder 14.

[0297] The susceptor holder 14 includes a base 30 that partially encloses one end of the interior passage 26. The base 30 includes a plurality of air inlets 32 that enable air to be drawn into the interior passage 26 through the partially enclosed end.

[0298] The susceptor holder 14 further includes a pair of perforated elements 34 that extend from an outer surface of the sidewall toward an open end of the susceptor holder 14 that is opposite the end that is partially enclosed by the base 30. The openings 28 in the sidewall of the susceptor holder 14 are disposed between the perforated elements 34 around the circumference of the sidewall, such that the perforated elements 34 are offset by about 90 degrees from the openings 28 around the circumference of the sidewall of the tubular susceptor. Each of the perforated elements 34 includes a point facing in the direction of the open end of the susceptor holder 14.

[0299] The cartridge 10 further includes an outer housing 36 formed of a moldable plastic material such as polypropylene. The outer housing 36 generally forms a hollow cylinder to define an interior space that contains the susceptor assembly 12 and the susceptor holder 14 therein.

[0300] The outer shell 36 forms a first portion of the cartridge 10 and the susceptor assembly 12 and susceptor holder 14 form a second portion of the cartridge 10. The second portion of the cartridge is slidable relative to the first portion of the cartridge between a storage configuration as shown in Figure 2a and 2b and a use configuration as shown in Figure 2c

[0301] The cartridge 10 has a mouth end and a connection end opposite the mouth end. The outer shell 36 defines a mouth end opening 38 at the mouth end of the cartridge 10. As described in detail below, the connection end is configured for connecting the cartridge 10 to an aerosol-generating device. The susceptor assembly 12 and susceptor holder 14 are positioned towards the connection end of the cartridge 10. The outer shell 36 has a greater outer width at the mouth end of the cartridge 10 than at the connection end, the mouth end and connection end being joined by a shoulder 37. This allows the connection end of the cartridge to be received in a cavity of the aerosol-generating device with the shoulder 37 positioning the cartridge in the correct position in the device. It also enables the mouth end of the cartridge 10 to be retained outside of the aerosol-generating device, with the mouth end conforming to the outer shape of the aerosol-generating device.

[0302] A liquid reservoir 40 is defined in the cartridge for holding a liquid aerosol-forming substrate 42. The liquid reservoir 40 is divided into two portions: a first portion 44 and a second portion 46. The first portion 44 of the liquid reservoir 40 is positioned towards the mouth end of the outer shell 36 and comprises an annular space defined by the outer shell 36. The annular space has an internal passage 48 extending between the mouth end opening 38 and the open end of the internal passage 26 of the susceptor holder 14. The second portion 46 of the liquid reservoir 40 is positioned towards the connection end of the outer shell 36 and comprises an annular space defined between the inner surface of the outer shell 36 and the outer surface of the susceptor holder 14. The base 20 of the tubular susceptor holder 14 is provided with an annular, ribbed elastomeric seal 50 which extends between the outer surface of the tubular susceptor 14 and the inner surface of the outer shell 36. The seal 50 provides a liquid-tight seal between the susceptor holder 14 and the outer shell 36 to ensure that the second portion 46 of the liquid reservoir 40 is able to hold the liquid aerosol-forming substrate 42.

[0303] As described in more detail below, the first portion 44 and second portion 46 of the liquid reservoir 40 are fluidically isolated from each other by an aluminium foil seal 52 which is pierceable by the perforated element 34 of the susceptor holder to allow the liquid aerosol-forming substrate 42 to flow between the first portion 44 and second portion 46 of the liquid reservoir.

[0304] ​An air passageway is formed through the cartridge 10 by the internal passageway 26 of the susceptor holder 14 and the internal passageway 48 through the first portion 44 of the liquid reservoir 40. The air passageway extends from the air inlet 32 in the base 30 of the susceptor holder 14 through the internal passageway 26 of the susceptor holder 14 and through the internal passageway 48 of the first portion 44 of the liquid reservoir 40 to the mouth end opening 38. The air passageway enables air to be drawn through the cartridge 10 from the connection end to the mouth end.

[0305] In the storage configuration, as shown in Figure 2a and 2b the base 30 of the susceptor holder 14 extends from the outer housing 36 and the perforated element 34 of the susceptor holder 14 is spaced apart from the seal 52 in the direction of the connection end of the cartridge 10. In this configuration, the liquid aerosol-forming substrate 42 is held in the first portion 44 of the liquid reservoir 40 and is isolated from the second portion 46 of the liquid reservoir 40 by the seal 52. Thus, in the storage configuration, the susceptor assembly 12 is isolated from the aerosol-forming substrate 42. Advantageously, sealing the liquid aerosol-forming substrate 42 in the first portion 44 of the liquid reservoir 40 can completely prevent the liquid aerosol-forming substrate 42 from leaking out of the cartridge 10 when the cartridge is in the storage configuration.

[0306] In the use configuration, as shown in Figure 2c the susceptor holder 14 and the susceptor assembly 12 are pushed into the outer housing 36 towards the mouth end. As the susceptor holder 14 is pushed towards the mouth end of the outer housing 36, the seal 50 at the base 30 of the susceptor holder 14 slides over the inner surface of the outer housing 36 to maintain a liquid-tight seal between the inner surface of the outer housing 36 and the outer surface of the tubular susceptor holder body when the base of the susceptor holder 14 is received in the outer housing. As the perforated element 34 of the susceptor holder 14 moves towards the mouth end, the perforated element 34 contacts and pierces the seal 52 to allow fluid communication between the first portion 44 of the liquid reservoir 40 and the second portion 46 of the liquid reservoir 40. The liquid aerosol-forming substrate 42 in the first portion 44 of the liquid reservoir 40 is released into the second portion 46 of the liquid reservoir 40 and the susceptor assembly 12 is exposed to the liquid aerosol-forming substrate 42.

