Aerosol generating device with thermal diffusion layer

Abstract

The present invention relates to an aerosol generating device comprising a cavity (14) adapted to receive a tobacco article (12), a heater (27) comprising a heating element configured to generate heat and a heat spreading layer configured to transfer the generated heat to the tobacco article (12) when the tobacco article (12) is received in the cavity (14), the heater (27) further comprising a sensor system (28) at least partially comprising said heat spreading layer.

Description

[Technical field]

[0001] The present invention relates to an aerosol generating device comprising a thermal spreading layer.

[0002] In particular, the aerosol generating device according to the invention is configured to work with tobacco articles, e.g. sticks, comprising a solid substrate capable of forming an aerosol when heated. Thus, such types of aerosol generating devices, also known as non-combustion heated devices, i.e. HNB devices, are adapted to generate an aerosol for inhalation by heating, rather than burning, a substrate, by conduction, convection and / or radiation. [Background technology]

[0003] The popularity and use of risk reduction or risk modification devices (also known as vaporizers) has grown rapidly in recent years as aids to assist habitual smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos, and rolling tobacco. A variety of devices and systems are available that heat or warm a vaporizable substance, as opposed to burning tobacco in traditional tobacco products.

[0004] A commonly available risk-reducing or risk-modifying device is the substrate-heated aerosol generating device or the heat-not-burn device (HNB device). This type of device typically generates an aerosol or vapor by heating an aerosol substrate, typically comprising moist tobacco or other suitable vaporizable material, to a temperature typically ranging from 150°C to 350°C. By heating the aerosol substrate but not combusting or burning it, an aerosol is released that contains the components desired by the user but that are not the toxic and carcinogenic by-products of combustion and burning. Furthermore, since the aerosol generated by heating tobacco or other vaporizable material typically does not contain the burnt or bitter taste resulting from combustion and burning that can be unpleasant to the user, the substrate therefore does not require the sugar and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0005] It is common to use one or more sensors located in proximity to the tobacco article to control the operation of the aerosol generating device. For example, a temperature sensor may be used to measure the temperature of the tobacco substrate and thus, in the case of an HNB device, to avoid its overheating, which may lead to it burning, or underheating, which may lead to a poor user experience. Other types of sensors may be used to determine the authenticity of the tobacco article, the pressure of the airflow channel, etc.

[0006] Using several sensors inside the device can be advantageous because it allows for better control of the device. However, a large number of sensors inside the device can be cumbersome. In particular, their placement inside the device can present significant problems that increase the cost of the device and can negatively affect its life cycle. Furthermore, some sensors, for example due to their placement relative to the tobacco article, can exhibit low measurement accuracy. Summary of the Invention [Problem to be solved by the invention]

[0007] One of the objectives of the present invention is to provide an aerosol generating device that can integrate multiple sensors without being cumbersome and without significantly increasing its cost and reducing its life cycle period. [Means for solving the problem]

[0008] To this end, the present invention relates to an aerosol generating device comprising a cavity adapted to receive a tobacco article, a heating element configured to generate heat, and a heater comprising a heat spreading layer configured to transfer the generated heat to the tobacco article when the tobacco article is received in the cavity, the heater further comprising a sensor system at least partially comprising said heat spreading layer.

[0009] Due to these features, the sensors forming the sensor system can be directly integrated into the heat spreading layer or the heat spreading layer can be used for at least some operational functions of the implementation of the sensor system. Because the heat spreading layer can be placed in contact with or very close to the tobacco article, the sensor of the sensor system can also be placed in close proximity to the tobacco article, which can improve the accuracy of the sensor's measurement relative to the tobacco article. Furthermore, because the heat spreading layer forms part of the sensor system, the placement of the sensor system inside the device can be more compact and less costly.

[0010] According to some embodiments, the heat spreading layer is a graphene layer, preferably the graphene layer is formed by inject printing.

[0011] Compared to conventional materials used to implement heaters and / or heat spreading layers in aerosol generating devices, graphene has a number of advantages.

[0012] First of all, graphene exhibits excellent in-plane conductivity (up to 5000 W / m / K) at room temperature, which is much better than that of copper (about 402 W / m / K) and aluminum (about 237 W / m / K). This is particularly advantageous for heat spreading layers intended to conduct and spread heat from heating elements. Graphene may therefore reduce the energy consumption of the device.

[0013] Moreover, graphene is less corroded under acid-alkali and moisture than metal or polymer-based heating materials. Moreover, graphene exhibits lightness, excellent stability, flexibility, and low thermal inertia. The flexibility of the graphene layer allows it to conform to any shape of the tobacco article and to be placed closer to, and advantageously in contact with, the tobacco article.

[0014] Graphene has a high optical transparency, i.e. about 80-90% in visible light. This feature of the heat spreading layer allows its extensive use in combination with different kinds of sensors, in particular in combination with optical sensors. It is therefore possible to arrange the sensor system at least partially within the heat spreading layer, i.e. for example on one or both sides of the heat spreading layer.

