Aerosol-generating system with hybrid susceptor

Abstract

A cartridge (10) for an aerosol-generating system comprises a liquid reservoir (40) for holding a liquid aerosol-forming substrate (42), a susceptor assembly (12) in fluid communication with the liquid reservoir (40), and a susceptor holder (14). The susceptor assembly (12) comprises a susceptor element (16, 18) having a heating region (24) and at least one mounting region (22). The heating region (24) comprises a first material which is a magnetic material that is heatable by penetration with an alternating magnetic field. The at least one mounting region (22) comprises a second material which is a non-magnetic material. The at least one mounting region (22) of the susceptor element is in contact with the susceptor holder (14). The proportion by weight of the first material in the heating region (24) is greater than the proportion by weight of the first material in the at least one mounting region (22).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an aerosol-generating system, and a cartridge for an aerosol-generating system. In particular, the present disclosure relates to an aerosol-generating system having an induction heating assembly, and a cartridge for an aerosol-generating system having an induction heating assembly, the cartridge comprising an aerosol-forming substrate and a susceptor assembly for heating the aerosol-forming substrate. BACKGROUND

[0002] Aerosol-generating systems that employ induction heating to heat an aerosol-forming substrate in order to generate an aerosol for inhalation by a user are generally known in the art. These systems typically comprise an aerosol-generating device comprising an induction heating assembly, and a cartridge comprising an aerosol-forming substrate that is capable of releasing volatile compounds upon heating, which cool to form an inhalable aerosol. The cartridge is configured to be coupled to the aerosol-generating device. The induction heating assembly comprises at least one inductor coil configured to generate an alternating magnetic field in a cavity. A susceptor, which forms part of the cartridge or device, is arranged in close proximity to the aerosol-forming substrate and within the alternating magnetic field. When the susceptor is penetrated by the alternating magnetic field, the susceptor is heated by at least one of Joule heating and magnetic hysteresis losses from eddy currents induced in the susceptor. The heated susceptor heats the aerosol-forming substrate so that volatile compounds are released from the aerosol-forming substrate, which cool to form an inhalable aerosol.

[0003] One advantage of induction 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.

[0004] Several susceptor configurations have been described in the prior art. In many of these configurations, portions of the susceptor are in contact with other parts of the cartridge, such as the cartridge's housing. This contact between the susceptor and other parts of the cartridge requires the other parts of the cartridge that are in contact with the susceptor to be configured to withstand the temperatures reached by the susceptor when it is heated. The contact between the susceptor and other parts of the cartridge can also cause heat to be conducted away from the susceptor, reducing the efficiency of the system when heating the aerosol-forming substrate.

[0005] It is desirable to provide a cartridge for an aerosol-generating system having a susceptor assembly that minimizes heat loss from the susceptor to other parts of the cartridge, without reducing heat transfer to the aerosol-forming substrate. SUMMARY

[0006] According to the present disclosure, there is provided a cartridge for an aerosol-generating system. The cartridge can comprise a liquid reservoir for holding a liquid aerosol-forming substrate. The cartridge can further comprise a susceptor assembly in fluid communication with the liquid reservoir. The susceptor assembly can comprise a susceptor element. The susceptor element can have a heating region comprising a first material. The first material can be a magnetic material that can be heated by penetration with an alternating magnetic field. The susceptor element can further comprise at least one mounting region comprising a second material. The second material can be a non-magnetic material. The cartridge can further comprise a susceptor holder. The at least one mounting region of the susceptor element can be in contact with the susceptor holder. A proportion by weight of the first material in the heating region can be greater than a proportion by weight of the first material in the at least one mounting region.

[0007] Advantageously, providing a susceptor element with regions formed of different materials can enable different regions of the susceptor element to have different properties. This can enable the susceptor element to maximise heat loss in some regions and minimise heat loss in other regions.

[0008] Advantageously, providing a susceptor element with a region comprising a non-magnetic material can reduce heating of the susceptor element at the region comprising the non-magnetic material compared to other regions of the susceptor element comprising a magnetic material.

[0009] Advantageously, providing a susceptor element with a region comprising a lower proportion by weight of a magnetic material than other regions of the susceptor element can reduce heating of the susceptor element at the region with the lower proportion by weight of the magnetic material compared to the other regions of the susceptor element comprising a higher proportion by weight of the magnetic material.

[0010] Advantageously, providing a susceptor element with at least one mounting region comprising a non-magnetic material and a lower proportion by weight of a magnetic material than a heating region of the susceptor element, wherein the at least one mounting region is in contact with a susceptor holder, can enable the mounting region in contact with the susceptor holder to exhibit reduced heating when penetrated with an alternating magnetic field compared to the heating region, and can minimise heat loss from the susceptor element to the susceptor holder.

[0011] The cartridge comprises a susceptor assembly. The susceptor assembly comprises a susceptor element. The susceptor assembly can further comprise a wicking element. The wicking element can be in fluid communication with the susceptor element. The wicking element can be in fluid communication with the liquid reservoir. The wicking element can be arranged to transport aerosol-forming substrate from the liquid reservoir to the susceptor element. In particular, the wicking element can be arranged to transport aerosol-forming substrate from the liquid reservoir across a major surface of the susceptor element. The susceptor element can be fixed to the wicking element. The susceptor element can be integral with the wicking element. The provision of a wicking element can improve wetting of the susceptor element and thus increase the aerosol generated by the system. The wicking element can allow the susceptor element to be made from a material that does not provide good wicking or wetting properties by itself.

[0012] In some embodiments, the susceptor assembly can comprise a plurality of susceptor elements. Where the susceptor assembly comprises a plurality of susceptor elements and a wicking element, each susceptor element can be arranged in fluid communication with the wicking element. In some embodiments, the susceptor assembly comprises a plurality of susceptor elements and a plurality of wicking elements.

[0013] In some preferred embodiments, the susceptor assembly comprises a first susceptor element and a second susceptor element, the second susceptor element being spaced apart from the first susceptor element. The wicking element can be arranged in the space between the first susceptor element and the second susceptor element. In some particularly preferred embodiments, the first susceptor element, the second susceptor element and the wicking element are substantially planar, and the first susceptor element is arranged at a first side of the planar wicking element and the second susceptor element is arranged at a second side of the planar wicking element opposite the first side.

[0014] Preferably, the susceptor assembly is arranged substantially outside the liquid reservoir. In particular, the or each susceptor element of the susceptor assembly can be arranged substantially outside the liquid reservoir. Preferably, at least a portion of a major surface of the or each susceptor element is not in direct contact with the liquid reservoir. Preferably, at least a portion of two opposing major surfaces of the susceptor assembly are in direct contact with air in the airflow pathway in the cartridge.

[0015] The susceptor element of the susceptor assembly comprises a heating region and at least one mounting region. The at least one mounting region is in contact with the susceptor holder. As used herein, the term "contact" means both direct and indirect contact.

[0016] Preferably, the at least one mounting region is in direct contact with the susceptor holder. As used herein, the term "direct contact" means contact between two components without any intervening material such that the surfaces of the two components are in contact with each other.

[0017] The at least one mounting region can be in indirect contact with the susceptor holder. As used herein, the term "indirect contact" means contact between two components via one or more intervening materials interposed between the two components such that the surfaces of the two components do not contact each other. For example, the at least one mounting region is in indirect contact with the susceptor element when a layer of adhesive is disposed between the surface of the at least one mounting region and the surface of the susceptor holder.

[0018] In some preferred embodiments, the at least one mounting region can extend into the liquid reservoir. In some preferred embodiments, the heating region in the susceptor element can be arranged outside the liquid reservoir. Advantageously, arranging the susceptor element, and in particular the heating region of the susceptor element, substantially outside the liquid 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 liquid reservoir. This can facilitate the release of volatile compounds from the aerosol-generating system.

[0019] As used herein, a "susceptor element" means an element that can be heated by penetration with 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 hysteresis losses.

[0020] The susceptor element comprises a heating region. The heating region is a region of the susceptor element that is configured to heat to a temperature required to vaporise the aerosol-forming substrate when penetrated by a suitable alternating magnetic field. The heating region is configured to heat to a substantially higher temperature than the mounting region in the presence of an alternating magnetic field.

[0021] The heating region comprises a first material. The first material is a magnetic material that can be heated by penetration with 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 can be heated by penetration with 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.

[0022] 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 any suitable proportion of the first material. 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.

[0023] The susceptor element further comprises at least one mounting region. The at least one mounting region of the susceptor element is a region of the susceptor element configured to contact the susceptor holder.

[0024] The at least one mounting region comprises a second material. The second material is 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.

[0025] The susceptor holder can contact the second material at the at least one mounting region of the susceptor element. The susceptor holder can contact the susceptor element only at the second material. Advantageously, providing contact between the susceptor holder and the susceptor element at the second material can help to minimise heat transfer from the susceptor element to the susceptor holder.

[0026] In some embodiments, the second material is non-metallic. For example, the second material can be a ceramic material.

[0027] 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 of 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.

[0028] In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimise heat transfer from the susceptor element to the susceptor holder. As used herein, an “electrically insulating” material means a material having a volume resistivity greater than about 1 x 1010ohm-meters (Qm) at 20 degrees Celsius (°C), typically greater than about 1 x 1011Qm, and often greater than about 1 x 1012Qm. 6 In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimise heat transfer from the susceptor element to the susceptor holder. As used herein, an “electrically insulating” material means a material having a volume resistivity greater than about 1 x 1010ohm-meters (Qm) at 20 degrees Celsius (°C), typically greater than about 1 x 1011Qm, and often greater than about 1 x 1012Qm. 9 In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimise heat transfer from the susceptor element to the susceptor holder. As used herein, an “electrically insulating” material means a material having a volume resistivity greater than about 1 x 1010ohm-meters (Qm) at 20 degrees Celsius (°C), typically greater than about 1 x 1011Qm, and often greater than about 1 x 1012Qm. 21 Suitable electrically insulating materials include glass, plastics, and certain ceramic materials.

[0029] In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimise heat transfer from the susceptor element to the susceptor holder. As used herein, an “electrically insulating” material means a material having a volume resistivity greater than about 1 x 1010ohm-meters (Qm) at 20 degrees Celsius (°C), typically greater than about 1 x 1011Qm, and often greater than about 1 x 1012Qm.

[0030] In some embodiments, the second material is an electrically insulating material. Advantageously, an electrically insulating second material can help to minimise heat transfer from the susceptor element to the susceptor holder. As used herein, an “electrically insulating” material means a material having a volume resistivity greater than about 1 x 1010ohm-meters (Qm) at 20 degrees Celsius (°C), typically greater than about 1 x 1011Qm, and often greater than about 1 x 1012Qm.

[0031] In some embodiments, the second material can be a hydrophilic material. In some embodiments, the second material can be a lipophilic material. Advantageously, providing a hydrophilic second material or a lipophilic second material can facilitate transport of aerosol-forming substrate through the susceptor element.

[0032] In some embodiments, the second material comprises a cellulosic material. For example, the second material can comprise rayon.

[0033] In some preferred embodiments, the at least one mounting region 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.

[0034] The at least one mounting region can comprise the first material. However, the at least one mounting region comprises a lower proportion of the first material than the heating region. The proportion of the first material by weight in the heating region is greater than the proportion of the first material by weight in the at least one mounting region. For example: the heating region of the susceptor element can comprise at least 90% by weight of the first material, and the at least one mounting region of the susceptor element can comprise less than 10% by weight of the first material, or the heating region of the susceptor element can comprise at least 80% by weight of the first material, and the at least one mounting region of the susceptor element can comprise less than 20% by weight of the first material, or the heating region of the susceptor element can comprise at least 70% by weight of the first material, and the at least one mounting region of the susceptor element can comprise less than 30% by weight of the first material, or the heating region of the susceptor element can comprise at least 60% by weight of the first material, and the at least one mounting region of the susceptor element can comprise less than 40% by weight of the first material, or the heating region of the susceptor element can comprise at least 50% by weight of the first material, and the at least one mounting region of the susceptor element can comprise less than 50% by weight of the first material.

