Aerosol-generating system for dielectrically heating liquid aerosol-forming substrate

Abstract

There is provided an aerosol-generating system (1) for dielectrically heating a liquid aerosol- forming substrate, the aerosol-generating system comprising a cartridge (10) comprising: a liquid storage portion (14) for holding a liquid aerosol-forming substrate; and a liquid transport element (18) for transporting liquid aerosol-forming substrate from the liquid storage portion to a dielectric heating portion (16) of the cartridge; and an aerosol-generating device (100) configured to be removably couplable to the cartridge, the aerosol-generating device comprising: an accommodation space (103) for removably accommodating at least a portion of the cartridge; and a dielectric heater (104) for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol- generating device.

Description

[0001] AEROSOL-GENERATING SYSTEM FOR DIELECTRICALLY HEATING LIQUID AEROSOL-FORMING SUBSTRATE

[0002] The present disclosure relates to an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate. In particular, but not exclusively, the present disclosure relates to a handheld electrically operated aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate to generate an aerosol and for delivering the aerosol into the mouth of a user. The present disclosure further relates to a cartridge for an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate and an aerosol-generating device for use with the cartridge.

[0003] Aerosol-generating systems that heat a liquid aerosol-forming substrate in order to generate an aerosol for delivery to a user are generally known in the prior art. These systems typically comprise a reservoir containing a liquid aerosol-forming substrate that is capable of releasing volatile compounds when heated. The aerosol-generating system typically also includes a heater for heating the liquid aerosol-forming substrate.

[0004] Known electrically operated aerosol-generating systems typically heat an aerosolforming substrate by one or more of: conduction of heat from a heating element to an aerosolforming substrate, radiation of heat from a heating element to an aerosol-forming substrate or drawing heated air through an aerosol-forming substrate. Most commonly, heating is achieved by passing an electrical current through an electrically resistive heating element that is supplied with liquid aerosol-forming substrate by some form of wick. When a user takes a puff on the aerosol-generating system, the electric current causes the heating element to be heated by resistive or Joule heating, which, in turn, heats the liquid aerosol-forming substrate supplied by the wick. This causes volatile compounds to be released from the liquid aerosolforming substrate that cool to form an aerosol. The aerosol is then drawn into a user’s mouth via a mouthpiece of the aerosol-generating system.

[0005] Inductive heating systems have also been proposed, in which Joule heating occurs as a result of eddy currents induced in a susceptor heating element.

[0006] A problem with the known heating arrangements above is that they may give rise to non-uniform heating of the aerosol-forming substrate. The portion of the aerosol-forming substrate closest to the heating element is heated more quickly or to a higher temperature than portions of the aerosol-forming substrate more remote from the heating element. This can result in so-called “hot-spots”.

[0007] It would be desirable to provide an aerosol-generating system that is able to more uniformly heat an aerosol-forming substrate while still being realisable in a compact or handheld system. According to an example of the present disclosure, there is provided an aerosolgenerating system for dielectrically heating a liquid aerosol-forming substrate. The aerosolgenerating system may comprise a liquid storage portion for holding a liquid aerosol-forming substrate. The aerosol-generating system may comprise a dielectric heater for heating the liquid aerosol-forming substrate. The aerosol-generating system may comprise a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the dielectric heater. The dielectric heater may comprise a heating space for receiving at least a portion of the liquid transport element.

[0008] According to an example of the present disclosure, there is provided an aerosolgenerating system for dielectrically heating a liquid aerosol-forming substrate. The aerosolgenerating system comprises a liquid storage portion for holding a liquid aerosol-forming substrate; a dielectric heater for heating the liquid aerosol-forming substrate; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the dielectric heater. The dielectric heater comprises a heating space for receiving at least a portion of the liquid transport element.

[0009] Advantageously, the aerosol-generating system is able to dielectrically heat the aerosol-forming substrate. Dielectric heating can be uniform within a volume of aerosolforming substrate, without the creation of hot spots. This form of heating also requires no contact between a heating element and the aerosol-forming substrate. This means that there is no need to clean a heating element that has a build-up of aerosol residue on it. The aerosolgenerating system allows for considerable design flexibility in terms of the shape, volume and composition of the aerosol-forming substrate and correspondingly the shape and volume of the heating space.

[0010] The aerosol-generating system may comprising an aerosol-generating device and a cartridge.

[0011] The cartridge may comprise the liquid storage portion and the liquid transport element. The liquid transport element may be configured to transport liquid aerosol-forming substrate from the liquid storage portion to a dielectric heating portion of the cartridge. The dielectric heating portion of the cartridge may be a protruding portion of the cartridge.

[0012] The aerosol-generating device may be configured to be removably couplable to the cartridge.

[0013] The aerosol-generating device may comprise an accommodation space for removably accommodating at least a portion of the cartridge. The accommodation space may be a cavity.

[0014] The aerosol-generating device may comprise the dielectric heater. The dielectric heater may be configured to heat the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol-generating device. Advantageously, by providing the dielectric heater in the aerosol-generating device, the cartridge does not require a heater or heating element. This may help to reduce the complexity of the cartridge. This may help to simplify the manufacture of the cartridge. This may reduce the cost of producing the cartridge. Furthermore, providing the heater in the device rather than the cartridge helps to reduce the material diversity in the cartridge which makes it easier to recycle the cartridge as there are fewer materials to separate. This helps to provide a more sustainable cartridge.

[0015] The aerosol-generating device may comprise a heating space for receiving the dielectric heating portion of the cartridge. The heating space may be a cavity resonator or a resonant cavity. The dielectric heater may comprise a cavity resonator or resonant cavity.

[0016] The dielectric heater may comprise a heating chamber having an interior defining the heating space for receiving the at least a portion of the liquid transport element.

[0017] The dielectric heater may comprise a coupler configured to couple an alternating electric field generator to the interior of the heating chamber to provide an alternating electric field in the heating space. The coupler may comprise a waveguide or transmission line. In one example, the coupler may comprise a coaxial cable.

[0018] The heating chamber may comprise a chamber housing. The chamber housing may substantially surround the heating chamber. The chamber housing may comprise an electrically conductive material. The chamber housing may form a faraday cage around the heating chamber to contain the alternating electric field within the heating chamber. The chamber housing may comprise an opening to enable at least a portion of the liquid transport element to be received in the heating chamber. The chamber housing may comprise an opening to enable at least a portion of the coupler to be received in the heating chamber.

[0019] The heating chamber may comprise a first region. The first region may comprise a first dielectric having a first relative permittivity. The heating chamber may comprise a second region. The second region may comprise a second dielectric having a second relative permittivity. The second relative permittivity may be less than the first relative permittivity such that the strength of the alternating electric field may be greater in the second region than in the first region.

[0020] As used herein, the term “relative permittivity”, £r, which may also be referred to as the “dielectric constant”, is used to mean the ratio of the electric permittivity of a material or substance or region to the electric permittivity of a vacuum, £o. AS used herein, the term “relative permittivity” refers to the real part of the complex, frequency-dependent relative permittivity, measured at a temperature of 20 degrees Celsius, in an alternating electric field with at a very low frequency (VLF) of 1 Kilohertz or less, as defined in the international standard I EC 62631-2-1 :2018. It will be appreciated that the frequency value of 1 Kilohertz is included here solely as a general reference and other definitions may use different frequencies.

[0021] As used herein, the terms “dielectric” and “dielectric material”, refer to an electrically insulative region or an electrically insulative material that becomes polarized under the influence of an external electric field. As used herein, the term “electrically insulative material” denotes a material having a resistivity of 1x104Ohm-metres, or more, at a temperature of 20 degrees Celsius.

[0022] Advantageously, providing the heating chamber with one or more regions having a lower relative permittivity compared to one or more other regions can concentrate the electric field in selected regions of the chamber, resulting in localised heating of an aerosol-forming substrate in the heating chamber. In particular, providing a second region having a second relative permittivity that is lower than the first relative permittivity of the first region, creates an alternating electric field in the heating chamber that is greater in the second region than in the first region. Such a configuration of the heating chamber establishes a gradient in the alternating electric field created in the heating chamber, such that the alternating electric field decreases through the heating space of the heating chamber from the second region to the first region. This can be used to apply different amounts of heating to an aerosol-forming substrate depending on the location of the aerosol-forming substrate in the heating chamber.

[0023] The first relative permittivity is preferably greater than 1 . The first relative permittivity of the first region may be any suitable value. For example, the first relative permittivity of the first region may be at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40. In some examples, the first relative permittivity is between 5 and 100. In some examples, the first relative permittivity is between 40 and 50.

[0024] The second relative permittivity may be any suitable value. For example, the relative permittivity of the second region may be 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, 5 or less, or about 1.

[0025] The second relative permittivity may be less than the first relative permittivity by at least 5, or more particularly by at least 10.

[0026] The first dielectric may be any suitable material. The first dielectric may be a ceramic material. For example, the first dielectric may comprise or consist of at least one of: alumina, MgNb2C>6, ZnNb2C>6, MgTa2Oe, ZnTa2Oe, ZrSnTiCU, Zn, Mg, Ta-based Perovskite, Barium oxide (BaCh) doped with one or more of Zn, Mg, Ta, Nb, Nd, La, Ti, Co, tungsten bronze, barium samarium titanium oxide (Ba6-3xSm8+2xTiisO54), and glass; the table below details values of relative permittivity erfor these exemplary materials:

[0027] In some examples, the first dielectric may be a polymeric material, such as polyether ketone (PEEK), Polyetherimide (PEI), polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyphthalamide (PPA), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polyimide (PI), PEEK-PFN Copolymers, and Eccostock variants like LoK, Flex-Lok, HIK500E

[0028] Preferably, the first dielectric comprises a material that is able to tolerate high temperatures, such as temperatures in the range 150 degrees Celsius to 350 degrees Celsius, or in the range from 250 degrees Celsius to 350 degrees Celsius, and rapid temperature changes.

[0029] The first region may substantially circumscribe a portion of the heating chamber. The first region may be substantially annular or tubular, having an inner passage defining a portion of the heating space.

[0030] The second dielectric may be any suitable material. The second dielectric may comprise a gas, such as air or any other suitable gas. The second region may comprise a space or volume comprising a gas, such as air. The second region may comprise a space or volume filled with a gas, such as air.

[0031] The second dielectric may be a polymeric material, such as polyether ketone (PEEK), Polyetherimide (PEI), polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyphthalamide (PPA), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polyimide (PI), PEEK-PFN Copolymers, and Eccostock variants like LoK, Flex-Lok, HIK500F.

[0032] The second region may substantially circumscribe a portion of the heating chamber. The second region may be substantially annular or tubular, having an inner passage defining a portion of the heating space.

[0033] At least a portion of the liquid transport element may be received in proximity to, or within, the second region.

[0034] The heating chamber may further comprise a third region. The third region may comprise a third dielectric having a third relative permittivity. The second region may be arranged between the first and third regions. The second relative permittivity being less than the first and third relative permittivities such that the strength of the alternating electric field is greater in the second region than in the first and third regions. Advantageously, providing the heating chamber with one or more regions having a lower relative permittivity compared to one or more other regions can concentrate the electric field in selected regions of the chamber, resulting in localised heating of an aerosol-forming substrate in the heating chamber. In particular, providing a second region having a second relative permittivity that is lower than the first and third relative permittivities of the first and third regions respectively, creates an alternating electric field in the heating chamber that is greater in the second region than in the first and third regions. Such a configuration of the heating chamber establishes an alternating electric field distribution within the heating chamber, in which the alternating electric field is greatest in the second region. This can be used to apply different amounts of heating to an aerosol-forming substrate depending on the location of the aerosol-forming substrate in the heating chamber.

