Method for manufacturing a sensor for an aerosol generating device

Abstract

The present invention relates to a method for manufacturing a sensor for an aerosol generating device, the method may include any of the following steps: providing a layer of flexible dielectric substrate, printing or mounting a first sensor component at a first location on the flexible dielectric substrate, printing or mounting a second sensor component at a second location on the flexible dielectric substrate, the second location being different from the first location, printing or mounting a third sensor component at a third location on the flexible dielectric substrate, the third location being different from the second location and different from the first location, and wrapping or folding the flexible dielectric substrate such that three layers of flexible dielectric substrate are formed, the first location, the second location and the third location overlapping each other, thereby forming a sensor. The present invention further relates to a sensor for use in an aerosol generating device. The present invention further relates to an aerosol generating device comprising a sensor.

Description

[Technical Field]

[0001] The invention further relates to a method for manufacturing a 3D sensor for an aerosol generating device.The invention further relates to a 3D sensor for use in an aerosol generating device.The invention further relates to an aerosol generating device comprising a 3D sensor. [Background technology]

[0002] It is known to provide aerosol-generating devices for producing an inhalable vapor. Such devices may heat an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilize, without burning the aerosol-forming substrate. The aerosol-forming substrate may be provided as part of an aerosol-generating article. The aerosol-generating article may have a rod shape for insertion of the aerosol-generating article into a cavity (such as a heating chamber) of the aerosol-generating device. A heating element may be disposed in or around the heating chamber to heat the aerosol-forming substrate when the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device. The aerosol-generating device may comprise multiple electronic components, such as a controller for controlling the operation of the heating element. One or more sensors, such as a temperature sensor, may also be employed, the output of which may be used to control the operation of a hearing element. Including any of these components within the aerosol-generating device may be difficult, as the aerosol-generating device should have a shape similar to that of a conventional cigarette.

[0003] It would be desirable to have an improved method for manufacturing sensors for aerosol-generating devices.It would be desirable to have a method for manufacturing sensors for aerosol-generating devices that has an improved form factor for aerosol-generating devices. Summary of the Invention

[0004] According to an embodiment of the present invention, there is provided a method for manufacturing a sensor for an aerosol generating device, the method comprising: providing a layer of flexible dielectric substrate; printing or mounting a first sensor component at a first location on a flexible dielectric substrate; printing or mounting a second sensor component at a second location on the flexible dielectric substrate, the second location being different from the first location; printing or mounting a third sensor component at a third location on the flexible dielectric substrate, the third location being different from the second location and different from the first location; wrapping or folding the flexible dielectric substrate so that three layers of the flexible dielectric substrate are formed, the first location, the second location, and the third location overlapping each other, thereby forming the sensor.

[0005] According to an embodiment of the present invention, there is provided a method for manufacturing a sensor for an aerosol generating device, the method comprising: providing a layer of flexible dielectric substrate; printing or mounting a first sensor component at a first location on a flexible dielectric substrate; printing or mounting a second sensor component at a second location on the flexible dielectric substrate, the second location being different from the first location; printing or mounting a third sensor component at a third location on the flexible dielectric substrate, the third location being different from the second location and different from the first location; wrapping or folding the flexible dielectric substrate so that three layers of the flexible dielectric substrate are formed, the first location, the second location, and the third location overlapping each other, thereby forming the sensor.

[0006] The sensor may be a 3D sensor.

[0007] Fabricating a 3D sensor in this manner improves the form factor of the sensor. For example, an aerosol generating device may have a cavity that acts as a heating chamber. The cavity may be a hollow cylindrical cavity. It may be necessary or beneficial to arrange the sensor at a point around the periphery of the cavity. The method described herein may create a tubular structure with a wrapped flexible dielectric substrate and sensor components, thereby creating a 3D sensor that can be optimally arranged around the cavity of an aerosol generating device.

[0008] The flexible dielectric substrate may be a polyimide sheet. The flexible dielectric substrate may be shaped to fit around the periphery of the cavity of the aerosol generating device.

[0009] The flexible dielectric substrate may be wrapped at least two times. Preferably, the flexible dielectric substrate may be wrapped at least three times. After wrapping the flexible dielectric substrate, at least three layers of the flexible dielectric substrate may be on top of each other. The flexible dielectric substrate may be wrapped such that the flexible dielectric substrate then has a hollow tubular shape. The flexible dielectric substrate may have a cylindrical shape after the wrapping step.