[0307] In the use configuration, the mounting regions 22 of the first susceptor element 16 and the second susceptor element 18 and the corresponding portion of the wicking element 20 extending into the second portion 46 of the liquid reservoir 40 are able to draw liquid aerosol-forming substrate 42 from the second portion 46 of the liquid reservoir 40 to the heating regions 24 of the first susceptor element 16 and the second susceptor element 18. Thus, in the use configuration, the cartridge 10 is ready for use to generate an aerosol by heating the aerosol-forming substrate 42. Although it is the wicking element 20 that transports the aerosol-forming substrate from the reservoir to the first and second susceptor elements by capillary action, the electrically conductive filaments also create capillary action in the interstices between the filaments of the mesh to wet the first susceptor element 16 and the second susceptor element 18. This wetting increases the contact area between the electrically conductive filaments of the susceptor elements and the aerosol-forming substrate.

[0308] The aerosol-generating device 60 comprises a generally cylindrical housing 62 having a connection end and a distal end opposite the connection end. A cavity 64 for receiving a cartridge at the connection end of the device 60 is located at the connection end of the device 60 and an air inlet 65 is provided through the outer housing 62 at the base of the cavity 64 to enable ambient air to be drawn into the cavity 64 at the base.

[0309] The device 60 further comprises an induction heating arrangement arranged within the housing 62. The induction heating arrangement comprises a pair of inductor coils 66, 68, a control circuit 70 and a power supply 72. The power supply 72 comprises a rechargeable nickel-cadmium battery which is recharged via an electrical connector (not shown) at the distal end of the device. The control circuit 70 is connected to the power supply 72 and to the first inductor coil 66 and the second inductor coil 68 such that the control circuit 70 controls the supply of power to the inductor coils 66, 68. The control circuit 70 is configured to supply an alternating current to the first inductor coil 66 and the second inductor coil 68.

[0310] A pair of inductor coils includes a first inductor coil 66 and a second inductor coil 68. The first inductor coil 66 is arranged at a first side of the cavity 64 and the second inductor coil 68 is arranged at a second side of the cavity 64 opposite the first inductor coil 66. Each of the inductor coils 66, 68 is substantially identical and includes a planar coil having a rectangular cross-section formed by rectangular cross-section wires. Each of the inductor coils 66, 68 extends substantially in a plane, with the first coil 66 extending in a first plane and the second coil 68 extending in a second plane. The first and second planes are substantially parallel to each other and extend substantially parallel to a central longitudinal axis of the cavity 64 at the connection end of the device 60. When the cartridge 10 is received in the cavity 64, the susceptor assembly 12 is arranged between the first and second inductor coils 66, 68 and the plane of the susceptor assembly 12 is arranged substantially parallel to the first and second planes.

[0311] A flux concentrator 69 is provided around each of the inductor coils in order to contain and concentrate the magnetic field within the cavity. The flux concentrator 69 can be formed of a magnetic material such as iron.

[0312] Each of the first and second inductor coils 66, 68 is configured such that when an alternating current is supplied to the inductor coils 66, 68, the inductor coils generate an alternating magnetic field in the cavity 64. The alternating magnetic field generated by each of the inductor coils 66, 68 is substantially perpendicular to the plane of the susceptor assembly 12 and the susceptor elements 16, 18.

[0313] The induction heating device is further configured such that the second inductor coil 68 generates an alternating magnetic field in the cavity 64 which is equal and opposite to the alternating magnetic field generated in the cavity 64 by the first inductor coil 66. In this embodiment, the first and second inductor coils 66, 68 are wound together and are substantially identical but wound in opposite directions. In this configuration, the first and second inductor coils 66, 68 generate an alternating magnetic field in the cavity 64 having substantially equal magnitude but in substantially opposite directions.

[0314] Figures 6a and 6b show Figure 1bFigure 6a shows the magnetic field during the first half of the cycle of the alternating current. Figure 6b shows the magnetic field during the second half of the cycle of the alternating current, in which the magnetic field is in the opposite direction. It can be seen that during both half cycles the magnetic field is equal and opposite on opposite sides of the susceptor assembly 12. This provides a balance of forces on the susceptor assembly. Equal and opposite magnetic fields can be achieved by winding the first and second inductor coils in opposite directions and supplying them with the same current. Equal and opposite magnetic fields can also be achieved by supplying the second inductor coil with an alternating current that is directly out of phase with the current supplied to the first inductor coil.

[0315] In operation, as indicated by the arrows in Figure 5, when a user draws on the mouth end opening 38 of the cartridge 10, ambient air is drawn through the air inlet 65 into the base of the cavity 64 and through the air inlet 32 in the base 30 of the cartridge 10. The ambient air flows from the base 30 through the cartridge 10 to the mouth end opening 38, through the air passage, and over the susceptor assembly 12. Figure 1b

[0316] When the system is activated, the control circuit 70 controls the supply of electrical power from the power supply 72 to the first and second inductor coils 66, 68. The control circuit 72 can comprise an air flow sensor (not shown) and the control circuit 72 can supply power to the inductor coils 66, 68 when the air flow sensor detects that a user is drawing on the cartridge 10. This type of control arrangement is well established in aerosol-generating systems such as inhalers and electronic cigarettes.