[0035] The third dielectric may be any suitable material. The third dielectric may be same as the first dielectric. The third dielectric may be a ceramic material. For example, the third dielectric may comprise or consist of at least one of: alumina, MgNb2Oe, ZnNb2Oe, MgTa2Oe, ZnTa2C>6, ZrSnTiCU, Zn, Mg, Ta-based Perovskite, Barium oxide (BaCh) doped with one or more of Zn, Mg, Ta, Nb, Nd, La, Ti, Co, tungsten bronze, barium samarium titanium oxide (Ba6-3xSm8+2xTii8O54), and glass.

[0036] In some examples, the third dielectric may be a polymeric material, such as polyether ketone (PEEK), Polyetherimide (PEI), polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyphthalamide (PPA), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polyimide (PI), PEEK-PFN Copolymers, and Eccostock variants like LoK, Flex-Lok, HIK500F.

[0037] Preferably, the third dielectric comprises a material that is able to tolerate high temperatures, such as temperatures in the range 150 degrees Celsius to 350 degrees Celsius, or in the range from 250 degrees Celsius to 350 degrees Celsius, and rapid temperature changes.

[0038] The third region may substantially circumscribe a portion of the heating chamber. The third region may be substantially annular or tubular, having an inner passage defining a portion of the heating space.

[0039] A length of the second region in a direction parallel to a longitudinal direction of the aerosol-generating system may be between 1 millimetre and 5 millimetres, more particularly between 2 millimetres and 4 millimetres.

[0040] The second region may comprise an air gap between the first and third regions.

[0041] The heating chamber may further comprise a constriction portion arranged at a point along the length of the interior of the heating chamber. The constriction portion may have a reduced cross-sectional area such that the alternating electric field is concentrated in the constriction portion.

[0042] The cross-sectional area of the heating chamber in the constriction portion in a plane orthogonal to the longitudinal axis of the heating chamber or aerosol-generating system may be less than 0.9 times, less than 0.8 times, less than 0.7 times, less than 0.6 times or less than 0.5 the cross-sectional area of the heating chamber outside the constriction portion. The cross-sectional area of the heating chamber in the constriction portion in a plane orthogonal to the longitudinal axis of the heating chamber or aerosol-generating system may be between 0.3 and 0.9 times, between 0.4 and 0.8 times, between 0.4 and 0.7 times, or between 0.4 and 0.6 times the cross-sectional area of the heating chamber outside the constriction portion.

[0043] The lateral distance between the side walls of the heating chamber in the constriction portion may be between 0.5 and 10 millimetres, between 1 and 8 millimetres, between 2 and 7 millimetres or between 3 and 6 millimetres.

[0044] The dielectric heater may comprise at least one pair of opposing electrodes. The pair of opposing electrodes may be spaced apart to define the heating space for receiving at least a portion of the liquid transport element.

[0045] The pair of opposing electrodes may have any suitable shape. The pair of opposing electrodes may be square or rectangular. Each one of the opposing electrodes may be substantially planar. The pair of opposing electrodes may be substantially parallel to one another. Each one of the opposing electrodes may have a curved cross-sectional profile. The pair of opposing electrodes may comprise curved opposing cylindrical segments.

[0046] A first dimension of each one of the electrodes may be 10 millimetres or less, 8 millimetres of less, 6 millimetres or less, 5 millimetres or less, 4 millimetres or less or 3 mm or less. A second dimension of each one of the electrodes may be 10 millimetres or less, 8 millimetres of less, 6 millimetres or less, 5 millimetres or less, 4 millimetres or less or 3 mm or less.

[0047] Each one of the pair of opposing electrodes may have a surface area between 4 square millimetres (mm2) and 100 square millimetres (mm2), between 4 square millimetres (mm2) and 60 square millimetres (mm2), between 4 square millimetres (mm2) and 40 square millimetres (mm2) or between 4 square millimetres (mm2) and 20 square millimetres (mm2).

[0048] The pair of opposing electrodes may be spaced apart by a distance of between 0.25 millimetres and 2 millimetres.

[0049] The surface area of one of the electrodes multiplied by the distance the electrodes are spaced apart may define a heating volume of the heating space.

[0050] The heating space may have a heating volume of between 1 cubic millimetre (mm3) and 200 cubic millimetres (mm3), between 4 cubic millimetres (mm3) and 60 cubic millimetres (mm3), between 4 cubic millimetres (mm3) and 40 cubic millimetres (mm3) or between 4 cubic millimetres (mm3) and 20 cubic millimetres (mm3). Preferably, the heating space has a heating volume of between 5 and 10 cubic millimetres (mm3).

[0051] The aerosol-generating system may be configured to supply the dielectric heater with a power of between 7 watts and 35 watts, between 7 watts and 30 watts, between 7 watts and 25 watts, between 7 watts and 20 watts or between 7 watts and 15 watts. Preferably, the aerosol-generating system is configured to supply the dielectric heater with a power of approximately 10 watts.

[0052] The aerosol-generating system may be configured to provide a suitable power density in the heating space between the pair of opposing electrodes. As used herein, the term “power density” is used to refer to the power provided per unit of heating volume in the heating space. Reducing the heating volume of the heating space for a given power will increase the power density.

[0053] The inventors have found that an aerosol-generating system that dielectrically heats a liquid aerosol-forming substrate, where aerosolization has to occur instantly without or with a very short heat-up phase (for example, less than 100 milliseconds (ms)), needs to provide a higher power density in its heating space than conventional heat-not-burn systems that dielectrically heat a cigarette-like consumable comprising a solid aerosol-forming substrate. In particular, the inventors have found that the power density needs to be around 50 to 100 times greater, or indeed even higher than this, in liquid-based systems than in heat-not-burn systems. A conventional heat-not-burn system will typically provide a power density of between 1 watt per cubic centimetre (W / cm3) and 25 watts per cubic centimetre (W / cm3).

[0054] The aerosol-generating system may be configured to provide a power density between the pair of opposing electrodes of between 35 watts per cubic centimetre (W / cm3) and 35 kilowatts per cubic centimetre (kW / cm3). The aerosol-generating system may be configured to provide a power density between the pair of opposing electrodes of between 50 watts per cubic centimetre (W / cm3) and 10 kilowatts per cubic centimetre (kW / cm3), between 50 watts per cubic centimetre (W / cm3) and 2.5 kilowatts per cubic centimetre (kW / cm3) or between 50 watts per cubic centimetre (W / cm3) and 1.25 kilowatts per cubic centimetre (kW / cm3). . The aerosol-generating system may be configured to provide a power density between the pair of opposing electrodes of between 170 watts per cubic centimetre (W / cm3) and 2.5 kilowatts per cubic centimetre (kW / cm3), between 250 watts per cubic centimetre (W / cm3) and 2.5 kilowatts per cubic centimetre (kW / cm3) or between 500 watts per cubic centimetre (W / cm3) and 2.5 kilowatts per cubic centimetre (kW / cm3). Preferably, the aerosol-generating system may be configured to provide a power density between the pair of opposing electrodes of between 1 kilowatts per cubic centimetre (kW / cm3) and 2 kilowatts per cubic centimetre (kW / cm3).

[0055] This range of power densities has been found to be particularly effective for dielectrically heating a liquid aerosol-forming substrate because such a power density can quickly (within 0.1 seconds) raise the temperature of the liquid aerosol-forming substrate to its vaporisation temperature to generate a sufficient amount of aerosol within a standard puff duration of approximately 3 seconds.

[0056] The aerosol-generating system may further comprise an airflow channel. The airflow channel may comprise an air inlet. The airflow channel may comprise an aerosol outlet. The airflow channel may pass through the liquid storage portion such that the liquid storage portion circumscribes the airflow channel. The at least a portion of the liquid transport element that is arranged to be received within the heating space may be arranged within the airflow channel. The liquid transport element may occupy the entire internal cross-sectional area of the airflow channel. The liquid transport element may be substantially flat or planar. The liquid transport element occupy only a portion of internal cross-section of airflow channel such that air can flow on one or either side of the liquid transport element. The liquid transport element may be arranged parallel to airflow direction.

[0057] The aerosol-generating system may further comprise a power supply for supplying power to the dielectric heater. The power supply may be any suitable power supply. Preferably, the power supply is a DC power supply. In one example, the power supply may be a DC power supply having a DC supply voltage in the range of about 2.5 Volts to about 4.5 Volts and a DC supply current in the range of about 0.1 Amp to about 10 Amps. This corresponds to a DC power supply in the range of about 0.5 watts to about 45 watts. In another example, the power supply may be configured to provide power in the range of 7 to 35 watts.

[0058] The power supply may be a battery. The battery may be a Lithium based battery, for example a Lithium-Cobalt, a Lithium-lron-Phosphate, a Lithium Titanate or a Lithium-Polymer battery. The battery may be a Nickel-metal hydride battery or a Nickel cadmium battery. The power supply may be another form of charge storage device such as a capacitor. The power supply may be rechargeable and be configured for many cycles of charge and discharge. The power supply may have a capacity that allows for the storage of enough energy for one or more user experiences of the aerosol-generating system; for example, the power supply may have sufficient capacity to allow for the continuous generation of aerosol for a period of around 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 supply may have sufficient capacity to allow for a predetermined number of puffs or discrete activations of the aerosol-generating system.

[0059] The aerosol-generating system may further comprise control circuitry for controlling the supply of the power to the dielectric heater. The control circuitry may comprise any suitable controller or electrical components. The controller may comprise a memory. Information for performing the above-described method may be stored in the memory. The control circuitry may comprise a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, or an application specific integrated chip (ASIC) or other electronic circuitry capable of providing control. The control circuitry may be configured to supply power to the dielectric heater intermittently, such as on a puff-by-puff basis.

[0060] The control circuitry may comprise an alternating electric field generator. The alternating electric field generator may be coupled to the dielectric heater. The alternating electric field generator may be configured to create an alternating electric field in the heating space of the dielectric heater.

[0061] Where the dielectric heater comprises a heating chamber, the alternating electric field generator may be coupled to the heating chamber by at least one coupler. The alternating electric field generator may be coupled to the heating chamber by a plurality of couplers. The alternating electric field generator may be any suitable generator. In some examples, the alternating electric field generator may be a voltage-controlled oscillator (VCO). In some embodiments, the alternating electric field generator may be a synthesizer.

[0062] Where the dielectric heater comprises at least one pair of opposing electrodes, the alternating electric field generator may comprise an oscillation circuit for driving the electrodes. The pair of opposing electrodes may form part of a feedback loop of the oscillation circuit. The pair of opposing electrodes may function as a capacitor within the feedback loop. The oscillation circuit may comprise a resonant circuit. The pair of opposing electrodes may form a load capacitor of the resonant circuit. The pair of opposing electrodes may be connected to the control circuitry by respective electrical contacts.

[0063] The alternating electric field generator may comprise one or more solid state radio frequency components. As used herein, “radio frequency” (RF), means a frequency between 50 MHz and 300 Gigahertz. Accordingly, as used herein, RF frequencies include microwave frequencies and ultra-high frequencies (UHF). Preferably, the alternating electric field generator comprises a solid state RF transistor. The solid state RF transistor may be part of a VCO. The solid state RF transistor may be part of a synthesizer.