[0015] More generally, the use of graphene layers as part of a sensor system has several important advantages. - Thermal energy is rapidly and uniformly distributed in parts that are provided with or covered with graphene layers. - Graphene is extremely strong and conducts electricity very well. - Graphene layers are extremely flexible. - Graphene layers can be adapted to a wide variety of substrates. The physical properties of the graphene layer can be adapted to change its properties so as to become a substrate for realizing different types of sensors or passive elements.

[0016] Regardless of the thermal conductivity properties of graphene, elements made from graphene may be used to make various sensors that may be useful in aerosol generating devices. In particular, graphene makes it possible to provide very thin sensors that can be easily integrated into the cavities of aerosol generating devices, without the need for more cumbersome packaging that is not flexible. The number of types of sensors that can be realized using graphene is very significant. It is also possible to use graphene to realize multiple sensors on a single graphene sheet.

[0017] Various techniques can be used to manufacture the graphene layers, for example they can be realized by inject printing, and therefore on substrates with complex shapes.

[0018] According to some embodiments, the sensor system comprises one or more sensors formed at least in part by the heat spreading layer, or more sensors cooperating with the heat spreading layer.

[0019] According to some embodiments, the or each sensor is capable of detecting at least one of the following events / factors: - Insertion of a tobacco article into the cavity. - Movement of the tobacco article relative to the cavity. - Tactile commands. - The level of contamination in the cavity. - Electromagnetic waves, in particular light signals. - Temperature. - Pressure. - Chemical elements. - gas.

[0020] If a sensor is used to detect the insertion of a tobacco article into the cavity, the operation of the aerosol generating device can, for example, be activated only upon the insertion of a tobacco article. This can, for example, avoid overheating of the device when the heating element is activated while no tobacco article is inserted into the cavity. Activation of the device can be performed manually by the user or upon a predefined event. The predefined event can include the insertion of the tobacco article itself and / or a puff made by the user. In this last case, a pressure sensor can be used to detect the pressure gradient inside the device.

[0021] In the more general case, the sensor can be used to detect any movement of the tobacco article relative to the cavity, which may mean the insertion of the tobacco article into the cavity or the removal of the tobacco article from the cavity. In this last case, operation of the aerosol generating device, in particular the heating element, may be stopped.

[0022] When a sensor is used to detect tactile commands, such tactile commands can be transmitted to a controller of the device that can modify / activate / disable at least certain functions of the device based on such commands.

[0023] If a sensor is used to detect the contamination level of the cavity, it is possible, for example, to detect accumulated contaminants in the cavity and avoid their heating or even retention. For example, if the contamination level of the cavity is greater than a first threshold, a warning message can be sent to the user. Such a message can be sent by the control device, for example, by using one or several LEDs or displays arranged on the body of the device. Optionally, if the contamination level of the cavity is greater than a second threshold, for example greater than the first threshold, the control device may, for example, stop the operation of the device until the cavity is cleaned.

[0024] If a sensor is used to detect electromagnetic waves, such as optical signals, these signals can be used, for example, to authenticate or identify a tobacco article. For example, a tobacco article can be provided with symbols or codes on its surface that can be optically read in the visible, UV, or infrared spectrum. In this case, these symbols / codes can encode data that can be verified by a controller of the device.

[0025] If a sensor is used to detect temperature, this measurement can be used by the controller to adapt the heating profile used to heat the tobacco article.

[0026] If a sensor is used to detect a pressure gradient, this measurement can be interrogated by a controller to activate a heating element.

[0027] Finally, if a sensor is used to detect a certain chemical element or gas (e.g., CO), the controller can use this information to adapt the heating profile and / or to send warning messages or any other type of message to the user.

[0028] According to some embodiments, one or several of said events / elements can be detected by measuring at least one of the following parameters of a corresponding sensor: - Mechanical deformation. - Change in electrical conductivity. - Piezoelectric effect. - Change in polarization.

[0029] For example, the insertion of a tobacco article into the cavity or the movement of the tobacco article within the cavity can be detected by a mechanical deformation of a corresponding sensor. Optionally, the deformation may be detected electrically or optically.

[0030] It is also possible to use the piezoelectric effect, for example, to detect deformations while moving a tobacco article within the cavity. For this purpose, the material of the sensor that is not piezoelectric (such as graphene) may be made piezoelectric by doping it. Such materials may be doped with lithium, hydrogen, potassium, and fluorine, as well as combinations of hydrogen and fluorine, and lithium and fluorine, on both sides of the lattice. In the case of graphene, doping only one side of the graphene, or doping both sides with different atoms, is key to the process, since it breaks the perfect symmetry of graphene, which would otherwise negate the piezoelectric effect.

[0031] The contamination level of the tactile instructions or cavities can be detected by using a change in the electrical conductivity of the corresponding sensor. For example, when using a sensor comprising graphene, the electrical conductivity of the graphene changes upon binding of substances called analytes to its surface, and their chemical components may be identified and measured. The magnitude of the conductivity change can be correlated to the concentration of the deposited contaminants.