[0010] During winding of the flexible dielectric substrate, each layer of the flexible dielectric substrate may be attached to one or both of the respective inner and outer layers. Exemplarily, the second layer of the flexible dielectric substrate may be attached to the first layer of the flexible dielectric substrate. The third layer of the flexible dielectric substrate may be attached to the second layer of the flexible dielectric substrate. The first layer of the flexible dielectric substrate may be the innermost layer. The third layer of the flexible dielectric substrate may be the outermost layer. The second layer of the flexible dielectric substrate may be the middle layer. The second layer of the flexible dielectric substrate may be sandwiched between the first layer of the flexible dielectric substrate and the third layer of the flexible dielectric substrate.

[0011] The formed 3D sensor may extend between three layers of flexible dielectric substrate. The 3D sensor may extend radially between the three layers of flexible dielectric substrate. The radial direction may be perpendicular to a tangent direction defined by the surface of the outermost layer of the flexible dielectric substrate.

[0012] One or more of the first sensor components may be an electrical sensor component, the second sensor component may be an electrical sensor component, and the third sensor component may be an electrical sensor component.

[0013] Exemplary electrical components are resistors, capacitors, inductors, microprocessors, electronic circuits, coupling circuits, cavities, studs, and heat sinks.

[0014] One or more of the first, second, and third sensor components may include a controller.

[0015] A controller may be configured to receive an output of the 3D sensor. The controller may be configured to control operation of the 3D sensor. The controller may comprise or be a sensor logic unit. The controller may be electrically connected to one or more of the first, second, and third sensor components via conductive tracks.

[0016] One or more of the first, second, and third sensor components may be non-functional before being wrapped or folded. In other words, two or more of the first, second, and third sensor components may become functional after being wrapped or folded. Two or more of the first, second, and third sensor components may form a functional sensor after being wrapped or folded.

[0017] The 3D sensor may comprise a pressure sensor.

[0018] The 3D sensor may be a pressure sensor.

[0019] The 3D sensor may be configured as a pressure 3D sensor for measuring the pressure of air inside the aerosol-generating device that is drawn through the device's airflow path by the user during a puff. The 3D sensor may be configured to measure the pressure difference or pressure drop between the pressure of the ambient air outside the aerosol-generating device and the pressure of the air drawn through the device by the user. The air pressure may be detected at the air inlet, the device's mouthpiece, the cavity, the heating chamber, or any other passage or chamber within the aerosol-generating device through which air flows. When a user draws on the aerosol-generating device, a negative pressure or vacuum is generated inside the device, and the negative pressure may be detected by the pressure 3D sensor. The term "negative pressure" is understood as a pressure that is relatively lower than the pressure of the ambient air. In other words, when a user draws on the device, the air drawn through the device has a pressure that is lower than the pressure of the ambient air outside the device. The start of a puff may be detected by the pressure 3D sensor when the pressure difference exceeds a predetermined threshold.

[0020] One of the first, second, and third sensor components may comprise a sealed cavity, and a different one of the first, second, and third sensor components may comprise a pressure sensitive resistor.

[0021] The pressure sensor of the 3D sensor may be formed by a sealed cavity and a pressure-sensitive resistor. The second sensor component may include a sealed cavity. The sealed cavity may be disposed at a second location on the flexible dielectric substrate. The first sensor component may include a cavity support at a first location on the flexible dielectric substrate. The sealed cavity may be supported on the cavity support. The third sensor component may include a pressure-sensitive resistor. The pressure-sensitive resistor may be disposed on the sealed cavity.

[0022] When ambient air is drawn into the aerosol generating device by a user, negative pressure is created in the airflow path. The sealed cavity may expand, and the 3D sensor may detect this negative pressure. The air inside the sealed cavity may have a relatively higher pressure than the air drawn through the airflow channel and having negative pressure, causing the sealed cavity to expand. The expansion of the sealed cavity may be detected by a pressure-sensitive resistor. Due to the placement of the pressure-sensitive resistor on the sealed cavity, the pressure-sensitive resistor may be pressurized when the sealed cavity expands. This may lead to a change in the resistance of the pressure-sensitive resistor. This change in resistance may be measured by a controller as described herein. The change in resistance may indicate the user's inhalation.

[0023] As an alternative to providing the sealed cavity as part of the second sensor component, the sealed cavity may be formed between three layers during winding or folding of the flexible dielectric substrate. Exemplarily, the first sensor component may comprise the base of the sealed cavity, the second sensor component may comprise the sidewalls of the sealed cavity, and the third sensor component may comprise the top wall of the sealed cavity. Thus, a completely sealed cavity may be formed by overlapping and winding or folding three layers of the flexible dielectric substrate such that the base of the sealed cavity is formed by the innermost layer having the first sensor component. The sidewalls of the sealed cavity may be formed by the second sensor component as the middle layer, and the top of the sealed cavity may be formed by the third sensor component as the outermost component.