[0064] The use of a solid state RF transistor, and other solid state RF components, may allow the aerosol-generating device to be compact, thereby assisting in the device being handheld or portable. The conventional means for producing RF frequency radiation for heating, such as in domestic microwave ovens, is a magnetron. Magnetrons are bulky and require high voltages to operate. Furthermore, magnetrons have a relatively unstable frequency output and have a relatively short service life. A RF transistor can provide for consistent operation over many more usage cycles and requires much lower operating voltages. Advantageously, one or more solid state RF transistors may be configured to generate and amplify the alternating electric field. Using a single transistor to provide both the generating and amplification of the alternating electric field allows for the aerosol-generating device to be compact. The solid state RF transistor may be, for example, a LDMOS transistor, a GaAs FET, a SiC MESFET or a GaN HFET.

[0065] Although it is preferable that the alternating electric field generator comprises a solid state RF transistor, it is envisaged that in some embodiments the alternating electric field generator may comprise a magnetron or other suitable signal source capable of generating an alternating electric field.

[0066] The alternating electric field created in the heating space of the dielectric heater may have any suitable frequency for dielectrically heating an aerosol-forming substrate. The alternating electric field may be a RF electric field. The alternating electric field may have a frequency of between 50 MHz and 300 Gigahertz, optionally a frequency of between 200 Megahertz and 50 Gigahertz, optionally a frequency of between 300 Megahertz and 30 Gigahertz, optionally a frequency of between 500 Megahertz and 20 Gigahertz, or a frequency of about 2.45 GHz.

[0067] The control circuitry further may comprise a puff detector for detecting when a user is taking a puff on the aerosol-generating system. The control circuitry may be configured to supply power to the dielectric heater in response to detecting a puff. The puff detector may be any suitable sensor that is capable of detecting when a user draws on the aerosolgenerating device. For example, the puff detector may be an airflow sensor, pressure sensor, temperature sensor or microphone.

[0068] According to another example of the present disclosure, there is provided a cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate. The cartridge may comprise a cartridge body comprising a liquid storage portion for holding a liquid aerosol-forming substrate. The cartridge may comprise a liquid transport element. The cartridge body may further comprise a protruding portion that extends from the liquid storage portion. The protruding portion may comprise at least a portion of the liquid transport element.

[0069] According to another example of the present disclosure, there is provided a cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate. The cartridge comprises: a cartridge body comprising a liquid storage portion for holding a liquid aerosol-forming substrate; and a liquid transport element. The cartridge body further comprises a protruding portion that extends from the liquid storage portion, the protruding portion comprising at least a portion of the liquid transport element.

[0070] The cartridge may not comprise a heater or heating element. The cartridge may not comprise any metallic components.

[0071] Advantageously, not providing the cartridge with a heater may help to reduce the complexity of the cartridge. This may help to simplify the manufacture of the cartridge. This may help to reduce the cost of producing the cartridge. Furthermore, providing the heater in the device rather than the cartridge helps to reduce the material diversity in the cartridge which makes it easier to recycle the cartridge as there are fewer materials to separate. This helps to provide a more sustainable cartridge.

[0072] The length of the protruding portion may be in a range between 5 millimetres and 40 millimetres, and more preferably between 7 millimetres and 30 millimetres.

[0073] The liquid transport element may comprises a porous element for providing capillary flow of the liquid aerosol-forming substrate. The porous element may have a relative permittivity of less than 5, and preferably less than 4. The porous element may comprise any suitable material. The porous element may comprise a polymeric fibrous material. The porous element may comprise cellulose acetate.

[0074] The cartridge may further comprise a pair of opposing electrodes. The pair of opposing electrodes may form part of the dielectric heater. The pair of opposing electrodes may be arranged to connect to the control circuitry of an aerosol-generating device via electrical contacts arranged in the aerosol-generating device. The liquid transport element may be arranged in a space between the opposing electrodes. The electrodes may be arranged on opposing sides of the protruding portion.

[0075] The cartridge may comprise a liquid 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 may be released by heating the liquid aerosolforming substrate.

[0076] The aerosol-forming substrate may comprise polar molecules which are susceptible to dipole interaction for dielectric heating, such as under the action of the alternating electric field in the heating space of the dielectric heater. For example, the aerosol-forming substrate may comprise water or an alcohol such a propylene glycol (PG) or vegetable glycerin (VG), or a combination of these, which are particularly susceptible to dielectric heating.

[0077] The aerosol-forming substrate may be liquid at room temperature. The aerosolforming substrate may comprise both liquid and solid components. The liquid aerosol-forming substrate may comprise nicotine. The nicotine containing liquid aerosol-forming substrate may be a nicotine salt matrix. The liquid aerosol-forming substrate may comprise plant-based material. The liquid aerosol-forming substrate may comprise tobacco. The liquid aerosolforming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds, which are released from the aerosol-forming substrate upon heating. The liquid aerosol-forming substrate may comprise homogenised tobacco material. The liquid aerosol-forming substrate may comprise a non-tobacco-containing material. The liquid aerosol-forming substrate may comprise homogenised plant-based material.

[0078] The liquid aerosol-forming substrate may comprise one or more aerosol-formers. An aerosol-former is any suitable known compound or mixture of compounds that, in use, facilitates formation of a dense and stable aerosol and that is substantially resistant to thermal degradation at the temperature of operation of the system. Examples of suitable aerosol formers include glycerine 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 glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. The liquid aerosol-forming substrate may comprise water, solvents, ethanol, plant extracts and natural or artificial flavours.

[0079] The liquid aerosol-forming substrate may comprise nicotine and at least one aerosolformer. The aerosol-former may be glycerine or propylene glycol. The aerosol former may comprise both glycerine and propylene glycol. The liquid aerosol-forming substrate may have a nicotine concentration of between about 0.5% and about 10%, for example about 2%.

[0080] According to another example of the present disclosure, there is provided an aerosolgenerating device for dielectrically heating a liquid aerosol-forming substrate. The aerosolgenerating device may be configured to be removably couplable to any of the above-described cartridges. The aerosol-generating device may comprise a dielectric heater for heating the liquid aerosol-forming substrate. The aerosol-generating device may comprise a power supply for supplying power to the dielectric heater. The aerosol-generating device may comprise control circuitry for controlling the supply of the power to the dielectric heater. The dielectric heater may comprise a heating space for receiving the protruding portion of the cartridge containing the at least a portion of the liquid transport element.

[0081] According to another example of the present disclosure, there is provided an aerosolgenerating device for dielectrically heating a liquid aerosol-forming substrate. The aerosolgenerating device is configured to be removably couplable to the any of the above-described cartridges. The aerosol-generating device comprising: a dielectric heater for heating the liquid aerosol-forming substrate; a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater. The dielectric heater comprises a heating space for receiving the protruding portion of the cartridge containing the at least a portion of the liquid transport element.

[0082] According to another example of the present disclosure, there is provided an aerosolgenerating system for dielectrically heating a liquid aerosol-forming substrate, the aerosol- generating system comprising a cartridge comprising: a liquid storage portion for holding a liquid aerosol-forming substrate; and a liquid transport element for transporting liquid aerosolforming substrate from the liquid storage portion to a dielectric heating portion of the cartridge; and an aerosol-generating device configured to be removably couplable to the cartridge, the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; and a dielectric heater for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol-generating device.

[0083] The aerosol-generating device may alternatively be referred to as a “cartridge holder”.

[0084] According to another example of the present disclosure, there is provided a cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate, the cartridge comprising: a cartridge body comprising a liquid storage portion for holding a liquid aerosol-forming substrate; a dielectric heating portion; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the dielectric heating portion.

[0085] According to another example of the present disclosure, there is provided an aerosolgenerating device for dielectrically heating a liquid aerosol-forming substrate, the aerosolgenerating device being configured to be removably couplable to any of the above-described cartridges, the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; a dielectric heater for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol-generating device; a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater.

[0086] Features described in relation to one of the above examples may equally be applied to other examples of the present disclosure.

[0087] The invention is defined in the claims. However, below there is provided a non- exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0088] Example Ex1 : An aerosol-generating system comprising a heater for heating an aerosol-forming substrate; wherein the heater comprises a heating space for receiving the aerosol-forming substrate.

[0089] Example Ex2: An aerosol-generating system according to Example Ex1 , wherein the aerosol-generating system is configured to heat a liquid aerosol-forming substrate, the aerosol-generating system comprising a liquid storage portion for holding a liquid aerosol- forming substrate; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the heater.

[0090] Example Ex3: An aerosol-generating system according to Example Ex2, wherein the heater is a dielectric heater and comprises a heating space for receiving at least a portion of the liquid transport element.

[0091] Example Ex4: An aerosol-generating system according to Example Ex3, wherein the dielectric heater comprises a heating chamber having an interior defining the heating space for receiving the at least a portion of the liquid transport element.

[0092] Example Ex5: An aerosol-generating system according to Example Ex4, wherein the dielectric heater further comprises a coupler configured to couple an alternating electric field generator to the interior of the heating chamber to provide an alternating electric field in the heating space.

[0093] Example Ex6: An aerosol-generating system according to Example Ex5, wherein the heating chamber comprises a first region comprising a first dielectric having a first relative permittivity.

[0094] Example Ex7: An aerosol-generating system according to Example Ex6, wherein the heating chamber comprises a second region comprising a second dielectric having a second relative permittivity.

[0095] Example Ex8: An aerosol-generating system according to Example Ex7, wherein the second relative permittivity is less than the first relative permittivity such that the strength of the alternating electric field is greater in the second region than in the first region.

[0096] Example Ex9: An aerosol-generating system according to Example Ex8, wherein the second relative permittivity is less than the first relative permittivity by at least 5.

[0097] Example Ex10: An aerosol-generating system according to Example Ex9, wherein the second relative permittivity is less than the first relative permittivity by at least 10.

[0098] Example Ex11 : An aerosol-generating system according to any of Examples Ex7 to Ex10, wherein the at least a portion of the liquid transport element is received in proximity to or within the second region.

[0099] Example Ex12: An aerosol-generating system according to any of Examples Ex6 to Ex11 , wherein the first dielectric comprises a ceramic or polymeric material.

[0100] Example Ex13: An aerosol-generating system according to any of Examples Ex7 to Ex12, wherein the second dielectric comprises air.

[0101] Example Ex14: An aerosol-generating system according to any of Examples Ex4 to Ex12, wherein the heating chamber further comprises a third region comprising a third dielectric having a third relative permittivity.

[0102] Example Ex15: An aerosol-generating system according to Example Ex14, wherein the second region is arranged between the first and third regions.

[0103] Example Ex16: An aerosol-generating system according to Example Ex15, wherein the second relative permittivity is less than the first and third relative permittivities such that the strength of the alternating electric field is greater in the second region than in the first and third regions.

[0104] Example Ex17: An aerosol-generating system according to Example Ex16, wherein a length of the second region in a direction parallel to a longitudinal direction of the aerosolgenerating system is between 1 millimetre and 5 millimetres,

[0105] Example Ex18: An aerosol-generating system according to Example Ex17, wherein a length of the second region in a direction parallel to a longitudinal direction of the aerosolgenerating system is between 2 millimetres and 4 millimetres.

[0106] Example Ex19: An aerosol-generating system according to Example Ex4, wherein the heating chamber further comprises a constriction portion arranged at a point along the length of the interior of the heating chamber, the constriction portion having a reduced cross-sectional area such that the alternating electric field is concentrated in the constriction portion.

[0107] Example Ex20: An aerosol-generating system according to any of Examples Ex4 to Ex19, wherein the heating chamber is a cavity resonator.

[0108] Example Ex21 : An aerosol-generating system according to Example Ex3, wherein the dielectric heater comprises at least one pair of opposing electrodes, the pair of opposing electrodes being spaced apart to define the heating space for receiving at least a portion of the liquid transport element.