[0032] The sensor, especially the sensor with the graphene layer, may be configured so that it acts as an adaptive polarizer. It may be placed on a smoking article and used to detect optical codes or symbols that have polarization properties. It may be placed on a smoking article and used to detect optical codes or symbols that have polarization properties. For fluorescent applications, its fluorescent properties can be tuned by changing its sheet size, chemical composition, and other factors. Because the graphene layer acts as a fluorescent layer, it may also be used in optical anti-counterfeiting sensors for smoking articles, acting as a light emitting diffuser.

[0033] According to some embodiments, the heat spreading layer forms an at least partially transparent window designed to be disposed between the sensor and the tobacco article.

[0034] This window can be particularly used to read optical codes or symbols on the exterior surface of a tobacco article, where the tobacco article can be received within the cavity and heated simultaneously while an optical sensor reads these codes or symbols.

[0035] The window can be placed in thermal contact with the opaque portion of the heat spreading layer, possibly by mechanical force, or by gluing, or by soldering, or by any process meaning a deposition process as known in the realization of thin films.

[0036] The window may have any shape, for example: - cylindrical shape (not necessarily of uniform diameter over its length), - closed or open ring shape, - tubes or rings with a rectangular or square cross section or any other non-circular cross section, - at least one flat or curved plate having a rectangular cross section, - a window having at least two cross sections with different curvatures; - a window having at least one flat surface and at least one curved surface; - Array of transparent heat-conducting windows It may have any shape such as.

[0037] According to some embodiments, the sensors are located in the corner sections and / or form an array in / on the sheets forming the heat spreading layer.

[0038] These features allow the sensor to be positioned in a suitable location relative to the tobacco article when the heat spreading layer is folded or rolled to form a cavity for receiving the tobacco article. Thus, the sensor can be positioned, for example, circumferentially relative to the tobacco article. Furthermore, if a heating element is incorporated within the heat spreading layer, the sensor can be positioned around the periphery of the sheet, spaced from the heating element.

[0039] According to some embodiments, the sensor system further comprises at least one optical emitter capable of emitting an optical signal.

[0040] According to some embodiments, the light emitter is at least partially formed in or cooperates with a heat spreading layer.

[0041] In some embodiments, the transmitter is at least partially formed in or cooperates with the heat spreading layer.

[0042] For example, the optical transmitter can be integrated into a heat spreading layer comprising graphene. In particular, the graphene layer may be configured as a graphene light source, which allows for the integration of very thin light sources into or on the heater element.

[0043] According to another example, the graphene layer may be used as a window to transmit electromagnetic radiation from a light source into the cavity and from the heater cavity to a light receiver. In different embodiments, the graphene layer may be made of a free-standing, possibly flexible, layer that is placed over a through aperture provided in the opaque portion of the heating element.

[0044] According to some embodiments, the heating element is at least partially embedded within the heat spreading layer.

[0045] In particular, the heating element may be partially or completely realized within a heat spreading layer, such as a graphene layer, which may be disposed on a flexible substrate, such as Kapton, that includes portions that are graphene-based sensors or graphene-based electronic structures.

[0046] The rGO (reduced graphene oxide) heating element can easily achieve a stable steady-state temperature of over 200°C when a voltage of 15V is applied, and is characterized by a time constant of about 4 seconds and a heat transfer coefficient of about 200°C cm2 / W.

[0047] According to some embodiments, the aerosol generating device further comprises a support defining an inner surface at least partially delimiting the cavity and configured to face or be in contact with the tobacco article, and an outer surface opposite the inner surface; The heat spreading layer is disposed on the inner or outer surface of the support.

[0048] When the heat spreading layer is disposed on the inner surface of the support, the heat spreading layer can be in direct contact with the tobacco article or can face the tobacco article when the tobacco article is received in the cavity. This embodiment is particularly advantageous when the heating element is at least partially embedded in the heat spreading layer. Thus, it is possible to minimize the heat loss during heating of the tobacco article.

[0049] When the heat spreading layer is disposed on the outer surface of the support, the heat spreading layer can spread heat uniformly to the support, and the tobacco article can be heated by the support, which may be in direct contact with the tobacco article or may face the tobacco article. The support may be made of aluminum, copper, SiO 2 , Al 2 O 3 The support may be made of any suitable heat-conducting material, such as SiO 2 , SiO 3 , SiO 4 , SiO 5 , SiO 6 , SiO 7 , SiO 8 , SiO 9 , SiO 2 , SiO 2 , SiO 3 , SiO 4 ...3 , SiO 2

[0050] According to some embodiments, the support is formed by at least one of the following elements: - Hollow cylinder. - Longitudinal bars. - Transverse ring. - Lattice.

[0051] According to some embodiments, the heat spreading layer is formed by a sheet, and it is therefore understood that the heat spreading layer comprises a single sheet, which may be continuous or may comprise a number of fingers designed to extend in the longitudinal direction.

[0052] Alternatively, the heat spreading layer may comprise a number of apertures arranged in any suitable manner.

[0053] According to some embodiments, the heat spreading layer is substantially transparent.