[0035] The at least one mounting region can comprise: 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.

[0036] The at least one mounting region can comprise: 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.

[0037] The heating region 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.

[0038] The heating region 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.

[0039] The heating region can comprise any suitable proportion of 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.

[0040] The at least one mounting region can comprise any suitable proportion of susceptor element. Typically, the at least one mounting region comprises a smaller proportion of 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 holder.

[0041] In some embodiments, the at least one mounting region is located near a periphery of the heating region, wherein 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.

[0042] As used herein, the term "length" refers to the primary dimension in the longitudinal direction of a feature or portion of a feature, such as a cartridge, susceptor assembly, susceptor element, heating region, and at least one mounting region. As used herein, the length of a feature refers to the primary dimension in the longitudinal direction of the feature measured from one outer surface or edge of the feature to an opposite outer surface or edge of the feature. For example, where the feature is arcuate and the longitudinal direction extends radially with respect to the arc and through the apex of the arc, the length of the feature is defined as the distance between one end of the arc and the apex of the arc measured in the longitudinal direction. For example, where the feature is arcuate and the longitudinal direction extends radially with respect to the arc and through both ends of the arc, the length of the feature is defined as the distance between the outer edges of the two ends of the arc measured in the longitudinal direction.

[0043] As used herein, the term "width" refers to the primary dimension in the lateral direction of a feature. The lateral direction is perpendicular to the longitudinal direction. As used herein, the width of a feature refers to the primary dimension in the lateral direction of the feature measured from one outer surface or edge of the feature to an opposite outer surface or edge of the feature.

[0044] As used herein, the term "thickness" refers to the dimension in a direction perpendicular to the longitudinal direction and the lateral direction.

[0045] In some embodiments, the at least one mounting region is secured to the susceptor holder. The at least one mounting region can be secured to the susceptor holder by an adhesive.

[0046] The at least one mounting region of the susceptor element can be arranged at any suitable location relative to the heating region of the susceptor element. In some preferred embodiments, the at least one mounting region of the susceptor element is at a periphery of the susceptor element. For example, the at least one mounting region can be located at a side of the susceptor element.

[0047] In some preferred embodiments, the at least one mounting region comprises a plurality of mounting regions. The susceptor element can comprise any suitable number of mounting regions. For example, the 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 holder to provide a more robust support for the susceptor element compared to a susceptor element with a single mounting region.

[0048] In some embodiments, the plurality of mounting regions can comprise a first mounting region positioned at one side of the susceptor element and a second mounting region 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.

[0049] In some embodiments, the plurality of mounting regions comprises 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. In some of these embodiments, the heating region has a length and the first and second mounting regions are positioned at the same location along the length of the heating region. In some of these embodiments, the first and second mounting regions are positioned at one end of the susceptor element. In some of these embodiments, the heating region has a length and the first and second mounting regions are positioned centrally along the length of the heating region. In some of these embodiments, the heating region has a length and the first and second mounting regions 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.

[0050] In some preferred embodiments, the plurality of mounting regions comprises a first mounting region and a second mounting region, the second mounting region being positioned opposite the first mounting region.

[0051] In some preferred embodiments, the plurality of mounting regions comprises 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.

[0052] In some embodiments, the plurality of mounting regions comprises a plurality of pairs of mounting regions, each pair of mounting regions comprising 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, the second side of the susceptor element being opposite the first side of the susceptor element.

[0053] In some embodiments, the plurality of mounting regions comprises a plurality of pairs of mounting regions, each pair of mounting regions comprising a first mounting region and a second mounting region, the second mounting region being positioned opposite the first mounting region.

[0054] The susceptor element can take any suitable form. The susceptor element can comprise, for example, a mesh, a flat spiral coil, a fibre or a fabric. In some embodiments, the susceptor element can comprise a sheet or a strip.

[0055] In some preferred embodiments, the susceptor element is substantially planar. The susceptor element can be planar. In other words, the susceptor element can extend substantially in a plane. The susceptor element can be flat. The susceptor element can be thin. In other words, the susceptor element can have a thickness dimension which can be substantially less than a width dimension and a length dimension of the susceptor element.

[0056] The thickness of the susceptor element is advantageously between 2 and 10 times the skin depth of the material of the susceptor element at the operating frequency of the system. When using multiple susceptor layers, having a thickness greater than the skin depth will minimise the interaction between the different susceptor layers. Having the susceptor layers less than 10 times the skin depth ensures that not too much susceptor material needs to be heated. Advantageously, the susceptor or heating element assembly has a thickness of no more than 2 mm. This allows the heating element or elements to be placed inside and across the small airflow channel.

[0057] At least a portion of the susceptor element can be fluid permeable. In some embodiments, the susceptor element is fluid permeable. As used herein, a "fluid permeable" element means an element that allows a liquid or gas to permeate therethrough. The susceptor element can have a plurality of openings formed therein to allow fluid to permeate through the openings. In particular, the susceptor element can allow an aerosol-forming substrate to permeate it in the gas phase or both the gas and liquid phases.

[0058] In some preferred embodiments, the susceptor element can comprise a mesh. The susceptor element can comprise an array of filaments forming a mesh. As used herein, the term "mesh" encompasses both a grid of filaments with spaces therebetween and an array of filaments. The term mesh also includes woven and non-woven fabrics.

[0059] The filaments can define voids between the filaments and the voids can have a width of between 10 and 100 microns. Preferably, the filaments create capillary action in the voids such that, in use, source liquid is drawn into the voids, thereby increasing the contact area between the susceptor element and the liquid.

[0060] The filaments can form a mesh having a size of between 160 and 600 US mesh (+ / - 10%) (i.e. between 160 and 600 filaments per inch (+ / - 10%)). The width of the voids can be between 35 and 140 microns, or between 25 and 75 microns. For example, the width of the voids can be 40 microns or 63 microns. The percentage of open area of the mesh (which is the ratio of the area of the voids to the total area of the mesh) is preferably between 25% and 56%. The mesh can be formed using different types of weave or mesh structure. Alternatively, the filaments are comprised of an array of filaments arranged parallel to each other.

[0061] The filaments can be formed by etching a sheet material such as a foil. This can be particularly advantageous when the heater assembly comprises a parallel array of filaments. If the heating element comprises a mesh or fabric of filaments, the filaments can be formed individually and woven together.

[0062] Preferably, the mesh is sintered. The filaments of the mesh can be sintered together. Advantageously, sintering the mesh creates an electrical bond between filaments extending in different directions. In particular, where the mesh comprises one or more of a woven and non-woven fabric, it is advantageous to sinter the mesh to create an electrical bond between overlapping filaments.

[0063] It is well known in the art that the mesh can also be characterised by its ability to retain liquid.

[0064] The diameter of the filaments of the mesh can be between 8 and 100 microns, between 30 and 100 microns, between 8 and 50 microns, or between 8 and 39 microns. The filaments of the mesh can have a diameter of approximately 50 microns.

[0065] The filaments of the mesh can have any suitable cross-section. For example, the filaments can have a circular cross-section or can have a flattened cross-section.

[0066] Advantageously, the mesh susceptor element can have a relative magnetic permeability of between 1 and 40,000. Lower magnetic permeability materials can be used when it is desirable for the majority of the heating to be dependent on eddy currents, while higher magnetic permeability materials can be used when a hysteresis effect is required. Preferably, the material has a relative magnetic permeability of between 500 and 40,000. This can provide efficient heating of the susceptor element.

[0067] In cases where the susceptor element includes a mesh, the heating region can include filaments of the first material. In some embodiments, the heating region can include filaments of the first material and filaments of the second material. The heating 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.

[0068] 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.

[0069] 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.

[0070] 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 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, forming the filaments in the weft direction at the at least one mounting region from the second material can reduce heat transfer from the susceptor element to the susceptor holder compared to a susceptor element having filaments in the weft direction formed from the first material at the at least one mounting region.

[0071] 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.

[0072] 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.

[0073] 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 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.

[0074] In the case where the susceptor element comprises a woven mesh, the at least one mounting region can comprise filaments of the first material along the warp and filaments of the first material along the weft, and the at least one mounting region can comprise filaments of the first material along the warp and filaments of the second material along the weft.

[0075] In the case where the susceptor element comprises a woven mesh, the at least one mounting region can comprise filaments of the first material along the warp and filaments of the first material along the weft, and the at least one mounting region can comprise filaments of the first material along the warp and filaments of the second material along the weft.

[0076] In the case where the susceptor element comprises a woven mesh, the at least one mounting region can comprise filaments of the first material along the warp and filaments of the first material along the weft, and the at least one mounting region can comprise filaments of the first material along the warp and filaments of the second material along the weft.

[0077] In the case where the susceptor element comprises a woven mesh, the at least one mounting region can comprise filaments of the first material along the warp and filaments of the first material along the weft, and the at least one mounting region can comprise filaments of the first material along the warp and filaments of the second material along the weft.

[0078] In the case where the susceptor element comprises a woven mesh, the at least one mounting region can comprise filaments of the first material along the warp and filaments of the first material along the weft, and the at least one mounting region can comprise filaments of the first material along the warp and filaments of the second material along the weft.

[0079] The susceptor assembly can be surrounded by a permeable, electrically insulating coating. The coating can comprise or consist of a permeable ceramic material. When the susceptor assembly comprises a coating, it can be a coating that holds the components of the susceptor assembly together such that the components 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 an alumina (AI2O3) or a silicon-based ceramic material. The coating can have a porosity of about 30%.

[0080] The susceptor assembly can comprise a wicking element. The wicking element can be in fluid communication with the susceptor element. The wicking element can be in fluid communication with the liquid reservoir. The wicking element can be configured to transfer aerosol-forming substrate from the liquid reservoir to the susceptor element.

[0081] The wicking element can comprise a capillary material. A capillary material is a material that is able to transfer 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 generally aligned to transport the liquid aerosol-forming substrate towards the susceptor element. 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 small 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.

[0082] The wicking element can comprise an electrically insulating material. The wicking element can comprise a thermally insulating material. The wicking element can comprise a hydrophilic material. The wicking element can comprise an oleophilic material. Advantageously, forming the wicking element from a hydrophilic or oleophilic material can facilitate the transport of aerosol-forming substrate through the wicking element.

[0083] The wicking element can comprise a non-metallic material. Examples of suitable materials for the wicking element are sponge or foam materials, ceramic or graphite-based materials in the form of fibres or sintered powders, foam metals or plastics materials, for example fibrous materials made from spun or extruded fibres such as cellulose acetate, polyester or bonded polyolefin, polyethylene, terylene or polypropylene fibres, nylon fibres or ceramic or glass fibres. Suitable materials for the wicking element can include cellulosic materials such as cotton or rayon. Preferably, the wicking element can comprise rayon. The wicking element can consist of rayon. 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 deposited on the wicking element. A wicking element comprising a porous ceramic material can be an advantageous substrate for the manufacturing process associated with the deposition of the electrically conductive material.

[0084] The susceptor assembly can be configured to hold a volume of liquid aerosol-forming substrate. 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 a small volume of liquid to be rapidly evaporated and with minimal thermal 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 1 millilitre and 10 millilitres of liquid aerosol-forming substrate.

[0085] The cartridge comprises a susceptor holder. The susceptor holder contacts at least one mounting region of the susceptor element. The susceptor holder secures the susceptor assembly in place in the cartridge.