[0109] Example Ex22: An aerosol-generating system according to Example Ex21 , wherein each one of the pair of opposing electrodes has a surface area between 4 square millimetres and 100 square millimetres.

[0110] Example Ex23: An aerosol-generating system according to Example Ex21 or Ex22, wherein the pair of opposing electrodes are spaced apart by a distance of between 0.25 millimetres and 2 millimetres.

[0111] Example Ex24: An aerosol-generating system according to any of Examples Ex21 to Ex23, wherein the aerosol-generating system is configured to provide a power density of between 50 watts per cubic centimetre and 1 .25 kilowatts per cubic centimetre between the pair of opposing electrodes.

[0112] Example Ex25: An aerosol-generating system according to any of Examples Ex21 to Ex24, wherein the pair of opposing electrodes are substantially planar or flat and are arranged parallel to one another.

[0113] Example Ex26: An aerosol-generating system according to any of Examples Ex21 to Ex24, wherein the pair of opposing electrodes are curved opposing cylindrical segments. Example Ex27: An aerosol-generating system according to any of Examples Ex2 to Ex26, further comprising an airflow channel having an aerosol outlet.

[0114] Example Ex28: An aerosol-generating system according to Example Ex27, wherein the at least a portion of the liquid transport element that is arranged to be received within the heating space is arranged within the airflow channel.

[0115] Example Ex29: An aerosol-generating system according to Example Ex28, wherein the liquid transport element occupies the entire internal cross-section of the airflow channel.

[0116] Example Ex30: An aerosol-generating system according to Example Ex28, wherein the liquid transport element is planar.

[0117] Example Ex31 : An aerosol-generating system according to Example Ex30, wherein the liquid transport element occupies only a portion of internal cross-section of airflow channel.

[0118] Example Ex32: An aerosol-generating system according to Example Ex30 or Ex31 , wherein the liquid transport element is arranged parallel to the airflow direction.

[0119] Example Ex33: An aerosol-generating system according to any of Examples Ex5 to Ex32, further comprising: a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of power to the dielectric heater, the control circuitry comprising an alternating electric field generator.

[0120] Example Ex34: An aerosol-generating system according to Example Ex33, wherein the alternating electric field generator is coupled to the heating chamber by the at least one coupler.

[0121] Example Ex34: An aerosol-generating system according to Example Ex33, wherein the alternating electric field generator comprises an oscillation circuit.

[0122] Example Ex35: An aerosol-generating system according to any of Examples Ex33 to Ex34, wherein the control circuitry further comprises a puff detector for detecting when a user is taking a puff on the aerosol-generating system.

[0123] Example Ex36: An aerosol-generating system according to Example Ex35, wherein the control circuitry is configured to supply power to the dielectric heater in response to detecting a puff.

[0124] Example Ex37: An aerosol-generating system according to any of Examples Ex33 to Ex36, wherein the control circuitry is configured to provide a heating power in the range of 7 to 35 watts.

[0125] Example Ex37: A cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate, the cartridge comprising: a cartridge body comprising a liquid storage portion for holding a liquid aerosol-forming substrate; and a liquid transport element; wherein the cartridge body further comprises a protruding portion that extends from the liquid storage portion, the protruding portion comprising at least a portion of the liquid transport element.

[0126] Example Ex38: A cartridge according to Example Ex37, wherein the liquid transport element comprises a porous element for providing capillary flow of the liquid aerosol-forming substrate, the porous element having a relative permittivity of less than 5.

[0127] Example Ex39: A cartridge according to Example Ex37 or Ex38, further comprising a pair of opposing electrodes, wherein the liquid transport element is arranged in a space between the opposing electrodes.

[0128] Example Ex40: An aerosol-generating device for dielectrically heating a liquid aerosolforming substrate, the aerosol-generating device being configured to be removably couplable to the cartridge according to Examples Ex37 to Ex39, the aerosol-generating device comprising: a dielectric heater for heating the liquid aerosol-forming substrate; a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater; wherein the dielectric heater comprises a heating space for receiving the protruding portion of the cartridge containing the at least a portion of the liquid transport element.

[0129] Example Ex41 : An aerosol-generating system for dielectrically heating a liquid aerosolforming substrate, the aerosol-generating system comprising a cartridge comprising: a liquid storage portion for holding a liquid aerosol-forming substrate; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to a dielectric heating portion of the cartridge; and an aerosol-generating device configured to be removably couplable to the cartridge, the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; and a dielectric heater for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol-generating device.

[0130] Example Ex42: An aerosol-generating system according to Example Ex41 , wherein the aerosol-generating device comprises a heating space for receiving the dielectric heating portion of the cartridge.

[0131] Example Ex43: An aerosol-generating system according to Example Ex41 or Ex42, wherein the dielectric heater comprises the heating space.

[0132] Example Ex44: An aerosol-generating system according to Example Ex43, wherein the dielectric heater comprises a heating chamber having an interior defining the heating space for receiving the at least a portion of the liquid transport element.

[0133] Example Ex45: An aerosol-generating system according to Example Ex44, wherein the dielectric heater further comprises a coupler configured to couple an alternating electric field generator to the interior of the heating chamber to provide an alternating electric field in the heating space. Example Ex46: An aerosol-generating system according to Example Ex45, wherein the heating chamber comprises a first region comprising a first dielectric having a first relative permittivity.

[0134] Example Ex47: An aerosol-generating system according to Example Ex46, wherein the heating chamber comprises a second region comprising a second dielectric having a second relative permittivity.

[0135] Example Ex48: An aerosol-generating system according to Example Ex47, wherein the second relative permittivity is less than the first relative permittivity such that the strength of the alternating electric field is greater in the second region than in the first region.

[0136] Example Ex49: An aerosol-generating system according to Example Ex48, wherein the second relative permittivity is less than the first relative permittivity by at least 5.

[0137] Example Ex50: An aerosol-generating system according to Example Ex49, wherein the second relative permittivity is less than the first relative permittivity by at least 10.

[0138] Example Ex51 : An aerosol-generating system according to any of Examples Ex47 to Ex50, wherein the at least a portion of the liquid transport element is received in proximity to or within the second region.

[0139] Example Ex52: An aerosol-generating system according to any of Examples Ex46 to Ex51 , wherein the first dielectric comprises a ceramic or polymeric material.

[0140] Example Ex53: An aerosol-generating system according to any of Examples Ex57 to Ex52, wherein the second dielectric comprises air.

[0141] Example Ex54: An aerosol-generating system according to any of Examples Ex44 to Ex52, wherein the heating chamber further comprises a third region comprising a third dielectric having a third relative permittivity.

[0142] Example Ex55: An aerosol-generating system according to Example Ex54, wherein the second region is arranged between the first and third regions.

[0143] Example Ex56: An aerosol-generating system according to Example Ex55, wherein the second relative permittivity is less than the first and third relative permittivities such that the strength of the alternating electric field is greater in the second region than in the first and third regions.

[0144] Example Ex57: An aerosol-generating system according to Example Ex56, wherein a length of the second region in a direction parallel to a longitudinal direction of the aerosolgenerating system is between 1 millimetre and 5 millimetres,

[0145] Example Ex58: An aerosol-generating system according to Example Ex57, wherein a length of the second region in a direction parallel to a longitudinal direction of the aerosolgenerating system is between 2 millimetres and 4 millimetres.

[0146] Example Ex59: An aerosol-generating system according to Example Ex54, wherein the heating chamber further comprises a constriction portion arranged at a point along the length of the interior of the heating chamber, the constriction portion having a reduced cross- sectional area such that the alternating electric field is concentrated in the constriction portion.

[0147] Example Ex60: An aerosol-generating system according to any of Examples Ex44 to Ex59, wherein the heating chamber is a cavity resonator.

[0148] Example Ex61 : An aerosol-generating system according to Example Ex43, wherein the dielectric heater comprises at least one pair of opposing electrodes, the pair of opposing electrodes being spaced apart to define the heating space for receiving at least a portion of the liquid transport element.

[0149] Example Ex62: An aerosol-generating system according to Example Ex61 , wherein each one of the pair of opposing electrodes has a surface area between 4 square millimetres and 100 square millimetres.

[0150] Example Ex63: An aerosol-generating system according to Example Ex61 or Ex62, wherein the pair of opposing electrodes are spaced apart by a distance of between 0.25 millimetres and 2 millimetres.

[0151] Example Ex64: An aerosol-generating system according to any of Examples Ex61 to Ex63, wherein the aerosol-generating system is configured to provide a power density of between 50 watts per cubic centimetre and 1 .25 kilowatts per cubic centimetre between the pair of opposing electrodes.

[0152] Example Ex65: An aerosol-generating system according to any of Examples Ex61 to Ex64, wherein the pair of opposing electrodes are substantially planar or flat and are arranged parallel to one another.

[0153] Example Ex66: An aerosol-generating system according to any of Examples Ex61 to Ex64, wherein the pair of opposing electrodes are curved opposing cylindrical segments.

[0154] Example Ex67: An aerosol-generating system according to any of Examples Ex42 to Ex66, further comprising an airflow channel having an aerosol outlet.

[0155] Example Ex68: An aerosol-generating system according to Example Ex67, wherein the at least a portion of the liquid transport element that is arranged to be received within the heating space is arranged within the airflow channel.

[0156] Example Ex69: An aerosol-generating system according to Example Ex68, wherein the liquid transport element occupies the entire internal cross-section of the airflow channel.

[0157] Example Ex70: An aerosol-generating system according to Example Ex68, wherein the liquid transport element is planar.

[0158] Example Ex71 : An aerosol-generating system according to Example Ex70, wherein the liquid transport element occupies only a portion of internal cross-section of airflow channel.

[0159] Example Ex72: An aerosol-generating system according to Example Ex70 or Ex71 , wherein the liquid transport element is arranged parallel to the airflow direction.

[0160] Example Ex73: An aerosol-generating system according to any of Examples Ex45 to Ex72, further comprising: a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of power to the dielectric heater, the control circuitry comprising an alternating electric field generator.

[0161] Example Ex74: An aerosol-generating system according to Example Ex73, wherein the alternating electric field generator is coupled to the heating chamber by the at least one coupler.

[0162] Example Ex75: An aerosol-generating system according to Example Ex73, wherein the alternating electric field generator comprises an oscillation circuit.

[0163] Example Ex76: An aerosol-generating system according to any of Examples Ex73 to Ex75, wherein the control circuitry further comprises a puff detector for detecting when a user is taking a puff on the aerosol-generating system.

[0164] Example Ex77: An aerosol-generating system according to Example Ex76, wherein the control circuitry is configured to supply power to the dielectric heater in response to detecting a puff.

[0165] Example Ex78: An aerosol-generating system according to any of Examples Ex73 to Ex77, wherein the control circuitry is configured to provide a heating power in the range of 7 to 35 watts.

[0166] Example Ex79: A cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate, the cartridge comprising: a liquid storage portion for holding a liquid aerosol-forming substrate; a dielectric heating portion; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the dielectric heating portion.

[0167] Example Ex80: A cartridge according to Example Ex79, wherein the dielectric heating portion comprises a protruding portion of the cartridge that extends from the liquid storage portion.

[0168] Example Ex81 : A cartridge according to Example Ex80, wherein the protruding portion comprises at least a portion of the liquid transport element.

[0169] Example Ex82: A cartridge according to Example Ex80 or Ex81 , further comprising a cartridge body, wherein the cartridge body comprises the liquid storage portion and protruding portion, the protruding portion extending from the liquid storage portion.

