Susceptor for use with an inductively heated aerosol-generating device or system

Abstract

The present invention relates to an inductively heatable susceptor (210) for use with an inductively heated aerosol-generating device or system (100). The susceptor (210) comprises an open-pored inductively heatable ceramic material for holding an aerosol-forming liquid (202) and heating the aerosol-forming liquid (202) under the influence of an alternating electromagnetic field. The present invention also relates to a cartridge (200) for use with an aerosol-generating device (100). The cartridge (200) comprises an aerosol-forming liquid (202) and a susceptor (210) according to the present invention, the susceptor holding at least a portion of the aerosol-forming liquid (202). The present invention also relates to an aerosol-generating device (100) for generating an aerosol by inductively heating an aerosol-forming liquid (202), wherein the device comprises a susceptor (210) according to the present invention.

Description

TECHNICAL FIELD

[0001] The present invention relates to a susceptor for holding and inductively heating an aerosol-forming liquid. The invention also relates to a cartridge for use with an aerosol-generating device, and to an aerosol-generating device and system for generating an aerosol by inductively heating an aerosol-forming liquid. BACKGROUND

[0002] Aerosol-generating systems based on inductively heating an aerosol-forming substrate are generally known from the prior art. These systems can comprise an inductive source for generating an alternating electromagnetic field which induces at least one of a heat-generating eddy current or a hysteresis loss in a susceptor. The so-heated susceptor is in thermal proximity to an aerosol-forming substrate which, when heated, is capable of releasing volatile compounds to form an aerosol. Depending on the type of aerosol-generating system, the susceptor and the aerosol-forming substrate can be provided together in an aerosol-generating article, in particular in a cartridge. The cartridge can be configured to be received in a cavity of an aerosol-generating device which in turn contains the inductive source. Several susceptor configurations have been described in the art in order to determine sufficient heating of the aerosol-forming substrate. However, in many cases, the susceptor is only in contact with a small portion of the aerosol-forming substrate. This can lead to non-uniform heating across the volume of the substrate, such that portions of the substrate are too low in temperature to form an aerosol. As a result, only a small portion of the substrate is effectively used for the user experience. However, increasing the heating power in order to heat all portions of the substrate to the required temperature for aerosol formation can lead to local overheating of those portions in direct contact with the susceptor.

[0003] It is therefore desirable to have a susceptor, and a cartridge and aerosol-generating device comprising the susceptor, which has the advantages of the prior art solutions but none of their limitations. In particular, it is desirable to have a susceptor, cartridge and aerosol-generating device which allows for uniform heating of the aerosol-forming substrate without the risk of local overheating. SUMMARY

[0004] According to the invention, there is provided an inductively heatable susceptor for use with an aerosol-generating device or system. The susceptor comprises a porous inductively heatable ceramic material for holding an aerosol-forming liquid and for heating the liquid under the influence of an alternating electromagnetic field. In particular, the susceptor can be made of or consist of this porous ceramic material.

[0005] The ceramic material according to the present application is characterized, on the one hand, by its open or open-pore structure, and, on the other hand, by its ability to be heatable under the influence of an alternating electromagnetic field. Thereby, the susceptor is advantageously both a storage medium for the aerosol-forming liquid to be heated and a heating element for inductively heating the liquid held therein. For this reason, the susceptor according to the present application can be regarded as a dual-function susceptor. Advantageously, the open-pore structure of the ceramic material allows the entire susceptor material to be uniformly soaked with the aerosol-forming liquid. Thus, the susceptor as a whole is in direct contact with the aerosol-forming liquid. At the same time, the entire volume of the susceptor can be uniformly heated under the influence of an alternating electromagnetic field. For this reason, the susceptor according to the present application advantageously allows the entire aerosol-forming liquid stored therein to be uniformly heated without the need for excessive heating. Furthermore, the susceptor according to the present application advantageously ensures a very consistent user experience, since the heatable amount of aerosol-forming liquid is related to the porosity and the overall volume of the susceptor, which are well-controllable parameters.

[0006] The open porosity of the susceptor provides a high holding capacity for the liquid aerosol-forming material. Thus, the liquid aerosol-forming material is securely held or retained in the susceptor. Advantageously, this reduces the risk of spillage compared to a liquid reservoir. In particular, this allows the susceptor, and any aerosol-generating article, device or system comprising such a susceptor, to be leak-proof. Additionally, upon heating, the open porosity of the susceptor material allows the vaporized aerosol-forming material to freely escape from the cartridge.

[0007] As used herein, the term "susceptor" refers to an element comprising a material capable of converting electromagnetic energy into heat. Thus, when located in an alternating electromagnetic field, the susceptor is heated. Generally, this can be caused by magnetic hysteresis losses and / or eddy currents induced in the susceptor, depending on the electrical, magnetic properties of the susceptor material. In ferromagnetic or ferrimagnetic susceptor materials, magnetic hysteresis losses occur due to the switching of magnetic domains within the material under the influence of an alternating electromagnetic field. If the susceptor material is electrically conductive, eddy currents can be induced. In the case of an electrically conductive ferromagnetic or ferrimagnetic susceptor material, heat can be generated due to both eddy currents and magnetic hysteresis losses. Thus, depending on the electrical, magnetic properties of the open-pore ceramic material, the open-pore inductively heatable ceramic material according to the present application can be heatable due to at least one of magnetic hysteresis losses or eddy currents. Thus, the open-pore inductively heatable ceramic material can be electrically conductive. Alternatively or additionally, the open-pore inductively heatable ceramic material can be ferromagnetic or ferrimagnetic. For example, the susceptor can comprise or consist of an electrically conductive ceramic material, such as lanthanum-doped strontium titanate or yttrium-doped strontium titanate. Likewise, the susceptor can comprise or consist of an open-pore ferrimagnetic or ferromagnetic ceramic material, such as a ceramic ferrite.

[0008] As used herein, the term "aerosol-forming liquid" relates to a liquid from which volatile compounds capable of forming an aerosol are released upon heating of the aerosol-forming liquid. The can contain solid and liquid aerosol-forming materials or components. The aerosol-forming liquid can comprise a tobacco-containing material containing volatile tobacco flavour compounds which are released from the liquid upon heating. Alternatively or additionally, the aerosol-forming substrate can comprise a non-tobacco material. The aerosol-forming liquid can also comprise an aerosol former. Examples of suitable aerosol formers are glycerol and propylene glycol. The aerosol-forming substrate can also comprise other additives and ingredients, such as nicotine or flavourings. In particular, the aerosol-forming liquid can comprise water, a solvent, ethanol, a plant extract and natural or artificial flavourings. The aerosol-forming liquid can also be a paste material, a small pouch of porous material comprising the aerosol-forming substrate or loose tobacco, for example mixed with a gelling or binding agent, which can contain a common aerosol former such as glycerol and which is then compressed or moulded into a plug.

[0009] The specific material and geometry of the susceptor can be selected to provide the desired heat generation and liquid uptake and retention effects. In general, the susceptor can have any desired shape. When used with an aerosol-generating article, device or system, the shape can depend on the specific role and mounting location. For example, the susceptor can have one of a cylindrical, disc, tube, cuboid or gasket-shaped configuration.