[0086] The susceptor holder is configured to withstand the susceptor assembly being raised to a temperature for heating an aerosol-forming substrate.

[0087] The susceptor holder can be formed from any suitable material that can withstand the susceptor being raised to a temperature for heating an aerosol-forming substrate. Preferably, the susceptor holder comprises a thermally insulating material. Advantageously, forming the susceptor holder from a thermally insulating material can minimise heat transfer from the susceptor element to the susceptor holder. Preferably, the susceptor holder comprises an electrically insulating material. The susceptor holder can be formed from a durable material. The susceptor holder can be formed from a liquid impermeable material. The susceptor holder can be formed from a mouldable plastics material such as polypropylene (PP) or polyethylene terephthalate (PET).

[0088] The susceptor holder can have any suitable shape and size.

[0089] In some preferred embodiments, the susceptor holder is tubular. The tubular susceptor can define an internal passageway. In some embodiments, the susceptor assembly extends into the internal passageway of the susceptor holder. In some preferred embodiments, the susceptor element extends into the internal passageway of the susceptor holder. The susceptor element can extend across the internal passageway of the susceptor holder. Where the susceptor element extends across the internal passageway of the susceptor holder, the susceptor element can comprise a first mounting region at a first side of the susceptor element in contact with the susceptor holder, and a second mounting region at a second side of the susceptor element opposite the first side in contact with the susceptor holder. Advantageously, arranging the susceptor element to contact the susceptor holder at opposite sides can enable the susceptor holder to robustly secure the susceptor element in place in the cartridge.

[0090] The internal passageway of the susceptor holder can extend substantially along a longitudinal axis. In some embodiments, the susceptor element is substantially planar, and the susceptor element extends parallel to the longitudinal axis. In some embodiments, the susceptor element is substantially planar, and the susceptor element extends perpendicular to the longitudinal axis.

[0091] In some embodiments, the internal passageway of the susceptor holder can form part of an air passageway of the cartridge. In these embodiments, the heating region of the susceptor element can be arranged in the internal passageway of the susceptor holder.

[0092] In some embodiments, the internal passageway of the susceptor holder can form part of a liquid reservoir of the cartridge. In these embodiments, at least one mounting region of the susceptor element can extend into the internal passageway of the susceptor holder.

[0093] The tubular susceptor holder can comprise at least one side wall. The tubular susceptor holder can have an open end such that the internal passageway of the susceptor holder is open at at least one end. The at least one side wall of the tubular susceptor holder can define an opening between the ends of the tubular susceptor holder. The 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, the 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.

[0094] The susceptor holder can be moulded onto the susceptor assembly. The moulded susceptor holder can hold the components of the susceptor assembly, such as the one or more susceptor elements and wicking elements, together such that the components are fixed together. The susceptor 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.

[0095] At least a portion of the susceptor holder can comprise a porous or permeable material, such as a ceramic material. The porous or permeable portion of the susceptor holder can be the region of the susceptor holder to which at least one mounting region of the susceptor assembly is mounted. Aerosol-forming substrate from the liquid reservoir can pass through the porous or permeable portion of the susceptor holder to the mounting region of the susceptor assembly. This advantageously provides a route for aerosol-forming substrate to pass from the liquid reservoir to the susceptor assembly and can increase the amount of aerosol-forming substrate supplied to the susceptor assembly.

[0096] The portion of the susceptor holder comprising the porous or permeable material can comprise an aluminium oxide (AI2O3) or a silicon-based ceramic material. The portion can have a porosity of about 30%.

[0097] The cartridge comprises a liquid reservoir. The liquid reservoir is configured to hold aerosol-forming substrate. In particular, the liquid reservoir is configured to hold liquid aerosol-forming substrate. The liquid reservoir can have any suitable shape and size depending on the requirements of the aerosol-generating system.

[0098] In some embodiments, the liquid reservoir comprises a retention material for retaining liquid aerosol-forming substrate. Where the liquid reservoir comprises a plurality of portions, the retention material can be positioned in one or more of the portions of the liquid reservoir, or in all of the portions of the liquid 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 above as being suitable for a wicking element.

[0099] In cases where the cartridge comprises a wicking element and a retaining material, the wicking element and the retaining material can be formed from the same material or different materials. The retaining material can be in fluid communication with the susceptor assembly. The retaining material can contact the susceptor assembly. The retaining material can be in fluid contact with the wicking element of the susceptor assembly. The retaining material can contact the wicking element of the susceptor assembly.

[0100] The cartridge can comprise an aerosol-forming substrate. As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. Volatile compounds can be released by heating the aerosol-forming substrate. Preferably, the cartridge comprises a liquid aerosol-forming substrate.

[0101] The aerosol-forming substrate can be liquid at room temperature. The aerosol-forming substrate can comprise both liquid and solid components. The liquid aerosol-forming substrate can comprise nicotine. The nicotine comprising liquid aerosol-forming substrate can be a nicotine salt substrate. The liquid aerosol-forming substrate can comprise a plant-based substrate. The liquid aerosol-forming substrate can comprise tobacco. The liquid aerosol-forming substrate can comprise a tobacco-containing material containing volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate can comprise homogenised tobacco material. The liquid aerosol-forming substrate can comprise a tobacco-free material. The liquid aerosol-forming substrate can comprise a homogenised plant-based material.

[0102] The liquid aerosol-forming substrate can comprise one or more aerosol formers. An aerosol former is any suitable known compound or mixture of compounds that, in use, is beneficial in forming a dense and stable aerosol and is substantially resistant to thermal degradation at the operating temperature of the system. Examples of suitable aerosol formers include glycerol and propylene glycol. 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. The liquid aerosol-forming substrate can comprise water, a solvent, ethanol, a plant extract and a natural or artificial flavourant.

[0103] The liquid aerosol-forming substrate can comprise nicotine and at least one aerosol former. The aerosol former can be glycerol or propylene glycol. The aerosol former can comprise both glycerol and propylene glycol. The liquid aerosol-forming substrate can have a nicotine concentration of between about 0.5% to about 10%, for example about 2%.

[0104] 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.

[0105] The susceptor assembly can be arranged in the outer housing. The susceptor holder can be arranged in the outer housing. In some embodiments, the susceptor holder can be integrally formed with the outer housing.

[0106] The outer housing can define part of the liquid reservoir. The outer housing can define the liquid reservoir. The outer housing and the liquid reservoir can be integrally formed. Alternatively, the liquid reservoir can be formed separately from the outer housing and arranged in the outer housing.

[0107] In some preferred embodiments in which the cartridge comprises an outer housing, the susceptor holder can secure the susceptor assembly to the outer housing. Advantageously, providing the cartridge with a susceptor 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.

[0108] 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 supplied with the aerosol-forming substrate.

[0109] The liquid reservoir can comprise two parts: a first part and a second part. A seal can be provided between the first part and the second part. The seal can be arranged to obstruct fluid communication between the first part of the liquid reservoir and the second part of the liquid reservoir. In other words, the seal can fluidically isolate the first part of the liquid reservoir from the second part of the liquid reservoir. In the storage configuration, the liquid aerosol-forming substrate can be held in the first part of the liquid reservoir. In the storage configuration, the seal can prevent the aerosol-forming substrate from flowing from the first part of the liquid reservoir to the second part of the liquid reservoir.

[0110] The first part of the cartridge can comprise the first part of the liquid reservoir and the seal. The second part of the cartridge can comprise the susceptor holder and the susceptor assembly. The susceptor holder can comprise one or more piercing elements. The one or more piercing elements can be arranged to pierce or penetrate the seal of the second part of the cartridge when the first and second parts of the cartridge are moved from the storage configuration to the use configuration.

[0111] When the first portion and the second portion of the cartridge are moved from the storage configuration to the use configuration, the one or more piercing elements of the susceptor holder can pierce the seal and enable the aerosol-forming substrate to flow from the first portion of the liquid reservoir to the second portion of the liquid reservoir.

[0112] The susceptor assembly can extend into the second portion of the liquid reservoir. Where the susceptor assembly comprises a wicking element, a portion of the wicking element can extend into the second portion of the liquid reservoir. Thus, when the cartridge is in the storage configuration, the susceptor assembly is isolated from the aerosol-forming substrate, and when the cartridge is in the use configuration, the susceptor assembly is supplied with aerosol-forming substrate from the second portion of the liquid reservoir.

[0113] The seal can be any suitable type of seal for preventing fluid flow between the first portion of the liquid reservoir and the second portion of the liquid reservoir. For example, the seal can comprise a metal foil, a plastic foil, or an elastomeric seal.

[0114] The first portion and the second portion of the cartridge can be moved relative to one another in any suitable manner. In some embodiments, the first portion and the second portion of the cartridge can slide relative to one another. In some embodiments, the first portion and the second portion of the cartridge can rotate relative to one another.

[0115] Where the susceptor holder is a tubular susceptor holder and the internal passageway of the susceptor holder forms part of the air passageway of the cartridge, the second portion of the liquid reservoir can be formed between the outer surface of the susceptor holder and the inner surface of the outer housing. In these embodiments, the second portion of the liquid reservoir can comprise an annular space between the susceptor holder and the outer housing. In these embodiments, the one or more piercing elements can be arranged at the outer surface of the susceptor holder.

[0116] Where the susceptor holder is a tubular susceptor holder and the internal passageway of the susceptor holder forms part of the liquid reservoir of the cartridge, the second portion of the liquid reservoir can be formed by the internal passageway of the susceptor holder. In these embodiments, the one or more piercing elements can be arranged within the internal passageway at the inner surface of the susceptor holder.

[0117] The cartridge can have a mouth end through which a user can draw generated aerosol. The cartridge can have a connection end configured to connect the cartridge to an aerosol-generating device.

[0118] Where the susceptor assembly comprises a substantially planar susceptor element, a first side of the susceptor element can face the mouth end, and a second side of the susceptor element can face the connection end. Preferably, however, the planar susceptor element extends in a plane that is substantially parallel to the longitudinal axis of the cartridge, to extend between the mouth end and the connection end. Where the planar susceptor element extends in a plane that is substantially parallel to the longitudinal axis of the cartridge, the first and second sides of the susceptor element face opposite sides of the cartridge, rather than the mouth end and the connection end of the cartridge.

[0119] The cartridge can define an air inlet. The air inlet can be arranged at or around the connection end of the cartridge. The cartridge can define a mouth end opening. A user can be able to draw through the mouth end opening an aerosol generated from the cartridge. The cartridge can define a closed airflow pathway from the air inlet to the air outlet. The closed airflow pathway can extend from the air inlet, through the susceptor element, to the mouth end opening.

[0120] The closed airflow pathway can pass through the liquid reservoir. For example, the liquid reservoir can have an annular cross-section defining an internal passage, and the airflow pathway can extend through the internal passage of the liquid reservoir.

[0121] Where the susceptor holder is a tubular susceptor holder, the internal passage of the tubular susceptor holder can form part of the closed airflow pathway. The closed airflow pathway can extend from the air inlet, at the connection end of the cartridge, through the internal passage of the tubular susceptor holder, through the internal passage of the liquid reservoir, to the mouth end opening.

[0122] In some embodiments, at least a portion of the airflow pathway is defined between the susceptor holder and the outer housing of the cartridge. At least a portion of the airflow pathway can be defined between the liquid reservoir and the outer housing of the cartridge. In some embodiments, the closed airflow pathway can extend from the air inlet, at the connection end of the cartridge, through the pathway between the susceptor holder and the outer housing, through the pathway between the liquid reservoir and the outer housing, to the mouth end opening.