[0317] When the system is activated, an alternating current is generated in each of the inductor coils 66, 68, which generates an alternating magnetic field in the cavity 64 that penetrates the susceptor assembly 12, such that the heating regions 24 of the first and second susceptor elements 16, 18 are heated.

[0318] The alternating magnetic field penetrates the susceptor assembly to induce eddy currents in the first and second susceptor elements. The first and second susceptor elements 16, 18 warm up to a temperature sufficient to vaporise the aerosol-forming substrate. The vaporised aerosol-forming substrate can escape from the wicking element 20 through the apertures in the mesh of the susceptor 16, 18. The susceptor assembly is configured to hold only a small volume of liquid aerosol-forming substrate sufficient for a single user draw. This is advantageous because it allows the small volume of liquid to be vaporised quickly and with minimal heat loss to other elements of the system or to the unvaporised liquid aerosol-forming substrate.

[0319] ​Furthermore, the aerosol-forming substrate closest to the first susceptor element 16 and the second susceptor element 18 is primarily evaporated at the outer surface of the wicking element 20. Because there are two susceptor elements 16, 18, the wicking element 20 is heated from both sides. Because the generated vapor can be generated primarily on the interface between the susceptor element and the wicking element, it is not necessary to escape from the wicking element through the body of the wicking element, which would otherwise cause the vapor to cool and possibly condense. Instead, the vapor escapes directly into the airflow passage through the permeable susceptor elements 16, 18.

[0320] Although it is the wicking element 20 that transports the aerosol-forming substrate from the reservoir to the first and second susceptor elements by capillary action, the conductive filaments also create capillary action in the interstices between the filaments of the mesh to wet the first and second susceptor elements 16, 18. This wetting increases the contact area between the conductive filaments of the susceptor elements and the aerosol-forming substrate.

[0321] Figure 7 is an exploded perspective view of another embodiment of a susceptor assembly 112 according to the present disclosure. In this embodiment, the first and second susceptor elements 116, 118 are composed of a perforated foil. The perforated foil is formed of AISI 430 stainless steel. In operation, the evaporated aerosol-forming substrate escapes from the wicking element through the perforations 120 of the perforated foil. The wicking element 20 is composed of rayon. Figure 7 The perforations 120 in are not drawn to scale.

[0322] Figure 8 is a perspective view of another embodiment of a susceptor assembly 212 according to the present disclosure. The first and second susceptor elements are composed of a conductive material that is deposited directly onto the wicking element 520. Only the first susceptor element 216 is visible in Figure 6. The second susceptor element is on the non-visible underside of the wicking element 220.

[0323] The conductive material has been deposited such that it forms a plurality of tracks that are distributed over the surface of the wicking element 220. These tracks form a mesh-like structure. In operation, the evaporated aerosol-forming substrate can advantageously escape from the wicking element 220 through the gaps 222 between the tracks. In this embodiment, the wicking element 220 is composed of a porous ceramic material. Such a porous ceramic material is a suitable substrate for the manufacturing process associated with the deposition of the conductive material.

[0324] Figure 9 is a perspective view of a susceptor assembly 312 that includes a ceramic coating 302. The ceramic is a permeable ceramic that allows the evaporated aerosol-forming substrate to escape. The first and second susceptor elements and the wicking element are represented by the line 304 in Figure 9 is a perspective view of a susceptor assembly 412 that includes a ceramic coating 402. The ceramic is a permeable ceramic that allows the evaporated aerosol-forming substrate to escape. The first and second susceptor elements and the wicking element are represented by the line 404 in Figure 9It was not drawn to scale.

[0325] Coating 302 improves the robustness and strength of the receptor assembly. Furthermore, when the receptor assembly includes a coating, the elements of the receptor components can be held together by the coating.

[0326] Figure 10a and Figure 10b A receptor component 412 with a different shape than previously shown is illustrated. Figure 10a and 10b In the middle, the receptor assembly is cross-shaped. Figure 10a A perspective view of the receptor assembly 412 is shown, and Figure 10b A plan view of the receptor assembly 412 is shown. Each of the first receptor element 416, the second receptor element 418, and the wicking element 420 generally forms a cross shape, and each element has the same length and width dimensions.

[0327] Each of the pair of mounting regions 22 of the sensor elements 416, 418 has a smaller surface area than the heating region 24. The length l of each mounting region 22 is... m The length l of the heating area is less than 24 h And the width w of each mounting area in mounting area 22 m Width w less than heating area 24 h In this embodiment, the heating region 24 has a length of approximately 6.50 mm. h and a width of approximately 3.50 mm. h And each of the mounting areas 22 has a length of approximately 2.50 mm. m and a width of approximately 1.15 mm. m Therefore, each of the first receptor element 16 and the second receptor element 18 has a total maximum length of about 6.50 mm and a total maximum width of about 5.80 mm.

[0328] Providing mounting regions 22 with a reduced cross-section compared to the heating region 24 to the first sensor element 416 and the second sensor element 418, and including at least a portion of the mounting region 22 from a non-magnetic material, helps reduce heating of the mounting region 22 when the sensor elements are penetrated by an alternating magnetic field. This configuration also helps reduce heat transfer from the sensor assembly 412 to the sensor holder 14.