[0170] Example Ex83: A cartridge according to any of Examples Ex79 to Ex82, wherein the liquid transport element comprises a porous element for providing capillary flow of the liquid aerosol-forming substrate, the porous element having a relative permittivity of less than 5.

[0171] Example Ex84: A cartridge according to any of Examples Ex79 to Ex83, wherein the cartridge does not comprise a heater or heating element.

[0172] Example Ex85: A cartridge according to any of Examples Ex79 to Ex84, wherein the cartridge does not comprise any metallic components.

[0173] Example Ex86: An aerosol-generating device for dielectrically heating a liquid aerosolforming substrate, the aerosol-generating device being configured to be removably couplable to the cartridge according to any of claims 15 to 21 , the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; a dielectric heater for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosol-generating device; a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater.

[0174] Example Ex87: An aerosol-generating device according to Example Ex86, further comprising a heating space for receiving the dielectric heating portion of the cartridge.

[0175] Example Ex88: An aerosol-generating device according to Example Ex86 or Ex87, wherein the dielectric heater comprises the heating space.

[0176] Examples will now be further described with reference to the figures in which:

[0177] Figure 1A is a schematic cross-sectional view of an aerosol-generating system according to an example of the present disclosure, the aerosol-generating system comprising an aerosol-generating device and a cartridge and the cartridge being shown removed from the aerosol-generating device;

[0178] Figure 1 B is a schematic cross-sectional view of the aerosol-generating system of Figure 1A showing the cartridge attached to the device;

[0179] Figure 2A is a schematic cross-sectional view of a heating chamber and cartridge for an aerosol-generating system according to another example of the present disclosure with the cartridge being shown removed from the heating chamber;

[0180] Figure 2B is a schematic cross-sectional view of the heating chamber and cartridge of Figure 2A showing the cartridge attached to the chamber;

[0181] Figure 3A is a schematic cross-sectional view of a heating chamber and cartridge for an aerosol-generating system according to another example of the present disclosure with the cartridge being shown removed from the heating chamber;

[0182] Figure 3B is a schematic cross-sectional view of the heating chamber and cartridge of Figure 3A showing the cartridge attached to the chamber;

[0183] Figure 4A is a schematic cross-sectional view of a heating chamber and cartridge for an aerosol-generating system according to another example of the present disclosure with the cartridge being shown removed from the heating chamber;

[0184] Figure 4B is a schematic cross-sectional view of the heating chamber and cartridge of Figure 4A showing the cartridge attached to the chamber;

[0185] Figure 5 is a schematic cross-sectional view of a cartridge according to an example of the present disclosure.

[0186] Figure 6A and 6B are plan views showing two different configurations for the liquid transport element of the cartridge of Figure 5.

[0187] Figure 7 is a schematic perspective view of a cartridge according to another example of the present disclosure.

[0188] Figure 8A is a schematic cross-sectional view of an aerosol-generating system according to another example of the present disclosure with the cartridge shown removed from the device;

[0189] Figure 8B is a schematic cross-sectional view of the aerosol-generating system of Figure 8A showing the cartridge attached to the device;

[0190] Figure 9A is a schematic perspective view of a cartridge according to another example of the present disclosure;

[0191] Figure 9B is a plan cross-sectional view of the cartridge of Figure 9A along the line B- B in Figure 9A;

[0192] Figure 10A is a schematic cross-sectional view of a cartridge according to another example of the present disclosure;

[0193] Figure 10B is a schematic cross-sectional view of an aerosol-generating device for coupling to or receiving the cartridge of Figure 10A according to another example of the present disclosure;

[0194] Figure 10C is a schematic cross-sectional view of an aerosol-generating system showing the cartridge of Figure 10A coupled to or received within a cavity of the aerosolgeneration device of Figure 10B;

[0195] Figure 11A is a schematic cross-sectional view showing the aerosol flow path through the aerosol-generating system of Figure 10C;

[0196] Figure 11 B is a schematic cross-sectional top view of the protruding portion of the cartridge of Figure 11 A taken along the line A-A in Figure 11 A.

[0197] It will be appreciated that at least some of the figures in the present application are schematic and have been simplified for the purposes of clarity. Consequently, some features may have been omitted and the features are not necessarily drawn to scale.

[0198] The terms ‘“distal”, “proximal”, “upstream” and “downstream” are used herein to describe the relative positions of components, or portions of components, of an aerosolgenerating device or system. Aerosol generating devices or systems according to the present disclosure have a proximal end through which, in use, an aerosol exits the article or device for delivery to a user, and have an opposing distal end. The proximal end of the aerosol generating device or system may also be referred to as the mouth end. In use, a user draws on the proximal end of the aerosol generating device or system in order to inhale an aerosol generated by the aerosol generating device or system. The terms upstream and downstream are relative to the direction of airflow or aerosol movement through the aerosol generating device or system when a user draws on the proximal end of the aerosol-generating device or system. The proximal end of the aerosol-generating device or system is downstream of the distal end of the aerosol-generating device or system.

[0199] Referring to Figure 1A, there is shown schematic cross-sectional view of an aerosolgenerating system 1 comprising an aerosol-generating device 100 and a cartridge 10. The cartridge 10 is shown removed from the aerosol-generating device 100. The aerosolgenerating system 1 is configured to dielectrically heat a liquid aerosol-forming substrate contained in the cartridge 10.

[0200] The cartridge 10 comprises a cartridge body 12 having a liquid storage portion 14 configured to hold a liquid aerosol-forming substrate (not shown). The cartridge body 12 has a protruding portion 16 that extends downwardly from a lower surface of the cartridge body 12. The length of the protruding portion may be in a range between 5 millimetres and 40 millimetres, and more preferably between 7 millimetres and 30 millimetres. It will be appreciated that the length of the protruding portion will be determined to a large degree by the distance between the lower surface of the cartridge body 12 and the heating space. A liquid transport element 18, or at least a portion of a liquid transport element 18, is arranged in the protruding portion 16 of the cartridge body 12. The liquid transport element 18 is in fluid communication with the liquid aerosol forming substrate contained in the liquid storage portion 14. The liquid transport element is configured to convey liquid aerosol-forming substrate into the protruding portion 16 of the cartridge 10, which acts as a dielectric heating portion of the cartridge 10.

[0201] The cartridge 10 further comprises an airflow channel 20 having an air inlet 22 and an aerosol outlet 24. The aerosol outlet 24 is arranged in a removable or fixed mouthpiece 26 of the aerosol-generating system 1 at a mouth end of the aerosol-generating system. At least a portion of the liquid transport element 18 is arranged within the airflow channel 20 so that volatile compounds that are vaporized from the liquid transport element 18 during heating are entrained in the airflow though the airflow channel 20. The airflow channel 20 passes through the liquid storage portion 14 such that the liquid aerosol-forming substrate is contained in a reservoir, for example an annular-shaped reservoir.

[0202] The aerosol-generating device 100 comprises an accommodation space 103 for removably accommodating the protruding portion 16 of the cartridge 10. The aerosolgenerating device 100 comprises a dielectric heater in the form of a heating chamber 104 arranged at a proximal end of the aerosol-generating device 100. The heating chamber 104 is configured to receive the protruding portion 16 of the cartridge and defines a heating space for dielectrically heating a liquid aerosol-forming substrate. The heating chamber 104 is substantially surrounded by a chamber housing 110 formed of metal, for example, copper or aluminium. In this example, the chamber housing 110 comprises a copper mesh. The electrically conductive chamber housing 110 helps to contain a generated electric field within the heating chamber 104. An opening 112 is provided in a proximal end of the heating chamber 104. The opening is configured to allow the protruding portion 16 of the cartridge 10 to be received within the heating chamber 104.

[0203] The aerosol-generating device 100 further comprises a device housing 102 containing the heating chamber 104, a power supply 106 in the form of a battery and control circuitry 108. The control circuitry is configured to control the supply of power to the heating chamber 104. The control circuitry 108 comprises an alternating electric field generator (not shown), which is configured to generate a high frequency (approximately 2.4 gigahertz) alternating electric voltage that is provided to the heating chamber 104 to generate an alternating electric field within the heating chamber 104. A coupler 114 is provided to couple the alternating field generator to the interior of the heating chamber 104. The coupler 114 may comprise a transmission line such as a coaxial cable. The coupler 114 is connected to the base of the heating chamber 104, that is, at a distal end of the heating chamber 104 opposite opening 112. A central conductor or pin 116 of the coupler 114 extends into the heating chamber 104 to provide an alternating electric field within the heating chamber 104.

[0204] The heating chamber 104 forms a cavity resonator. Accordingly, when a liquid aerosolforming substrate comprising polar molecules is received in the heating chamber 104, and an alternating electric field is created in the heating chamber 104 via the coupler 114, the liquid aerosol-forming substrate may be dielectrically heated to generate an aerosol.

[0205] The device housing 102 comprises an air inlet 118 to allow air to enter the aerosolgenerating device 100 when a user takes a puff. When the cartridge 10 is connected to the aerosol-generating device 100 (see Figure 1 B), the air inlet 118 is in fluid communication with the aerosol outlet 24 of the cartridge 10 via the heating chamber 104 and air inlet 22 of the cartridge 10. A puff detector 120 is also provided for detecting when a user is taking a puff on the aerosol-generating system 1. In this example, the puff detector 120 is a pressure sensor and detects a reduction in air pressure within the aerosol-generating device 100 when a user inhales. However, it will be appreciated that any suitable type of puff detector could be used. The puff detector 120 is connected to the control circuitry 108, which is configured to provide an alternating electric field within the heating chamber 104 in response to receiving a signal from the puff detector 120 indicating that a user is taking a puff. Figure 1 B shows the aerosol-generating system 1 of Figure 1A with the cartridge 10 attached or connected to the aerosol-generating device 100. When the cartridge 10 is connected to the aerosol-generating device 100, the protruding portion 16 of the cartridge 10 containing the liquid transport element 18 is received within the heating space defined by the heating chamber 104 such that the liquid aerosol-forming substrate contained within the liquid transport element 18 can be dielectrically heated.

[0206] In use, a user connects the cartridge 10 to the aerosol-generating device 100. When they want to take a puff on the aerosol-generating system 1 , the user inhales on the mouthpiece 26. This causes air to be drawn in through air inlet 118 in device housing 102, through the copper mesh of the chamber housing 110 of the heating chamber and into the airflow channel 20 of the cartridge 10 via air inlet 22. The puff is detected by puff detector 120, which sends a signal to the control circuitry 108 that a puff is being taken. In response to the signal from the puff detector 120, the control circuitry 108 activates dielectric heating by providing an alternating electric field within the heating chamber 104. This heats the liquid aerosol-forming substrate contained within the liquid transport element located within the heating chamber 104 resulting in an aerosol being generated. The aerosol is entrained in the air flowing through the airflow channel 20 and exits the aerosol outlet 24 formed in the mouthpiece 26 and enters the user’s mouth.

[0207] Figure 2A is a schematic cross-sectional view of a heating chamber 104 and cartridge 10 for an aerosol-generating system according to another example of the present disclosure. The cartridge 10 is shown removed from the heating chamber 104. The cartridge 10 and heating chamber 104 are similar to those of the aerosol-generating system 1 of Figure 1A and like reference numerals have been used to label like components. For simplicity, the remainder of the aerosol-generating device 100 of Figure 1A comprising the device housing 102, power supply 106 and control circuitry 108 have been omitted from Figure 2A. However, it will be appreciated that heating chamber 104 of Figure 2A forms part of an aerosolgenerating device in a similar way to that of Figure 1 A and operates in a similar fashion.