[0054] The invention and its advantages will be better understood on reading the following description, given purely as a non-limiting example, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0055] [Figure 1] 1 is a schematic diagram of an aerosol generating device according to the present invention and a tobacco article received in the aerosol generating device, the aerosol generating device comprising a heat spreading layer, a support and a sensor system. [Diagram 2] 3A to 3C are schematic diagrams showing different examples of the arrangement of a thermal diffusion layer and a support. [Diagram 3] 3A to 3C are schematic diagrams showing different examples of the arrangement of a thermal diffusion layer and a support. [Figure 4] 3A to 3C are schematic diagrams showing different examples of the arrangement of a thermal diffusion layer and a support. [Diagram 5] 3A to 3C are schematic diagrams showing different examples of the arrangement of a thermal diffusion layer and a support. [Figure 6] 3A to 3C are schematic diagrams showing different examples of the arrangement of a thermal diffusion layer and a support. [Figure 7] 1A to 1C are schematic diagrams showing different examples of the arrangement of the sensor system relative to the thermal spreading layer. [Figure 8] 1A to 1C are schematic diagrams showing different examples of the arrangement of the sensor system relative to the thermal spreading layer. [Figure 9] 3A to 3C are schematic diagrams illustrating the operation of a sensor system according to different examples of the present invention. [Figure 10] 3A to 3C are schematic diagrams illustrating the operation of a sensor system according to different examples of the present invention. [Figure 11] 3A to 3C are schematic diagrams illustrating the operation of a sensor system according to different examples of the present invention. [Figure 12] 3A to 3C are schematic diagrams illustrating the operation of a sensor system according to different examples of the present invention. [Figure 13] 3A to 3C are schematic diagrams illustrating the operation of a sensor system according to different examples of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] Before the present invention is described, it is to be understood that the invention is not limited to the details of construction set forth in the following description, as it will be apparent to one skilled in the art having the benefit of this disclosure that the invention is capable of other embodiments and of being practiced or carried out in various ways.

[0057] As used herein, the term "aerosol generating device" or "device" may include a vapor inhalation device for delivering an aerosol, including an aerosol for vapor inhalation, to a user by an aerosol generating unit (e.g., an aerosol generating element that generates vapor that condenses into an aerosol before being delivered to an outlet of the device, e.g., at a mouthpiece, for the user to inhale). The device may be portable. "Portable" may refer to a device for use when held by a user. The device may be adapted to generate a variable amount of aerosol (as opposed to a fixed amount of aerosol), for example, by activating a heating system for a variable amount of time, the generation of which may be controlled by a trigger. The trigger may be user-activated, such as a vaping button and / or an inhalation sensor. The inhalation sensor may be sensitive to the inhalation strength as well as the inhalation duration, allowing for the provision of a variable amount of vapor (to mimic the smoking effect of a conventional combustible smoking article, such as a cigarette, cigar, or pipe). The device may include a temperature regulation control to drive the temperature of the heater and / or heated aerosol generating material (aerosol precursor) to a particular target temperature and then maintain the temperature at the target temperature that enables efficient generation of the aerosol.

[0058] As used herein, the term "aerosol" may include a suspension of vaporizable material as one or more of solid particles, liquid droplets, and gas. The suspension may be in a gaseous state, including air. Aerosol herein generally refers to or may include a vapor. The aerosol may include one or more components of a precursor.

[0059] As used herein, the term "vaporizable material" or "aerosol-forming precursor" may refer to one or more of a liquid, solid, gel, mousse, foam, or other substance. The vaporizable material may be processable by the heating system of the device to form an aerosol, as defined herein. The vaporizable material may include one or more of nicotine, caffeine, or other active ingredients. The active ingredients may be carried by a carrier, which may be a liquid. The carrier may include propylene glycol or glycerin. Flavorings may also be included. Flavorings may include ethyl vanillin (vanilla), menthol, isoamyl acetate (banana oil), or the like. The solid aerosol-forming material may be in the form of a rod, including processed tobacco material, corrugated sheets, or oriented strips or strips of reconstituted tobacco (RTB).

[0060] An aerosol generating device 10 according to the present invention is shown in Figure 1. As shown in this figure, the aerosol generating device 10 is configured to operate with a tobacco article 12 when the tobacco article 12 is received within a cavity 14 bounded by the aerosol generating device 10.

[0061] The tobacco article 12 extends according to an article axis X, which in the example of FIG. 1 coincides with the device axis Y. The tobacco article 12 has, for example, a generally cylindrical shape. This cylindrical shape is circular in cross section along its length. Advantageously, according to some embodiments, the tobacco article 12 has a shape and / or dimensions substantially equal to the shape and / or dimensions of a conventional cigarette. For example, the tobacco article 12 may form a HNB article (heated non-burning article) having substantially the same shape and / or dimensions as a conventional cigarette. However, in some alternative embodiments, the tobacco article 12 may have other manageable shapes different from a conventional cigarette, such as a parallelepiped type, a pebble type shape, etc. The tobacco article 12 may also be of a larger or smaller size (e.g., in the longitudinal or circumferential direction).

[0062] Advantageously, according to the present invention, the tobacco article 12 is a conventional cigarette or is a known HNB article.