[0010] The susceptor can be a monolithic body comprising or made of a porous inductively heatable ceramic material. The monolithic body can be a compact solid body. This configuration advantageously allows providing a compact monolithic storage medium for the aerosol-forming liquid to be heated. In particular, the monolithic susceptor body can be a monolithic pellet or a pressed article.

[0011] Alternatively, the susceptor can comprise a plurality of susceptor elements, wherein each susceptor element comprises or is made of or consists of a porous inductively heatable ceramic material. Likewise, each susceptor element can be a monolithic body, in particular a compact solid body. For example, the susceptor can be a solid bulk material of individual susceptor elements, such as individual susceptor pellets. The susceptor can be a susceptor granulate.

[0012] The amount of aerosol-forming liquid held and heated by the susceptor is related to the porosity of the open-cell ceramic material. Preferably, the open-cell electrically inductively heatable ceramic material has a porosity between 20% and 60%. A porosity in this range proves to be advantageous in terms of the amount of aerosol-forming liquid held and heated by the susceptor in order to provide a suitable user experience. The porosity can be chosen such that the susceptor holds a predetermined amount of aerosol-forming liquid. Preferably, the predetermined amount of liquid corresponds to a predefined number of puffs available when using the susceptor in combination with an aerosol-generating device or system. The porosity can also be chosen with respect to a specific airflow management through the susceptor. For example, the porosity can be chosen in order to provide a specific resistance to draw (RTD).

[0013] Preferably, the heating of the aerosol-forming liquid is based on hysteresis losses only. Thus, the heating of the susceptor, i.e. the heating of the open-cell electrically inductively heatable ceramic material, is mainly or even only caused by hysteresis losses. Thus, the open-cell ceramic material is preferably only ferrimagnetic or ferromagnetic. Accordingly, the open-cell electrically inductively heatable ceramic material is preferably electrically non-conductive, or, if at all, very weakly conductive. As will be described in more detail below, this can be desirable in order to limit the heatability of the susceptor to temperatures corresponding to the Curie temperature of the susceptor material. In a non-conductive material, no eddy currents occur, and thus no heating due to eddy currents.

[0014] Ferrimagnetic and ferromagnetic materials are characterized in that they hold a spontaneous magnetization below the Curie temperature and do not show magnetic order above this temperature. Thus, above their Curie temperature, ferrimagnetic or ferromagnetic materials are paramagnetic, and thus no heating due to hysteresis losses occurs any more. Thus, in case the open-cell ceramic material of the susceptor is not electrically conductive but only ferrimagnetic or ferromagnetic, above the Curie temperature, the inductive heatability even completely disappears. This effect can advantageously be used to control the heating temperature of the susceptor. Thus, the open-cell electrically inductively heatable ceramic material of the susceptor can have a Curie temperature chosen so as to correspond to the maximum temperature to which the susceptor should be heated to, in order to avoid or at least reduce the likelihood of rapid overheating. The Curie temperature can deviate from this maximum temperature by about 1% to 3%. The electrically inductively heatable ceramic material of the susceptor can be chosen to have a Curie temperature below 400°C, preferably below 380°C or below 360°C. Preferably, the electrically inductively heatable ceramic material has a Curie temperature between 150°C and 300°C. This is particularly suitable for those susceptor comprising only one single ferrimagnetic ceramic material.

[0015] As mentioned above, the open-pored inductively heatable ceramic material is preferably a ceramic ferrite. As used herein, a ferrite is a ferrimagnetic ceramic compound derived from iron oxides such as hematite (Fe203) or magnetite (Fe304) and oxides of other metals. Typically, ferrites are not electrically conductive.

[0016] In particular, the open-pored inductively heatable ceramic material can comprise or can at least be one of the following:

[0017] - a manganese magnesium ferrite;

[0018] - a nickel zinc ferrite; or

[0019] - a cobalt zinc barium ferrite.

[0020] As mentioned above, the nickel zinc ferrite can comprise or consist of a Mg x Mn y Fe z O4-type composition, wherein x = 0.4-1.1, y = 0.3-0.9, and z = 1-2, and wherein the atomic fractions x, y, and z of the metal cations Mg, Mn, and Fe are such that the total charge of the metal cations is balanced with the total charge of the oxygen anions. In particular, the open-pored inductively heatable ceramic material can comprise or can be one of the following:

[0021] - Mg 0.77 Mn 0.58 Fe 1.65 O4 with a Curie temperature of about 270°C;

[0022] - Mg 0.55 Mn 0.88 Fe 1.55 O4 with a Curie temperature of about 262°C;

[0023] - Mg 1.03 Mn 0.35 Fe 1.37 O4 with a Curie temperature of about 190°C.

[0024] As mentioned above, the nickel zinc ferrite can comprise or consist of a Ni x Zn 1-x Fe2 O4-type composition, wherein x = 0.3-0.7, and wherein the atomic fractions of the metal cations Ni, Zn, and Fe are such that the total charge of the metal cations is balanced with the total charge of the oxygen anions. In particular, the open-pored inductively heatable ceramic material can comprise or can for example be a Ni 0.5 Zn 0.5 Fe2 O4 with a Curie temperature of about 258°C.

[0025] As mentioned above, the cobalt zinc barium ferrite can comprise Co 1.75 Zn 0.25 Ba2 Fe 12 O 22 or can consist of, having a Curie temperature of about 279°C.

[0026] A method for producing a susceptor comprising a porous inductively heatable ceramic material according to the present application can comprise the following steps:

[0027] - mixing powdered raw components of the ceramic material;

[0028] - dissolving cellulose into a solvent;

[0029] - mixing the dissolved cellulose with the mixed raw components to obtain a slurry mixture;

[0030] - drying the slurry mixture;

[0031] - pressing the dried mixture to form a pellet of a desired shape;

[0032] - calcining the pellet to form a porous pellet;

[0033] - annealing the porous pellet.

[0034] The step of mixing powdered raw components of the ceramic material and the step of mixing the dissolved cellulose with the mixed raw components can be combined, i.e. the raw components of the ceramic material and the dissolved cellulose can be mixed together in a single step.

[0035] Instead of using a solvent, the treatment of the cellulose and the powdered raw material can be done in dry conditions. Thus, an alternative method for producing a susceptor comprising a porous inductively heatable ceramic material according to the present application can comprise the following steps:

[0036] - mixing powdered raw components of the ceramic material and cellulose to obtain a dry mixture;

[0037] - pressing the dry mixture to form a pellet of a desired shape;

[0038] - calcining the pellet to form a porous pellet;

[0039] - annealing the porous pellet.

[0040] As used herein, "calcination" is a process of heat treatment in an atmosphere of air or oxygen at a temperature between 550°C and 1300°C. Calcination can be performed in a calcination furnace. The calcination furnace can be a steel cylinder which rotates inside a heated furnace interior and performs indirect high-temperature processing within a controlled atmosphere. With regard to the ceramic material according to the present application, calcination is intended to burn the cellulose and, if present, remove the solvent. During this process, the open-cell structure of the desired ceramic material is formed. Preferably, the pellets are calcined at a temperature of about 1200°C.

