Aerosol-generating device with heated mouthpiece

Abstract

The invention relates to an aerosol-generating device comprising a main body (12), a mouthpiece (14) with a peripheral wall (44) defining an airflow passage (38) and a cavity (22) for receiving a cartridge (16). The cavity (22) is arranged between the main body (12) and the mouthpiece (14). The peripheral wall (44) of the mouthpiece (14) comprises a surface heater (42). The invention also relates to an aerosol-generating system (10) comprising the aerosol-generating device and a cartridge (16).

Description

[0001] AEROSOL-GENERATING DEVICE WITH HEATED MOUTHPIECE

[0002] The present invention relates to an aerosol-generating device and to an aerosolgenerating system comprising the aerosol-generating device and a cartridge.

[0003] It is known to provide an aerosol-generating device for generating an inhalable vapor. Such devices may heat aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate are volatilised without burning the aerosolforming substrate. Aerosol-forming substrate may be provided as part of a cartridge. The cartridge together with the aerosol-generating device may form an aerosol-generating system. The cartridge may be received in a cavity, such as a heating chamber of the aerosol-generating device. A heating element may be arranged in or around the heating chamber for heating the aerosol-forming substrate once the cartridge is inserted into the heating chamber of the aerosol-generating device. The aerosol-generating device may comprise a mouthpiece for closing the cavity once the cartridge has been inserted into the cavity. During operation, aerosol may condensate downstream of the cartridge. Formation of condensates may take place in particular, if the generated aerosol is warmer than the ambient air and the device structures downstream from the heating chamber. Aerosol passing through the mouthpiece may encounter a temperature gradient at the cooler inner surfaces of the mouthpiece, which may lead to condensation of the aerosol. The condensed aerosol may travel along an inner side of the peripheral wall of the mouthpiece towards the mouthpiece outlet. This may result in unwanted contamination or leakage.

[0004] It would be desirable to have an aerosol-generating device that is configured to prevent excessive accumulation of condensate and residues in the mouthpiece. It would be desirable to have an aerosol-generating device offering an enhanced user experience. It would be desirable to have an aerosol-generating device offering a clean and pleasant user experience.

[0005] According to an embodiment of the invention there may be provided an aerosolgenerating device comprising a main body, a mouthpiece with a peripheral wall defining an airflow passage and a cavity for receiving a cartridge. The cavity may be arranged between the main body and the mouthpiece. The peripheral wall of the mouthpiece may comprise a surface heater.

[0006] According to an embodiment of the invention there is provided an aerosol-generating device comprising a main body, a mouthpiece with a peripheral wall defining an airflow passage and a cavity for receiving a cartridge. The cavity is arranged between the main body and the mouthpiece. The peripheral wall of the mouthpiece comprises a surface heater. By providing a surface heater in the peripheral wall of the mouthpiece condensation of aerosol may be reduced or avoided. The surface heater aims at increasing the temperature of a region of the mouthpiece, which corresponds to an area prone to condensate buildup during the operation of the aerosol-generating device. Accordingly, by incorporating a surface heater within the mouthpiece, the present invention addresses the challenges posed by temperature gradients between the warmer aerosol and the cooler inner surfaces of an aerosol-generating device. The proposed design effectively minimizes condensation on the inner walls of the mouthpiece, thereby reducing the likelihood of liquid accumulation and subsequent solute deposition. As a result, the device maintains optimal efficiency, ensures unobstructed aerosol flow, and enhances the overall user experience by preventing unpleasant odors from residue buildup.

[0007] The aerosol-generating device may comprise the main body and a mouthpiece.

[0008] The main body of the aerosol-generating device may comprise a power supply, preferably a battery, for powering a heating element of the aerosol-generating system.

[0009] The main body of the aerosol-generating device may comprise electric circuitry, preferably comprising a controller, for controlling the supply of electrical energy from the power supply to the heating element.

[0010] The cavity of the aerosol-generating device may be arranged at a proximal end of the main body. The cavity may have a hollow cylindrical shape. The cavity may have a circular cross-section. Alternatively, the cavity may have a rectangular or oval cross-section.

[0011] The main body may comprise an air inlet. The air inlet may be fluidly connected with the base of the cavity. When a user draws on the mouthpiece, ambient air may be drawn into an airflow channel of the aerosol-generating device through the air inlet. From the airflow channel running through the main body, the air may be drawn into the cavity at one or more apertures at the base of the cavity. This section of the cavity may be referred to as the main body outlet. When the cartridge is received in the cavity, the air may then be drawn into the cartridge through a cartridge inlet. The cartridge inlet may be arranged at a distal end of the cartridge. The air may then be drawn through the cartridge, particularly through the substrate storage of the cartridge and subsequently out of the cartridge through the cartridge outlet. The air then enters the mouthpiece, particularly through a mouthpiece inlet. The airflow channel may continue through the mouthpiece towards a mouthpiece outlet. The user may put his or her lips at the mouthpiece outlet to inhale the generated aerosol.

[0012] The mouthpiece of the aerosol-generating device may be arranged such that the mouthpiece may close the cavity. Closing the cavity may be performed after insertion of the cartridge into the cavity. In other words, the cartridge may be sandwiched between the main body of the aerosol-generating device and the closed mouthpiece of the aerosol-generating device after insertion of the cartridge into the cavity.

[0013] The mouthpiece may be connected to the main body. The mouthpiece may be hingedly connected to the main body. The mouthpiece may be opened in order to allow insertion of the cartridge into the cavity. The mouthpiece may be closed to lock the cartridge in place.

[0014] The mouthpiece may define a mouthpiece inlet and a mouthpiece outlet. The mouthpiece inlet may be in fluid communication with the cavity. The mouthpiece outlet may be configured for discharging an aerosol.