[0123] According to the present disclosure, there is provided a cartridge for an aerosol-generating system, the cartridge comprising: a liquid reservoir for holding a liquid aerosol-forming substrate; and a susceptor assembly in fluid communication with the liquid reservoir. The susceptor assembly comprises a susceptor element having an array of filaments forming a woven mesh. The woven mesh comprises filaments of a first material along the weft direction. The woven mesh further comprises filaments of a second material along the warp direction.

[0124] In some preferred embodiments, the first material is a magnetic material that can be heated by penetration with an alternating magnetic field. The first material can comprise any suitable magnetic material. For example, the first material can comprise a ferritic stainless steel. Suitable ferritic stainless steels include AISI 400 series stainless steels, such as AISI 409, 410, 420 and 430 stainless steels.

[0125] In some preferred embodiments, the second material is a non-magnetic material. The second material can be any suitable non-magnetic material. In some embodiments, the second material is a non-magnetic metal. In some preferred embodiments, the second material is a non-magnetic austenitic stainless steel. Suitable austenitic stainless steels include AISI 300 series stainless steels, such as AISI 304, 309, and 316 stainless steels. The second material can be a non-magnetic ceramic, plastic, or cellulose material. In some embodiments, the second material can be cotton or rayon.

[0126] The tube may further include a receptor retainer. The receptor retainer may contact the receptor element along a radial filament. Advantageously, contact along the radial filament minimizes heat transfer from the receptor element to the receptor retainer. The receptor retainer may contact the receptor element at multiple locations. In some embodiments, the receptor retainer contacts the receptor element at a first location and a second location, which are radially spaced apart.

[0127] In some embodiments, the first material is a non-magnetic material, and the second material is a magnetic material that can be heated by penetrating with an alternating magnetic field. In these embodiments, the tube may further include a receptor holder, which may contact the receptor element at a filament along the weft direction. In these embodiments, the receptor holder may contact the receptor element at multiple locations. The receptor holder may contact the receptor element at a first position and a second position, which are spaced apart in the weft direction.

[0128] According to this disclosure, an aerosol generation system is provided, which includes a cylinder as described herein and an aerosol generation device configured as a receiving cylinder.

[0129] According to this disclosure, an aerosol generation system is also provided, comprising an aerosol generation apparatus including a receptor assembly as described herein and a receptor retainer as described herein. The aerosol generation apparatus may also include a liquid reservoir as described herein. Such an aerosol generation system includes the features of the cylinder described herein within the aerosol generation apparatus.

[0130] The aerosol generating system can be a handheld aerosol generating system configured to allow a user to inhale through the mouthpiece opening to draw in the aerosol. The aerosol generating system can have a size comparable to a conventional cigar or cigarette. The aerosol generating system can have an overall length between approximately 30 mm and approximately 150 mm. The aerosol generating system can have an outer diameter between approximately 5 mm and approximately 30 mm.

[0131] The aerosol generation system can be configured to deliver nicotine to users.

[0132] The aerosol-generating device can comprise an induction heating assembly. The induction heating assembly can comprise at least one inductor coil, a power supply and a control circuit. The power supply and the control circuit can be connected to the at least one inductor coil and configured to supply an alternating current to the at least one inductor coil to generate an alternating magnetic field. The susceptor assembly can be arranged to be penetrated by the alternating magnetic field from the at least one inductor coil such that the susceptor element is heated by the alternating magnetic field.

[0133] In case the aerosol-generating system comprises a cartridge, the at least one inductor coil can be arranged in the device such that the alternating magnetic field penetrates the cartridge and, in particular, the susceptor assembly in the cartridge when the cartridge is received by the aerosol-generating device. The aerosol-generating device can comprise a cavity for receiving the cartridge. The at least one inductor coil can be arranged such that the alternating magnetic field penetrates the cavity. The at least one inductor coil can be arranged at the cavity, in the cavity or around the cavity. In some embodiments, the at least one inductor coil can define the cavity. The at least one inductor coil can be a tubular, spiral or solenoid coil substantially defining the cavity. In other embodiments, the coil can be arranged at a side of the cavity.

[0134] In some embodiments, in which the susceptor element is planar and extends parallel to the plane, the at least one inductor coil can be arranged to generate the alternating magnetic field penetrating the susceptor assembly in a direction substantially parallel to the plane.

[0135] In some embodiments, in which the susceptor element is planar and extends parallel to the plane, the at least one inductor coil can be arranged to generate the alternating magnetic field penetrating the susceptor assembly in a direction substantially perpendicular to the plane.

[0136] The induction heating assembly can comprise any suitable number of inductor coils. The aerosol-generating system can comprise a single inductor coil. The aerosol-generating system can comprise a plurality of inductor coils. The induction heating assembly can comprise one, two, three, four, five, six, seven or eight inductor coils.

[0137] The at least one inductor coil can have any suitable form. In some embodiments, the at least one inductor coil can be a tubular or solenoid coil. In some embodiments, the at least one inductor coil can be a planar or flat inductor coil. The tubular or solenoid inductor coil can define the susceptor assembly. The planar or flat inductor coil can be arranged at a side of the susceptor assembly. The planar or flat inductor coil can be circular, oval or rectangular. Preferably, the shape of the planar or flat inductor coil substantially corresponds to the shape of the susceptor element.

[0138] Where the susceptor assembly is substantially planar, and in particular the susceptor element is planar extending parallel to a first plane, the at least one inductor coil can be a flat inductor coil extending in a second plane substantially parallel to the first plane. In this arrangement, the at least one inductor coil is arranged to generate an alternating magnetic field that penetrates the susceptor assembly in a direction substantially perpendicular to the first plane.

[0139] In some preferred embodiments, the susceptor assembly comprises a planar susceptor assembly, and the induction heating assembly comprises a first flat inductor coil and a second flat inductor coil. The planar susceptor assembly extends in a first plane, the first inductor coil extends in a second plane parallel to the first plane, and the second inductor coil extends in a third plane parallel to the first plane and the second plane. The susceptor assembly is arranged between the first inductor coil and the second inductor coil. In this arrangement, the first inductor coil generates an alternating magnetic field that penetrates the susceptor assembly from a first side in a direction substantially perpendicular to the first plane, and the second inductor coil generates an alternating magnetic field that penetrates the susceptor assembly from a second side opposite the first side in a direction substantially perpendicular to the first plane. Advantageously, this arrangement can provide efficient, uniform heating of the susceptor element. The inventors have found that this arrangement can enable an alternating current having a relatively low frequency to be supplied to the inductor coils, resulting in the generation of an alternating magnetic field of lower frequency, which can allow a simpler and cheaper control circuit to be employed to supply the alternating current. The inventors have also found that this arrangement can enable the inductor coils to be spaced apart from the susceptor assembly at an increased distance compared to other arrangements, while maintaining a desired aerosol generated from the aerosol-generating system.

[0140] In these preferred embodiments, the induction heating assembly is configured such that the first inductor coil and the second inductor coil generate similar sized alternating magnetic fields in opposite directions. In some of these preferred embodiments, the first inductor coil and the second inductor coil can be electrically connected to form a single electrically conductive path. In these embodiments, the first inductor coil can be wound in an opposite direction to the second inductor coil, such that the alternating magnetic fields generated by the first inductor coil and the second inductor coil are generated in opposite directions. Alternatively, the first inductor coil and the second inductor coil can be wound in the same direction, and the control circuit can be configured to supply an alternating current to each of the first inductor coil and the second inductor coil, such that the alternating magnetic fields generated by the first inductor coil and the second inductor coil are generated in opposite directions. The first inductor coil and the second inductor coil can be substantially identical. The first inductor coil and the second inductor coil can be substantially identical, but wound in different directions.

[0141] In some preferred embodiments, the susceptor element is substantially planar and extends parallel to the first plane; and the at least one inductor coil comprises a first inductor coil and a second inductor coil, the first inductor coil being positioned on a first side of the susceptor assembly extending parallel to the first plane, and the second inductor coil being positioned on a second side of the susceptor assembly opposite the first side and extending parallel to the first plane. The susceptor element can be positioned between the first inductor coil and the second inductor coil. Preferably, the susceptor element is substantially equidistant from the first inductor coil and the second inductor coil. The system can be configured such that the first inductor coil and the second inductor coil generate magnetic fields equal to and opposite to each other. The control circuitry can be configured to provide current to the inductor coils such that the first inductor coil provides a force on the susceptor assembly equal to and opposite to the second inductor coil.

[0142] The induction heating assembly can further comprise at least one flux concentrator arranged to contain the alternating magnetic field generated by the at least one inductor coil.

[0143] The control circuitry can comprise a microprocessor. The microprocessor can be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC), or other circuitry capable of providing control. The control circuit can be configured to continuously power the at least one inductor coil after activation of the device, or can be configured to power intermittently, such as on a puff-by-puff basis. The power can be supplied to the induction heating assembly in the form of current pulses, for example by means of pulse width modulation (PWM). The control circuitry can comprise a DC / AC inverter, which can comprise a class-D or class-E power amplifier. The control circuitry can comprise other electronic components. For example, in some embodiments, the control circuitry can comprise any of a sensor, a switch, a display element.

[0144] The power source can be a DC power source. The power source can be a battery. The battery can be a lithium-based battery, such as 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; for example, the power source can have a capacity that allows for the storage of energy sufficient 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.

[0145] The control circuit and power supply are configured to provide an alternating current to the at least one inductor coil. As used herein, "alternating current" means an electric current that periodically reverses direction. The alternating current can have any suitable frequency. A suitable frequency of the alternating current can be between 100 kilohertz (kHz) and 30 megahertz (MHz). Where the at least one inductor coil is a tubular inductor coil, the alternating current can have a frequency between 500 kilohertz (kHz) and 30 megahertz (MHz). Where the at least one inductor coil is a flat coil, the alternating current can have a frequency between 100 kilohertz (kHz) and 1 megahertz (MHz).

[0146] Driving an alternating current through the 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).

[0147] The aerosol-generating device can comprise a housing. The housing can be elongate. The housing can comprise any suitable material or combination of materials. Examples of suitable materials include metal, alloy, 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.

[0148] The aerosol-generating device housing can define a cavity for receiving a 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.

[0149] The aerosol-generating device can have a connection end configured to connect the aerosol-generating device to a cartridge. The connection end can comprise a cavity for receiving a cartridge.

[0150] The aerosol-generating device can have a distal end opposite the connection end. The distal end can comprise an electrical connector configured to connect the aerosol-generating device to an electrical connector of an external power supply for charging a power supply of the aerosol-generating device.

[0151] It will be appreciated that any features described herein in relation to one embodiment of a cartridge or aerosol-generating device can also be applicable to other embodiments of cartridges and aerosol-generating devices according to the present disclosure. Features described in relation to one embodiment can equally apply to another embodiment according to the present disclosure. It will also be appreciated that an aerosol-generating system according to the present disclosure can be provided in an aerosol-generating device without a cartridge. Accordingly, any of the features described herein in relation to a cartridge can equally apply to an aerosol-generating device.

[0152] The application is defined in the claims. However, 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.

[0153] EX1. A cartridge for an aerosol-generating system, the cartridge comprising:

[0154] a liquid reservoir for holding a liquid aerosol-forming substrate;

[0155] a susceptor assembly in fluid communication with the liquid reservoir, the susceptor assembly comprising a susceptor element having:

[0156] a heating region comprising a first material, the first material being a magnetic material capable of being heated by penetration with an alternating magnetic field; and

[0157] at least one mounting region comprising a second material, the second material being a non-magnetic material; and

[0158] a susceptor holder, wherein at least one mounting region of the susceptor element is in contact with the susceptor holder,

[0159] wherein the proportion by weight of the first material in the heating region is greater than the proportion by weight of the first material in the at least one mounting region.