[0329] Figure 11 a-11e illustrates various other shapes of receptor elements according to different embodiments of the present disclosure.

[0330] Figure 11a shows a susceptor element having two rectangular mounting regions 22 located at one side of the rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length substantially shorter than the width and length of the heating region 24. The mounting regions 22 are located at opposite ends of the heating region 24, such that the susceptor element generally forms the shape of the letter "C".

[0331] Figure 11 b shows a susceptor element having two rectangular mounting regions 22 located at opposite sides of the rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length substantially shorter than the width and length of the heating region 24. The mounting regions 22 are located at the same end of the heating region 24, such that the susceptor element generally forms the shape of the letter "T".

[0332] Figure 11 c shows a susceptor element having two rectangular mounting regions 22 located at opposite sides of the rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length substantially shorter than the width and length of the heating region 24. The mounting regions 22 are located at different positions along the length of the heating region 24, spaced apart from the ends of the heating region 24.

[0333] Figure 11 d shows a susceptor element having two rectangular mounting regions 22 located at opposite sides of the rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length substantially shorter than the width and length of the heating region 24. The mounting regions 22 are located at opposite ends of the heating region 24, such that the susceptor element generally forms the shape of the letter "S" or "Z".

[0334] Figure 11 e shows a susceptor element having one rectangular mounting region 22 located at one side of the rectangular heating region 24. The mounting region 22 has a width and length substantially shorter than the width and length of the heating region 24. The mounting region 22 is located at a central position along the length of the heating region 24.

[0335] Figure 12 a-12i shows other alternative shapes of susceptor elements according to different embodiments of the present disclosure.

[0336] Figure 12 a-12c shows a susceptor element having a substantially rectangular heating region 24 and mounting regions 22, wherein each mounting region 22 of each susceptor element is substantially identical, and has a width and length substantially shorter than the width and length of the heating region 24.

[0337] Figure 12a shows a sensor element having two pairs of mounting regions 22 arranged at opposite ends of a heating region 24. Each pair of mounting regions includes one mounting region 22 located on one side of the heating region 24 and one mounting region 22 located on the opposite side of the heating region 24, such that the sensor element generally forms the shape of the letter "H".

[0338] Figure 12 b illustrates a sensor element having a pair of mounting regions 22 arranged on opposite sides of a heating region 24. The mounting regions 22 are located at the same central position along the length of the heating region 24, such that the sensor element generally forms a cross shape.

[0339] Figure 12 c illustrates a sensor element having two pairs of mounting regions 22, which are arranged at different locations along the length of the heating region 24, spaced apart from the ends of the heating region 24 and from another pair of mounting regions 22. Each pair of mounting regions 22 includes one mounting region 22 located on one side of the heating region 24 and one mounting region 22 located on the opposite side of the heating region 24, and they are located at the same position along the length of the heating region 24.

[0340] Figure 12 df shows a basic similarity Figure 12 The sensor element shown in ac, wherein one or more of the edges of the mounting region 22 or the heating region 24 are angled, such that one or more of the mounting region 22 and the heating region 24 are not rectangular.

[0341] Figure 12 d shows a basic similarity Figure 12 a is a sensor element, wherein as the mounting region 22 extends outward from the heating region 24, the inner edge of the mounting region 22 converges toward the center along the length of the heating region 24.

[0342] Figure 12 e shows a basic similarity Figure 12 b is a sensor element of a sensor element, wherein as the mounting region 22 extends outward from the heating region 24, the edge of the mounting region 22 diverges in the direction of the length of the heating region 24.

[0343] Figure 12 f shows a basic similarity Figure 12 c is a sensor element of a sensor element, wherein as the mounting region 22 extends outward from the heating region 24, the edge of the mounting region 22 diverges in the direction of the length of the heating region 24.

[0344] Figure 12 gi shows a basic similarity Figure 12a susceptor element of the susceptor element shown in a-c, wherein one or more of the edges of the mounting region 22 or the heating region 24 are curved such that one or more of the mounting region 22 and the heating region 24 are not rectangular.

[0345] Figure 12 g shows a susceptor element substantially similar to Figure 12 a susceptor element of the susceptor element shown in a, wherein the inner edge of the mounting region 22 is curved inwardly to form a concave inner edge of the mounting region 22.

[0346] Figure 5 h shows a susceptor element substantially similar to Figure 12 b, wherein the edges of the mounting region 22 are curved outwardly to form a convex mounting region 22.

[0347] Figure 5 i shows a susceptor element substantially similar to Figure 12 c, wherein the edges of the mounting region 22 are curved outwardly to form a convex mounting region 22.

[0348] Figure 12 , 13b, 13c show another embodiment of an aerosol-generating system. The system again comprises a cartridge 10 and a device 80. The cartridge 10 is the same as the cartridge shown in Figure 13a 、 2b and 2c, and is shown in use configuration. However, in this embodiment, the device is configured such that the inductor coils are positioned inside the cartridge in use.

[0349] The aerosol-generating device 80 comprises a generally cylindrical housing 82 having a connection end and a distal end opposite the connection end. A cavity 81 for receiving the connection end of a cartridge is located at the connection end of the device 80, and an air inlet 85 is provided through the outer housing 82 at the base of the cavity 81 to enable ambient air to be drawn into the cavity at the base.