[0015] The cavity of the aerosol-generating device is configured for receiving the cartridge in use. The cartridge may comprise a cartridge inlet and the main body may comprise a main body outlet. The cartridge inlet may be fluidly connected with the main body outlet. The cartridge inlet may be formed by one or both of the proximal air openings and the distal air openings.

[0016] The cartridge may comprise a cartridge outlet. The cartridge outlet may be fluidly connected with the mouthpiece inlet. The cartridge outlet may be formed by one or both of the proximal air openings and the distal air openings.

[0017] The peripheral wall of the mouthpiece may be configured to circumscribe the mouthpiece. The peripheral wall of the mouthpiece may comprise an outer surface of the mouthpiece.

[0018] The surface heater may be disposed within the peripheral wall of the mouthpiece. In more detail, the surface heater may be disposed on an inner side of the peripheral wall of the mouthpiece. By providing the surface heater at an inner side of the peripheral wall of the mouthpiece efficient heating of the portion of the mouthpiece, which in use comes in contact with the aerosol, may be achieved.

[0019] The surface heater may be part of the peripheral wall. The surface heater may be formed embedded within the peripheral wall. The surface heater may be arranged inside of the peripheral wall.

[0020] The surface heater may comprise a heated element. The heated element may have different forms depending on the specific heating method used.

[0021] The surface heater of the mouthpiece may be a resistive heater. The resistive heater may comprise a resistive heating element. The resistive heater may comprise a plurality of resistive heating elements. In this case the heated element is formed by the one or more resistive heater elements. The one or more resistive heating elements may be designed with a meandering pattern. The one or more resistive heating elements may extend evenly across the heated area of the peripheral wall of the mouthpiece. By configuring the one or more resistive heating elements to extend evenly across the heated area of the peripheral wall of the mouthpiece, a homogeneous heating of the mouthpiece may be achieved. In particular it may be avoided that cold spots which are not sufficiently heated are generated. Such cold spots are undesired since they may specifically lead to condensation of the warm aerosol.

[0022] The one or more resistive heating elements may be configured as thin filaments, strips, layers or wires. The controller may be configured to provide electrical power from the power source of the aerosol-generating device to energize the one or more resistive heating elements.

[0023] The resistive heater may comprise a contact portion to connect the resistive heater to a power source in the main body. The contact portion of the resistive heater may be configured to be engaged with a corresponding contact portion of the main device. The main device contact portion may be electrically connected to the power source of the main device. When the mouthpiece is attached to the main device and when the mouthpiece is closed to lock the cartridge in place, the contact portion of the resistive heater may be coupled with the corresponding contact portion of the main device to connect the resistive heater of the mouth piece to the power source of the main device.

[0024] The surface heater may also be configured as an inductive heater. An inductive heater may comprise an induction coil and a susceptor provided in the peripheral wall of the mouthpiece.

[0025] In an inductive heater the susceptor surface represents the heating element in which heat is generated. The susceptor may therefore advantageously be disposed on an inner side of the peripheral wall of the mouthpiece. By providing the susceptor at an inner side of the peripheral wall of the mouthpiece efficient heating of the portion of the mouthpiece, which in use comes in contact with the aerosol, may be achieved. The susceptor may comprise one or more susceptor elements. The heated element of an inductive heater is formed by the one or more susceptor elements.

[0026] The induction coil may be located in vicinity to the susceptor. Advantageously the induction coil is located in a radial direction outwardly from the susceptor in the peripheral wall of the mouthpiece.

[0027] The induction heater may comprise a contact portion to connect the induction coil of the induction heater to a power source in the main body. The contact portion of the induction heater may be configured to be engaged with a corresponding contact portion of the main device. The main device contact portion may be electrically connected to the power source of the main device. When the mouthpiece is attached to the main device and when the mouthpiece is closed to lock the cartridge in place, the contact portion of the induction heater may be coupled with the corresponding contact portion of the main device to connect the induction coil of the inductive heater of the mouth piece to the power source of the main device. In embodiments the aerosol-generating device may be configured to be operated with a heated cartridge. The aerosol-generating device may further be configured to comprise a surface heater that is configured as a conductive heater. A conductive heater may be configured to receive heat from the heated cartridge. In such embodiments, heat generated in or at the cartridge may be thermally conducted to the mouthpiece.

[0028] The conductive heater may comprise a heat conductive element. The heat conductive element may be configured to capture residual heat emitted from the heated cartridge.

[0029] The conductive heater may comprise a thermal bridge. The thermal bridge may extend between the heat conductive element in the peripheral wall of the mouthpiece and the cavity of the main device in which the cartridge is heated.

[0030] The thermal bridge may comprise a plurality of thermally conductive components extending between the heat conductive element and the cartridge. The conductive components may be configured as metallic coatings or as a set of metallic plates. The conductive components may extend along a wall portion of the cavity of the aerosol-generating device.

[0031] The conductive components may be configured to absorb heat released from the cartridge. The heat conductive element and the thermally conductive components of the thermal bridge may be made from materials with a high thermal conductivity. The heat conductive element and the thermally conductive components of the thermal bridge be configured to comprise additional thermal insulation shielding material to achieve a more efficient heat transfer.

[0032] The heat conductive element in the peripheral wall of the mouthpiece may be configured to function as a heat sink. The temperature of the heat conductive element may be lower than the temperature at the cavity comprising the heated cartridge. Accordingly, thermal energy may flow from the heated cartridge via the thermal bridge towards the heat conductive element.

[0033] The heated element of a conductive heater is formed by the one or more heat conductive elements.