[0041] The cellulose has two functions. First, the cellulose acts as a binder between the particles of the mixed raw components in the pellets. Second, the cellulose particles advantageously act as displacement bodies to form the open-cell structure.

[0042] The pressure applied to the dry mixture to form the pellets of the desired shape can be in the range of 5 to 10 t / cm 2 (tons per square centimeter). For example, a load of 10 tons can be applied on a circular sample with a diameter of 13 mm.

[0043] The open-cell pellets are preferably annealed at a temperature in the range of 500°C to 700°C, in particular at a temperature of about 600°C.

[0044] Prior to the step of mixing the powdered raw components, the method can further comprise the step of sieving the raw components of the ceramic material to select the powder particles of the raw components having a specific particle size in a desired range. Preferably, the specific particle size is between 50 pm and 80 pm.

[0045] The method can further comprise the step of grinding the raw components prior to mixing the raw components and, if provided, prior to sieving the raw components.

[0046] After the grinding step, the method can further comprise the step of drying the ground raw components prior to mixing the raw components and, if provided, prior to sieving the raw components.

[0047] Preferably, the susceptor can be part of or can be a consumable aerosol-generating article pre-soaked with an aerosol-forming liquid in order to be ready for use with an aerosol-generating device comprising an inductive heat source. Thus, the susceptor can further comprise an aerosol-forming liquid held in the open-cell electrically inductively heatable ceramic material. That is, the susceptor can comprise an open-cell electrically inductively heatable ceramic material holding or (pre-)soaked with an aerosol-forming liquid. In particular, the open-cell electrically inductively heatable ceramic material can hold or can be (pre-)soaked with a predetermined amount of aerosol-forming liquid. Preferably, the predetermined amount of liquid corresponds to a predefined number of puffs available when using the susceptor in combination with an aerosol-generating device.

[0048] Alternatively, the susceptor can be an integral part of the aerosol-generating device. Thus, the present application also provides an aerosol-generating device for generating aerosol by inductively heating an aerosol-forming liquid. The aerosol-generating device comprises an induction source comprising an induction coil for generating an alternating electromagnetic field. Further, the device comprises a susceptor according to the application and as described herein, the susceptor comprising an open-pored inductively heatable ceramic material for holding and heating an aerosol-forming liquid. The susceptor is positioned relative to the induction coil such that it can be inductively heated by the alternating electromagnetic field in operation of the device.

[0049] For generating the alternating electromagnetic field, the induction source can comprise an alternating current (AC) generator. The AC generator can be powered by a power source of the aerosol-generating device. The AC generator can be operatively coupled to the induction coil. The AC generator is configured to generate a high-frequency oscillating current to pass through the induction coil to generate the alternating electromagnetic field. As used herein, high-frequency oscillating current means an oscillating current having a frequency between 500 kHz and 30 MHz, preferably between 1 MHz and 10 MHz, and more preferably between 5 MHz and 7 MHz.

[0050] The device can further comprise a circuit, preferably comprising the AC generator. The circuit can advantageously comprise a DC / AC inverter, which can comprise a class-D or class-E power amplifier. The circuit can be connected to a power source of the aerosol-generating device. The circuit can comprise a microprocessor, which can be a programmable microprocessor, a microcontroller, or an application-specific integrated chip (ASIC), or other electronic circuitry capable of providing control. The circuit can comprise further electronic components. The circuit can be configured to regulate the supply of current to the induction coil. The current can be supplied to the induction coil continuously after activation of the system, or can be supplied intermittently, for example on a puff-by-puff basis.

[0051] As already mentioned above, the aerosol-generating device advantageously comprises a power source, preferably a battery, such as a lithium iron phosphate battery. As an alternative, the power source can be another form of charge storage device, such as a capacitor. The power source can need recharging and can have a capacity that allows storing enough energy for one or more user experiences. For example, the power source can have sufficient capacity to allow continuous generation of aerosol for a period of about six minutes or a whole multiple of six minutes. In another example, the power source can have sufficient capacity to allow a predetermined number of puffs or discrete activations of the induction coil.

[0052] The device can comprise a single induction coil or multiple induction coils. The number of induction coils can depend on the number of susceptor elements. The induction coil or multiple induction coils can have a shape that matches the shape of the susceptor. Likewise, the induction coil or multiple induction coils conform to the shape of the housing of the aerosol-generating device. For example, the induction coil or multiple induction coils can be a spiral coil or a flat spiral coil. The induction coil can be wound around a ferrite core. As used herein, "flat spiral coil" means a coil that is generally a planar coil, where the axis of the coil winding is orthogonal to the surface on which the coil lies. The flat spiral induction can have any desired shape within the plane of the coil. For example, the flat spiral coil can have a circular shape, or can have a generally oblong or rectangular shape. However, the term "flat spiral coil" as used herein encompasses planar coils as well as flat spiral coils shaped to conform to a curved surface. The use of a flat spiral coil allows for the design of a compact device with a simple design that is robust and inexpensive to manufacture. The coil can be kept within the device housing and need not be exposed to the generated aerosol, such that deposits and possible corrosion on the coil can be prevented. The induction coil can be covered by an anti-corrosion coating or a housing. The induction coil can have a diameter of between 5 mm and 10 mm. The induction coil can be positioned on or adjacent to the surface of the cavity closest to the power source. This reduces the amount and complexity of electrical connections within the device.

[0053] In use, it is advantageous to bring the susceptor in close proximity to the induction coil in order to ensure that the alternating electromagnetic field penetrates the open- celled electrically inductively heatable ceramic material. Advantageously, the susceptor is positioned in the vicinity of the induction coil. It is also desirable that the distance between the induction coil and the susceptor is substantially constant over the extent of the susceptor to ensure uniform heating. Preferably, the minimum distance between the susceptor and the induction coil is below 2 mm, in particular below 1 mm, or even below 0.5 mm.

[0054] The aerosol-generating device can comprise a device housing. The device housing can comprise the susceptor, the induction source, the induction coil, the AC generator, the electrical circuit, and the power source. As will be described further below, the device housing can also comprise a reservoir for storing an aerosol-forming liquid or a liquid retention element or both.

[0055] The device housing can also comprise a cavity in which the susceptor can be at least partially arranged. The cavity can have an inner surface. The induction coil can be positioned on or adjacent to the surface of the cavity closest to the power source. The induction coil can be shaped to conform to the inner surface of the cavity. Alternatively, the induction coil can be within the cavity. In particular, the cavity can be an aerosol-generating chamber.

[0056] The device housing can comprise a main body and a mouthpiece portion. The cavity can be in the main body and the mouthpiece portion can have an outlet through which aerosol generated by the device can be drawn. The induction coil can be arranged in the main body, in the mouthpiece portion or in both the main body and the mouthpiece portion. As used herein, the term'mouthpiece portion' means a portion of the device that is placed in the mouth of a user in order to directly inhale aerosol generated by the aerosol-generating system. The aerosol is delivered through the mouthpiece into the mouth of the user.