[0350] The device 80 further comprises an induction heating arrangement arranged within the housing 82. The induction heating arrangement comprises a pair of inductor coils 86, 88, a control circuit 83 and a power supply 84. The power supply 84 comprises a rechargeable nickel-cadmium battery which is recharged via an electrical connector (not shown) at the distal end of the device. The control circuit 83 is connected to the power supply 84 and to the first inductor coil 86 and the second inductor coil 88 such that the control circuit 83 controls the supply of power to the inductor coils 86, 88. The control circuit 83 is configured to supply an alternating current to the first inductor coil 86 and the second inductor coil 88.

[0351] A pair of inductor coils includes a first inductor coil 86 and a second inductor coil 88. The first inductor coil 86 and the second inductor coil 88 extend into the cavity 81 and are held within a coil housing 89. When the cartridge is coupled to the device, the first inductor coil 86 is positioned on one side of the susceptor assembly 12 and the second inductor coil 88 is positioned on the opposite side of the susceptor assembly from the first inductor coil 86. Each of the inductor coils 86, 88 is substantially identical and includes a planar coil having a rectangular cross-section formed from rectangular cross-section wire. The rectangular shape of the second inductor coil 88 is shown in FIG. 13b which is a view of the device rotated 90 degrees. Each of the inductor coils 86, 88 extends substantially in a plane, with the first coil 86 extending in a first plane and the second coil 88 extending in a second plane. The first and second planes are substantially parallel to each other and extend substantially parallel to the central longitudinal axis of the cavity 81 at the connection end of the device 80. When the cartridge 10 is received in the cavity 81, the susceptor assembly 12 is disposed between the first inductor coil 86 and the second inductor coil 88 and the plane of the susceptor assembly 12 is disposed substantially parallel to the first and second planes. FIG. 13c is an end view of the device showing the position of the coil housing 89 within the cavity 81. The device and cartridge housing have a keying arrangement to ensure that the cartridge can only be received in the cavity 81 in the desired orientation to ensure that the susceptor assembly is positioned between the inductor coils. Figure 2a The rectangular shape of the second inductor coil 88 is shown more clearly in FIG. 13b which is a view of the device rotated 90 degrees. Each of the inductor coils 86, 88 extends substantially in a plane, with the first coil 86 extending in a first plane and the second coil 88 extending in a second plane. The first and second planes are substantially parallel to each other and extend substantially parallel to the central longitudinal axis of the cavity 81 at the connection end of the device 80. When the cartridge 10 is received in the cavity 81, the susceptor assembly 12 is disposed between the first inductor coil 86 and the second inductor coil 88 and the plane of the susceptor assembly 12 is disposed substantially parallel to the first and second planes. FIG. 13c is an end view of the device showing the position of the coil housing 89 within the cavity 81. The device and cartridge housing have a keying arrangement to ensure that the cartridge can only be received in the cavity 81 in the desired orientation to ensure that the susceptor assembly is positioned between the inductor coils.

[0352] As in the embodiment of FIG. 1, each of the first inductor coil 86 and the second inductor coil 88 is configured such that when an alternating current is supplied to the inductor coils 86, 88, the inductor coils generate an alternating magnetic field in the cavity 81. The alternating magnetic field generated by each of the inductor coils 86, 88 is substantially direction perpendicular to the plane of the susceptor assembly 12 and the susceptor element.

[0353] The inductive heating device is further configured such that the second inductor coil 88 generates an alternating magnetic field in the cavity 81 that is equal and opposite to the alternating magnetic field generated in the cavity by the first inductor coil 86. As Figure 13a As shown schematically in FIG. 1, in this embodiment, the first inductor coil 86 and the second inductor coil 88 are wound in opposite directions and are substantially identical. In this configuration, the first inductor coil 86 and the second inductor coil 88 generate an alternating magnetic field on either side of the susceptor assembly having substantially equal magnitude but in substantially opposite directions.

[0354] Figure 14 is Figure 14a schematic diagram of the coil arrangement of 13b and 13c. It can be seen that the first inductor coil 86 and the second inductor coil 88 are connected in series, but wound in opposite directions to each other. Thus, when an alternating current is supplied to the inductor coils, they generate alternating magnetic fields in opposite directions to each other. One major surface of the susceptor assembly experiences the magnetic field generated by the first inductor coil 86 and the opposite major surface of the susceptor assembly experiences the magnetic field generated by the second inductor coil 86. The susceptor assembly, and in particular the susceptor elements, are positioned substantially equidistant between the first inductor coil and the second inductor coil, and thus this arrangement means that the forces (such as Lorentz forces) generated by the magnetic fields on the one or more susceptor elements are balanced. This reduces the deformation and movement of the susceptor elements when compared to an arrangement using only a single inductor coil. Furthermore, if there is any misalignment of the susceptor assembly, this arrangement will tend to move the susceptor assembly to a central position equidistant between the first inductor coil and the second inductor coil.

[0355] Figure 13a and 15b A schematic diagram of a cartridge 10 for an aerosol-generating device according to another embodiment of the disclosure is shown. Figure 15a The cartridge 10 shown in FIG. 3 is substantially similar to the cartridge 10 shown in FIG. 2, and like features are denoted by the same reference numerals.