[0034] An aerosol-generating device comprising a mouthpiece that is exclusively heated by a conduction heater as described above, may have a reliable and simple mechanical structure. In particular, such aerosol-generating device does not require any releasable electrical contacts between the mouthpiece and the main body.

[0035] A conductive heater may be employed additionally or alternatively to a resistive heater or to an inductive heater.

[0036] The mouthpiece may be made from suitable materials. The mouthpiece may be made from materials such as metals, alloys, plastics or composite materials containing one or more of those materials, or ceramics. The plastics materials may include thermoplastics that are suitable for food or pharmaceutical applications, for example, polypropylene, polyetheretherketone (PEEK) and polyethylene.

[0037] The peripheral wall of the mouthpiece may have a layered structure. The individual layers of the mouthpiece may be configured to fulfil different technical objectives.

[0038] These layers may include an outermost structural layer. The outermost structural layer may be the layer that comes into contact with the user’s lips. The outermost structural layer may be made from materials, such as metals, alloys, plastics or composite materials containing one or more of those materials, or ceramics. The plastics materials may include thermoplastics that are suitable for food or pharmaceutical applications, for example, polypropylene, polyetheretherketone (PEEK) and polyethylene.

[0039] The layers of the mouthpiece may include a thermally insulating layer. A thermally insulating layer may be useful to protect the user from excessive heat generated by the surface heater of the mouthpiece. Suitable materials for the thermally insulating layer include but are not limited to materials, such as polyurethane, polyethylene (PE), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), glass, ceramics, and metallic alloys.

[0040] A thermally insulating layer of the peripheral wall of the mouthpiece may comprise a chambered structure forming thermally insulating air gaps. Since air is a good thermal insulator, such structure may enhance the thermal insulation capabilities of the thermally insulating layer. In particular, the insulating layer of the peripheral wall of the mouthpiece may be configured to reduce heat transfer from the heated element to the outermost structural layer.

[0041] The mouthpiece may further comprise a support layer. A support layer may be used to support the heated element of the mouthpiece. Suitable materials for the support layer include but are not limited to dielectric materials, such as polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE or PTFCE) and polyetheretherketone.

[0042] The mouthpiece may further comprise an interface layer. An interface layer may have heat dissipative properties to enhance heat transfer from the heated element. An interface layer may be made from dielectric materials. Such dielectric materials may be useful to electrically insulate the heated element from the environment. In particular the interface layer may be used to electrically insulate the heated element from the airflow passage defined in the mouthpiece. Suitable materials for the interface layer comprise but are not limited to dielectric materials such as polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE or PTFCE) and polyetheretherketone. The support layer and the interface layer may be made from dielectric materials for encapsulating the heated element. Such design can be generally manufactured by depositing a metal layer onto a dielectric thin film support, etching the metal layer into the desired pattern, applying another layer of dielectric thin film over the etched heated element, and then heat pressing to seal the heated element within the dielectric layers.

[0043] The layered structure of the mouthpiece may comprise an outermost structural layer, an insulating layer, a support layer holding the heated element, and an innermost layer interfacing with the airflow passage.

[0044] The peripheral wall of the mouthpiece may further comprise a temperature sensor. The temperature sensor may be connected to a controller of the aerosol-generating device. The temperature sensor may be configured to detect a temperature of the inner side of the peripheral wall of the mouthpiece.

[0045] Upon detection, the temperature sensor may generate an electrical signal that can be transmitted to the controller via a suitable electric terminal. The controller may process the received electrical signal to determine the current temperature of the inner side of the peripheral wall of the mouthpiece.

[0046] The controller may be configured to adjust power output to the surface heater of the mouthpiece based on the temperature detected with the temperature sensor. If the detected temperature is lower than a predetermined threshold temperature, the controller may increase the power supply to the surface heater. Conversely, if the temperature is above a desired upper temperature threshold, the controller may be configured to decrease the supply of electrical power to the surface heater. Accordingly, providing a temperature sensor within or at the peripheral wall of the mouthpiece allows to maintain the mouthpiece temperature within a temperature range in which condensation built-up along the inner side of the mouthpiece is reduced or even prevented. The inclusion of a temperature sensor that communicates with the controller allows for real-time adjustments of the temperature of the mouthpiece. If the detected temperature is outside a desired range, the controller may adjust the power output to the surface heater, ensuring optimal conditions within the mouthpiece.

[0047] The cartridge may have a length. The length may be measured along the longitudinal central axis of the cartridge. The length may be measured from a proximal end of the cartridge to a distal end of the cartridge.

[0048] The cartridge may have a width. The width of the cartridge may be measured perpendicular to the length of the cartridge.

[0049] The cartridge may have a thickness. The thickness of the cartridge may be measured perpendicular to the length of the cartridge and perpendicular to the width of the cartridge.

[0050] The width of the cartridge may be larger than the thickness of the cartridge. The cartridge may be configured as a replaceable cartridge. In other words, the cartridge may be provided as external to the aerosol-generating device so that the cartridge can be received by the aerosol-generating device, more particularly by the cavity of the aerosol-generating device. After the cartridge is spent, the spent cartridge can be removed from the cavity of the aerosol-generating device and a fresh cartridge can be inserted into the cavity of the aerosol-generating device.

[0051] The cartridge may comprise a substrate storage portion. The substrate storage portion may be fluidly connected with the cartridge outlet.

[0052] The heating element may be arranged in the cartridge. The heating element may be arranged in the cartridge in order to heat the aerosol-forming substrate also arranged in the cartridge.