[0024] The top of the sealed cavity may include or be formed by a flexible diaphragm. The flexible diaphragm may allow expansion of the sealed cavity to occur. The pressure-sensitive resistor may be disposed on the flexible diaphragm. The pressure-sensitive resistor may be overlaid on the flexible diaphragm.

[0025] Alternatively, only the first sensor component and the second sensor component may be used to form the sealed cavity, or only the second sensor component and the third sensor component may be used to form the sealed cavity.

[0026] During wrapping, the first location may be on an innermost layer of the flexible dielectric substrate, the second location may be on a middle layer of the flexible dielectric substrate, and the third location may be on an outermost layer of the flexible dielectric substrate.

[0027] The 3D sensor may comprise a spectrometer.

[0028] The 3D sensor may be a spectrometer.

[0029] One of the first, second, and third sensor components may comprise a light source. One of the first, second, and third sensor components may comprise a detector.

[0030] Exemplarily, the first sensor component may comprise a light source and the third sensor component may comprise a detector.

[0031] The spectrometer may be configured to detect a gas.

[0032] One of the first, second, and third sensor components may comprise a portion of the spectrometer cavity such that the spectrometer cavity is formed after the winding or folding step.

[0033] Exemplarily, the first sensor component may comprise the base of the spectrometer cavity, the second sensor component may comprise a sidewall of the spectrometer cavity, and the third sensor component may comprise a top wall of the spectrometer cavity. Alternatively, only the first and second sensor components may comprise a portion of the spectrometer cavity, or only the second and third sensor components may comprise a portion of the spectrometer cavity.

[0034] The base of the spectrometer cavity may include a first hole. The top wall of the spectrometer cavity may include a second hole. The base of the spectrometer cavity may include a first shutter capable of opening and closing the first hole. The top wall of the spectrometer cavity may include a second shutter capable of opening and closing the second hole. When the first shutter and the second shutter are closed, the spectrometer cavity is sealed. When the first shutter and the second shutter are open, gas can enter the spectrometer cavity. One or both of the first shutter and the second shutter may be configured to open when subjected to negative pressure. In other words, one or both of the first shutter and the second shutter may be configured to open during a user's inhalation.

[0035] The light source and detector may be disposed within the spectrometer cavity. When the first shutter and the second shutter are open, gas can enter the spectrometer cavity. This gas may affect the detector output. The detector output may be affected, for example, by scattering of the light from the light source by the gas inside the spectrometer cavity.

[0036] One or both of the light source and the detector may be electrically connected to a controller as described herein. Because the light source and the detector are disposed within the spectrometer cavity, electrical connection may be facilitated by conductive tracks connecting one or both of the light source and the detector through a through-substrate connector. The through-substrate connector may extend through one or more of the first, second, and third layers of the flexible dielectric substrate.

[0037] The 3D sensor may comprise a temperature sensor.

[0038] The 3D sensor may be a temperature sensor.

[0039] One of the first, second, and third sensor components may include a heat-sensitive material, and a different one of the first, second, and third sensor components may comprise a pressure-sensitive resistor.

[0040] During a temperature change, the heat-sensitive material may expand or contract. This expansion or contraction may pressurize the pressure-sensitive resistor. The resulting resistance change may be detected by a controller as described herein.

[0041] For example, a first sensor component may include a heat-sensitive material and a third sensor component may include a pressure-sensitive resistor, or vice versa. The second sensor component may include a through-hole. The heat-sensitive material may extend through the through-hole. The pressure-sensitive resistor may be disposed on or against the pressure-sensitive resistor.

[0042] The heat-sensitive material may be attached to the flexible dielectric substrate via pins. A plate may be disposed on the opposite side of the flexible dielectric substrate layer. The pins may pass through the flexible dielectric substrate and then connect to the plate to secure the heat-sensitive material in place.

[0043] The temperature sensors may comprise at least two, preferably at least three, separate temperature sensors disposed at different locations on the wrapped or folded flexible dielectric substrate. Preferably, in this embodiment, only a single controller is provided, and all of the temperature sensors are connected to the single controller. When the 3D sensor is disposed around the cavity of the aerosol generation device, the temperature sensors may be arranged to measure the temperature at different parts of the cavity.

[0044] The 3D sensor may comprise a flow sensor configured to detect airflow through an airflow channel of the aerosol generating device to detect inhalation by a user.