[0160] EX2. The cartridge according to example EX1, wherein the at least one mounting region of the susceptor element is at a periphery of the susceptor element.

[0161] EX3. The cartridge according to any one of examples EX1 to EX2, wherein the susceptor holder comprises an electrically insulating material.

[0162] EX4. The cartridge according to any one of examples EX1 to EX3, wherein the susceptor holder comprises a thermally insulating material.

[0163] EX5. The cartridge according to any one of examples EX1 to EX4, wherein the cartridge comprises an outer housing, and wherein the susceptor holder secures the susceptor assembly to the outer housing.

[0164] EX6. The cartridge according to any one of examples EX1 to EX5, wherein the second material is an electrically insulating material.

[0165] EX7. The cartridge according to any one of examples EX1 to EX6, wherein the second material is a thermally insulating material.

[0166] EX8. The cartridge according to any one of examples EX1 to EX7, wherein the second material is non-metallic.

[0167] EX9. A cartridge according to any one of Examples EX1 to EX8, wherein the second material is a hydrophilic material.

[0168] EX10. A cartridge according to any one of Examples EX1 to EX9, wherein the second material is an oleophilic material.

[0169] EX11. A cartridge according to any one of Examples EX1 to EX10, wherein the second material comprises a cellulosic material.

[0170] EX12. A cartridge according to Example EX11, wherein the second material comprises a rayon.

[0171] EX13. A cartridge according to any one of Examples EX1 to EX12, wherein the first material comprises a ferritic stainless steel.

[0172] EX14. A cartridge according to any one of Examples EX1 to EX13, wherein the heating region of the susceptor element comprises:

[0173] at least 10 wt% of the first material, or

[0174] at least 20 wt% of the first material, or

[0175] at least 30 wt% of the first material, or

[0176] at least 40 wt% of the first material, or

[0177] at least 50 wt% of the first material, or

[0178] at least 60 wt% of the first material, or

[0179] at least 70 wt% of the first material, or

[0180] at least 80 wt% of the first material, or

[0181] at least 90 wt% of the first material.

[0182] 15. A cartridge according to any one of Examples EX1 to EX13, wherein the at least one mounting region of the susceptor element comprises:

[0183] 90 wt% or less of the first material, or

[0184] 80 wt% or less of the first material, or

[0185] 70 wt% or less of the first material, or

[0186] 60 wt% or less of the first material, or

[0187] 50 wt% or less of the first material, or

[0188] 40 wt% or less of the first material, or

[0189] 30 wt% or less of the first material, or

[0190] 20 wt% or less of the first material, or

[0191] 10 wt% or less of the first material.

[0192] 16. The cartridge according to any one of Examples EX1 to EX13, wherein the heating region of the susceptor element comprises:

[0193] 90 wt% or less of the second material, or

[0194] 80 wt% or less of the second material, or

[0195] 70 wt% or less of the second material, or

[0196] 60 wt% or less of the second material, or

[0197] 50 wt% or less of the second material, or

[0198] 40 wt% or less of the second material, or

[0199] 30 wt% or less of the second material, or

[0200] 20 wt% or less of the second material, or

[0201] 10 wt% or less of the second material.

[0202] 17. The cartridge according to any one of Examples EX1 to EX13, wherein the at least one mounting region of the susceptor element comprises:

[0203] at least 10 wt% of the second material, or

[0204] at least 20 wt% of the second material, or

[0205] at least 30 wt% of the second material, or

[0206] at least 40 wt% of the second material, or

[0207] at least 50 wt% of the second material, or

[0208] at least 60 wt% of the second material, or

[0209] at least 70 wt% of the second material, or

[0210] at least 80 wt% of the second material, or

[0211] at least 90 wt% of the second material.

[0212] EX18. A cartridge according to any one of Examples EX1 to EX13, the heating region of the susceptor element comprises:

[0213] at least 10 wt% of the first material and less than 90 wt% of the second material, or at least 20 wt% of the first material and less than 80 wt% of the second material, or at least 30 wt% of the first material and less than 70 wt% of the second material, or at least 40 wt% of the first material and less than 60 wt% of the second material, or at least 50 wt% of the first material and less than 50 wt% of the second material, or at least 60 wt% of the first material and less than 40 wt% of the second material, or at least 70 wt% of the first material and less than 30 wt% of the second material, or at least 80 wt% of the first material and less than 20 wt% of the second material, or at least 90 wt% of the first material and less than 10 wt% of the second material.

[0214] EX19. A cartridge according to any one of Examples EX1 to EX13, wherein the at least one mounting region of the susceptor element comprises:

[0215] at least 10 wt% of the second material and less than 90 wt% of the first material, or at least 20 wt% of the second material and less than 80 wt% of the first material, or at least 30 wt% of the second material and less than 70 wt% of the first material, or at least 40 wt% of the second material and less than 60 wt% of the first material, or at least 50 wt% of the second material and less than 50 wt% of the first material, or at least 60 wt% of the second material and less than 40 wt% of the first material, or at least 70 wt% of the second material and less than 30 wt% of the first material, or at least 80 wt% of the second material and less than 20 wt% of the first material, or at least 90 wt% of the second material and less than 10 wt% of the first material.

[0216] EX20. A cartridge according to any one of Examples EX1 to EX13, wherein:

[0217] the heating region of the susceptor element comprises at least 90 wt% of the first material, and the at least one mounting region of the susceptor element comprises less than 10 wt% of the first material, or

[0218] the heating region of the susceptor element comprises at least 80 wt% of the first material, and the at least one mounting region of the susceptor element comprises less than 20 wt% of the first material, or

[0219] the heating region of the susceptor element comprises at least 70 wt% of the first material, and the at least one mounting region of the susceptor element comprises less than 30 wt% of the first material, or

[0220] the heating region of the susceptor element comprises at least 60 wt% of the first material, and the at least one mounting region of the susceptor element comprises less than 40 wt% of the first material, or

[0221] the heating region of the susceptor element comprises at least 50 wt% of the first material, and the at least one mounting region of the susceptor element comprises less than 50 wt% of the first material.

[0222] EX21. The cartridge according to any one of Examples EX1 to EX13, wherein the heating region of the susceptor element is comprised of the first material.

[0223] EX22. The cartridge according to any one of Examples EX1 to EX13, wherein the at least one mounting region of the susceptor element is comprised of the second material.

[0224] EX23. The cartridge according to any one of Examples EX1 to EX22, wherein the susceptor element is fluid permeable.

[0225] EX24. The cartridge according to any one of Examples EX1 to EX23, wherein the susceptor element comprises an array of filaments forming a web.

[0226] EX25. The cartridge according to Example EX24, wherein the web is non-woven.

[0227] EX26. The cartridge according to Example EX24, wherein the web is woven.

[0228] EX27. The cartridge according to Example EX26, wherein the at least one mounting region comprises filaments of the first material along the weft direction and filaments of the second material along the warp direction, and wherein the at least one mounting region comprises filaments of the second material along the weft direction and filaments of the second material along the warp direction.

[0229] EX28. A cartridge according to example EX26, wherein the at least one mounting region is comprised of a filament of the first material in the weft direction and a filament of the second material in the warp direction, and wherein the at least one mounting region is comprised of a filament of the second material in the weft direction and a filament of the second material in the warp direction.

[0230] EX29. A cartridge according to example EX26, wherein the at least one mounting region comprises a filament of the first material in the warp direction and a filament of the second material in the weft direction, and wherein the at least one mounting region comprises a filament of the second material in the warp direction and a filament of the second material in the weft direction.

[0231] EX30. A cartridge according to example EX26, wherein the at least one mounting region is comprised of a filament of the first material in the warp direction and a filament of the second material in the weft direction, and wherein the at least one mounting region is comprised of a filament of the second material in the warp direction and a filament of the second material in the weft direction.

[0232] EX31. A cartridge according to example EX26, wherein the at least one mounting region comprises a filament of the first material in the weft direction and a filament of the first material in the warp direction, and wherein the at least one mounting region comprises a filament of the first material in the weft direction and a filament of the second material in the warp direction.

[0233] EX32. A cartridge according to example EX26, wherein the at least one mounting region is comprised of a filament of the first material in the weft direction and a filament of the first material in the warp direction, and wherein the at least one mounting region is comprised of a filament of the first material in the weft direction and a filament of the second material in the warp direction.

[0234] EX33. A cartridge according to example EX26, wherein the at least one mounting region comprises a filament of the first material in the warp direction and a filament of the first material in the weft direction, and wherein the at least one mounting region comprises a filament of the first material in the warp direction and a filament of the second material in the weft direction.

[0235] EX34. A cartridge according to example EX26, wherein the at least one mounting region is comprised of a filament of the first material in the warp direction and a filament of the first material in the weft direction, and wherein the at least one mounting region is comprised of a filament of the first material in the warp direction and a filament of the second material in the weft direction.

[0236] EX35. A cartridge according to any one of examples EX1 to EX34, wherein the susceptor element is substantially planar.

[0237] EX36. The cartridge according to any one of Examples EX1 to EX35, wherein the susceptor holder is tubular and defines an internal passageway, and wherein the susceptor element extends into the internal passageway of the susceptor holder.

[0238] EX37. The cartridge according to Example EX36, wherein the susceptor element extends across the internal passageway of the susceptor holder.

[0239] EX38. The cartridge according to any one of Examples EX36 or EX37, wherein the internal passageway of the susceptor holder extends substantially along a longitudinal axis, and wherein the susceptor element is substantially planar and extends parallel to the longitudinal axis.

[0240] EX39. The cartridge according to any one of Examples EX36 or EX37, wherein the internal passageway of the susceptor holder extends substantially along a longitudinal axis, and wherein the susceptor element is substantially planar and extends perpendicular to the longitudinal axis.

[0241] EX40. The cartridge according to any one of Examples EX36 to EX39, wherein the susceptor holder comprises at least one sidewall, and wherein the at least one sidewall of the tubular susceptor holder defines an opening between the end portions of the tubular susceptor holder.

[0242] EX41. The cartridge according to Example EX40, wherein the at least one mounting region of the susceptor element extends into the opening of the tubular susceptor holder.

[0243] EX42. The cartridge according to Example EX40, wherein the at least one sidewall of the tubular susceptor holder defines a plurality of openings between the end portions of the susceptor holder, wherein the at least one mounting region comprises a plurality of mounting regions, and wherein each mounting region of the susceptor element extends into one of the plurality of openings in the at least one sidewall of the tubular susceptor holder.

[0244] EX43. The cartridge according to any one of Examples EX1 to EX42, wherein the susceptor holder is in contact with the second material at the at least one mounting region of the susceptor element.

[0245] EX44. The cartridge according to any one of Examples EX1 to EX43, wherein the at least one mounting region comprises a plurality of mounting regions.

[0246] 45. The cartridge according to Example EX44, wherein the plurality of mounting regions comprises a first mounting region and a second mounting region, the first mounting region being positioned at one side of the susceptor element and the second mounting region being positioned at the same side of the susceptor element as the first mounting region.

[0247] EX46. A cartridge according to example EX45, wherein 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.

[0248] EX47. A cartridge according to example EX44, wherein the plurality of mounting regions comprises 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.

[0249] EX48. A cartridge according to example EX47, wherein the heating region has a length, and wherein the first mounting region and the second mounting region are positioned at the same location along the length of the heating region.

[0250] EX49. A cartridge according to example EX47, wherein the first mounting region and the second mounting region are positioned at one end of the susceptor element.

[0251] EX50. A cartridge according to example EX47, wherein the heating region has a length, and wherein the first mounting region and the second mounting region are positioned centrally along the length of the heating region.

[0252] EX51. A cartridge according to example EX47, wherein the heating region has a length, and wherein the first mounting region and the second mounting region are positioned at different locations along the length of the heating region.