[0053] The electrical contacts of the cartridge may electrically contact the heating element. The electrical contacts may be arranged on the housing of the cartridge. When the cartridge is received in the cavity of the aerosol-generating device, the electrical contacts of the cartridge may electrically contact corresponding electrical contacts of the aerosol-generating device, preferably of a main body of the aerosol-generating device. The electrical contacts of the aerosol-generating device may be electrically contacted with the power supply of the aerosolgenerating device. In this way, when the cartridge is received in the cavity, the power supply of the aerosol-generating device can power the heating element of the cartridge.

[0054] The heating element may be configured as a resistive heating element. The heating element may comprise heating tracks. The heating tracks may be arranged in a wound, coiled, zigzag or spiral pattern.

[0055] Alternatively, the heating element may be configured as an inductive heating element. In case of being an inductive heating element, the heating element may comprise an induction coil. Potentially, the heating element may further comprise a susceptor element which may be heated by eddy currents induced by an alternating current running through the induction coil. The susceptor element in this case may be arranged inside of the induction coil. The susceptor element may be provided in the cartridge while the induction coil may be provided in the aerosol-generating device, particularly the main body of the aerosol-generating device. Alternatively, both the susceptor element as well as the induction coil may be provided in the cartridge.

[0056] The cartridge may be configured as described in one of WO2022154863, WO2022154869 and WO2021262266, which are incorporated herein by reference. Specifically, cartridge dimensions and internal volumes as described in one of WO2022154863, WO2022154869 and WO2021262266, which are incorporated herein by reference. The cartridge may be configured as a replaceable cartridge. The cartridge may comprise a substrate storage for holding the aerosol-forming substrate.

[0057] The aerosol-forming substrate may be as described in one of WO2022154863, WO2022154869 and WO2021262266, which are incorporated herein by reference.

[0058] The aerosol-forming substrate may be solid. The aerosol-forming substrate may comprise tobacco, preferably consist of tobacco. The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may contain an aerosol former, preferably glycerin.

[0059] Alternatively, the aerosol-forming substrate may be liquid or gel-like. Also in this case, the aerosol-forming substrate may comprise one or more of tobacco, nicotine and an aerosol former, preferably glycerin.

[0060] The aerosol-forming substrate may be held in a matrix. The matrix may be arranged within the substrate storage. The matrix may comprise, preferably consists of, a capillary material.

[0061] As used herein, the terms ‘proximal’, ‘distal’, ‘downstream’ and ‘upstream’ are used to describe the relative positions of components, or portions of components, of the aerosolgenerating device in relation to the direction in which a user draws on the aerosol-generating device during use thereof.

[0062] The aerosol-generating device may comprise a mouth end through which in use an aerosol exits the aerosol-generating device and is delivered to a user. The mouth end may also be referred to as the proximal end. In use, a user draws on the proximal or mouth end of the aerosol-generating device in order to inhale an aerosol generated by the aerosolgenerating device. The mouth end may be part of the mouthpiece. The aerosol-generating device comprises a distal end opposed to the proximal or mouth end. The proximal or mouth end of the aerosol-generating device may also be referred to as the downstream end and the distal end of the aerosol-generating device may also be referred to as the upstream end. Components, or portions of components, of the aerosol-generating device may be described as being upstream or downstream of one another based on their relative positions between the proximal, downstream or mouth end and the distal or upstream end of the aerosolgenerating device.

[0063] As used herein, an ‘aerosol-generating device’ relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of a cartridge. An aerosol-generating device may be a smoking device that interacts with an aerosol-forming substrate of a cartridge to generate an aerosol that is directly inhalable into a user’s lungs through the user's mouth. An aerosol-generating device may be a holder. The device may be an electrically heated smoking device. The aerosol-generating device may comprise a housing, electric circuitry, a power supply and a heating chamber. As used herein with reference to the present invention, the term ‘smoking’ with reference to a device, article, system, substrate, or otherwise does not refer to conventional smoking in which an aerosol-forming substrate is fully or at least partially combusted. The aerosol-generating device of the present invention is arranged to heat the aerosol-forming substrate to a temperature below a combustion temperature of the aerosol-forming substrate, but at or above a temperature at which one or more volatile compounds of the aerosol-forming substrate are released to form an inhalable aerosol.

[0064] The aerosol-generating device may comprise electric circuitry. The electric circuitry may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electric circuitry may comprise further electronic components. The electric circuitry may be configured to regulate a supply of power to the heating element. The heating element may be part of the cartridge. Power may be supplied to the heating element continuously following activation of the aerosol-generating device or may be supplied intermittently, such as on a puff-by-puff basis. The power may be supplied to the heating element in the form of pulses of electrical current. The electric circuitry may be configured to monitor the electrical resistance of the heating element, and preferably to control the supply of power to the heating element dependent on the electrical resistance of the heating element.

[0065] The aerosol-generating device may comprise a power supply, typically a battery, within a main body of the aerosol-generating device. In one embodiment, the power supply is a Lithium-ion battery. Alternatively, the power supply may be a Nickel-metal hydride battery, a Nickel cadmium battery, or a Lithium based battery, for example a Lithium-Cobalt, a Lithium- Iron-Phosphate, Lithium Titanate or a Lithium-Polymer battery. As an alternative, the power supply may be another form of charge storage device such as a capacitor. The power supply may require recharging and may have a capacity that enables to store enough energy for one or more usage experiences; for example, the power supply may have sufficient capacity to continuously generate aerosol for a period of around six minutes or for a period of a multiple of six minutes. In another example, the power supply may have sufficient capacity to provide a predetermined number of puffs or discrete activations of the heating element.