[0057] The device can comprise an air path extending from at least one air inlet to at least one air outlet. Preferably, the air outlet is the outlet of the mouthpiece. The air path passes over the susceptor, in particular the outer surface of the open cell ceramic material. The air path can pass through the cavity. The air path can also pass over the induction coil. By allowing air to flow through the device to pass over the coil, a compact system can be achieved. The induction coil can be positioned adjacent to the susceptor. The air path can comprise an air flow passage provided between the induction coil and the susceptor element. Vaporised aerosol-forming material can be entrained in the air flowing in the air flow passage, which subsequently cools to form aerosol that escapes through the air outlet.

[0058] The open cell ceramic material of the susceptor can be (pre-) soaked with a predetermined amount of aerosol-forming liquid, for example for a single use of the device. However, it can be preferred to use the device and the susceptor integrated therein multiple times. Therefore, the device can be configured for repeatedly or continuously soaking the susceptor with aerosol-forming liquid. In this regard, the aerosol-generating device can further comprise a reservoir for holding or storing the aerosol-forming liquid. The reservoir can be replaceable or refillable. The reservoir can be arranged within the housing of the device, in particular within the main body of the device. For soaking the susceptor with aerosol-forming liquid (re-soaking), the reservoir is in fluid communication with the susceptor, for example through a fluid channel or a fluid tube.

[0059] The transfer of aerosol-forming liquid from the reservoir to the susceptor preferably occurs due to gravity. Alternatively, the liquid transfer can occur due to capillary action, for example through a capillary wick element between the reservoir and the susceptor. The aerosol-generating device can further comprise a pumping device, for example a micro-pump, for transferring the aerosol-forming liquid from the reservoir to the susceptor.

[0060] Preferably, the aerosol-generating device can be configured such that soaking the susceptor with aerosol-forming liquid from the reservoir only occurs in a specific position of the device, for example an upper or top position of the device. As used herein, the position of the device mainly refers to the orientation of the device in space, in particular in terms of gravity. In other words, the aerosol-generating device can be configured such that soaking the susceptor with aerosol-forming liquid from the reservoir requires orienting the device to a specific position. The specific position can be denoted as'soaking position'. Advantageously, this reduces the risk of undesired soaking or even over-soaking beyond the capacity of the susceptor.

[0061] The aerosol-generating device can be configured such that the transfer of aerosol-forming liquid from the reservoir to the susceptor preferably only occurs due to gravity. To this end, the relative arrangement between the susceptor and the reservoir can be such that in a particular soak position of the device, the susceptor is arranged at a level lower than the level of the reservoir. In contrast, in an operating position of the device, i.e. during aerosol generation, the susceptor is preferably arranged at a level higher than the level of the reservoir. Thus, in the operating position, there is no transfer of aerosol-forming liquid from the reservoir to the susceptor. If any, excess aerosol-forming liquid can flow back from the susceptor or fluid channel / fluid tube into the reservoir in the operating position.

[0062] Alternatively or additionally, the fluid communication between the susceptor and the reservoir is interruptible or releasable. In particular, the aerosol-generating device can be configured such that the reservoir is in fluid communication with the susceptor only in a particular soak position of the device. At least in the operating position of the device, and also in any position other than the soak position, the fluid communication can be deactivated, released, interrupted or closed. To achieve an interruptible or releasable fluid communication, the aerosol-generating device can comprise a valve for controlling the fluid communication between the reservoir and the susceptor. The valve can be a gravity-actuated valve which only opens in a particular position of the device, e.g. the upside-down or top position of the device. The valve can be a controllable electromagnetic valve. The electromagnetic valve can be manually controllable, e.g. by a switch. Alternatively, the electromagnetic valve can be coupled to an electric circuit of the aerosol-generating device for controlling the closing and opening of the valve. The electric circuit can further comprise a position sensor, e.g. a microchip-packaged MEMS gyroscope, for determining the position of the aerosol-generating device. Thus, the electric circuit can be configured to only open the electromagnetic valve if the position sensor detects that the aerosol-generating device is in a particular position. In case the position sensor detects any other position, the valve is closed by the electric circuit.

[0063] The aerosol-generating device can further be configured such that the heating of the susceptor is deactivated during the soaking of the susceptor with aerosol-forming liquid. Advantageously, this prevents the unintentional formation of gas in the reservoir.

[0064] The aerosol-generating device can be configured such that the aerosol passage towards the aerosol output of the aerosol-generating device is closed during the soaking of the susceptor with aerosol-forming liquid. Advantageously, this prevents the aerosol-forming liquid from being unintentionally inhaled by a user of the device.

[0065] Due to the open-pore structure of the ceramic material, the susceptor already provides a higher liquid retention capacity. Nonetheless, the aerosol-generating device can also comprise a liquid retention element for holding additional aerosol-forming liquid. The liquid retention element can comprise a high retention or high release material (HRM) for storing liquid aerosol-forming substrate. Advantageously, the liquid retention element can be a storage medium for the aerosol-forming liquid with which the susceptor is soaked. To this end, the liquid retention element is preferably in direct contact with the susceptor. Thus, the aerosol-forming liquid stored in the liquid retention element can easily be transported to the susceptor by, for example, capillary action. The aerosol-forming liquid retained in the liquid retention element is preferably not available for aerosolization before leaving the retention element. The liquid retention element can be electrically non-conductive. The liquid retention element can also be paramagnetic or diamagnetic. Preferably, the liquid retention element can be inductively non-heatable. The liquid retention element can be arranged in combination with the aerosol-generating device so as to be unaffected or only minimally affected by the alternating electromagnetic field of the induction coil.

[0066] The aerosol-generating device can comprise both a liquid retention element and a reservoir for aerosol-forming liquid. Preferably, the reservoir is in fluid communication with the liquid retention element, which in turn can be in fluid communication with the susceptor. Thus, the liquid retention element is (re)filled by means of the reservoir, while the susceptor is soaked by means of the liquid retention element.

[0067] As mentioned above, the susceptor can be part of a consumable aerosol-generating article, or can be a consumable aerosol-generating article pre-soaked with aerosol-forming liquid in order to be ready for use with an aerosol-generating device comprising an induction source. Preferably, the aerosol-generating article can be part of a cartridge for use with an aerosol-generating device, or can be a cartridge. Thus, the present application also provides a cartridge for use with an inductively heatable aerosol-generating device. The cartridge comprises an aerosol-forming liquid and an inductively heatable susceptor according to the present application and as described herein. The susceptor comprises or is made of or consists of an open-pore inductively heatable ceramic material as described herein, which retains at least a portion of the aerosol-forming liquid contained in the cartridge. In addition to retaining at least a portion of the aerosol-forming liquid, the inductively heatable ceramic material also allows for inductively heating the aerosol-forming liquid retained therein under the influence of an alternating electromagnetic field.