[0253] EX52. A cartridge according to example EX47, wherein 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.

[0254] EX53. A cartridge according to example EX47, wherein the plurality of mounting regions comprises a first mounting region and a second mounting region, the second mounting region is positioned opposite the first mounting region.

[0255] EX54. A cartridge according to example EX47, wherein the plurality of mounting regions comprises:

[0256] a first pair of mounting regions positioned at a first end of the susceptor element at opposite sides of the susceptor element; and

[0257] 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.

[0258] EX55. According to the cylinder of Example EX47, the plurality of mounting regions include a plurality of pairs of mounting regions, each pair of mounting regions including a first mounting region located at a first side of the sensor element and a second mounting region located at a second side of the sensor element, the second side of the sensor element being opposite to the first side of the sensor element.

[0259] EX56. According to the cylinder of Example EX47, the plurality of mounting areas include a plurality of pairs of mounting areas, each pair of mounting areas including a first mounting area and a second mounting area, the second mounting area being positioned relative to the first mounting area.

[0260] EX57. A cylinder according to any one of Examples EX1 to EX56, wherein the at least one mounting area is located adjacent to the periphery of the heating area, wherein the heating area has a length and a width, and the at least one mounting area has a length and a width.

[0261] EX58. The cylinder according to Example EX57, wherein the length of the at least one mounting area is less than the length of the heating area.

[0262] EX59. The cylinder according to Example EX58, wherein the length of at least one mounting area is less than three-quarters of the length of the heating area.

[0263] EX60. According to Example EX58, the length of the at least one mounting area does not exceed half the length of the heating area.

[0264] EX61. According to Example EX58, the length of the at least one mounting area does not exceed one-quarter of the length of the heating area.

[0265] EX62. A cylinder according to any one of Examples EX57 to EX61, wherein the width of the at least one mounting area is smaller than the width of the heating area.

[0266] EX63. The cylinder according to Example EX62, wherein the length of the at least one mounting area is less than three-quarters of the length of the heating area.

[0267] EX64. The cylinder according to Example EX62, wherein the length of the at least one mounting area does not exceed half the length of the heating area.

[0268] EX65. According to Example EX62, the length of the at least one mounting area does not exceed one-quarter of the length of the heating area.

[0269] EX66. A cartridge for an aerosol generation system, the cartridge comprising:

[0270] a liquid reservoir for holding a liquid aerosol-forming substrate;

[0271] a susceptor assembly in fluid communication with the liquid reservoir, the susceptor assembly comprising a susceptor element having an array of filaments forming a woven mesh, the woven mesh comprising:

[0272] filaments of a first material along the weft direction; and

[0273] filaments of a second material along the warp direction.

[0274] EX67. A cartridge according to example EX66, wherein the first material is a magnetic material capable of being heated by penetration with an alternating magnetic field, and the second material is a non-magnetic material.

[0275] EX68. A cartridge according to example EX66 or EX67, wherein the cartridge further comprises a susceptor holder, the susceptor holder being in contact with the susceptor element at a filament along the weft direction.

[0276] EX69. A cartridge according to example EX68, wherein the susceptor holder is in contact with the susceptor element at a first position and a second position, the first position and the second position being spaced apart in the weft direction.

[0277] EX70. A cartridge according to example EX66, wherein the first material is a non-magnetic material, and the second material is a magnetic material capable of being heated by penetration with an alternating magnetic field.

[0278] EX71. A cartridge according to example EX70, wherein the cartridge further comprises a susceptor holder, the susceptor holder being in contact with the susceptor element at a filament along the warp direction.

[0279] EX72. A cartridge according to example EX71, wherein the susceptor holder is in contact with the susceptor element at a first position and a second position, the first position and the second position being spaced apart in the warp direction.

[0280] EX73. A cartridge according to any one of examples EX67 to EX72, wherein the magnetic material comprises ferritic stainless steel.

[0281] EX74. A cartridge according to example EX73, wherein the ferritic stainless steel comprises one of AISI 430, 420 or 410.

[0282] EX75. A cartridge according to any one of examples EX67 to EX74, wherein the non-magnetic material comprises AISI 304 or 316.

[0283] EX75. A cartridge according to any one of Examples EX1 to EX74, comprising an air inlet, an air outlet, and an airflow passageway between the air inlet and the air outlet.

[0284] EX76. A cartridge according to Example EX75, wherein a portion of the susceptor assembly is within the airflow passageway.

[0285] EX77. A cartridge according to Example EX75 or EX76, wherein a heating region of the susceptor element is within the airflow passageway.

[0286] EX78. A cartridge according to any one of Examples EX75 to EX77, wherein aerosol-forming substrate vaporised by the susceptor assembly is able to escape into the airflow passageway.

[0287] EX79. An aerosol-generating system according to any one of Examples EX75 to EX78, wherein the air outlet is provided in a mouth end of the cartridge, through which mouth end aerosol generated is able to be drawn by a user.

[0288] EX80. A cartridge according to any one of Examples EX1 to EX79, wherein the susceptor assembly or a heating region of the susceptor assembly is able to hold between 2 millilitres and 10 millilitres of liquid aerosol-forming substrate.

[0289] EX81. A cartridge according to any one of Examples EX1 to EX80, wherein the susceptor assembly further comprises a wicking element.

[0290] EX82. A cartridge according to Example EX81, wherein the wicking element is in fluid communication with the susceptor element.

[0291] EX83. A cartridge according to Example EX81 or EX82, wherein the wicking element is in fluid communication with the liquid reservoir.

[0292] EX84. A cartridge according to Example EX83, wherein the wicking element is arranged to transport aerosol-forming substrate from the liquid reservoir to the susceptor element.

[0293] EX85. A cartridge according to Example EX84, wherein the wicking element is arranged to transport aerosol-forming substrate from the liquid reservoir across a major surface of the susceptor element.

[0294] EX86. A cartridge according to any one of Examples EX81 to EX85, wherein the susceptor element is fixed to the wicking element.

[0295] EX87. A cartridge according to any one of Examples EX81 to EX85, wherein the susceptor element is integral with the wicking element.

[0296] EX88. A cartridge according to any one of Examples EX1 to EX87, wherein the susceptor assembly comprises a plurality of susceptor elements.

[0297] EX89. A cartridge according to Example EX88, wherein the susceptor assembly comprises a wicking element, and wherein each susceptor element is arranged in fluid communication with the wicking element.

[0298] EX90. A cartridge according to any one of Examples EX1 to EX89, wherein the susceptor assembly comprises a first susceptor element and a second susceptor element, the second susceptor element being spaced apart from the first susceptor element.

[0299] EX91. A cartridge according to Example EX90, wherein a wicking element is arrangeable in a space between the first susceptor element and the second susceptor element.

[0300] EX92. A cartridge according to Example EX90 or EX91, wherein the first, second and wicking elements are substantially planar, and the first susceptor is arranged at a first side of the planar wicking element, and the second susceptor is arranged at a second side of the planar wicking element opposite the first side.

[0301] EX93. A cartridge according to any one of Examples EX90 to EX92, wherein the wicking element comprises a sheet of cotton or rayon.

[0302] EX94. An aerosol-generating system comprising:

[0303] a cartridge according to any one of Examples EX1 to EX93; and

[0304] an aerosol-generating device configured to receive the cartridge, the aerosol- generating device comprising:

[0305] at least one inductor coil arranged to generate an alternating magnetic field that penetrates a susceptor element of the cartridge when the cartridge is received in the device; and

[0306] control circuitry connected to the at least one inductor coil and configured to supply an alternating current to the inductor coil to generate the alternating magnetic field.

[0307] EX95. An aerosol-generating system comprising:

[0308] a liquid reservoir for holding a liquid aerosol-forming substrate;

[0309] a susceptor assembly in fluid communication with the liquid reservoir, the susceptor assembly comprising a susceptor element having:

[0310] a heating region comprising a first material, the first material being a magnetic material capable of being heated by penetration with an alternating magnetic field; and

[0311] at least one mounting region comprising a second material, the second material being a non-magnetic material, wherein a weight proportion of the first material in the heating region is greater than a weight proportion of the first material in the at least one mounting region;

[0312] a susceptor holder, wherein the at least one mounting region of the susceptor element is in contact with the susceptor holder;

[0313] at least one inductor coil arranged to generate an alternating magnetic field that penetrates the susceptor element; and

[0314] a control circuit connected to the at least one inductor coil and configured to supply an alternating current to the inductor coil to generate the alternating magnetic field.

[0315] EX96. An aerosol-generating system according to example EX95, wherein the aerosol- generating system comprises:

[0316] a cartridge comprising the liquid reservoir; and

[0317] an aerosol-generating device configured to be coupled to the cartridge, the aerosol- generating device comprising the at least one inductor coil, and the control circuit.

[0318] EX97. An aerosol-generating system according to example EX96, wherein the cartridge further comprises the susceptor assembly and the susceptor holder.

[0319] EX98. An aerosol-generating system according to any one of examples EX94 to EX97, wherein the susceptor element is a planar susceptor element extending in a plane, and the at least one inductor coil is configured to provide a magnetic field at the susceptor element that is perpendicular to the plane of the susceptor element.

[0320] EX99. An aerosol-generating system according to any one of examples EX94 to EX97, wherein the susceptor element is a planar susceptor element extending in a plane, and the at least one inductor coil is configured to provide a magnetic field at the susceptor element that is parallel to the plane of the susceptor element.

[0321] EX100. An aerosol-generating system according to any one of examples EX94 to EX99, wherein the at least one inductor coil is a solenoid inductor coil.

[0322] EX101. An aerosol-generating system according to any one of Examples EX94 to EX100, wherein the at least one inductor coil defines the susceptor assembly.

[0323] EX102. An aerosol-generating system according to any one of Examples EX94 to EX99, wherein the at least one inductor coil is a planar inductor coil.

[0324] EX103. An aerosol-generating system according to Example EX102, wherein the at least one inductor coil is rectangular.

[0325] EX104. An aerosol-generating system according to any one of Examples EX94 to EX103, wherein the at least one inductor coil comprises a plurality of inductor coils.

[0326] EX105. An aerosol-generating system according to any one of Examples EX94 to EX98, wherein:

[0327] the susceptor element is substantially planar and extends parallel to a first plane;

[0328] the at least one inductor coil comprises a first inductor coil and a second inductor coil, the first inductor coil being positioned on a first side of the susceptor assembly extending parallel to the first plane, the second inductor coil being positioned on a second side of the susceptor assembly opposite the first side and extending parallel to the first plane; and

[0329] the susceptor element is positioned between the first inductor coil and the second inductor coil.

[0330] EX106. An aerosol-generating system according to Example EX105, wherein the susceptor element is substantially equidistant from the first inductor coil and the second inductor coil.

[0331] EX107. An aerosol-generating system according to Example EX105 or EX106, wherein the system is configured such that the first inductor coil and the second inductor coil generate magnetic fields equal to and opposite to each other.