[0066] The cavity of the aerosol-generating device may have an open end into which the cartridge is inserted. The open end may be a proximal end. The cavity may have a closed end opposite the open end. The closed end may be the base of the cavity. The closed end may be closed except for the provision of air apertures arranged in the base. The base of the cavity may be flat. The base of the cavity may be circular. The base of the cavity may be arranged upstream of the cavity. The open end may be arranged downstream of the cavity. The cavity may have an elongate extension. The cavity may have a longitudinal central axis. A longitudinal direction may be the direction extending between the open and closed ends along the longitudinal central axis. The longitudinal central axis of the cavity may be parallel to the longitudinal axis of the aerosol-generating device.

[0067] The cavity may be configured as a heating chamber. The cavity may have a cylindrical shape. The cavity may have a hollow cylindrical shape. The cavity may have a shape corresponding to the shape of the aerosol-generating article to be received in the cavity. The cavity may have a circular cross-section. The cavity may have an elliptical or rectangular crosssection. The cavity may have an inner diameter corresponding to the outer diameter of the aerosol-generating article.

[0068] An airflow channel may run through the cavity. Ambient air may be drawn into the aerosol-generating device, into the cavity and towards the user through the airflow channel. Downstream of the cavity, the mouthpiece may be arranged. The airflow channel may extend through the mouthpiece.

[0069] In any of the aspects of the disclosure, the heating element of the cartridge and / or the heating element of the mouthpiece may comprise an electrically resistive material. Suitable electrically resistive materials include but are not limited to: semiconductors such as doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys and composite materials made of a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum platinum, gold and silver. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminium- titaniumzirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese- , gold- and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel, Timetai® and iron-manganese-aluminium based alloys. In composite materials, the electrically resistive material may optionally be embedded in, encapsulated or coated with an insulating material or vice-versa, depending on the kinetics of energy transfer and the external physicochemical properties required.

[0070] As described, in any of the aspects of the disclosure, the heating element may be part of a cartridge. The cartridge may comprise an internal heating element or an external heating element, or both internal and external heating elements, where "internal" and "external" refer to the aerosol-forming substrate. An internal heating element may take any suitable form. For example, an internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different electro-conductive portions, or an electrically resistive metallic tube. Alternatively, the internal heating element may be one or more heating needles or rods that run through the center of the aerosol-forming substrate. Other alternatives include a heating wire or filament, for example a Ni-Cr (Nickel-Chromium), platinum, tungsten or alloy wire or a heating plate. Optionally, the internal heating element may be deposited in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material, such as ceramic material, and then sandwiched in another insulating material, such as a glass. Heaters formed in this manner may be used to both heat and monitor the temperature of the heating elements during operation.

[0071] An external heating element, which is particularly preferred, may take any suitable form. For example, an external heating element may take the form of one or more flexible heating foils or tracks on a dielectric substrate, such as polyimide. The flexible heating foils or tracks can be shaped to conform to the perimeter of the substrate receiving cavity. Alternatively, an external heating element may take the form of a metallic grid or grids, a flexible printed circuit board, a molded interconnect device (MID), ceramic heater, flexible carbon fibre heater or may be formed using a coating technique, such as plasma vapour deposition, on a suitable shaped substrate. An external heating element may also be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of suitable insulating materials. An external heating element formed in this manner may be used to both heat and monitor the temperature of the external heating element during operation.

[0072] As an alternative to an electrically resistive heating element, the heating element of the mouthpiece or of the cartridge may be configured as an induction heating element. The induction heating element may comprise an induction coil and a susceptor. In general, a susceptor is a material that is capable of generating heat, when penetrated by an alternating magnetic field. If the susceptor is conductive, then typically eddy currents are induced by the alternating magnetic field. If the susceptor is magnetic, then typically another effect that contributes to the heating is commonly referred to hysteresis losses. Hysteresis losses occur mainly due to the movement of the magnetic domain blocks within the susceptor, because the magnetic orientation of these will align with the magnetic induction field, which alternates. Another effect contributing to the hysteresis loss is when the magnetic domains will grow or shrink within the susceptor. Commonly all these changes in the susceptor that happen on a nano-scale or below are referred to as “hysteresis losses”, because they produce heat in the susceptor. Hence, if the susceptor is both magnetic and electrically conductive, both hysteresis losses and the generation of eddy currents will contribute to the heating of the susceptor. If the susceptor is magnetic, but not conductive, then hysteresis losses will be the only means by which the susceptor will heat, when penetrated by an alternating magnetic field. According to the invention, the susceptor may be electrically conductive or magnetic or both electrically conductive and magnetic. An alternating magnetic field generated by one or several induction coils heat the susceptor, which then transfers the heat to the aerosol-forming substrate, such that an aerosol is formed. The heat transfer may be mainly by conduction of heat. Such a transfer of heat is best, if the susceptor is in close thermal contact with the aerosol-forming substrate.

[0073] As used herein, the term ‘cartridge’ refers to an element comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, a cartridge may be a smoking cartridge that generates an aerosol that is directly inhalable into a user’s lungs through the user's mouth. A cartridge may be disposable.

[0074] As used herein, the term ‘aerosol-forming substrate’ relates to a substrate capable of releasing one or more volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. An aerosol-forming substrate may conveniently be part of an aerosol-generating article or smoking article.

[0075] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosolforming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds which are released from the substrate upon heating. The aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may comprise an aerosol former that facilitates the formation of a dense and stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0076] The aerosol-generating substrate preferably comprises homogenised tobacco material, an aerosol-former and water. Providing homogenised tobacco material may improve aerosol generation, the nicotine content and the flavour profile of the aerosol generated during heating of the aerosol-generating article. Specifically, the process of making homogenised tobacco involves grinding tobacco leaf, which more effectively enables the release of nicotine and flavours upon heating.