[0208] The cartridge 10 of Figure 2A has the same construction as that of Figure 1 A with the exception that the protruding portion 16 of the cartridge 10 extends further below the bottom of the liquid storage portion 14. The liquid transport element 18, which is located near or at a distal end of the protruding portion 16 is therefore also located further away from the bottom of the liquid storage portion 14.

[0209] The aerosol-generating device of Figure 2A comprises an accommodation space 103 for removably accommodating the protruding portion 16 of the cartridge 10. The heating chamber 104 of Figure 2A is configured to receive the extended protruding portion 16 of the cartridge 10 and defines a heating space for dielectrically heating a liquid aerosol-forming substrate. The heating chamber 104 is substantially surrounded by a chamber housing 110 and has an opening 112 provided in a proximal end of the heating chamber 104. The opening 112 is configured to allow the protruding portion 16 of the cartridge 10 to be received within the heating chamber 104. The coupler 114 is connected to the base of the heating chamber 104, that is, at a distal end of the heating chamber 104 opposite opening 112. A central conductor or pin 116 of the coupler 114 extends into the heating chamber 104 to provide an alternating electric field within the heating chamber 104.

[0210] The chamber housing 110 of the heating chamber 104 of Figure 2A comprises two regions, a first region 122, and a second region 124. The first region 122 and the second region 124 are arranged end-to-end sequentially in a direction parallel to the longitudinal axis of the aerosol-generating system and circumscribe a central heating space within the heating chamber which can be occupied by the protruding portion 16 of the cartridge 10. The first region 122 extends from the end of the chamber housing 110 having the opening 112 in a longitudinal direction of the aerosol-generating system towards the base of the heating chamber 104 having the coupler 114 and terminates at a point near the middle of the length of the heating chamber 104. The second region 124 extends from the distal end of the first region 122 towards the base of the heating chamber 104 and terminates near the proximal end of the pin 116.

[0211] The first region 122 comprises a first dielectric 126, in particular, an annular body of a dielectric ceramic material. In this example, the dielectric ceramic material is alumina having a relative permittivity of about 10. The first dielectric 126 has a central passageway 130 passing through its length or height that corresponds to, and is aligned with, the opening 112 in the chamber housing 112. The second region 124 comprises a second dielectric 128, in particular, a space filled with air. Accordingly, the second region 124 is a dielectric region, with a relative permittivity of about 1 . The second region 124 has a lower relative permittivity than the first region 122. Since the relative permittivity of the second region 124 is lower than the relative permittivity of the first region 122, an alternating electric field created in the heating chamber 104 is greater in the portion of the heating chamber 104 that is circumscribed by the second region 124, that is, at the end closer to the coupler 114, than in the portion of the heating chamber 104 that is circumscribed by the first region 122. Such a configuration of the heating chamber establishes a gradient in the alternating electric field created in the heating chamber 104, such that the alternating electric field decreases through the central heating space of the heating chamber 104 from the end having the coupler 114 to the end with the opening 112.

[0212] Figure 2B shows the heating chamber 104 and cartridge 10 of Figure 2A with the cartridge 10 attached or connected to the heating chamber 104. When the cartridge 10 is connected to the heating chamber 104, the protruding portion 16 of the cartridge 10 containing the liquid transport element 18 is received within the heating space defined by the heating chamber 104. The length of the protruding portion 16 is such that the liquid transport element 18 is arranged in the second region 124 of the heating chamber 124, that is the region having the greater alternating electric field, when the cartridge 10 is connected to the heating chamber 104. The increased electric field strength in the second portion 124 increases the dielectric heating of the liquid aerosol-forming substrate in the liquid transport element 18, helping to generate aerosol more quickly. However, it will be appreciated that the liquid transport element 18 can be located at various points along the length of the protruding portion depending on the degree of heating required due to the above-mentioned gradient in the alternating electric field created in the heating chamber 104 by the first 122 and second 124 regions.

[0213] Figure 3A is a schematic cross-sectional view of a heating chamber 104 and cartridge 10 for an aerosol-generating system according to another example of the present disclosure. The cartridge 10 is shown removed from the heating chamber 104. The cartridge 10 and heating chamber 104 are similar to those of the aerosol-generating systems of Figures 1A and 2A and like reference numerals have been used to label like components. For simplicity, the remainder of the aerosol-generating device 100 of Figure 3A comprising the device housing 102, power supply 106 and control circuitry 108 have been omitted from Figure 3A. However, it will be appreciated that heating chamber 104 of Figure 3A forms part of an aerosolgenerating device in a similar way to that of Figure 1 A and operates in a similar fashion.

[0214] The cartridge 10 of Figure 3A has the same construction as that of Figures 1A and 2A with the exception that the protruding portion 16 of the cartridge 10 extends further below the bottom of the liquid storage portion 14. The liquid transport element 18, which is located near or at a distal end of the protruding portion 16 is therefore also located further away from the bottom of the liquid storage portion 14.

[0215] The aerosol-generating device of Figure 3A comprises an accommodation space 103 for removably accommodating the protruding portion 16 of the cartridge 10. The heating chamber 104 of Figure 3A is configured to receive the extended protruding portion 16 of the cartridge 10 and defines a heating space for dielectrically heating a liquid aerosol-forming substrate. The heating chamber 104 is substantially surrounded by a chamber housing 110 and has an opening 112 provided in a proximal end of the heating chamber 104. The opening 112 is configured to allow the protruding portion 16 of the cartridge 10 to be received within the heating chamber 104. The coupler 114 is connected to the base of the heating chamber 104, that is, at a distal end of the heating chamber 104 opposite opening 112. A central conductor or pin 116 of the coupler 114 extends into the heating chamber 104 to provide an alternating electric field within the heating chamber 104. The chamber housing 110 of the heating chamber 104 of Figure 3A comprises three regions, a first region 122, a second region 124 and a third region 132. The first to third regions 122, 124 and 132 are arranged end-to-end sequentially in a direction parallel to the longitudinal axis of the aerosol-generating system and circumscribe a central heating space within the heating chamber which can be occupied by the protruding portion 16 of the cartridge 10. The first region 122 extends from the end of the chamber housing 110 having the opening 112 in a longitudinal direction of the aerosol-generating system towards the base of the heating chamber 104 having the coupler 114 and terminates at a point near the middle of the length of the heating chamber 104. The second region 124 extends a short distance from the distal end of the first region 122 towards the base of the heating chamber 104 and occupies the midsection of the heating chamber 104. The third region 132 extends from the distal end of the second region 122 towards the base of the heating chamber 104 and terminates in the region of the pin 116 of the coupler 114.

[0216] The first region 122 comprises a first dielectric 126 and the third region comprises a third dielectric 134. In this example, the first 126 and third 134 dielectrics are the same and comprise an annular body of a dielectric ceramic material. In particular, the dielectric ceramic material is alumina having a relative permittivity of about 10. The first 126 and third 132 dielectrics have a central passageway 130 passing through their length or height that correspond to, and are aligned with, the opening 112 in the chamber housing 110. The second region 124 comprises a second dielectric 128, in particular, a space filled with air. Accordingly, the second region 124 is a dielectric region, with a relative permittivity of about 1. The second region 124 effectively forms an air gap between the first 126 and third 134 dielectrics. In this example, the air gap has a length in a longitudinal direction of the aerosol-generating system of approximately 4 millimetres. However, it will be appreciated that other lengths could be used depending on the configuration of the aerosol-generating system.

[0217] The second region 124 has a lower relative permittivity than the first 122 and third 132 regions. Since the relative permittivity of the second region 124 is lower than the relative permittivity of the first 122 and third 132 regions, an alternating electric field created in the heating chamber 104 is greater in the portion of the heating chamber 104 that is circumscribed by the second region 124, that is, in the air gap between the first 126 and third 134 dielectrics, than in the portion of the heating chamber 104 that is circumscribed by the first 122 and 132 regions. Such a configuration of the heating chamber 104 establishes an alternating electric field distribution within the heating chamber 104, in which the alternating electric field is greatest in the second region 124.

[0218] Figure 3B shows the heating chamber 104 and cartridge 10 of Figure 3A with the cartridge 10 attached or connected to the heating chamber 104. When the cartridge 10 is connected to the heating chamber 104, the protruding portion 16 of the cartridge 10 containing the liquid transport element 18 is received within the heating space defined by the heating chamber 104. The length of the protruding portion 16 is such that the liquid transport element 18 is arranged in the second region 124 of the heating chamber 124, that is the region having the greatest alternating electric field, when the cartridge 10 is connected to the heating chamber 104. The increased electric field strength in the second portion 124 increases the dielectric heating of the liquid aerosol-forming substrate in the liquid transport element 18, helping to generate aerosol more quickly. However, it will be appreciated that the liquid transport element 18 can be located at various points along the length of the protruding portion depending on the degree of heating required due to the above-mentioned distribution in the alternating electric field created in the heating chamber 104 by the first, second and third regions 122, 124 and 132.

[0219] Figure 4A is a schematic cross-sectional view of a heating chamber 104 and cartridge 10 for an aerosol-generating system according to another example of the present disclosure. The cartridge 10 is shown removed from the heating chamber 104. The cartridge 10 and heating chamber 104 are similar to those of the aerosol-generating systems of Figure 1A and like reference numerals have been used to label like components. For simplicity, the remainder of the aerosol-generating device 100 of Figure 4A comprising the device housing 102, power supply 106 and control circuitry 108 have been omitted from Figure 4A. However, it will be appreciated that the heating chamber 104 of Figure 4A forms part of an aerosolgenerating device in a similar way to that of Figure 1 A and operates in a similar fashion.

[0220] The cartridge 10 of Figure 4A has the same construction as that of Figure 1 A with the exception that the protruding portion 16 of the cartridge 10 extends further below the bottom of the liquid storage portion 14. The liquid transport element 18, which is located near or at a distal end of the protruding portion 16 is therefore also located further away from the bottom of the liquid storage portion 14.

[0221] The aerosol-generating device of Figure 4A comprises an accommodation space 103 for removably accommodating the protruding portion 16 of the cartridge 10. The heating chamber 104 of Figure 4A is configured to receive the extended protruding portion 16 of the cartridge 10 and defines a heating space for dielectrically heating a liquid aerosol-forming substrate. The heating chamber 104 is substantially surrounded by a chamber housing 110 and has an opening 112 provided in a proximal end of the heating chamber 104. The opening 112 is configured to allow the protruding portion 16 of the cartridge 10 to be received within the heating chamber 104. The coupler 114 is connected to the base of the heating chamber 104, that is, at a distal end of the heating chamber 104 opposite opening 112. A central conductor or pin 116 of the coupler 114 extends into the heating chamber 104 to provide an alternating electric field within the heating chamber 104.

[0222] The heating chamber 104 further comprises a constriction portion 136 arranged at a point along the length of the interior of the heating chamber 136. In this example, the constriction portion 136 is shown arranged at approximately the midpoint of the length of the heating chamber 104. However, it will be appreciated that the constriction portion 136 could be arranged in any suitable location. The constriction portion 136 has a reduced cross- sectional area in a plane transverse to the longitudinal axis of the aerosol-generating system, that is, the heating chamber 104 has a reduce width and depth at the location of the constriction portion. Consequently, the side walls 110b of the chamber housing 110 are closer together in the constriction region 136 than they are outside the constriction region 136. This results in the intensity of the alternating electric field being concentrated in the constriction portion 136.

[0223] In the example of Figure 4A, the alternating electric field created in the heating chamber 104 is greater in the portion of the heating chamber 104 that is circumscribed by the constriction portion 136 than in the remaining portions of the heating chamber 104. Such a configuration of the heating chamber 104 establishes an alternating electric field distribution within the heating chamber 104, in which the alternating electric field is greatest in the constriction portion 136.