[0068] The cartridge is consumable, in particular a single-use, aerosol-generating article. It is configured to be received in a cavity of an aerosol-generating device, which in turn comprises an induction source for inductively heating a susceptor of the cartridge when the cartridge is received in the cavity. In operation, the induction source generates an alternating magnetic field that penetrates the susceptor of the cartridge received in the cavity. Depending on the electric, magnetic properties of the inductively heatable ceramic material, the alternating magnetic field induces at least one of an eddy current or a hysteresis loss in the susceptor. As a result, the susceptor heats up, thereby vaporizing the aerosol-forming liquid held therein. Due to the open-pore structure of the ceramic material, the vaporized aerosol-forming liquid can pass through the susceptor and subsequently cool down to form an aerosol.

[0069] It is preferred that the susceptor holding the aerosol-forming liquid can substantially constitute the cartridge, i.e. the consumable aerosol-generating article. In this case, the susceptor can hold the entire aerosol-forming liquid of the cartridge. In other words, the cartridge according to the present application can consist only of a susceptor soaked with aerosol-forming liquid. Advantageously, such a cartridge proves to be simple, cheap and robust.

[0070] Additionally, the cartridge can comprise a cartridge housing at least partially enclosing the soaked susceptor. It is preferred that the cartridge housing completely encloses the susceptor, i.e. the susceptor can be within the cartridge housing.

[0071] When the cartridge housing is received in the cavity of the aerosol-generating device, the housing is preferably not electrically conductive.

[0072] The susceptor can fill at least a portion of the interior space of the cartridge housing.

[0073] The cartridge housing can be at least partially or completely removable in order to at least partially or completely release the susceptor. In operation, this allows the vaporized aerosol-forming liquid to freely escape from the cartridge and vice versa, allowing air to enter the susceptor. Especially in the case that the cartridge constitutes a consumable aerosol-generating article substantially consisting of a susceptor soaked with aerosol-forming liquid, the cartridge housing can be a casing or cover of the susceptor, which can be at least partially or completely removed before the cartridge is engaged with the aerosol-generating device, i.e. before the at least partially or completely released susceptor is engaged with the aerosol-generating device.

[0074] The cartridge housing can comprise at least one fluid permeable portion. As used herein, a 'fluid permeable portion' is a portion of the cartridge housing that allows a gas, preferably also a liquid, to permeate therethrough. In particular, the at least one fluid permeable portion of the cartridge housing allows the aerosol-forming liquid, in the gas phase or both the gas and liquid phases, to permeate therethrough. The cartridge housing can have a plurality of fluid permeable portions. Preferably, at least one of those portions of the cartridge housing that covers or is in contact with the susceptor can be fluid permeable. Even the entire cartridge housing can be fluid permeable. The latter configuration proves advantageous with respect to cartridges that are completely filled by a susceptor soaked with aerosol-forming liquid, or with respect to cartridges that essentially consist of a susceptor soaked with aerosol-forming liquid.

[0075] Due to the high retention capacity of the susceptor material, the susceptor itself can also form at least a portion of the cartridge housing. The susceptor can even form the entire cartridge housing. For example, the cartridge can be a hollow cylinder comprising a circumferential wall and two end walls. The circumferential wall and the end walls form the housing of the cartridge. At least one of the end walls or at least a portion of the circumferential wall, or both, can be formed by the susceptor.

[0076] The susceptor can only partially fill the volume of the cartridge housing. Advantageously, the empty internal volume of the cartridge can serve as a reservoir or storage filled with aerosol-forming liquid. A portion of the surface of the susceptor facing the interior of the cartridge can be in direct contact with the aerosol-forming liquid. Thus, when heated, the aerosol-forming liquid held in the susceptor vaporizes and is released from the cartridge through the open cell structure of the ceramic susceptor material. At the same time, the susceptor is continuously refilled or re-soaked by the aerosol-forming liquid stored in the cartridge reservoir or storage. Compared to cartridges in which the susceptor completely fills the volume of the cartridge, cartridges having an empty volume filled with aerosol-forming liquid have a greater operating time. This is because the liquid storage capacity of the susceptor volume is lower compared to the same size of free volume.

[0077] The total surface corresponding to the outer contour of the susceptor body present on the outer surface of the cartridge can be about 25 mm 2 .

[0078] Other advantages and features of the cartridge according to the present application have been described above with respect to the susceptor and will not be repeated.

[0079] According to the present application, there is also provided an aerosol-generating system for generating an aerosol by inductively heating an aerosol-forming liquid. The system comprises an aerosol-generating device and a cartridge according to the present application and as described herein. Thus, the cartridge comprises an aerosol-forming liquid and an inductively heatable susceptor according to the present application and as described herein, the susceptor holding at least a portion of the aerosol-forming liquid. The cartridge is configured for use with the aerosol-generating device, i.e. for engagement with the aerosol-generating device for generating an aerosol by inductively heating the aerosol-forming liquid contained in the cartridge. To this end, the aerosol-generating device comprises a device housing containing a cavity for receiving at least a portion of the cartridge. The aerosol-generating device further comprises an induction source within the device housing, the induction source comprising an induction coil for generating an alternating electromagnetic field. The aerosol-generating device and the cartridge are configured such that upon receiving the cartridge in the cavity, the susceptor is positioned relative to the induction coil so as to be inductively heatable by the alternating electromagnetic field.

[0080] The induction coil can be positioned on or adjacent to an inner surface of the cavity. The induction coil can be shaped to conform to the inner surface of the cavity. Alternatively, the induction coil can be within the cavity. In some embodiments, the induction coil can be within an internal passageway of the cartridge when the cartridge is engaged with the device.

[0081] The device housing can comprise a main body and a mouthpiece portion. The cavity can be in the main body and the mouthpiece portion can have an outlet through which aerosol generated by the system can be drawn. The induction coil can be in the mouthpiece portion or in the main body. Alternatively, the mouthpiece portion can be provided as part of the cartridge.

[0082] The device can comprise an air path extending from at least one air inlet to at least one air outlet. Preferably, the air outlet is the outlet of the mouthpiece. The air path passes through the susceptor, in particular the outer surface of the open cell ceramic material. The air path can pass through the cavity. The air path can also pass through the induction coil. By allowing air to flow through the device to pass through the coil, a compact system can be achieved. In use, when the cartridge is engaged with the device, i.e. received in the cavity, the induction coil can be positioned adjacent to the susceptor. The air path can comprise an air flow passage provided between the induction coil and the susceptor element when the cartridge is received in the cavity. Vaporised aerosol-forming material can be entrained in the air flowing in the air flow passage, which then cools to form an aerosol and can escape through the air outlet.

[0083] In contrast to the aerosol-generating device described above, the aerosol-generating device described here does not comprise an internal susceptor for the aerosol-forming liquid nor does it comprise an internal reservoir, e.g. a liquid reservoir, for the aerosol-forming liquid. However, apart from this, the aerosol-generating device described here can be similar or identical to the aerosol-generating device described above.

[0084] In particular, the induction source and the induction coil of the aerosol-generating device described herein can be similar or identical to the induction source and the induction coil of the aerosol-generating device described above. Likewise, the aerosol-generating device described herein can also comprise at least one of the AC generator, the electric circuit and the power source as described above.