[0077] The present invention also relates to an aerosol-generating system comprising an aerosol-generating device as described herein and a cartridge configured to be received in the cavity of the aerosol-generating device.

[0078] The cartridge may comprise an aerosol-forming substrate. The cartridge may comprise a heating element. The heating element of the cartridge may be configured to heat the aerosolforming substrate of the cartridge. The heating element of the cartridge may be provided in addition to the surface heater of the peripheral wall of the mouthpiece. 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.

[0079] Example 1 . An aerosol-generating device comprising: a main body, a mouthpiece with a peripheral wall defining an airflow passage and a cavity for receiving a cartridge, the cavity being arranged between the main body and the mouthpiece, wherein the peripheral wall of the mouthpiece comprises a surface heater.

[0080] Example 2. The aerosol-generating device according to example 1 , wherein the mouthpiece defines a mouthpiece inlet and a mouthpiece outlet.

[0081] Example 3. The aerosol-generating device according to example 2, wherein the mouthpiece inlet is in fluid communication with the cavity.

[0082] Example 4. The aerosol-generating device according to any one of examples 2 and 3, wherein the mouthpiece outlet is configured for discharging an aerosol.

[0083] Example 5. The aerosol-generating device according to any one of the preceding examples, wherein the surface heater is disposed within the peripheral wall of the mouthpiece.

[0084] Example 6. The aerosol-generating device according to any one of the preceding examples, wherein the surface heater is disposed on an inner side of the peripheral wall of the mouthpiece.

[0085] Example 7. The aerosol-generating device according to any one of the preceding examples, wherein the surface heater is a resistive heater.

[0086] Example 8. The aerosol-generating device according to any one of the preceding examples, wherein the resistive heater comprises a resistive heating element.

[0087] Example 9. The aerosol-generating device according to any one of the preceding examples, wherein the resistive heating element extends evenly across the heated area of the peripheral wall of the mouthpiece.

[0088] Example 10. The aerosol-generating device according to any one of the preceding examples, wherein the resistive heating element is designed with a meandering pattern.

[0089] Example 11. The aerosol-generating device according to any one of the preceding examples, wherein the resistive heater comprises a plurality of resistive heating elements.

[0090] Example 12. The aerosol-generating device according to example 11 , wherein the resistive heating elements are configured as thin filaments, strips, layers or wires. Example 13. The aerosol-generating device according to any one of the preceding examples, wherein the resistive heater comprises a contact portion to connect the resistive heater to a power source in the main body.

[0091] Example 14. The aerosol-generating device according to any one of the preceding examples, wherein the surface heater is configured as an inductive heater.

[0092] Example 15. The aerosol-generating device according to example 14, wherein the inductive heater comprises an induction coil and a susceptor provided in the peripheral wall of the mouthpiece.

[0093] Example 16. The aerosol-generating device according to example 15, wherein the induction coil is located radially outwardly from the susceptor in the peripheral wall of the mouthpiece.

[0094] Example 17. The aerosol-generating device according to any one of the preceding examples, wherein the aerosol-generating device is configured to operate with a heated cartridge and wherein the surface heater is configured as a conductive heater.

[0095] Example 18. The aerosol-generating device according to example 17, wherein the conductive heater comprises a heat conductive element, wherein the heat conductive element is configured to capture residual heat emitted from the heated cartridge.

[0096] Example 19. The aerosol-generating device according to example 18, wherein the conductive heater comprises a thermal bridge extending between the heat conductive element in the peripheral wall of the mouthpiece and the cavity of the main device in which the cartridge is heated.

[0097] Example 20. The aerosol-generating device according to any one of examples 17 to 19, wherein the heat conductive element in the peripheral wall of the mouthpiece functions as a heat sink.

[0098] Example 21. The aerosol-generating device according to any one of the preceding examples, wherein the peripheral wall of the mouthpiece has a layered structure.

[0099] Example 22. The aerosol-generating device according to example 21 , wherein the layered structure comprises an outermost structural layer, an insulating layer, a support layer holding the heated element, and an innermost layer interfacing with the airflow passage.

[0100] Example 23. The aerosol-generating device according to example 22, wherein the insulating layer of the peripheral wall of the mouthpiece is configured to reduce heat transfer from the heated element to the outermost structural layer.

[0101] Example 24. The aerosol-generating device according to examples 22 or 23, wherein the insulating layer of the peripheral wall of the mouthpiece comprises a chambered structure forming thermally insulating air gaps. Example 25. The aerosol-generating device according to examples 21 to 24, wherein the innermost layer in the mouthpiece comprises dielectric material encapsulating the heated element.

[0102] Example 26. The aerosol-generating device according to any one of the preceding examples, wherein the peripheral wall of the mouthpiece comprises a temperature sensor.

[0103] Example 27. The aerosol-generating device according to any one of the preceding examples, wherein the temperature sensor is connected to a controller of the aerosolgenerating device.

[0104] Example 28. The aerosol-generating device according to any one of the preceding examples, wherein the controller is configured to adjust power output to the surface heater of the mouthpiece based on the temperature detected with the temperature sensor.

[0105] Example 29. The aerosol-generating device according to any of the preceding examples, wherein the mouthpiece is configured to be arranged covering the cavity to enclose the cartridge, when the cartridge is received in the cavity.

[0106] Example 30. The aerosol-generating device according to any of the preceding examples, wherein the mouthpiece is hingedly connected to the main body.

[0107] Example 31. The aerosol-generating device according to any of the preceding examples, wherein the mouthpiece is configured to be removably attached to the main body.

[0108] Example 32. An aerosol-generating system comprising an aerosol-generating device according to any of the preceding examples, and a cartridge configured to be received in the cavity of the aerosol-generating device.