[0224] Figure 4B shows the heating chamber 104 and cartridge 10 of Figure 3A with the cartridge 10 attached or connected to the heating chamber 104. When the cartridge 10 is connected to the heating chamber 104, the protruding portion 16 of the cartridge 10 containing the liquid transport element 18 is received within the heating space defined by the heating chamber 104. The length of the protruding portion 16 is such that the liquid transport element 18 is arranged in the constriction portion 136 of the heating chamber 104, that is the region having the greatest alternating electric field, when the cartridge 10 is connected to the heating chamber 104. The increased electric field strength in the second portion 124 increases the dielectric heating of the liquid aerosol-forming substrate in the liquid transport element 18, helping to generate aerosol more quickly. However, it will be appreciated that the liquid transport element 18 can be located at various points along the length of the protruding portion depending on the degree of heating required due to the above-mentioned distribution in the alternating electric field created in the heating chamber 104 by the constriction portion 136.

[0225] Figure 5 is a schematic cross-sectional view showing the interior of a cartridge 10 for an aerosol-generating system of the present disclosure in more detail. The cartridge 10 is similar to that of the aerosol-generating system 1 of Figure 1A and like reference numerals have been used to label like components.

[0226] The cartridge 10 comprises a cartridge body 12 having a liquid storage portion 14 configured to hold a liquid aerosol-forming substrate 15. The cartridge body 12 has a protruding portion 16 that extends downwardly from a lower surface of the cartridge body 12. The protruding portion 16 is hollow and contains liquid channels 17 that are in fluid communication with the liquid storage portion 14 in the cartridge body 12 so that liquid aerosolforming substrate 15 can fill the liquid channels 17. A liquid transport element 18 is arranged in the protruding portion 16 of the cartridge body 12. Opposing ends of the liquid transport element 18 extend into the liquid channels 17 so that the liquid transport element is in fluid communication with the liquid aerosol-forming substrate 15 in the liquid channels 17. The liquid transport element 18 comprises a porous or capillary material and liquid aerosol-forming substrate is transported through the liquid transport element 18 by capillary action. The liquid transport element 18 is configured to convey and hold liquid aerosol-forming substrate in a heating space of a dielectric heater of an aerosol-generating device.

[0227] The cartridge 10 further comprises an airflow channel 20 having an air inlet 22 at its distal end and an aerosol outlet 24 arranged in a mouthpiece 26 at a proximal or mouth end of the cartridge. The liquid transport element 18 extends from the liquid channels 17 across the airflow channel such that at least a portion of the liquid transport element 18 is arranged within the airflow channel 20 Accordingly, volatile compounds that are vaporized from the liquid aerosol-forming substrate held in the liquid transport element 18 during heating are entrained in the airflow though the airflow channel 20. The airflow channel 20 passes through the liquid storage portion 14 such that the liquid aerosol-forming substrate 15 is contained in an annular-shaped reservoir circumscribing the airflow channel 20.

[0228] Figure 6A and 6B are plan views showing two different configurations for the liquid transport element 18 of the cartridge 10 of Figure 5. In the configuration of Figure 6A, the liquid transport element 18 covers the entire cross-sectional area of the airflow channel 20. In this example, air passing through the airflow channel 20 has to pass through the porosity of the liquid transport element 18. The porosity of the liquid transport element 18 therefore helps to define the resistance to draw (RTD) of the cartridge 10 and aerosol-generating system. Different porosities can be used to achieve different RTDs.

[0229] In the configuration of Figure 6B, the liquid transport element 18 has a planar shape and only covers a portion of the cross-sectional area of the airflow channel 20. In this example, air passing through the airflow channel 20 can pass on either side of the liquid transport material. RTD can be defined by the non-obstructed open bypass space in the airflow channel 20 either side of the liquid transport element 18 or by the dimensions of the air inlet further upstream, for example, the air inlet in the aerosol-generating device 10 of Figure 1A. Although this example shows an airflow channel 20 having a circular lateral cross-section, any suitable geometric shape can be used. Figure 7 is a schematic perspective view of a cartridge 200 according to another example of the present disclosure. The cartridge 200 of Figure 7 has a similar construction to the cartridge 10 of Figure 5 with the exception that the overall shape of the cartridge is different, that is, the overall shape of the cartridge of Figure 7 is cuboid.

[0230] The cartridge 200 comprises a cartridge body 212 having a liquid storage portion 214 configured to hold a liquid aerosol-forming substrate 215. An airflow channel 220 passes through the liquid storage portion 214 and comprises an air inlet 222 at a distal end of the cartridge 200 and an aerosol outlet 224 arranged in a mouthpiece 226 at a proximal or mouth end of the cartridge 200. A planar liquid transport element 218 is arranged within the airflow channel 220 near the air inlet 222. Opposing ends of the liquid transport element 218 extend through the walls of the airflow channel 220 so that the liquid transport element is in fluid communication with the liquid aerosol-forming substrate 215 in the liquid storage portion 214. The liquid transport element 218 comprises a porous or capillary material and liquid aerosolforming substrate is transported through the liquid transport element 218 by capillary action. The liquid transport element 218 is configured to convey and hold liquid aerosol-forming substrate in a heating space of a dielectric heater of an aerosol-generating device.

[0231] The liquid transport element 218 extends across a portion of the cross-sectional area of the airflow channel 220. Accordingly, volatile compounds that are vaporized from the liquid aerosol-forming substrate held in the liquid transport element218 during heating are entrained in the airflow though the airflow channel 220. The cartridge 200 of Figure 7 does not have a protruding portion extending below the cartridge body like the cartridge 10 of Figure 5. Instead, the lower portion of the cartridge 200 containing the liquid transport element 218 is received within an aerosol-generating device (not shown) and the dielectric heater is configured to concentrate heating in the vicinity of the liquid transport element 218 that spans the airflow channel 220.

[0232] Figure 8A is a schematic cross-sectional view of an aerosol-generating system 3 comprising an aerosol-generating device 300 and a cartridge 10 according to another example of the present disclosure. The cartridge 10 is shown removed from the device 300. The aerosol-generating system 3 is configured to dielectrically heat a liquid aerosol-forming substrate contained in the cartridge 10.

[0233] The cartridge 10 of Figure 8A has the same construction as that of Figure 1A and like reference numerals have been used to label like components. In the interests of conciseness, the cartridge 10 will not be further described here. Please refer to the description of the cartridge 10 of Figure 1A above.

[0234] The aerosol-generating device of Figure 8A comprises an accommodation space 343 for removably accommodating the protruding portion 16 of the cartridge 10. The aerosol- generating device 300 comprises a dielectric heater in the form of a pair of opposing electrodes arranged near a proximal end of the aerosol-generating device 100 that can be fed with a high frequency voltage, for example a radio frequency (RF) voltage, to generate an alternating electric field therebetween. The pair of opposing electrodes comprises a first electrode 340 and a spaced apart opposing second electrode 342. The space 344 between the first 340 and second 342 opposing electrodes is configured to receive the protruding portion 16 of the cartridge 10 and defines a heating space for dielectrically heating a liquid aerosol-forming substrate. An opening 312 is provided in a proximal end of the aerosolgenerating device 300. The first 340 and second 342 electrodes are arranged below and to either side of the opening 312. The opening 312 is configured to allow the protruding portion 16 of the cartridge 10 to be received within the space 344.

[0235] The aerosol-generating device 300 further comprises a device housing 302 containing the first 340 and second 342 electrodes, a power supply 306 in the form of a battery and control circuitry 308. The control circuitry is configured to control the supply of power to the first 340 and second 342 electrodes. For example, the control circuitry 308 can comprise an alternating electric field generator in the form of an oscillation circuit for supplying the first 340 and second 342 electrodes via first 346 and second 348 electrical contacts with an alternating high-frequency voltage, to generate an alternating electric field between electrodes 340, 342. For example, the first 340 and second 342 electrodes can form part of a capacitor that is located in a feedback loop of the oscillation circuit. When power is supplied to the oscillation circuit, the oscillation circuit generates an alternating electric field across the first 340 and second 342 electrodes, which can be used to dielectrically heat a liquid aerosol-forming substrate.

[0236] The device housing 302 comprises an air inlet 318 to allow air to enter the aerosolgenerating device 300 when a user takes a puff. When the cartridge 10 is connected to the aerosol-generating device 300 (see Figure 8B), the air inlet 318 is in fluid communication with the aerosol outlet 24 of the cartridge 10 via the heating space 344 and air inlet 22 of the cartridge 10. A puff detector 320 is also provided for detecting when a user is taking a puff on the aerosol-generating system 3. In this example, the puff detector 320 is a pressure sensor and detects a reduction in air pressure within the aerosol-generating device 300 when a user inhales. However, it will be appreciated that any suitable type of puff detector could be used. The puff detector 320 is connected to the control circuitry 308, which is configured to provide an alternating electric field between the first 340 and second 342 electrodes in response to receiving a signal from the puff detector 320 indicating that a user is taking a puff.

[0237] Figure 8B shows the aerosol-generating system 3 of Figure 8A with the cartridge 10 attached or connected to the aerosol-generating device 300. When the cartridge 10 is connected to the aerosol-generating device 300, the protruding portion 16 of the cartridge 10 containing the liquid transport element 18 is received within the heating space 344 between the first 340 and second 342 electrodes such that the liquid aerosol-forming substrate contained within the liquid transport element 18 can be dielectrically heated.

[0238] In use, a user connects the cartridge 10 to the aerosol-generating device 300. When they want to take a puff on the aerosol-generating system 3, the user inhales on the mouthpiece 26. This causes air to be drawn in through air inlet 318 in device housing 302, through the heating space 344 between first 340 and second 342 electrodes and into the airflow channel 20 of the cartridge 10 via air inlet 22. The puff is detected by puff detector 320, which sends a signal to the control circuitry 308 that a puff is being taken. In response to the signal from the puff detector 320, the control circuitry 308 activates dielectric heating by providing an alternating electric field between the first 340 and second 342 electrodes. This heats the liquid aerosol-forming substrate contained within the liquid transport element located within the heating space 344 resulting in an aerosol being generated. The aerosol is entrained in the air flowing through the airflow channel 20 and exits the aerosol outlet 24 formed in the mouthpiece 26 and enters the user’s mouth.

[0239] Figure 9A is a schematic perspective view of a cartridge 400 according to another example of the present disclosure. The cartridge 400 of Figure 9A has a similar construction to the cartridge 10 of Figure 8A with the exception that the overall shape of the cartridge is cuboid and the cartridge 400 does not have a protruding portion holding a liquid transport element. The cartridge 400 can be configured to be used with the aerosol-generating device 300 of Figure 8A. The lower portion of the cartridge 400 containing the liquid transport element (not shown) is received within the aerosol-generating device 300.

[0240] The cartridge 400 comprises a cartridge body 412 having a liquid storage portion 414 configured to hold a liquid aerosol-forming substrate. An airflow channel 420 passes through the liquid storage portion 414. These components have the same function as in the cartridge 10 of Figure 8A and will not be described further here.