[0085] Further features and advantages of the aerosol-generating device described herein, in particular of the induction source, the induction coil, the AC generator, the electric circuit and the power source, have been described with respect to the aerosol-generating device described above and will not be repeated. BRIEF DESCRIPTION OF DRAWINGS

[0086] The application will be further described, by way of example only, with reference to the accompanying drawings in which:

[0087] Figure 1 schematically illustrating an aerosol-generating system according to a first embodiment of the application;

[0088] Figure 2 schematically illustrating a cross-sectional view of the aerosol-generating system according to Figure 1 schematically illustrating a cross-sectional view of the aerosol-generating system according to

[0089] Figure 3 schematically illustrating an aerosol-generating system according to a second embodiment of the application;

[0090] Figure 4 schematically illustrating a first embodiment of a cartridge according to the application;

[0091] Figure 5 schematically illustrating a perspective view of the cartridge according to Figure 4 schematically illustrating a perspective view of the cartridge according to

[0092] Figure 6 schematically illustrating a second embodiment of a cartridge according to the application;

[0093] Figure 7 schematically illustrating a perspective view of the cartridge according to Figure 6 schematically illustrating a perspective view of the cartridge according to

[0094] Figures 8 to 17 schematically illustrating a further embodiment of a cartridge according to the application;

[0095] Figure 18 schematically illustrating an aerosol-generating device according to a first embodiment of the application; and

[0096] Figure 19 schematically illustrating an aerosol-generating device according to a second embodiment of the application. DETAILED DESCRIPTION

[0097] Figure 1is a schematic illustration of an aerosol-generating system 1 according to a first embodiment of the application. The system comprises an aerosol-generating device 100 and a cartridge 200 engaged with the aerosol-generating device 100. The device 100 comprises a main body having a main body housing 101 containing a lithium-ion battery as a power source 102 and a control circuit 104. The main body housing 101 defines a cavity 112 in which the cartridge 200 is received. The device 100 further comprises a mouthpiece portion 120 comprising an outlet 124. The housing of the mouthpiece portion 120 and the main body housing 101 together form the housing of the device 100. The mouthpiece portion can be connected to the main body by any type of connection, for example by a hinged connection, a snap fit or a screw connection. An air inlet 122 is defined in the main body housing 101.

[0098] A flat spiral induction coil 110 is arranged within the cavity 112. The coil 110 is operatively connected to the control circuit 104. The coil 110 is also shown in Figure 2 . The coil 110 is formed by stamping or cutting a spiral coil from a copper sheet. The coil 110 is positioned proximate to the inner surface of the cavity 112 at the level of the air inlet 122, opposite the end surface of the cartridge 200. Thus, air drawn through the inlet 122 towards the outlet 124 passes through a passage formed between the coil 112 and the end surface of the cylindrical cartridge 200. Advantageously, the flat spiral coil allows for a simple interface between the device and the cartridge, which in turn allows for a simple and inexpensive cartridge design.

[0099] In this embodiment, the cartridge 200 has a cylindrical shape. The cylindrical cartridge 200 comprises a cartridge housing 204 containing an aerosol-forming liquid 202. The aerosol-forming liquid can be held by a capillary material. The cartridge housing 204 is fluid impermeable but has an open end covered by a susceptor 210. Further details of the cartridge 200 are shown in Figure 4 and Figure 5 . In this embodiment, the susceptor 210 is a compact solid susceptor body made of a porous ferrimagnetic ceramic material, for example Ni 0.5 Zn 0.5 Fe2 O4. The susceptor body 210 has a cylindrical shape and is inserted into the open end of the cartridge housing 204. Thus, the susceptor 210 forms at least a portion of the cartridge housing 204. The cylindrical susceptor body 210 has an axial length of between 3 mm and 6 mm, preferably between 4 and 5 mm. The total surface area corresponding to the cylindrical outer profile of the susceptor body 21 can be approximately 25 mm 2 .

[0100] The inner end surface of the cylindrical susceptor body 210 faces the interior of the cartridge housing 204 so as to be in direct contact with the aerosol-forming liquid 202 contained in the cartridge 200. Due to the open structure of the ceramic material, the susceptor is soaked with the aerosol-forming liquid 202. Thus, the susceptor 210 holds at least a portion of the aerosol-forming liquid 202 contained in the cartridge 200. The outer end surface of the cylindrical susceptor body 210 forms the outer surface of the cartridge 200. Thus, when heated, the aerosol-forming liquid held in the susceptor vaporizes and can freely escape from the cartridge 200 through the outer end surface of the open susceptor body 210.

[0101] The open structure serves to provide a high retention capacity for the liquid aerosol-forming material. Due to this, the aerosol-forming liquid is securely held or retained in the susceptor 210. Advantageously, despite the fact that a portion of the cartridge housing is made of an open material, this allows the cartridge 200 to be leak-proof with respect to the aerosol-forming liquid 202 contained therein. Vice versa, after heating, the open porosity of the susceptor material allows the vaporized aerosol-forming material to be freely released from the cartridge.

[0102] When the cartridge 200 is engaged with the aerosol-generating device 100 and received in the cavity 112, the susceptor element 210 is positioned adjacent to the flat spiral coil 110. The cartridge 200 can include a keying feature to ensure that it cannot be inserted upside down into the device.

[0103] In use, a user can puff on the mouthpiece portion 120 to draw air through the air inlet 122 into the cavity 112 and the mouthpiece portion 120, and out through the outlet 124 into the user’s mouth. The device can include a puff sensor 106 in the form of a microphone for detecting when a user puffs on the mouthpiece. The puff sensor 106 can be part of the control circuit 104. The puff sensor 106 can be arranged within the cavity, close to the air inlet 122. When a puff is detected, the circuit 104 provides a high-frequency oscillating current to the coil 110. This generates an oscillating magnetic field that passes through the susceptor 210. As a result, the susceptor 210 heats up due to hysteresis losses and reaches a temperature sufficient to vaporize the aerosol-forming liquid held in the open pores of the susceptor material. The vaporized aerosol-forming material is entrained in the air flowing from the air inlet 122 towards the air outlet 124. Along this line, the vapor cools to form an aerosol within the mouthpiece portion 120 before escaping through the outlet 124. After a puff is detected, the control circuit 104 supplies the oscillating current to the coil 110 for a predetermined duration, in this example five seconds, and then cuts off the current until a new puff is detected.

[0104] Figure 3 is a schematic illustration of an aerosol-generating system 1 according to a second embodiment of the application. The system 1 comprises an aerosol-generating device 100 and a cartridge 200. This second embodiment differs from the first embodiment described above in thatFigure 1 The first embodiment shown is identical. Thus, in both embodiments, identical features of the aerosol-generating device and the cartridge are denoted with identical reference numerals. Instead of a flat spiral induction coil, the aerosol-generating device 100 according to the second embodiment comprises a spiral induction coil 170 positioned in the cavity 112 such that, when the cartridge is received in the cavity 112, the susceptor 210 is arranged within the spiral induction coil 170. Applying a high-frequency oscillating current to the coil 170 generates a substantially uniform oscillating magnetic field inside the spiral coil 170. Thus, when the cartridge 200 is engaged with the aerosol-generating device 100, the susceptor 120 is uniformly affected by the oscillating magnetic field, which proves advantageous in terms of uniform heating of the susceptor. Alternatively, the spiral induction coil 170 can also be arranged on the inner surface of the cavity 112, or even within the wall of the main body housing 101, which allows for a simple and compact design of the aerosol-generating device 100.