[0332] EX108. An aerosol-generating system according to any one of Examples EX105 to EX107, wherein the control circuit is configured to provide a current to the inductor coils such that the first inductor coil provides a force on the susceptor assembly equal to and opposite to the second inductor coil. BRIEF DESCRIPTION OF DRAWINGS

[0333] Several examples will now be described, by way of non-limiting example, with reference to the accompanying drawings in which:

[0334] Figure 1a a schematic view of a cartridge for an aerosol-generating system according to an example of the disclosure, wherein the cartridge is in a storage configuration;

[0335] Figure 1b a schematic view of the cartridge of Figure 1a rotated 90 degrees about a central longitudinal axis of the cartridge;

[0336] Figure 1c a schematic view of the cartridge of Figure 1a wherein the cartridge is in a use configuration;

[0337] Figure 2a a side view of a susceptor assembly of the cartridge of Figure 1a and 1b ;

[0338] Figure 2b a perspective view of the susceptor assembly of Figure 2a ;

[0339] Figure 2c a plan view of the susceptor assembly of Figure 2a ;

[0340] Figure 3a a schematic view of an aerosol-generating system according to an example of the disclosure, the aerosol-generating system comprising a cartridge of Figure 1a and 1b received in an aerosol-generating device;

[0341] Figure 3b a schematic view of the aerosol-generating system of Figure 3a rotated 90 degrees about a central longitudinal axis of the aerosol-generating system;

[0342] Figure 4 a-e show plan views of example susceptor elements according to the disclosure;

[0343] Figure 5 a-i show plan views of other example susceptor elements according to the disclosure;

[0344] Figure 6a a schematic view of a cartridge for an aerosol-generating system according to another example of the disclosure, wherein the cartridge is in a storage configuration;

[0345] Figure 6b a schematic view of the cartridge of Figure 6a wherein the cartridge is in a use configuration;

[0346] Figure 7 a schematic view of an aerosol-generating system according to a second example of the disclosure, the aerosol-generating system comprising a cartridge ofFigure 6a and 6b a cartridge;

[0347] Figure 8a shows a plan view of a susceptor element according to another example of the disclosure.

[0348] Figure 8b shows a plan view of a susceptor element according to another example of the disclosure. Figure 8a DETAILED DESCRIPTION

[0349] Figure 1a 1b and 1c show schematic views of a cartridge 10 for an aerosol-generating device according to embodiments of the disclosure.

[0350] The cartridge 10 comprises a susceptor assembly 12 mounted in a susceptor holder 14. Figure 2a 2b The susceptor assembly 12 is shown in more detail in Figures 1b and 2c. The susceptor assembly 12 is planar and thin, having a thickness dimension substantially smaller than the length and width dimensions. The susceptor assembly 12 is in the form of a cross and comprises three layers: 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 susceptor element 16, the second susceptor element 18 and the wicking element 20 generally forms the shape of a cross and each element has the same length and width dimensions. As described in more detail below, the first susceptor element 16 and the second susceptor element 18 are substantially identical and comprise a sintered mesh formed of ferritic stainless steel wire and austenitic stainless steel wire. The wicking element 20 comprises a porous body of rayon. The wicking element 20 is configured to transport liquid from an externally exposed surface of the wicking element 20 to the first susceptor element 16 and the second susceptor element 18.

[0351] Each of the first susceptor element 16 and the second susceptor element 18 comprises 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. In this embodiment, the mounting regions 22 are arranged at the same central location along the length of the heating region 24.

[0352] Each of the pair of mounting regions 22 has a smaller surface area than the heating region 24. The length l m of each of the mounting regions 22 is less than the length l h ​​​and each of the mounting regions 22 has a length / of about 2.50 millimetres m less than the width w of the heating region 24 h In this embodiment, the heating region 24 has a length / of about 6.50 millimetres h and a width w of about 3.50 millimetres h and each of the mounting regions 22 has a length / of about 2.50 millimetres m and a width w of about 1.15 millimetres m Thus, each of the first susceptor element 16 and the second susceptor element 18 has a total maximum length of about 6.50 millimetres, and a total maximum width of about 5.80 millimetres.

[0353] The heating region 24 is configured to be heatable by penetration of an alternating magnetic field for vaporising an aerosol-forming substrate. The pair of mounting regions 22 is 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. The pair of mounting regions 22 is configured to minimise heat transfer from the susceptor assembly 12 to the susceptor holder 14.

[0354] Each of the first susceptor element 16 and the second susceptor element 18 comprises a mesh having filaments extending in a first direction, and filaments extending in a second direction substantially perpendicular to the first direction. The heating region 24 comprises filaments of AISI 410 stainless steel (ferritic stainless steel) extending in both the first direction and the second direction. The pair of mounting regions 22 comprises filaments of AISI 410 stainless steel extending in the first direction, and filaments of AISI 316 stainless steel (austenitic stainless steel) extending in the second direction. Thus, the heating region 24 is composed of a magnetic material, and the pair of mounting regions 22 is partially composed of a magnetic material, and partially composed of a non-magnetic material. The proportion by weight of AISI 410 stainless steel in the heating region 24 is greater than the proportion by weight of AISI 410 in each of the pair of mounting regions 22.

[0355] Providing the first susceptor element 16 and the second susceptor element 18 with mounting regions 22 having a reduced cross-section compared to the heating region 24, and at least partially comprising mounting regions 22 from a non-magnetic material, helps to reduce heating of the mounting regions 22 when the susceptor elements are penetrated by an alternating magnetic field. This configuration also helps to reduce heat transfer from the susceptor assembly 12 to the susceptor holder 14.

[0356] It should be appreciated that in other embodiments, the heating region 24 and the pair of mounting regions 22 can be formed from other combinations of magnetic and non-magnetic materials. For example, in some embodiments, the heating region 24 includes wires of AISI 410 stainless steel (ferritic stainless steel) extending in the first direction, and wires of AISI 316 stainless steel (austenitic stainless steel) extending in the second direction. In these embodiments, the pair of mounting regions 22 can include wires 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.

[0357] The susceptor holder 14 includes a tubular body formed from a moldable plastic material such as polypropylene. The tubular body of the susceptor holder 14 includes a sidewall defining an internal passageway 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 arranged along the length of the susceptor holder 14.

[0358] The susceptor assembly 12 is arranged within the internal passageway 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 regions 24 of the first susceptor element 16 and the second susceptor element 18 are entirely arranged within the internal passageway 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.

[0359] 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.

[0360] The susceptor holder 14 includes a base 30 that partially encloses one end of the internal passageway 26. The base 30 includes a plurality of air inlets 32 that enable air to be drawn into the internal passageway 26 through the partially enclosed end.

[0361] The susceptor holder 14 further comprises a pair of piercing elements 34 extending from an outer surface of the side wall towards an open end of the susceptor holder 14, which is opposite to the end partially closed by the base 30. The opening 28 in the side wall of the susceptor holder 14 is arranged between the piercing elements 34 around the circumference of the side wall, such that the piercing elements 34 are offset by approximately 90 degrees from the opening 28 around the circumference of the side wall of the tubular susceptor. Each of the piercing elements 34 comprises a point facing in the direction of the open end of the susceptor holder 14.

[0362] The cartridge 10 further comprises an outer housing 36 formed from a mouldable plastics material such as polypropylene. The outer housing 36 forms a generally hollow cylinder to define an inner space containing the susceptor assembly 12 and the susceptor holder 14 therein.

[0363] 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 1a and 1b and a use configuration as shown in Figure 1c .

[0364] The cartridge 10 has a mouth end and a connection end opposite the mouth end. The outer housing 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 the susceptor holder 14 are positioned towards the connection end of the cartridge 10. The outer housing 36 is wider externally 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. This allows the connection end of the cartridge to be received in a cavity of an aerosol-generating device, with the shoulder 37 positioning the cartridge in the correct position in the device. This 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 external shape of the aerosol-generating device.

[0365] 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 located towards the mouth end of the outer housing 36 and comprises an annular space defined by the outer housing 36. The annular space has an internal passageway 48 extending between the mouth end opening 38 and the open end of the internal passageway 26 of the susceptor holder 14. The second portion 46 of the liquid reservoir 40 is located towards the connection end of the outer housing 36 and comprises an annular space defined between the inner surface of the outer housing 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 holder 14 and the inner surface of the outer housing 36. The seal 50 provides a liquid-tight seal between the susceptor holder 14 and the outer housing 36 to ensure that the second portion 46 of the liquid reservoir 40 is able to hold the liquid aerosol-forming substrate 42.

[0366] As described in more detail below, 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 is pierceable by the piercing element 34 of the susceptor holder to allow the liquid aerosol-forming substrate 42 to flow between the first portion 44 and the second portion 46 of the liquid reservoir.

[0367] 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.

[0368] In the storage configuration, as shown in Figure 1a and 1b the base 30 of the susceptor holder 14 extends from the outer housing 36 and the piercing 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.

[0369] In the use configuration, as shown in Figure 1cAs shown in Figure 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 a liquid-tight 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 piercing element 34 of the susceptor holder 14 is moved towards the mouth end, the piercing 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 regions 22 of the first and second susceptor elements 16, 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 the liquid aerosol-forming substrate 42 from the second portion 46 of the liquid reservoir 40 to the heating regions 24 of the first and second susceptor elements 16, 18. Thus, in the use configuration, the cartridge 10 is ready for use to generate an aerosol by heating the aerosol-forming substrate 42.

[0370] Figure 3a and 3b An aerosol-generating system is shown, comprising a cartridge 10 in a use configuration received in an aerosol-generating device 60. Figure 1a 、 1b and 1 c. The aerosol-generating system is portable and has a size comparable to a conventional cigar or cigarette.

[0371] 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 62 at the base of the cavity 64 to enable ambient air to be drawn into the cavity 64 at the base.

[0372] The device 60 further comprises an induction heating arrangement arranged within the housing 62. The induction heating arrangement comprises a pair of induction 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 and second induction coils 66, 68 such that the control circuit 70 controls the supply of power to the induction coils 66, 68. The control circuit 70 is configured to supply an alternating current to the first and second induction coils 66, 68.

[0373] The pair of inductor coils includes a first inductor coil 66 and a second inductor coil 68. The first inductor coil 66 is disposed at a first side of the cavity 64 and the second inductor coil 68 is disposed 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 disposed between the first inductor coil 66 and the second inductor coil 68 and the plane of the susceptor assembly 12 is disposed substantially parallel to the first and second planes.

[0374] Each of the first inductor coil 66 and the second inductor coil 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.

[0375] The induction heating device is further configured such that the second inductor coil 68 generates an alternating magnetic field in the cavity 64 that 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 inductor coil 66 and the second inductor coil 68 are wound in series together and are substantially identical but wound in opposite directions. In this configuration, the first inductor coil 66 and the second inductor coil 68 generate an alternating magnetic field in the cavity 64 having substantially equal magnitudes but in substantially opposite directions.

[0376] In operation, as indicated by the arrows in Figure 3b 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, as indicated by the arrows in

[0377] When the system is activated, control circuitry 70 controls the supply of power from power supply 72 to first inductor coil 66 and second inductor coil 68. Control circuitry 72 can comprise an airflow sensor (not shown) and when the airflow sensor detects a user drawing on cartridge 10, control circuitry 72 can provide power to inductor coils 66, 68. This type of control arrangement has been used for many years in aerosol-generating systems such as inhalers and electronic cigarettes.

[0378] When the system is activated, an alternating current is generated in each of inductor coils 66, 68, which generates an alternating magnetic field in cavity 64 that penetrates susceptor assembly 12, such that the heating regions 24 of first susceptor element 16 and second susceptor element 18 are heated. Liquid aerosol-forming substrate in second portion 44 of liquid reservoir 40 is drawn into susceptor assembly 12 by wicking element 20 to the heating regions 24 of first susceptor element 16 and second susceptor element 18. The liquid aerosol-forming substrate at the heating regions 24 of susceptor elements 16, 18 is heated and volatile compounds from the heated aerosol-forming substrate are released into the air passage of cartridge 10, which cool to form an aerosol. The aerosol is entrained in the air drawn through the air passage of cartridge 10 and is drawn out of cartridge 10 at mouth end opening 38 for inhalation by a user.

[0379] Figure 4 a-4e illustrates susceptor elements of various shapes in accordance with different embodiments of the present disclosure.