[0063] With reference to Fig. 1, the tobacco article 12 comprises a filter / cooling portion 21 and a storage portion 22. These portions may be assembled together by a common wrapper (not shown) comprising paper, aluminium foil or a combination thereof. In the example of Fig. 1, the filter / cooling portion 21 extends according to the article axis X and is adjacent to the storage portion 22. The storage portion 22 also extends along the article axis X and may, for example, be slightly longer than the filter / cooling portion 21. According to another example, the storage portion 22 is the same length as the filter / cooling portion 21 or is shorter than this filter / cooling portion 21.

[0064] The filter / cooling portion 21 forms the mouth end of the tobacco article 12 designed to contact the mouth / lips of the user. This portion 21 further comprises a filter and / or cooling segment designed to filter and / or cool the aerosol formed by the storage portion 22 in response to heating. For example, the filter / cooling portion 21 may comprise a filter segment at the mouth end of the article and a tubular element (e.g. a paper tube) between the filter segment and the storage portion 22. In some embodiments, the filter / cooling portion 21 is not provided. In this case, for example, the storage portion 22 may form the mouth end of the article 12. In this case, a replaceable filter / cooling mouthpiece may be used, which may be connected to the tobacco article 12.

[0065] The storage portion 22 contains a vaporizable material as defined above. In some embodiments, the storage portion 22 may further comprise one or several heating elements configured to cooperate with corresponding heating elements of the aerosol generating device 10 to heat the vaporizable material. For example, the heating elements in the storage portion 22 may include a number of susceptors capable of heating the vaporizable material when placed within a magnetic field.

[0066] The cavity 14 is adapted to at least partially receive the tobacco article 12. For example, the cavity 14 extends according to the device axis Y. In particular, according to the example of FIG. 1, the cavity 14 is adapted to completely receive the storage portion 22 of the tobacco article 12. Advantageously, the length of the storage portion 22 is substantially equal to the length of the cavity 14. The cross-sectional shape of the cavity 14 corresponds, for example, to the cross-sectional shape of the tobacco article 12. The general shape of the cavity can be defined by a support 24 (not shown in FIG. 1), which can be made of a thermally conductive material such as aluminum or copper. In some cases, the support 24 can be at least partially transparent, for example made of SiO 2 Or Al 2 O 3 Examples of particular shapes and configurations of the support 24 are described in further detail below.

[0067] 1, the aerosol generating device 10 comprises a housing 25 which comprises the various internal components of the device 10 which ensure its various functions. For example, the housing 25 comprises a heater 27 which causes heating of the storage portion 22 of the tobacco article 12, a sensor system 28 which monitors the operation of the aerosol generating device 10, a controller 29 which controls, inter alia, the operation of the heater 27, and a battery 30 which supplies power to the heater 27 and to the controller 29.

[0068] The battery 30 is, for example, a known battery designed to be charged using a power source provided by an external source and to provide a direct current of a predefined voltage. The battery 30 may be associated with a battery charger, which may connect the battery 30 to the external source and which may comprise for this purpose a power connector (such as a mini-USB or USB-C connector) or a wireless charging connector. The battery charger may also control the power delivered to the battery 30 from the external source, for example according to a predefined charging profile. Such a charging profile may, for example, prescribe the charging voltage of the battery depending on its charge level. In some alternative embodiments, instead of the battery 30, the housing 25 may only include a power connector for connecting the device 10 to an external power source, for example by a wire. In this case, the device 10 may only operate when connected to this external power source.

[0069] The controller 29 is configured to control the operation of the heater 27 by controlling the power supply by the battery 30 or, in an alternative embodiment, by an external power source. To this end, the controller 29 can, for example, apply a predefined heating profile to control the operation of the heater 27. In some embodiments, the heating profile can be selected depending on the nature or type of the tobacco article 12. For example, the heating profile is selected depending on the flavoring contained in the storage portion 22 of the tobacco article 12. Additionally or alternatively, in some embodiments, the heating profile can be selected depending on data provided by the sensor system 28, as described in more detail below. More generally, the controller 29 can receive measurements taken by the sensor system 28 and can process these measurements to determine one or several control instructions.

[0070] The heater 27 comprises a heating element configured to generate heat and a heat spreading layer 32 configured to transfer the generated heat to the tobacco article 12, and in particular to the storage portion 22, when the tobacco article 12 is received in the cavity 14. In some embodiments, the heater 27 comprises a plurality of heat spreading layers 32 as defined above.

[0071] The heating element may be powered by a battery 30 according to a heating profile selected by the controller 29. According to different embodiments of the invention, the heating element may be integrated into the heat spreading layer 32 or connected to the heat spreading layer. For example, the heating element may comprise a resistive wire, in particular a metal wire, which may extend at least in a part of the heat spreading layer 32. According to another example, the heating element may be realized entirely in the heat spreading layer 32, for example on a flexible substrate such as Kapton. The heating element may be made of graphene.

[0072] The heat spreading layer 32 is arranged adjacent to the support 24 so as to be as close as possible to the storage portion 22 of the tobacco article 12. Advantageously, at least one of the elements selected from the heat spreading layer 32 and the support 24 is arranged to be in contact with the storage portion 22 or facing the storage portion 22 while being spaced from the storage portion 22 by a small distance, for example including 1 mm to 5 mm. In the first case, the storage portion 22 is heated by conduction. In the second case, the storage portion 22 is heated by convection.