[0105] Figures 1 to 5 The cartridge 200 according to the embodiment shown in the middle has a simple and robust design, which can be manufactured at low cost compared to commercially available atomizers. However, other configurations are possible, such as Figures 6 to 16 shown.

[0106] Figure 6 and Figure 7 An alternative cartridge design with a hollow cylindrical shape is shown schematically. The susceptor 210 is a compact susceptor body made of a perforated ferrimagnetic ceramic material, which forms a circumferential portion of the circumferential wall of the cartridge housing 204. Thus, the susceptor 220 has a tubular shape. The hollow cartridge 200 contains an aerosol-forming liquid inside, a portion of which is held in the susceptor 210. As Figure 6 and 7 The cartridge shown can be designed to be engaged with an aerosol-generating device comprising a spiral induction coil as shown in Figure 3 The aerosol-generating device is preferably designed such that, when the cartridge is engaged with the aerosol-generating device, the susceptor is positioned coaxially within the interior of the spiral coil. Thus, the heating of the susceptor is advantageously extremely uniform. Moreover, compared to the cartridge designs shown in Figure 4 and 5 The cartridge design shown in Figure 6 and 7 has a larger active heating volume, resulting in a more intense user experience compared to the cartridge designs shown in

[0107] Figure 8A cross-sectional view of another cartridge design is schematically shown in which the cartridge is completely filled with susceptor 210. In this embodiment, the susceptor 210 is a compact susceptor body made of a porous ferrimagnetic ceramic material, providing high retention for the liquid aerosol-forming substrate. Thus, the cartridge 200 of this embodiment advantageously reduces the risk of spillage, for example, compared to a liquid reservoir. In case of a faulty crack of the cartridge, the high retention material of the susceptor avoids unintended contact of the aerosol-forming liquid with active electrical components and biological tissue of the device.

[0108] The cartridge 200 comprises a cartridge housing 204 at least partially enclosing the susceptor 210. In use, vaporized aerosol-forming substrate can escape from the cartridge through those parts of the susceptor not covered by the cartridge housing.

[0109] The cartridge housing 204 can also completely enclose the susceptor 210. In this case, at least a portion of the cartridge housing 204 can be fluid permeable to allow vaporized aerosol-forming substrate to escape from the cartridge. Preferably, the entire cartridge housing 204 is fluid permeable, as shown. Figure 9 Advantageously, this allows for a maximized user experience.

[0110] Alternatively, the susceptor 210 can be contained in a non-permeable cartridge housing 204 that completely encloses the susceptor 210, as shown. Figure 10 Advantageously, this prevents the soaked susceptor from drying out. As shown in Figure 11 At least a portion of the cartridge housing 204 can be removable or openable before the cartridge is engaged with the aerosol-generating device, i.e. before the partially or completely released susceptor is engaged with the aerosol-generating device. In Figure 11 embodiments, the cartridge housing 204 can be removable at the end face. After removal of the end face portion of the cartridge housing 204, the partially open cartridge can be engaged with the aerosol-generating device. During operation, vaporized aerosol-forming substrate can escape from the cartridge through the open end face.

[0111] Likewise, cartridge designs according to Figure 4 and 5 or Figure 6 and 7 may comprise a cartridge housing 204 that also covers the outer surface of the susceptor 210. The portion of the cartridge housing 204 covering the susceptor will be removed or opened before the cartridge is engaged with the aerosol-generating device. The removable or openable portion of the cartridge housing can be regarded as a protective cover for the susceptor. The outer surface susceptor can be flush with the outer surface of the remaining portion of the cartridge housing, or recessed such that the outer surface cartridge housing is smooth.

[0112] Figure 12 and Figure 13Another cartridge design is schematically shown, wherein the entire cartridge housing 204 is a protective cover or a packaging sleeve to be removed before the remaining part of the cartridge is engaged with the aerosol-generating device. With respect to cartridges consisting essentially of a compact susceptor body (cf. Figure 12 ) or comprising a closed surface enclosing an aerosol-forming liquid or a hollow susceptor body (cf. Figure 13 ), such a cover or sleeve can prove advantageous. In both embodiments, the susceptor body essentially constitutes the consumable aerosol-generating article to be engaged with the aerosol-generating device after removal of the packaging sleeve 204 surrounding the article. As shown in Figure 12 and 13 , the surrounding packaging sleeve 204 can be opened at an end face, allowing the susceptor body to be taken out. With respect to the susceptor design shown in Figure 13 , the closed susceptor surface can be considered the remaining housing of those cartridge parts to be engaged with the aerosol-generating device.

[0113] Instead of an integral susceptor body, the susceptor can also comprise a plurality of susceptor elements 211. As shown in Figure 14 , the susceptor elements can be individual susceptor pellets 211 soaked with aerosol-forming liquid, forming a susceptor granulate. The susceptor elements 211 can be contained in a cartridge housing 204, at least a portion of which is fluid permeable. As an example, a portion of the cartridge housing or the entire cartridge housing can have a meshed configuration, e.g. be made of stainless steel mesh. In Figure 14 , the entire cartridge housing 204 is fluid permeable. Advantageously, such a cartridge housing 204 holds the individual susceptor elements together but allows the vaporized aerosol-forming substrate to escape from the cartridge.

[0114] Alternatively, the susceptor elements 211 can be contained in a non-permeable cartridge housing 204, as shown in Figure 15 . Advantageously, this prevents the soaked pellets from drying out. As shown in Figure 16 , at least a portion of the cartridge housing can be removable or openable in order to allow the individual susceptor elements to be taken out (cf. Figure 17 ), which can then be filled into the cavity of the aerosol-generating device. If the individual susceptor elements are to be received in the aerosol-generating device as bulk material, i.e. as loose pieces, without a cartridge housing, the aerosol-generating device can comprise a receptacle for receiving and securely holding the susceptor elements in the cavity. At least a portion of the receptacle can be fluid permeable to allow the vaporized aerosol-forming substrate to escape from the receptacle. The receptacle can comprise a filling opening. The filling opening can be closed, e.g. by a lid or by the mouthpiece of the aerosol-generating device.