[0356] The cartridge 10 comprises two susceptor assemblies 12 mounted in a susceptor holder 14. Each susceptor assembly 12 is planar and thin, and shaped in the form of a letter “C”. Each susceptor assembly 12 has three elements arranged in a line, a wick element arranged between a first susceptor element and a second susceptor element. Figure 15a The susceptor assembly 12 of a-3c has the same three element configuration as the susceptor assembly 12 of a-3b, with a wick element arranged between a first susceptor element and a second susceptor element (not shown). As with the susceptor assembly 12 of a-3b, the first susceptor element and the second susceptor element are arranged in a line, and the wick element is arranged between the first susceptor element and the second susceptor element. Figure 3 As shown in FIG. 3, each susceptor element has a rectangular heating region and two mounting regions arranged at opposite ends of the heating region.

[0357] The susceptor holder 14 comprises a tubular body comprising a side wall defining an internal passage 26 having an open end. Two pairs of openings 28 extend through the side wall, each pair of openings 28 having one opening at one side of the susceptor holder 14 and another opening at an opposite side of the susceptor holder 14.

[0358] In this embodiment, each of the two susceptor assemblies 12 is arranged generally outside the internal passage 26 of the tubular susceptor holder 14 and extends in a plane parallel to the central longitudinal axis of the susceptor holder 14. The heating region of each susceptor element is arranged entirely outside the internal passage 26, and each of the mounting regions extends through one of the openings 28 in the side wall of the susceptor holder.

[0359] The susceptor holder includes a base 30 that partially encloses one end of the internal passage 26. In this embodiment, the base 30 forms a liquid-tight seal with the internal passage 26, such that the internal passage is configured to hold a liquid. The base 30 includes a plurality of air inlets 32; however, the air inlets 32 are arranged outside the internal passage 26.

[0360] The susceptor holder 14 further includes a pair of perforated elements 34 that extend from the inner surface of the side wall into the internal passage 26 towards the central longitudinal axis of the susceptor holder 14.

[0361] The cartridge 10 further includes an outer housing 36 that forms a generally hollow cylinder to define an internal space containing the susceptor assembly 12 and the susceptor holder 14 therein. The outer housing 36 forms a first portion of the cartridge 10, and the susceptor assembly 12 and the susceptor holder 14 form a second portion of the cartridge 10. The second portion of the cartridge is slidable relative to the first portion of the cartridge between a storage configuration as shown in Figure 15a and a use configuration as shown in Figure 15a

[0362] The cartridge 10 has a mouth end defining a mouth end opening 38, and a connection end configured for connecting the cartridge 10 to an aerosol-generating device. The susceptor assembly 12 and the susceptor holder 14 are positioned towards the connection end of the cartridge 10. The outer width of the outer housing 36 is greater at the mouth end of the cartridge 10 than at the connection end, the mouth end and the connection end being joined by a shoulder 37.

[0363] A liquid reservoir 40 is defined in the cartridge for holding a liquid aerosol-forming substrate 42. The liquid reservoir 40 is divided into two portions: a first portion 44 and a second portion 46. The first portion 44 of the liquid reservoir 40 is positioned towards the mouth end of the outer housing 36 and comprises a cylindrical space defined by the inner wall of the outer housing 36. The second portion 46 of the liquid reservoir 40 is positioned towards the connection end of the outer housing 36 and comprises a cylindrical space defined by the internal passage 26 of the susceptor holder 14.

[0364] ​The first portion 44 and the second portion 46 of the liquid reservoir 40 are fluidically isolated from one another by an aluminium foil seal 52, which can be pierced by the perforated element 34 of the susceptor holder to allow liquid aerosol-forming substrate 42 to flow between the first portion 44 and the second portion 46 of the liquid reservoir.

[0365] The first passageway 48 is defined between the outer surface of the inner wall defining the first portion 44 of the liquid reservoir 40 and the inner surface of the outer wall of the outer housing 36. The first passageway 48 extends between the mouth end opening 38 and the susceptor holder 14. The second passageway 49 is defined between the inner surface of the outer wall of the outer housing 36 and the outer surface of the susceptor holder 14. The base 30 of the tubular susceptor holder 14 is provided with an annular ribbed elastomer seal 50, which extends between the outer surface of the tubular susceptor 14 and the inner surface of the outer wall of the outer housing 36. The seal 50 provides an airtight seal between the susceptor holder 14 and the outer housing 36.

[0366] An air passageway is formed through the cartridge 10 by the first passageway 48 and the second passageway 49. The air passageway extends from the air inlet 32 in the base 30 of the susceptor holder 14, through the second passageway 49, and through the first passageway 48 to the mouth end opening 38. The air passageway enables air to be drawn through the cartridge 10 from the connection end to the mouth end.

[0367] In the storage configuration, as shown in Figure 15b the base 30 of the susceptor holder 14 extends out of the outer housing 36 and the perforated element 34 of the susceptor holder 14 is spaced apart from the seal 52 in the direction of the connection end of the cartridge 10. In this configuration, the liquid aerosol-forming substrate 42 is held in the first portion 44 of the liquid reservoir 40 and is isolated from the second portion 46 of the liquid reservoir 40 by the seal 52.