[0109] Features described in relation to one embodiment may equally be applied to other embodiments of the invention.

[0110] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0111] Fig. 1 shows a sectional side view of an aerosol-generating system comprising an aerosol-generating device and a removable cartridge;

[0112] Fig. 2 shows a proximal section of the aerosol-generating device with a closed mouthpiece;

[0113] Fig. 3 shows a sectional side view of an aerosol-generating device with a mouthpiece comprising a resistive heating element;

[0114] Fig. 4 shows a plan cross-sectional view through the mouthpiece of Fig. 3;

[0115] Fig. 5 shows a sectional side view of an aerosol-generating device with a mouthpiece comprising an inductive heating element; and Fig. 6 shows a sectional side view of an aerosol-generating device with a mouthpiece comprising a conductive heating element.

[0116] Figure 1 shows an aerosol-generating system 10 comprising an aerosol-generating device. The aerosol generating device comprises a main body 12 and the mouthpiece 14. The aerosol-generating system 10 further comprises a cartridge 16.

[0117] The main body 12 of the aerosol-generating device comprises a power supply 18 in the form of a battery and a controller 20 for controlling the supply of electrical energy from the power supply 18 to the cartridge 16. More specifically, the power supplied from the power supply 18 to the heating element (not shown in Figure 1) of the cartridge 16.

[0118] The cartridge 16 can be inserted into a cavity 22 of the main body 12 of the aerosolgenerating device. The cavity 22 is arranged at a proximal end of the main body 12.

[0119] The mouthpiece 14 is hingedly connected with the main body 12. When the cartridge 16 is inserted into the cavity 22 of the main body 12, the mouthpiece 14 may be closed so that the cartridge 16 is sandwiched between the main body 12 and the mouthpiece 14.

[0120] The closed configuration of the mouthpiece 14 is shown in Figure 2. The cartridge 16 is received in the cavity 22 of the main body 12. Further, the mouthpiece 14 closes off the proximal end of the cartridge 16.

[0121] At a base 24 of the cavity 22, a main body outlet 26 is arranged. The main body outlet 26 allows airflow into the cavity 22. The main body outlet 26 is fluidly connected with an airflow channel (not shown) of the main body 12 which, in turn, is fluidly connected with an air inlet (not shown) of the main body 12 allowing ambient air to be drawn into the main body 12 and into the cavity 22.

[0122] The main body outlet 26 is fluidly connected with a cartridge inlet 28. Hence, ambient air can be drawn into the cartridge 16 via the cartridge inlet 28. The cartridge inlet 28 is arranged at a distal end of the cartridge 16.

[0123] The cartridge 16 comprises aerosol-forming substrate. The aerosol-forming substrate is arranged in the cartridge chamber.

[0124] After travelling through the cartridge 16, the vaporized aerosol-forming substrate entrained in the airflow exits the cartridge 16 via a cartridge outlet 30. The cartridge outlet 30 is arranged at a proximal end of the cartridge 16.

[0125] The cartridge 16 further comprises a heating element (not shown) for heating the aerosol-forming substrate of the cartridge 16 so that the aerosol-forming substrate can be vaporized.

[0126] Downstream of the cartridge outlet 30, the air 32 enters a mouthpiece inlet 34 and travels through the mouthpiece 14. At a proximal end of the mouthpiece 14, the aerosol exits the mouthpiece 14 at the mouthpiece outlet 36 for inhalation by a user. An air passage 38 is defined in the mouthpiece 14 between the mouthpiece inlet 34 and the mouthpiece outlet 36.

[0127] Figure 3 shows a cross-sectional of an aerosol-generating device with a mouthpiece 14 comprising a resistive heater 40. The resistive heater comprises a heated element in form of resistive heating element 42 that is disposed within an inner side 46 of the peripheric wall 44 of the mouthpiece 14. The resistive heating element 42 is designed with a meandering pattern traced to surround the inner side 46 of the peripheric wall 44 of the mouthpiece 14. The formation of consistent gaps between neighbouring sections of the meandering pattern prevents excessive heating in specific areas of the mouthpiece 14. Moreover, the regular meandering pattern allows for homogeneous heating of the inner side 46 of the peripheric wall 44 of the mouthpiece 14.

[0128] Electric wiring 48 connects the resistive heater 40 to an electric contact portion 50 of the mouthpiece 14. In the closed configuration shown in Fig. 3, the electric contact portion 50 of the mouthpiece 14 couples with a corresponding electrical connection portion 52 on the main housing 12. In this way an electrical communication of the resistive heater 40 with the power source 18 and the control unit 20 of the main device 12 is established.

[0129] Fig. 4 shows a plan cross-sectional view through the mouthpiece along line A-A of Fig. 3. As depicted in Fig. 4 the peripheral wall 44 of the mouthpiece 14 is formed from a plurality of individual layers. The resistive heater 40 is formed embedded within the layered structure of the peripheral wall 44 of the mouthpiece 14.

[0130] In the exemplary configuration of the mouthpiece depicted in Fig. 4 the peripheral wall 44 comprises a total of four layers, namely an outermost structural layer 60, an insulating layer 62, a support layer 64 holding the resistive heater 40 and an innermost layer 66 interfacing with the aerosol travelling through the air passage 38 defined by the mouthpiece 14.

[0131] The outermost structural layer 60 is formed from food grade polyetheretherketone (PEEK).

[0132] The insulating layer 62 is formed from polyethylene terephthalate (PET) and prevents heat generated by the resistive heater 40 from being transferred to the outer structural layer 60, which typically contacts the lips of a user.

[0133] The support layer 64 is formed from polytetrafluoroethylene (PTFE). The resistive heater comprises a resistive heating element 42 in the form of a meandering, metallic track that is deposited onto the support layer 64.