[0073] Fig. 2 shows different examples of the arrangement of the heat spreading layer 32 relative to the support 24. In particular, according to example A of Fig. 2, the support 24 defines an outer surface in contact with the heat spreading layer 32. In example B of Fig. 2, the support 24 defines an inner surface in contact with the heat spreading layer 32. In other words, in example A, the heat spreading layer 32 is arranged externally relative to the support 24, and in example B, the heat spreading layer 32 is arranged internally. Thus, in example B, the heat spreading layer 32 is intended to be in contact with or directly facing the storage portion 22 of the tobacco device 12.

[0074] According to both examples of Fig. 2, the support 24 has a continuous cylindrical shape extending along the device axis Y. However, the support 24 can have any other suitable shape and can include, for example, longitudinal bars, short rings, a lattice, etc. Thus, in the example of Fig. 3, the support 24 includes longitudinal bars extending along the device axis Y. In the example of Fig. 4, the support 24 includes a lattice formed by longitudinal bars and short rings extending along the device axis Y.

[0075] In the examples of figures 2-4, the heat spreading layer 32 is formed by a continuous sheet, for example of rectangular shape, which is wound on the inside or outside of the support 24. However, other shapes of the heat spreading layer 32 may also be possible. Thus, as shown in the right part of figure 5, the heat spreading layer 32 may be formed from a sheet with a number of fingers (four in the example of the figure). These fingers are intended to extend longitudinally along the device axis Y when the heat spreading layer 32 is wound around the support 24, as shown in the left part of the same figure. In this configuration, the heat spreading layer 32 only partially covers the outer surface of the support 24. In a variant, the same heat spreading layer 32 can be arranged on the inner surface of the support 24.

[0076] The heat spreading layer 32 can be arranged in any other suitable manner on the support 24. Thus, as shown in Fig. 6, the heat spreading layer 32 may be realized by inject printing directly on the support 24. This embodiment is particularly advantageous when the heat spreading layer 32 is made from graphene. In some embodiments, the heat spreading layer 32 may be formed by several sheets.

[0077] Advantageously, according to the invention, the heat spreading layer 32 comprises or is formed from graphene. Furthermore, the heat spreading layer 32 may be made at least partially transparent. For example, the heat spreading layer 32 may be transparent over more than 90% of its surface. The transparency of the heat spreading layer 32 may be comprised between 10% and 100%, advantageously between 20% and 90%.

[0078] According to the invention, the sensor system 28 is integrated in the heater 27 and in particular comprises at least partly the heat spreading layer 32. This means that the sensor system 28 comprises one or more sensors which are at least partly formed by the heat spreading layer 32 or which cooperate with the heat spreading layer 32 to provide corresponding measurement values. The arrangement of the sensors of the sensor system 28 depends on the nature of these sensors and the measurements they are able to provide.

[0079] In the example of Figure 7, four sensors 40 are incorporated into the heat spreading layer 32. In particular, as shown in this figure, the sensors 40 may be incorporated, two at each opposite corner of the sheet forming the heat spreading layer 32. Thus, when the heat spreading layer 32 is wrapped about the device axis Y, the sensors are located on different ends of the cavity, two sensors adjacent its open end and two sensors adjacent its closed end.

[0080] 8, an array of five sensors 40 is disposed at one end of the sheet forming the heat spreading layer 32. Thus, when the sheet is wrapped around or inside the support 24, the sensors 40 are circumferentially located around the cavity 14. According to this example, for example, gaps 42 may space the array of sensors 40 from heating elements embedded in the heat spreading layer 32.

[0081] Of course, the sensors of the sensor system 28 may be positioned relative to the heat spreading layer 32 according to any other suitable method.

[0082] According to the invention, the or each sensor is capable of detecting at least one of the following events / elements: - Insertion of the tobacco article 12 into the cavity 14. - Movement of the tobacco article 12 relative to the cavity 14. - Tactile commands. - Contamination level in cavity 12. - Electromagnetic waves, in particular light signals. - Temperature. - Pressure, - Chemical elements. - gas.

[0083] These elements / events can be detected by one or several sensors by measuring at least one of the following parameters: - Mechanical deformation. - Change in electrical conductivity. - Piezoelectric effect. - Change in polarization.

[0084] Hereinafter, some examples of sensors are provided that allow the detection of at least one of the above cited events / elements using one or more types of measurements.

[0085] [Example 1] According to one example, the insertion of the tobacco article and / or any other movement inside the cavity 12 is detected by a sensor that measures the mechanical deformation of at least a portion of the heat spreading layer 32 .

[0086] In this case, as shown in Fig. 9, the support 24 may comprise a window 50 and a heat spreading layer 32, possibly arranged on the inside or outside of the support 24, so as to deform when the tobacco article 12 is slid along the device axis Y near the window 50 (lower part of the figure). The mechanical deformation can be detected by a sensor arranged directly on the heat spreading layer 32. Optionally, the deformation may be detected electrically or optically by a sensor arranged on or near the heat spreading layer 32.