[0380] Figure 4 a illustrates a susceptor element having two rectangular mounting regions 22 located at one side of a rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length that is substantially shorter than the width and length of heating region 24. The mounting regions 22 are located at opposite ends of heating region 24, such that the susceptor element forms substantially the shape of the letter “C”.

[0381] Figure 4 b illustrates a susceptor element having two rectangular mounting regions 22 located at opposite sides of a rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and length that is substantially shorter than the width and length of heating region 24. The mounting regions 22 are located at the same end of heating region 24, such that the susceptor element forms substantially the shape of the letter “T”.

[0382] Figure 4c shows a susceptor element having two rectangular mounting regions 22 located at opposite sides of a rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and a length that are 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 end portions of the heating region 24.

[0383] Figure 4 d shows a susceptor element having two rectangular mounting regions 22 located at opposite sides of a rectangular heating region 24. Each mounting region 22 is substantially identical, having a width and a length that are 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".

[0384] Figure 4 e shows a susceptor element having one rectangular mounting region 22 located at one side of a rectangular heating region 24. The mounting region 22 has a width and a length that are 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.

[0385] Figure 5 a-5i shows other alternative shapes of susceptor elements according to different embodiments of the present disclosure.

[0386] Figure 5 a-5c 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 a length that are substantially shorter than the width and length of the heating region 24.

[0387] Figure 5 a shows a susceptor 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 at one side of the heating region 24 and one mounting region 22 located at an opposite side of the heating region 24, such that the susceptor element generally forms the shape of the letter "H".

[0388] Figure 5 b shows a susceptor element having one pair of mounting regions 22 arranged at 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 susceptor element generally forms a cross shape.

[0389] Figure 5c 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.

[0390] Figure 5 df shows a basic similarity Figure 5 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.

[0391] Figure 5 d shows a basic similarity Figure 5 a is a sensor element of a sensor element, wherein as the mounting region 22 extends away from the heating region 24, the inner edge of the mounting region 22 converges toward the central position along the length of the heating region 24.

[0392] Figure 5 e shows a basic similarity Figure 5 b is a sensor element of a sensor element, wherein as the mounting region 22 extends away from the heating region 24, the edge of the mounting region 22 diverges in the direction of the length of the heating region 24.

[0393] Figure 5 f shows a basic similarity Figure 5 c is a sensor element, wherein as the mounting region 22 extends away from the heating region 24, the edge of the mounting region 22 diverges in the direction of the length of the heating region 24.

[0394] Figure 5 gi shows a basic similarity Figure 5 The sensor element shown in ac has one or more edges of the mounting region 22 or the heating region 24 that are curved, such that one or more of the mounting region 22 and the heating region 24 are not rectangular.

[0395] Figure 5 g shows a basic similarity Figure 5 a is a sensor element of a sensor element, wherein the inner edge of the mounting region 22 is bent inward to form a recessed inner edge of the mounting region 22.

[0396] Figure 5 h shows a basic similarity Figure 6a b is a sensor element of a sensor element, wherein the edge of the mounting region 22 is bent outward to form a protruding mounting region 22.

[0397] Figures 1a-1c i shows a susceptor element substantially similar to Figures 1a-1c c, wherein the edges of the mounting region 22 are curved outwardly to form a convex mounting region 22.

[0398] Figure 4 and 6b shows a schematic view of a cartridge 10 for an aerosol-generating device according to another embodiment of the disclosure. The cartridge 10 shown in Figure 6 is substantially similar to the cartridge 10 shown in Figure 6a and like features are denoted by like reference numerals.

[0399] 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 the letter “C”. Each susceptor assembly 12 has the same three-layer construction as the susceptor assembly 12 of Figure 6b with a wicking element arranged between the first and second susceptor elements (not shown). As Figure 6a a, each susceptor element has a rectangular heating region and two mounting regions arranged at one side of the heating region at opposite ends of the heating region.

[0400] 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.

[0401] In this embodiment, each of the two susceptor assemblies 12 is arranged substantially 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.

[0402] The susceptor holder comprises a base 30 that partially closes one end of the internal passage 26. In this embodiment, the base 32 forms a liquid-tight seal with the internal passage 26 such that the internal passage is configured to hold a liquid. The base 30 comprises a plurality of air inlets 32; however, the air inlets 32 are arranged outside the internal passage 26.

[0403] The susceptor holder 14 further comprises a pair of piercing elements 34 extending from an inner surface of the side wall into the internal passage 26 towards the central longitudinal axis of the susceptor holder 14.

[0404] The cartridge 10 further comprises an outer housing 36 forming a generally hollow cylinder to define an interior space containing the susceptor assembly 12 and susceptor holder 14 therein. The outer housing 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 6b and a use configuration as shown in Figure 7 .

[0405] 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 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 connection end being joined by a shoulder 37.

[0406] 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 passageway 26 of the susceptor holder 14.

[0407] The first portion 44 and second portion 46 of the liquid reservoir 40 are fluidically isolated from one another by an aluminium foil seal 52 which is pierceable by the piercing 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.

[0408] A 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. A 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 20 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 holder 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.

[0409] 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.

[0410] In the storage configuration, as shown in Figure 6a , the base 30 of the susceptor holder 14 extends out of the outer housing 36 and the piercing 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.

[0411] In the use configuration, as shown in Figure 3a , 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 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 piercing element 34 of the susceptor holder 14 moves towards the mouth end, the piercing 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.

[0412] Figure 7 An aerosol-generating system is shown comprising the cartridge 10 in the use configuration received in an aerosol-generating device 60. The cartridge 10 is as described above in relation to Figure 8a and 6b . The aerosol-generating device 60 is substantially similar to the aerosol-generating device 60 shown in Figure 8a and 3b and like features are denoted by like reference numerals.

[0413] 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 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 at the base of the cavity 64 to enable ambient air to be drawn into the cavity 64 at the base.

[0414] The device 60 further comprises an induction heating arrangement arranged within the housing 62. The induction heating arrangement comprises a single inductor coil 66, 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 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.

[0415] The inductor coil 66 comprises a solenoid coil which defines the cavity 64. When the cartridge 10 is received in the cavity 64, the susceptor assembly 12 is also defined by the inductor coil 66.

[0416] The inductor coil 66 is configured such that when an alternating current is supplied to the inductor coil 66, the inductor coil generates an alternating magnetic field in the cavity 64. The alternating magnetic field generated by the inductor coil 66 is directed substantially parallel to the plane of the susceptor assembly 12 and the susceptor element.

[0417] In operation, as indicated by the arrows in ​ 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.

[0418] When the system is activated, the control circuit 70 controls the supply of power from the power supply 72 to the inductor coil 66. 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 that a user is drawing on the cartridge 10.

[0419] When the system is activated, an alternating current is generated in the inductor coil 66, which generates an alternating magnetic field in the cavity 64 that penetrates the susceptor assembly 12, causing the heating region of the susceptor element to heat. 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 cooling 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.

[0420] ​ and 8b A susceptor element according to another embodiment of the disclosure is shown.

[0421] The susceptor element 100 comprises a woven wire mesh. Some of the woven wires 102 extend in a warp direction, and some of the woven wires 104 extend in a substantially perpendicular weft direction.

[0422] The wires 104 extending in the weft direction comprise a magnetic material, such as AISI 409 stainless steel. The wires 102 extending in the warp direction comprise a non-magnetic material, for example AISI 316 stainless steel. The mesh is sintered such that an electrical bond is created at the contact points between the wires 102 extending in the warp direction and the wires 104 extending in the weft direction.

[0423] The susceptor element 100 is a planar element that extends substantially in a plane. The wires 102 extending in the warp direction are woven together with the wires 104 extending in the weft direction such that the wires 102 extending in the warp direction extend further out of the plane of the susceptor element 100 than the wires 104 extending in the weft direction. In other words, the wires 102 extending in the warp direction define the maximum thickness of the susceptor element 100.

[0424] As shown in ​ Since the wires 102 extending in the warp direction define the maximum thickness of the susceptor element 100, the susceptor holder 14 in contact with the susceptor element 100 is only in contact with the wires 102 extending in the warp direction.

[0425] Since the wires 102 extending in the warp direction are not composed of a magnetic material, the wires 102 extending in the warp direction are not directly heated by the induction of eddy currents or magnetic hysteresis losses when the susceptor element 100 is exposed to an alternating magnetic field. Therefore, the wires 102 extending in the warp direction in contact with the susceptor holder 14 transfer less heat to the susceptor holder 14 than if the wires were composed of a magnetic material.

[0426] For purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about." Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges, which can or can not be specifically elucidated herein. Thus, in this context, a number A is understood as A ± {5%} A. Within this context, a number A can be considered to include values within the general standard error for a measurement of the property modified by the number A. In certain instances in the appended claims, the number A can deviate from the percentage recited above, provided that the amount by which A deviates does not materially affect the basic characteristics and novel features of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges, which can or can not be specifically elucidated herein.

Claims

1. A cartridge for use in an aerosol-generating system, the cartridge comprising: a liquid reservoir for holding a liquid aerosol-forming substrate; a susceptor assembly in fluid communication with the liquid reservoir, the susceptor assembly comprising a susceptor element comprising: a heating region comprising a first material, the first material being a magnetic material capable of being heated by penetration with an alternating magnetic field; and at least one mounting region comprising the first material and a second material, the second material being a non-magnetic material; and a susceptor holder, wherein the at least one mounting region of the susceptor element is in contact with the susceptor holder, wherein the proportion by weight of the first material in the heating region is greater than the proportion by weight of the first material in the at least one mounting region.

2. The cartridge of claim 1, wherein the at least one mounting region of the susceptor element is at a periphery of the susceptor element.

3. The cartridge of any one of claims 1 to 2, wherein the susceptor holder comprises at least one of an electrically insulating material and a thermally insulating material.

4. The cartridge of any one of claims 1 to 2, wherein the susceptor holder is tubular and defines an internal passageway, wherein the susceptor element extends into the internal passageway of the susceptor holder, wherein the internal passageway of the susceptor holder extends substantially along a longitudinal axis, and wherein the susceptor element is substantially planar and extends parallel to the longitudinal axis.

5. The cartridge of any one of claims 1 to 2, wherein the second material is at least one of an electrically insulating material and a thermally insulating material.

6. The cartridge of any one of claims 1 to 2, wherein the second material is at least one of a hydrophilic material and a oleophilic material.

7. The cartridge of any one of claims 1 to 2, wherein the susceptor element comprises an array of filaments forming a mesh.

8. The cartridge of claim 7, wherein the mesh is woven.

9. The cartridge of claim 8, wherein the heating region comprises filaments of the first material along at least one of a weft direction and a warp direction.

10. The cartridge of claim 8, wherein the at least one mounting region comprises filaments of the second material along at least one of a weft direction and a warp direction.

11. The cartridge of any one of claims 1 to 2, wherein the susceptor element is substantially planar.

12. The cartridge of any one of claims 1 to 2, wherein the susceptor holder is tubular and defines an internal passageway, and wherein the susceptor element extends into the internal passageway of the susceptor holder.

13. The cartridge of any one of claims 1 to 2, wherein the susceptor holder is in contact with the second material at the at least one mounting region of the susceptor element.

14. The cartridge of any one of claims 1 to 2, wherein the at least one mounting region comprises a plurality of mounting regions.

15. An aerosol-generating system, the aerosol-generating system comprising: a cartridge according to any one of claims 1 to 14; and An aerosol-generating device configured to receive the cartridge, the aerosol-generating device comprising: at least one inductor coil arranged to generate an alternating magnetic field that penetrates a susceptor element of the cartridge when the cartridge is received in the device; and a control circuit connected to the at least one inductor coil and configured to supply an alternating current to the inductor coil to generate the alternating magnetic field.

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