[0045] One of the first, second, and third sensor components may comprise a freestanding cantilever structure. One of the first, second, and third sensor components may comprise two separate electrodes in electrical contact with the freestanding cantilever structure. As air moves across the freestanding cantilever structure, the resistance across the two separate electrodes may change. The micro- or nanoelectronic architecture of the sensor may be implemented in such a way that at least two surfaces are sensitive to changes in environmental conditions, preferably external airflow in this case. The two surfaces of the electrodes may act as polarities, and their electrical properties may change when temperature and / or humidity changes. As an example, an electronic humidity sensor can incorporate polyaniline nanofibers (PAni), which have a high response to humidity changes and rapidly change their electrical resistance. The same occurs using a PVA nanomesh humidity sensor structure. Using either of these materials, PAni, or PVA nanomesh, it is possible to assemble / construct sensors as described herein, such as those presented in the figures described below (e.g., 2A and 4A).

[0046] This change in resistance may be detected by a controller as described herein. The resistance changes to indicate a user's inhalation.

[0047] The 3D sensor may include one or more of a humidity sensor, a chemical composition sensor, and a biological signal sensor. An exemplary humidity sensor may include a zinc oxide nanostructure layer deposition as a coating for humidity sensing. The sensor may be fabricated as a freestanding cantilever structure as described herein. The sensor may be fabricated using thin-film technology. In this case, when a thin structure of ZnO nanomaterial is exposed to a moisture pulse of 95% relative humidity from standard room temperature conditions of about 60% relative humidity, the electrical resistance may change by more than four-fold, and the resistance of the applied coated film may decrease rapidly and highly reliably with increasing relative humidity, providing a wide range of possibilities for measuring gradients with sufficient accuracy for humidity sensing.

[0048] The free-standing cantilever structure may allow the flexible surfaces of the two electrodes to act as a membrane that undergoes microdeformations upon airflow conditions due to fundamental fluid mechanics and the properties of the materials comprising the membrane, which also changes its electrical properties by changing its shape upon bending.

[0049] Due to the concept of designing sensors based on overlapping thin film layers as described herein, it is then possible that different layers may have different properties and sensing in different "directions." As an example, the assemblies presented in Figures 2A or 4A described below, when the layers are arranged to overlap, may thereby allow for forming a sensor structure, which may not only sense in an internal direction and sense an internal area / volume, but may also sense in an external direction and sense an external area / volume.

[0050] The present invention further relates to a 3D sensor for use in an aerosol generating device, the 3D sensor being manufactured according to any of the methods described herein.

[0051] The present invention further relates to an aerosol generating device comprising a 3D sensor as described herein.

[0052] As used herein, the terms "proximal," "distal," "downstream," and "upstream" are used to describe the relative position of a component or portion of a component of an aerosol generating device with respect to the direction in which a user draws on the aerosol generating device during use.

[0053] The aerosol generating device may have an oral end through which the aerosol exits the aerosol generating device and is delivered to the user during use. The oral end may also be referred to as the proximal end. During use, a user draws on the proximal or oral end of the aerosol generating device to inhale the aerosol generated by the aerosol generating device. The aerosol generating device has a distal end opposite the proximal or oral end. The proximal or oral 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 oral end of the aerosol generating device and the distal or upstream end of the aerosol generating device.

[0054] As used herein, "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 an aerosol-generating article, for example part of a smoking article. The aerosol-generating device may be a smoking device that interacts with the aerosol-forming substrate of the aerosol-generating article to generate an aerosol that is inhalable directly through the user's mouth into the user's lungs. The aerosol-generating device may be a holder. The device may be an electrically heated smoking device. The aerosol-generating device may comprise a housing, an electrical circuit, a power source, a heating chamber, and a heating element.

[0055] As used herein in relation to the present invention, the term "smoking", in relation to a device, article, system, substrate or otherwise, does not refer to conventional smoking, in which the aerosol-forming substrate is completely 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 the combustion temperature of the aerosol-forming substrate but above the temperature at which one or more volatile compounds of the aerosol-forming substrate are released, in order to form an inhalable aerosol.

[0056] The aerosol generating device may comprise an electrical circuit. The electrical circuit may comprise a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electrical circuit may comprise further electronic components. The electrical circuit may be configured to regulate the supply of power to the heating element. Power may be supplied to the heating element continuously following activation of the aerosol generating device, or may be supplied intermittently, such as with each puff. Power may be supplied to the heating element in the form of current pulses. The electrical circuit may be configured to monitor the electrical resistance of the heating element and to control the supply of power to the heating element, preferably in response to the electrical resistance of the heating element. The electrical circuit may comprise a 3D sensor and a controller electrically connected to the 3D sensor. The aerosol generating device may be operated by the controller based on the output of the 3D sensor.