[0087] The window 50 can have any suitable shape, for example: - cylindrical shape (not necessarily of uniform diameter over its length), - closed or open ring shape, - tubes or rings with a rectangular or square cross section or any other non-circular cross section, - at least one flat or curved plate having a rectangular cross section, - a window having at least two cross sections with different curvatures; - a window having at least one flat surface and at least one curved surface; - Array of transparent heat-conducting windows The shape may be any suitable shape, such as:

[0088] [Example 2] According to another example, the insertion of a tobacco article and / or any other movement inside the cavity 12 is detected using the piezoelectric effect of the heat spreading layer 32 .

[0089] In this case, for example, a heat spreading layer 32 made from graphene may be doped with lithium, hydrogen, potassium, and fluorine, as well as combinations of hydrogen and fluorine, and lithium and fluorine, on both sides of the lattice. Doping only one side of the graphene, or doping both sides with different atoms, is key to the process, since it breaks the perfect physical symmetry of graphene, which would otherwise negate the piezoelectric effect. This makes the heat spreading layer 32 piezoelectric, if not initially.

[0090] In a variant, the insertion and / or any other movement of the tobacco article inside the cavity 12 is detected using an optical signal. This variant is shown diagrammatically in FIG.

[0091] According to Fig. 11, two windows 50 are arranged in the support 24 facing each other. Each window 50 overlaps with a heat spreading layer 32. In this case, the sensor system 28 comprises an optical emitter 61 arranged facing one of the windows 50 and an optical receiver 62 arranged facing the other window 50. Both the emitter 61 and the receiver 62 can be connected to a controller 29. The controller 29 can detect the presence of a tobacco article 12 in the cavity 14, for example, when the optical signal emitted by the emitter 61 is not received by the receiver 62, or is not received in a different form.

[0092] In this example, it is assumed that the heat spreading layer 32 is at least partially transparent to at least some optical signals (visible, infrared, or UV).

[0093] [Example 3] According to another example, one or more tactile sensors may be located, for example, on the outer surface of the device. For example, these sensors may be integrated into the graphene layer and connected to the controller 29 to transmit corresponding tactile commands. Thus, the sensors may have a wider sensitivity.

[0094] To avoid direct contact of the user's fingers with the graphene layer, a mechanical system may be provided that is intended to extend between the user's fingers and the surface of the graphene layer. Such a mechanical system comprises, for example, one or several buttons intended to be activated by the user and thermally insulating connection means. These connection means may, for example, connect the or each button to a corresponding tactile sensor on the graphene layer and may further comprise a biasing element, as a spring or another elastic element, that may cause the button to take up its initial position after being activated by the user.

[0095] [Example 4] According to another example, at least one sensor is used as a contamination sensor for monitoring the contamination level of the cavity 14 .

[0096] For example, the electrical conductivity of some materials, such as graphene, changes upon binding of substances called analytes to their surface so that their chemical constituents may be identified and measured. The magnitude of the conductivity change may be correlated to the concentration of contaminants deposited on the thermal spreading layer 32. Such sensors may be electrical or optical.

[0097] An example of an optical sensor is shown in Fig. 10. According to this example, the sensor system 28 comprises an optical emitter 61 and an optical receiver 62, which are arranged facing a window 50 formed in the support, similar to the window 50 in Fig. 9. In this case, a heat spreading layer 32, for example made of graphene, may overlap the window 50, so that the emitter 61 can emit an optical signal that crosses the heat spreading layer 32, and the receiver 62 can receive an optical signal that is reflected, for example, by the outer surface of the tobacco article 12. Both the emitter 61 and the receiver 62 can be connected to a controller 29. By comparing the reflected optical signal with the emitted optical signal, the controller 29 can be adapted to determine the contamination level of the heat spreading layer 32.

[0098] In this example, it is assumed that the heat spreading layer 32 is at least partially transparent to at least some optical signals (visible, infrared, or UV).

[0099] [Example 5] According to another example, the sensor system 28 comprises an optical emitter 61, e.g. a light source, which is integrated with the heat spreading layer 32, as shown in Fig. 12. In this case, the arrangement of the heat spreading layer 32 and the structure 24 can be similar to that shown in Fig. 10. In particular, as in Fig. 10, the sensor system 28 comprises an optical receiver 62 facing the window 50. The only difference in the arrangement in Fig. 12 is that the optical emitter 61 is integrated with the heat spreading layer 32 at the window 50.

[0100] This arrangement can be used for detection purposes similar to those described above, and furthermore, as in the previous case, it is contemplated that the heat spreading 32 layer is at least partially transparent to at least some optical signals (visible, infrared, or UV).

[0101] [Example 6] According to another example, the heat spreading layer 32, for example made from graphene, may be configured such that it acts as an adaptive polarizer, which may be placed on the smoking article 12 and utilized to detect optical codes having polarization properties.

[0102] For these purposes, one of the arrangements described with reference to figures 10 to 12 may be used, in particular in this case the sensor system further comprises an optical emitter 61 and an optical receiver 62 similar to those described with reference to these figures.