[0134] The interface layer 66 is formed from a dielectric thin film that is applied on the support layer 64 holding the resistive heater 40. The interface layer 66 prevents the resistive heater 40 from contact with the aerosol flowing through the aerosol passage 38 formed by the mouthpiece 14. In Fig. 5 an alternative embodiment of a heated mouthpiece 14 for an aerosolgenerating device is depicted. The mouthpiece 14 of this aerosol-generating device comprises also a layered structure. The surface heater of the mouthpiece 14 is formed as an inductive heater 70. The structure of the mouthpiece 14 is similar to the structure as described with Fig. 4. However instead of the resistive heating element 42, the heated element is formed from an array of susceptors 72 made from metallic material that is provided in the layer structure of the mouthpiece 14. Embedded within the mouthpiece 14 and located in a radial direction outwardly from the array of susceptors 72 there is provided an induction coil 74 for generation of an alternating magnetic field. The induction coil 74 is connected via electric wiring 48 to electric contact portions 50,52 to establish an electrical communication of the inductive heater 70 with the power source 18 and the controller 20 of the main device 12.

[0135] In the mouthpiece 14 depicted in Fig. 5 there is also provided a temperature sensor 76. Temperature sensor 76 is connected with the controller 76 and allows to monitor and control the temperature of the inner side 46 of the peripheric wall 44 of the mouthpiece 14.

[0136] Fig. 6 shows a sectional side view of an aerosol-generating device with a mouthpiece 14 comprising a surface heater formed as a conductive heater 80.

[0137] The mouthpiece 14 of Fig. 6 also comprises a layered structure. The structure of the mouthpiece 14 is similar to the structure as described with Fig. 4. However instead of the resistive heating element 42 the heated element is formed from a heat conductive element 82 that is provided in the layer structure of the mouthpiece 14

[0138] The heat conductive element 82 is disposed in proximity to the inner side 46 of the peripheric wall 44 of the mouthpiece 14. As illustrated in Figure 6, the heat conductive element 82 is designed with a meandering pattern, traced similar to the previously described pattern for the resistive heating element 42 shown in Fig. 3.

[0139] In the embodiment shown in Fig. 6 the cartridge 16 comprises a heating element (not shown) which is used to evaporate volatile components of an aerosol-forming substrate to form the inhalable aerosol. Residual heat from the heated cartridge 16 is thermally conducted from the cartridge 16 to the heat conductive element 82. To this end upper corner portions 84 of the wall of the cavity 22 of the aerosol-generating device holding the cartridge 16 are formed from a highly thermally conductive material. These corner portions 84 are thermally connected via a thermal bridge 86 to the heat conductive element 82 of the conductive heater 80 of the mouthpiece 14.

[0140] The thermally conductive components in this embodiment are configured to gather residual heat during the heating phase of the cartridge 16. The heat conductive element 82 of the mouthpiece 14 functions as a heat sink for the heat generated by the heated cartridge 16. In this way excessive heat that is generated in the cartridge 16 may be used in a passive way by the thermally conductive components of the mouthpiece 14. No additional electrical energy is consumed for heating the inner surface 46 of the peripheral wall 44 of the mouthpiece 14. Further, no electrical contact portions between the mouthpiece 14 and the main device 12 are required in this embodiment.

Claims

Claims1. An aerosol-generating device comprising: a main body, a mouthpiece with a peripheral wall defining an airflow passage and a cavity for receiving a cartridge, the cavity being arranged between the main body and the mouthpiece, wherein the peripheral wall of the mouthpiece comprises a surface heater.

2. The aerosol-generating device according to claim 1 , wherein the surface heater is disposed within the peripheral wall of the mouthpiece.

3. The aerosol-generating device according to any one of the preceding claims, wherein the surface heater is disposed on an inner side of the peripheral wall of the mouthpiece.

4. The aerosol-generating device according to any one of the preceding claims, wherein the surface heater is a resistive heater.

5. The aerosol-generating device according to claim 4, wherein the resistive heater comprises one or more resistive heating elements.

6. The aerosol-generating device according to any one of the preceding claims, wherein the surface heater is configured as an inductive heater.

7. The aerosol-generating device according to claim 6, wherein the inductive heater comprises an induction coil and a susceptor provided in the peripheral wall of the mouthpiece.

8. The aerosol-generating device according to any one of the preceding claims, wherein the aerosol-generating device is configured to operate with a heated cartridge and wherein the surface heater is configured as a conductive heater.

9. The aerosol-generating device according to claim 8, wherein the conductive heater comprises a heat conductive element, wherein the heat conductive element is configured to capture residual heat emitted from the heated cartridge.

10. The aerosol-generating device according to claim 9, wherein the conductive heater comprises a thermal bridge extending between the heat conductive element in the peripheral wall of the mouthpiece and the cavity of the main device in which the cartridge is heated.11 . The aerosol-generating device according to any one of the preceding claims, wherein the peripheral wall of the mouthpiece has a layered structure.

12. The aerosol-generating device according to claim 11 , wherein the layered structure comprises an outermost structural layer, an insulating layer, a support layer holding the heated element, and an innermost layer interfacing with the airflow passage.

13. The aerosol-generating device according to any one of the preceding claims, wherein the peripheral wall of the mouthpiece comprises a temperature sensor.

14. The aerosol-generating device according to any one of the preceding claims comprising a controller, wherein the controller is configured to adjust power output to the surface heater of the mouthpiece based on the temperature detected with the temperature sensor.

15. An aerosol-generating system comprising an aerosol-generating device according to any of the preceding claims, and a cartridge configured to be received in the cavity of the aerosol-generating device.

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