[0368] In the use configuration, as shown in Figure 15aAs shown in Figure 1 1, the susceptor holder 14 and susceptor assembly 12 are pushed into the outer housing 36 towards the mouth end. As the susceptor holder 14 is pushed towards the mouth end of the outer housing 36, the seal 50 at the base 30 of the susceptor holder 14 slides over the inner surface of the outer housing 36 to maintain an airtight seal between the inner surface of the outer housing 36 and the outer surface of the tubular susceptor holder body as the base of the susceptor holder 14 is received in the outer housing. As the perforated element 34 of the susceptor holder 14 is moved towards the mouth end, the perforated element 34 contacts and pierces the seal 52 to allow fluid communication between the first portion 44 of the liquid reservoir 40 and the second portion 46 of the liquid reservoir 40. The liquid aerosol-forming substrate 42 in the first portion 44 of the liquid reservoir 40 is released into the second portion 46 of the liquid reservoir 40 and the susceptor assembly 12 is exposed to the liquid aerosol-forming substrate 42. In the use configuration, the mounting region 22 of the susceptor element and the corresponding portion of the wicking element extending into the second portion 46 of the liquid reservoir 40 are able to draw the liquid aerosol-forming substrate 42 from the second portion 46 of the liquid reservoir 40 to the heating region 24 of the susceptor element.

[0369] Figure 15b and 16b An aerosol-generating system is shown, comprising a cartridge 10 of Figure 16a and 15b in a use configuration received in an aerosol-generating device 60. Figure 15a An aerosol-generating system is shown, comprising a cartridge 10 of Figure 16b rotated 90 degrees about the longitudinal axis of the system. The aerosol- generating device 60 is substantially similar to the aerosol-generating device 60 shown in Figure 16a and 1b and similar features are denoted by similar reference numerals.

[0370] The aerosol-generating device 60 comprises a generally cylindrical housing 62 having a connection end and a distal end opposite the connection end. A cavity 64 for receiving the connection end of the cartridge is located at the connection end of the device 60 and an air inlet 65 is provided through the outer housing at the base of the cavity 64 to enable ambient air to be drawn into the cavity 64 at the base.

[0371] The device 60 further comprises an induction heating arrangement arranged within the housing 62. The induction heating arrangement comprises two pairs of induction coils, a control circuit 70 and a power supply 72. In Figure 1aOnly a pair of inductor coils 90, 91 are visible. The power supply 72 comprises a rechargeable nickel-cadmium battery which is recharged via an electrical connector (not shown) at the distal end of the device. A control circuit 70 is connected to the power supply 72 and to the inductor coil 66, such that the control circuit 70 controls the supply of power to the inductor coil 66. The control circuit 70 is configured to supply an alternating current to the inductor coil 66.

[0372] The inductor coils comprise a pair of opposing planar inductor coils positioned around each susceptor assembly 12 when the cartridge 10 is received in the cavity 64. The inductor coils are sized and shaped to match the size and shape of the heating region of the susceptor element.

[0373] The inductor coils 90, 91 are configured such that when an alternating current is supplied to the inductor coils, the inductor coils generate opposing alternating magnetic fields on opposite sides of the susceptor assembly 12. The alternating magnetic fields generated by the inductor coils are directed substantially perpendicular to the plane of the susceptor assembly 12 and the susceptor element.

[0374] In operation, as shown by the arrows in Figure 16b When a user draws on the mouth end opening 38 of the cartridge 10, ambient air is drawn through the air inlet 65 into the base of the cavity 64 and through the air inlet 32 in the base 30 of the cartridge 10 into the cartridge 10. The ambient air flows from the base 30 through the cartridge 10 to the mouth end opening 38, through the air passage, and over the susceptor assembly 12.

[0375] When the system is activated, the control circuit 70 controls the supply of power from the power supply 72 to the inductor coils 90, 91. The control circuit 72 can comprise an air flow sensor (not shown) and the control circuit 72 can provide power to the inductor coil 66 when the air flow sensor detects a user drawing on the cartridge 10.

[0376] When the system is activated, an alternating current is generated in the inductor coils 90, 91 which generates an alternating magnetic field in the cavity 64 which penetrates the susceptor assembly 12 such that the heating region of the susceptor element is heated. Liquid aerosol-forming substrate in the second portion 44 of the liquid reservoir 40 is drawn through the wicking element into the susceptor assembly 12 to the heating region of the susceptor element. The liquid aerosol-forming substrate at the heating region of the susceptor element is heated and volatile compounds from the heated aerosol-forming substrate are released into the air passage of the cartridge 10, the volatile compounds cool to form an aerosol. The aerosol is entrained in the air drawn through the air passage of the cartridge 10 and is drawn out of the cartridge 10 at the mouth end opening 38 for inhalation by a user.

[0377] Figure 10a and 17bA receptor element according to another embodiment of the present disclosure is shown.

[0378] The sensor element 100 includes a woven mesh. Some of the woven filaments 102 extend along the warp direction, and some of the woven filaments 104 extend along the weft direction, which is substantially perpendicular to the warp direction.

[0379] The filaments 104 extending in the weft direction comprise a magnetic material, such as AISI 409 stainless steel. The filaments 102 extending in the warp direction comprise a non-magnetic material, such as AISI 316 stainless steel. The mesh is sintered, resulting in an electrical bond at the contact points between the warp-extending filaments 102 and the weft-extending filaments 104.

[0380] The receptor element 100 is a planar element that extends substantially in a plane. Warp filaments 102 and weft filaments 104 are woven together such that the warp filaments 102 extend further outward from the plane of the receptor element 100 than the weft filaments 104. In other words, the warp filaments 102 define the maximum thickness of the receptor element 100.

[0381] like Figure 17a Figure 17a As shown, since the filament 102 extending in the warp direction defines the maximum thickness of the sensor element 100, the sensor retainer 14 that contacts the sensor element 100 only contacts the filament 102 extending in the warp direction.