[0103] [Example 7] According to another example, the heat spreading layer 32 made from graphene in the form of graphene oxide (CO) may be configured as a fluorescent layer whose emission wavelength can be changed by changing the wavelength of the excitation light. For fluorescent applications, its fluorescent properties can be tuned by changing its sheet size, chemical composition, and other factors. Since the graphene layer acts as a fluorescent layer, it may also be used in optical anti-counterfeiting sensors for smoking articles, acting as an emission diffuser.

[0104] [Example 8] According to another example, at least one sensor is used as a contamination sensor for monitoring the contamination level of the cavity 14, as in example 4.

[0105] However, in this case, the heat spreading layer 32 made from graphene may be configured as an optical receiver to detect the deposited contamination layer by measuring the change in the refractive index of the graphene layer. The excellent optical and electronic properties of graphene make it attractive for sensors that use electromagnetic waves known as plasmons that propagate along the surface of a conducting material in response to light exposure. Substances can be detected by the controller 29 by measuring how the refractive index of the sensor changes when the substance of interest is close to the graphene surface.

[0106] [Example 9] According to another example, the heat spreading layer 32 made of graphene may be used as a high mobility photoconductive layer in detectors that detect UV, visible, and infrared light. Existing vision systems based only on silicon can detect visible light and are limited to 1.5 μm. Graphene may be used as a photon-to-charge converter by using a layer with quantum dots, which are now widely available.

[0107] Thus, a vision system or intensity detector system may be provided to detect wavelengths from the UV to the mid-infrared.

[0108] This case is shown diagrammatically in Figure 13, where the heat spreading layer 32 is transparent and may be used to transmit light from the optical emitter 61 and simultaneously detect the light. In other words, in this case the heat spreading layer 32 acts as an optical receiver 62.

Claims

1. - A cavity (14) adapted for receiving tobacco articles (12), - A heater (27) comprising a heating element configured to generate heat, and a heat diffusion layer (32) formed of a sheet and configured to transfer the generated heat to the tobacco article (12) when the tobacco article is received in the cavity (14), further comprising a sensor system (28), the heater (27) and Equipped with, The sensor system (28) - At least partially with the heat diffusion layer (32), - One or more sensors formed at least partially by the heat diffusion layer (32), or one or more sensors cooperating with the heat diffusion layer (32) Equipped with, Aerosol generating device (10).

2. The heat diffusion layer (32) is a graphene layer, preferably the graphene layer is formed by injection printing. The aerosol generating device (10) according to claim 1.

3. When the tobacco article (12) is received into the cavity (14), the heat diffusion layer (32) is positioned between the heating element and the tobacco article (12). The aerosol generating device (10) according to claim 1.

4. The aforementioned sensor or each sensor - Insertion of the tobacco article (12) into the cavity (14), - Movement of the tobacco article (12) to the cavity (14), - Tactile commands, - Contamination level of the cavity (14), - Electromagnetic waves, especially optical signals, - temperature, - Pressure, - chemical elements, - gas It is possible to detect at least one of the events / elements. The aerosol generating device (10) according to claim 1.

5. One or more of the aforementioned events / elements are parameters of the corresponding sensor. - Mechanical deformation, - Changes in electrical conductivity, - Piezoelectric effect, - Change in polarization This can be detected by measuring at least one of the following: The aerosol generating device (10) according to claim 4.

6. The heat diffusion layer (32) forms at least partially transparent windows (50) designed to be positioned between the sensor and the cigarette article (12). The aerosol generating device (10) according to claim 1.

7. - The sensor system (28) comprises a plurality of sensors (40), - The sensor (40) is arranged in a corner section and / or forms an array of the sheets that form the heat diffusion layer (32) / forms an array on the sheets that form the heat diffusion layer (32), The aerosol generating device (10) according to claim 1.

8. The sensor system (28) further comprises at least one optical light-emitting element (61) capable of emitting an optical signal. The aerosol generating device (10) according to claim 1.

9. The optical light-emitting element (61) is at least partially formed in the thermal diffusion layer (32), or is capable of emitting an optical signal that crosses the thermal diffusion layer (32). The aerosol generating device (10) according to claim 8.

10. The heating element is at least partially incorporated into the heat diffusion layer (32). The aerosol generating device (10) according to claim 1.

11. A support (24) defines an inner surface that at least partially partitions the cavity (14) and is configured to face or be in contact with the tobacco article (12), and an outer surface opposite to the inner surface. Furthermore, The heat diffusion layer (32) is disposed on the inner surface or outer surface of the support (24). The aerosol generating device (10) according to claim 1.

12. The support (24) - Hollow cylinder, - Longitudinal bar, - Transverse ring, - Lattice Formed by at least one of the elements of The aerosol generating device (10) according to claim 11.

13. The support (24) is made from a metal such as aluminum or copper, or SiO ２ Or Al ２ O ３ Made from virtually transparent materials such as The aerosol generating device (10) according to claim 11.

14. The sheet forming the heat diffusion layer (32) comprises a plurality of finger portions that are continuous or designed to extend in the longitudinal direction. The aerosol generating device (10) according to claim 1.

15. The heat diffusion layer (32) is substantially transparent. An aerosol generating device (10) according to any one of claims 1 to 14.

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