[0241] The cartridge 400 further comprises recesses 430 formed in two opposing external surfaces of the cartridge 400. The recesses extend from the distal end of the cartridge 400 and are sized to accommodate the first 340 and second 342 electrodes of the aerosolgenerating device 300 of Figure 8A. For the avoidance of doubt, the first 340 and second 342 electrodes shown in Figure 9A are not part of the cartridge 400 but are part of the aerosolgenerating device. The first 340 and second 342 electrodes of the aerosol-generating device are configured to slide into and out of recesses 430 formed in the cartridge 400 in the directions of arrow A in Figure 9A when the cartridge 400 is inserted into and removed from the aerosolgenerating device. Figure 9B is a plan cross-sectional view of the cartridge of Figure 9 along the line B-B in Figure 9A. As can be seen in Figure 9B, the liquid transport element 418 is substantially planar and has opposing ends that extend through the walls of the airflow channel 420 so that the liquid transport element 418 is in fluid communication with the liquid aerosol-forming substrate 415 in the liquid storage portion 214. The liquid transport element 418 extends across a portion of the cross-sectional area of the airflow channel 420 leaving spaces on either side of the liquid transport element 418 for air to flow past.

[0242] The recesses 430 for receiving the first 340 and second 342 electrodes (see Figure 9A) are arranged either side of the liquid transport element 418. The recesses 430 are arranged such that the first 340 and second 342 electrodes are in contact with, or in close proximity to, the inner faces 430a of the recesses 430, that is, as close to the liquid transport element 418 as possible. By using a substantially planar liquid transport 418 and thin airflow channel 420, the distance between the first 340 and second 342 electrodes can be reduced, thereby increasing the strength of the alternating electric field between the first 340 and second 342 electrodes. This helps to dielectrically heat the liquid aerosol-forming substrate 415 held in the liquid transport element 418 between the first 340 and second 342 electrodes.

[0243] In the example of Figure 9B, the distance d between the inner faces 430a of the recesses 430 and hence the approximate distance between the first 340 and second 342 electrodes is 1 millimetre. Referring to Figure 9A, the dimensions of the major faces of each of the first 340 and second 342 electrodes are approximately 3 millimetres by 3 millimetres and therefore the electrodes 340, 342 have a surface area of approximately 9 square millimetres. The surface area of the electrodes 340, 342 multiplied by their distance apart d defines a heating volume of the heating space between electrodes 340, 342. The electrical power supplied to the electrodes 340, 342 divided by the heating volume defines a power density that the aerosol-generating system is capable of providing. In the example of Figures 9A and 9B, the heating volume is approximately 9 cubic millimetres (mm3) and the aerosolgenerating system is configured to provide a power of approximately 10 watts. Therefore, the power density in the heating space between the first 340 and second 342 electrodes is approximately 1.1 kilowatts per cubic centimetre (kW / cm3) .

[0244] In the examples of Figures 8A and 9A, the first 340 and second 342 electrodes are part of the aerosol-generating device 300. However, it will be appreciated that the first 340 and second 342 electrodes could be part of the cartridge 10. In such an arrangement, the first 340 and second 342 electrodes would be fixed in the recesses 430 in the cartridge 400 and would connect to the control circuitry 308 via the first 346 and second 348 electrical contacts in the aerosol-generating device 300.

[0245] Figure 10A shows a schematic view of a cartridge 500 for use in an aerosol-generating system. The cartridge 500 has a cartridge body or main body 509 comprising a liquid-storage portion 510 and a protruding portion 520 extending from the main body 509, which acts as a dielectric heating portion of the cartridge 10. The liquid-storage portion 510 is configured to store a liquid aerosol-forming substrate 515. The cartridge 500 further comprises a liquid transport element 525 positioned between the liquid storage portion 510 and an airflow passage 530 leading to an aerosol outlet 535. In the embodiment of Figure 10A, the liquid transport element 525 is situated in the protruding portion 520 of the cartridge 500, with a portion of the liquid transport element 525 extending into the liquid storage portion 510 to assist in drawing liquid aerosol-forming substrate into the protruding portion 520 for heating within a heating cavity or heating space of an aerosol-generating device. In other embodiments, the liquid transport element 525 may be entirely situated within the protruding portion 520 of the cartridge 500. Cartridge 500 further comprises a mouthpiece portion 540 on the aerosol outlet 535 for a user to draw aerosol from the cartridge 500.

[0246] Figure 10B shows a schematic view of an aerosol-generating device 600 for coupling to or receiving the cartridge 500 of Figure 10A. Aerosol-generating device 600 comprises a body 610 housing a power supply and control electronics 620, an accommodation space for receiving the cartridge 500 and a heating chamber 640 for receiving the protruding portion 620 of the cartridge 600. In the example, the accommodation space comprises a cavity 650 for receiving the cartridge 500. The heating chamber 640 defines a heating space for dielectrically heating a liquid aerosol-forming substrate.

[0247] Figure 10C shows a schematic view of an aerosol-generating system 700 comprising the cartridge 500 of Figure 10A received within the cavity 650 of the aerosol-generation device 600 of Figure 10B. Surrounding the heating chamber 640 is a cavity coupled to a microwave generator and guiding system 630. The heating chamber 640 is configured to direct the generated microwaves into the heating chamber 640 to heat liquid aerosol-forming substrate 515 held in the liquid transport element 525 in the protruding portion 520 of the cartridge 500 to generate an aerosol. The aerosol-generating device 600 in Figure 10B comprises a mouthpiece portion 660 for a user to draw aerosol from the aerosol outlet 535 from the cartridge 500. The inlet of mouthpiece portion 660 is also fluidly coupled to a separate air inlet 670 on the aerosol-generating device 600 enabling the aerosol generated in the cartridge 500 to be combined with external air from outside the aerosol-generating device 600 in the mouthpiece portion 660.

[0248] Figure 11 A is a schematic cross-sectional view showing the aerosol flow path through the aerosol-generating system 700 of Figure 10C. In the cartridge 500, the protruding portion 520 is situated in a bottom portion of the cartridge 500 with an aerosol outlet 535 being located at an opposing top portion of the cartridge 500. The airflow passage 530 comprises an L or II bend from a surface of the liquid transport element 525 to direct aerosol generated in the protruding portion 520 back through the main body of the cartridge 500 through a tubular section of the airflow passage 530 towards the aerosol outlet 535 in the top portion of the cartridge 500.

[0249] Figure 11 B is a cross-sectional view of the protruding portion 520 of the cartridge 500 of Figure 11A taken along the line A-A’ in Figure 11A. The protruding portion 520 is shown inserted within the heating chamber 640 of the aerosol-generating device 600 of Figure 11A. The airflow passage 530 is eccentrically disposed within the protruding portion 520 so that it arranged at an opposite edge of the protruding portion 520 to the microwave generator and guiding system 630. The remaining space within the internal cross-sectional area of the protruding portion 520 is occupied by the liquid transport element 525. The liquid aerosolforming substrate contained in the liquid transport element 525 is heated by the microwaves generated by the microwave generator and guiding system 630, which enter the heating chamber 640 in the direction of arrow B in Figure 11 B.

[0250] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5 percent (5%) of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

1. Claims1. An aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate, the aerosol-generating system comprising: a cartridge comprising: a liquid storage portion for holding a liquid aerosol-forming substrate; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to a dielectric heating portion of the cartridge; an aerosol-generating device configured to be removably couplable to the cartridge, the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; and a dielectric heater for heating the liquid aerosol-forming substrate in the dielectric heating portion of the cartridge when the cartridge is coupled to the aerosolgenerating device.

2. An aerosol-generating system according to claim 1 , wherein the aerosol-generating device comprises a heating space for receiving the dielectric heating portion of the cartridge.

3. An aerosol-generating system according to claim 1 or 2, wherein the dielectric heater comprises the heating space.

4. An aerosol-generating system according to claim 3, wherein the dielectric heater comprises: a heating chamber having an interior defining the heating space for receiving the at least a portion of the liquid transport element; and a coupler configured to couple an alternating electric field generator to the interior of the heating chamber to provide an alternating electric field in the heating space.

5. An aerosol-generating system according to claim 4, wherein the heating chamber comprises a first region and a second region, the first region comprising a first dielectric having a first relative permittivity and the second region comprising a second dielectric having a second relative permittivity, the second relative permittivity being less than the first relative permittivity such that the strength of the alternating electric field is greater in the second region than in the first region.

6. An aerosol-generating system according to claim 4, wherein the heating chamber further comprises a constriction portion arranged at a point along the length of the interior of the heating chamber, the constriction portion having a reduced cross-sectional area such that the alternating electric field is concentrated in the constriction portion.

7. An aerosol-generating system according to claim 3, wherein the dielectric heater comprises at least one pair of opposing electrodes, the pair of opposing electrodes being spaced apart to define the heating space for receiving at least a portion of the liquid transport element.

8. An aerosol-generating system according to claim 7, wherein each one of the pair of opposing electrodes has a surface area between 4 square millimetres and 100 square millimetres.

9. An aerosol-generating system according to claim 7 or 8, wherein the pair of opposing electrodes are spaced apart by a distance of between 0.25 millimetres and 2 millimetres.

10. An aerosol-generating system according to any of claims 7 to 9, wherein the aerosolgenerating system is configured to provide a power density of between 50 watts per cubic centimetre and 10 kilowatts per cubic centimetre between the pair of opposing electrodes.11 An aerosol-generating system according to any preceding claim, further comprising an airflow channel having an aerosol outlet, wherein the at least a portion of the liquid transport element that is arranged to be received within the heating space is arranged within the airflow channel.

12. An aerosol-generating system according to any preceding claim, further comprising: a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater, the control circuitry comprising an alternating electric field generator.

13. An aerosol-generating system according to claim 12, wherein the control circuitry further comprises a puff detector for detecting when a user is taking a puff on the aerosolgenerating system, the control circuitry being configured to supply power to the dielectric heater in response to detecting a puff.

14. An aerosol-generating system according to claim 12 or 13, wherein the control circuitry is configured to provide a heating power in the range of 7 to 35 watts.

15. A cartridge for use with an aerosol-generating system for dielectrically heating a liquid aerosol-forming substrate, the cartridge comprising: a liquid storage portion for holding a liquid aerosol-forming substrate; a dielectric heating portion; and a liquid transport element for transporting liquid aerosol-forming substrate from the liquid storage portion to the dielectric heating portion.

16. A cartridge according to claim 15, wherein the dielectric heating portion comprises a protruding portion of the cartridge that extends from the liquid storage portion.

17. A cartridge according to claim 16, wherein the protruding portion comprises at least a portion of the liquid transport element.

18. A cartridge according to claim 16 or 17, further comprising a cartridge body, wherein the cartridge body comprises the liquid storage portion and protruding portion, the protruding portion extending from the liquid storage portion.

19. A cartridge according to any of claims 15 to 18, wherein the liquid transport element comprises a porous element for providing capillary flow of the liquid aerosol-forming substrate, the porous element having a relative permittivity of less than 5.

20. A cartridge according to any of claims 15 to 19, wherein the cartridge does not comprise a heater or heating element.

21. A cartridge according to any of claims 15 to 20, wherein the cartridge does not comprise any metallic components.

22. An aerosol-generating device for dielectrically heating a liquid aerosol-forming substrate, the aerosol-generating device being configured to be removably couplable to the cartridge according to any of claims 15 to 21 , the aerosol-generating device comprising: an accommodation space for removably accommodating at least a portion of the cartridge; a dielectric heater for heating the liquid aerosol-forming substrate in the dielectricheating portion of the cartridge when the cartridge is coupled to the aerosol-generating device; a power supply for supplying power to the dielectric heater; and control circuitry for controlling the supply of the power to the dielectric heater.

23. An aerosol-generating device according to claim 22, further comprising a heating space for receiving the dielectric heating portion of the cartridge.

24. An aerosol-generating device according to claim 22 or 23, wherein the dielectric heater comprises the heating space.

Images