[0115] Figure 18A first embodiment of an aerosol-generating device 100 according to another aspect of the application is schematically illustrated. Instead of being engageable with a separate cartridge containing a susceptor and an aerosol-forming liquid to be heated, the aerosol-generating device 100 itself comprises a susceptor 180 according to the application and as described herein, which is an internal susceptor 180 made of a porous ferrimagnetic ceramic material. Similar to the aerosol-generating device as shown in Figure 1 and 3 the device 100 according to Figure 13 comprises a main body having a main body housing 101 containing a battery 102 and a control circuit 104. The main body housing 101 defines a cavity 112 in which the internal susceptor 180 is arranged. The device 100 further comprises a mouthpiece portion 120 comprising an outlet 124. The housing of the mouthpiece portion 120 and the main body housing 101 together form the housing of the device 100. The mouthpiece portion is removably connected to the main body. An air inlet 122 is defined in the main body housing. Within the cavity 112 is a helical induction coil 170. The coil 170 is operably connected to the control circuit 104 and encloses the cylindrical susceptor body 180. When the circuit 104 provides a high frequency oscillating current to the coil 170, an oscillating magnetic field is generated that passes through the susceptor 180. As a result, the susceptor 180 heats up due to hysteresis losses, thereby vaporizing the aerosol-forming liquid held in the porous structure of the susceptor 180. The vaporized aerosol-forming material is entrained in the air flow that is accumulated when a user draws air through the air inlet 122, into the cavity 112 and the mouthpiece portion 120 and out of the outlet 124.

[0116] In the present example, the axial length extension of the helical coil 170 substantially corresponds to the axial length extension of the cylindrical susceptor 180. Of course, the coil 170 can also be configured so as to enclose only an axial portion of the susceptor 180. Advantageously, the degree of overlap between the coil and the susceptor 180 can be used to pre-set the amount of aerosol-forming liquid to be heated and vaporized, so as to optimize the user experience.

[0117] To allow for repeated (re)filling of the sensor 180 with the aerosol-forming liquid, the aerosol generating apparatus 100 also includes a reservoir 185 for the aerosol-forming liquid. The reservoir is replaceable or refillable. The reservoir 185 is disposed within the main housing 101 of the apparatus 100. The reservoir 185 is in fluid communication with the sensor 180 via a fluid passage 186. A controllable valve 187 is disposed in conjunction with the fluid passage 186. The valve 187 is operatively connected to a circuit 104 to control the opening and closing of the valve. The aerosol generating apparatus 100 is configured to open the valve 186 only in the upper / lower or top position of the apparatus. Therefore, immersing the sensor 180 with the aerosol-forming liquid from the reservoir 185 requires orienting the apparatus 100 to this specific 'immersion' position. Advantageously, this reduces the risk of undesirable immersion or even over-immersion exceeding the capacity of the sensor 180. The transfer of the aerosol-forming liquid from the reservoir 185 to the sensor 180 preferably occurs due to gravity. To detect the corresponding position of the device, device 100 may include a position sensor (not shown) as part of circuit 104. Additionally, circuit 104 may be configured to deactivate the heating process in the 'immersion' position to prevent the formation of unintended gases. Furthermore, circuit 104 may be configured to block the air path toward outlet 124 during (re)filling of sensor 180 to prevent unintended inhalation of the aerosol-forming liquid by the user. For this purpose, device 100 may include a baffle (not shown). Device 100 may also be configured to heat sensor 180 only in one or more predetermined 'use' positions.

[0118] Figure 19 A second embodiment of an aerosol generating device 100, including an internal receptor 180, is schematically shown. This embodiment is similar to... Figure 18 The embodiments shown are substantially the same. Therefore, in both embodiments, the same features of the aerosol generating apparatus are indicated by the same reference numerals. Additionally, according to... Figure 19 The device 100 includes a liquid retention element 190 made of a high retention or high release material (HRM). The liquid retention element 190 serves as a storage medium for aerosol-forming liquid to continuously immerse the sensor 180. For this purpose, the liquid retention element 190 is in direct contact with the sensor 180. The aerosol-forming liquid stored in the liquid retention element 190 is transferred to the sensor 180 via capillary action. The liquid retention element 190 is non-conductive and paramagnetic, and therefore cannot be heated inductively. For this reason, the induction coil 170 only surrounds the sensor 180. The liquid retention element is in fluid communication with a reservoir 185 via a fluid channel 186 for (re)filling with aerosol-forming liquid from the reservoir 185. Figure 18 The embodiments shown in the figure describe Figure 19 Other advantages of the embodiments shown herein will not be repeated.

Claims

1. A cartridge for use with an aerosol-generating device or system, the cartridge comprising an electrically inductively heatable susceptor comprising a porous electrically inductively heatable ceramic material for holding an aerosol-forming liquid and for heating the aerosol-forming liquid under the influence of an alternating electromagnetic field, wherein the susceptor comprises a plurality of susceptor elements, each susceptor element being a unitary body comprising the porous electrically inductively heatable ceramic material, that is: the porous structure of the ceramic material allows the susceptor to be uniformly soaked with aerosol-forming liquid, wherein, The open-pored inductively heatable ceramic material is inductively heatable due to the presence of at least one of eddy currents or hysteresis losses in the open-pored inductively heatable ceramic material.

2. The cartridge of claim 1, wherein, The open-pored inductively heatable ceramic material comprises or consists of at least one of: manganese magnesium ferrite; nickel zinc ferrite; or cobalt zinc barium ferrite.

3. The cartridge of claim 1, wherein, The open-pored inductively heatable ceramic material has a porosity of between 20% and 60%.

4. The cartridge of claim 1, wherein, The open-pored inductively heatable ceramic material has a Curie temperature of between 150 °C and 400 °C.

5. The cartridge of claim 1, wherein, The open-pored inductively heatable ceramic material is an electrically non-conductive material.

6. The cartridge according to claim 1, further comprising an aerosol-forming liquid held in the open-pored inductively heatable ceramic material.

7. The cartridge of claim 1, wherein, The cartridge comprises a cartridge housing surrounding the susceptor, wherein the cartridge housing is at least partially removable or comprises at least one fluid permeable portion.

8. The cartridge of claim 7, wherein, The susceptor forms at least a portion of the cartridge housing.

9. The cartridge of claim 8, wherein, The susceptor only partially fills a volume of the cartridge housing.

10. The cartridge of any one of claims 1-9, wherein, The susceptor is soaked with the aerosol-forming liquid.

11. An aerosol-generating system for generating an aerosol by inductively heating an aerosol-forming liquid, the aerosol-generating system comprising an aerosol-generating device and a cartridge according to one of claims 1 to 10 for use with the aerosol-generating device, the aerosol-generating device comprising: a device housing comprising a cavity for receiving at least a portion of the cartridge; an induction source comprising an induction coil for generating an alternating electromagnetic field; and wherein the susceptor of the cartridge is positioned relative to the induction coil so as to be inductively heatable by the alternating electromagnetic field. The aerosol-generating device further comprises a replaceable or refillable reservoir for holding an aerosol-forming liquid, wherein the reservoir is in releasable fluid communication with the susceptor for soaking the susceptor with the aerosol-forming liquid.

12. An aerosol-generating system according to claim 11, wherein, The aerosol-generating device further comprises a liquid retention element for holding an aerosol-forming liquid, wherein the liquid retention element is in direct contact with the susceptor.

13. An aerosol-generating system according to claim 11 or 12, wherein, ​

Images