[0382] Since the filament 102 extending along the warp direction is not made of magnetic material, when the sensor element 100 is exposed to an alternating magnetic field, the filament 102 extending along the warp direction will not be directly heated by eddy current induction or hysteresis loss.

[0383] For the purposes of this specification and the appended claims, unless otherwise indicated, all figures representing quantities, quantities, percentages, etc., shall be understood to be modified by the term "about" in all cases. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically listed herein. Thus, in this context, the number A is understood as A ± {5%}A. Within this context, the number A can be considered as a value within the general standard error for the measurement of the attribute modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of deviation from A does not materially affect the essential and novel features of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically listed herein.

Claims

1. An electrically heated aerosol-generating system comprising: at least one inductor coil; a power supply connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil to generate an alternating magnetic field; a housing containing a reservoir of aerosol-forming substrate; and a substantially planar susceptor assembly configured to be heated by the alternating magnetic field and comprising a first susceptor element, a second susceptor element and a wicking element in fluid communication with the reservoir, the first and second susceptor elements being integral with or fixed to the wicking element; wherein a space is defined between the first and second susceptor elements, the wicking element occupies the space and the reservoir is positioned outside the space; and wherein the first and second susceptor elements are fluid permeable.

2. An electrically heated aerosol-generating system according to claim 1, wherein the susceptor assembly or a heated region of the susceptor assembly holds between 2 and 10 millilitres of liquid aerosol-forming substrate.

3. An electrically heated aerosol-generating system according to claim 1 or 2, wherein the first and second susceptor elements each comprise a mesh of electrically conductive filaments, a flat spiral coil of electrically conductive filaments, a fibre of electrically conductive filaments or a fabric of electrically conductive filaments.

4. An electrically heated aerosol-generating system according to claim 1 or 2, wherein the first and second susceptor elements each comprise electrically conductive material printed on or otherwise deposited onto the wicking element as a film or a plurality of tracks.

5. An electrically heated aerosol-generating system according to claim 1 or 2, wherein the first and second susceptor elements each comprise a perforated foil.

6. An electrically heated aerosol-generating system according to any preceding claim, wherein the substantially planar susceptor assembly extends parallel to a first plane, and wherein the system is configured such that the at least one inductor coil provides a magnetic field at the susceptor assembly perpendicular to the first plane.

7. An electrically heated aerosol-generating system according to any preceding claim, wherein the aerosol-generating system further comprises an airflow passage extending between an air inlet and an air outlet, wherein airflow in the airflow passage passes over a surface of the first susceptor element and a surface of the second susceptor element.

8. An electrically heated aerosol-generating system according to claim 7, wherein the reservoir comprises a fluid channel extending towards the susceptor assembly.

9. An electrically heated aerosol-generating system according to claim 7 or 8, wherein the housing comprises an inner wall and an outer wall, such that an inner passage is defined by the inner wall, the inner passage being surrounded by a space defined between the inner wall and the outer wall.

10. An electrically heated aerosol-generating system according to claim 9, wherein the airflow pathway is at least partially defined by the internal passage, and the reservoir is at least partially defined by the space surrounding the internal passage.

11. An electrically heated aerosol-generating system according to claim 9, wherein the reservoir is at least partially defined by the internal passage, and the airflow pathway is at least partially defined by an annular space.

12. An electrically heated aerosol-generating system according to any one of the preceding claims, wherein the susceptor assembly is surrounded by an electrically insulating, permeable coating.

13. An electrically heated aerosol-generating system according to any one of the preceding claims, wherein the susceptor assembly has a thickness of no more than two millimetres.

14. An electrically heated aerosol-generating system according to any one of the preceding claims, further comprising a susceptor assembly holder, the susceptor assembly being mounted on the susceptor assembly holder.

15. An electrically heated aerosol-generating system according to claim 14, wherein the susceptor assembly holder is tubular and has at least one side wall.

16. An electrically heated aerosol-generating system according to any one of the preceding claims, comprising an aerosol-generating device and a cartridge configured to be used with the device; the aerosol-generating device comprising the at least one inductor coil, the power supply means and a device housing configured to engage at least a portion of the cartridge when the cartridge is used with the aerosol-generating device; and the cartridge comprising the susceptor assembly and a cartridge housing; wherein, when the cartridge is engaged with the aerosol-generating device, the at least one inductor coil is positioned around or adjacent to the susceptor assembly.

17. A cartridge for use in an electrically heated aerosol-generating system comprising an aerosol-generating device, the cartridge being configured to be used with the device, wherein the device comprises: a device housing configured to engage at least a portion of the cartridge when the cartridge is used with the aerosol-generating device; at least one inductor coil; and power supply means connected to the at least one inductor coil and configured to provide an alternating current to the at least one inductor coil such that the inductor coil generates an alternating magnetic field within the cartridge; the cartridge comprising: a cartridge housing defining a reservoir containing an aerosol-forming substrate; and a substantially planar susceptor assembly configured to be heated by the alternating magnetic field and comprising a first susceptor element, a second susceptor element and a wicking element in fluid communication with the reservoir, the first susceptor element and the second susceptor element being integral with or fixed to the wicking element; wherein a space is defined between the first susceptor element and the second susceptor element, the wicking element occupying the space and the reservoir being positioned outside the space; and wherein the first susceptor element and the second susceptor element are fluid permeable.

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