[0057] The aerosol generating device may include a power source, typically a battery, within the main body of the aerosol generating device. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium-cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery). Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for storage of energy sufficient for one or more use experiences; for example, the power source may have a capacity sufficient to continuously generate aerosol for approximately a six-minute period, or a multiple of six minutes. In another example, the power source may have a capacity sufficient to provide a predetermined number of puffs or discontinuous activation of the heating element.

[0058] The cavity of the aerosol generating device may have an open end into which the aerosol-generating article 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 a base of the cavity. The closed end may be closed except for the provision of an air opening disposed within 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 disposed upstream of the cavity. The open end may be disposed downstream of the cavity. The cavity may have an elongated extension. The cavity may have a longitudinal central axis. The longitudinal axis may be a direction extending along the longitudinal central axis between the open end and the closed end. The longitudinal central axis of the cavity may be parallel to the longitudinal axis of the aerosol generating device.

[0059] 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 cross-section. The cavity may have an inner diameter corresponding to the outer diameter of the aerosol-generating article. A flexible dielectric substrate having sensor components forming the 3D sensor may be disposed to at least partially, preferably completely, surround the cavity.

[0060] An airflow channel may extend through the cavity. Ambient air may be drawn through the airflow channel into the aerosol-generating device, into the cavity, and toward the user. Downstream of the cavity, a mouthpiece may be disposed, or the user may inhale the aerosol-generating article directly. The airflow channel may extend through the mouthpiece.

[0061] In any aspect of the present disclosure, the heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum platinum, gold, and silver. Examples of suitable metal alloys include stainless steel, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, gold-, and iron-containing alloys, as well as nickel-, iron-, cobalt-, and stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum-based alloys. In composite materials, the electrically resistive material may optionally be embedded in, encapsulated in, or coated with the insulating material, or vice versa, depending on the required energy transfer kinetics and external physicochemical properties.

[0062] As described, in any of the aspects of the present disclosure, the heating element may be part of the aerosol-generating device. The aerosol-generating device may include an internal heating element, an external heating element, or both an internal and an external heating element, where "internal" and "external" refer to the aerosol-forming substrate. The internal heating element may take any suitable form. For example, the 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 conductive portions or an electrically resistive metal tube. Alternatively, the internal heating element may be one or more heated needles or rods that pass through the center of the aerosol-forming substrate. Other alternatives include a heated wire or filament, such as Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire or heating plate. Optionally, the internal heating element may be disposed within or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal with a well-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 a ceramic material, and then sandwiched in another insulating material, such as glass. The heater thus formed may be used to both heat the heating element and monitor its temperature during operation.

[0063] The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils can be shaped to fit the periphery of the substrate-receiving cavity. Alternatively, the external heating element may take the form of a metal grid, a flexible printed circuit board, a molded-in circuit component (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a suitably shaped substrate. The external heating element may also be formed using a metal that has a well-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 material. The external heating element thus formed may be used both to heat the external heating element and to monitor the temperature of the external heating element during operation.

[0064] As an alternative to an electrically resistive heating element, the heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. Generally, the susceptor is a material capable of generating heat when penetrated by an alternating magnetic field. When placed within the alternating magnetic field, if the susceptor is conductive, the alternating magnetic field typically induces eddy currents. If the susceptor is magnetic, another effect that typically contributes to heating is commonly referred to as hysteresis loss. Hysteresis loss occurs primarily due to the movement of magnetic domain blocks within the susceptor as their magnetic orientation aligns with the alternating induced magnetic field. Another effect that contributes to hysteresis loss is when magnetic domains expand or contract within the susceptor. Generally, all of these changes, which occur at the nanoscale or below within the susceptor, generate heat within the susceptor, hence the term "hysteresis loss." Thus, if the susceptor is both magnetic and conductive, both hysteresis loss and the generation of eddy currents will contribute to the heating of the susceptor. If the susceptor is magnetic but not conductive, hysteresis loss will be the only means by which the susceptor will heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive or magnetic, or both conductive and magnetic. The alternating magnetic field generated by one or several induction coils heats the susceptor, which then transfers heat to the aerosol-forming substrate, thereby forming the aerosol. Heat transfer may be primarily by conduction. Such heat transfer is best when the susceptor is in intimate thermal contact with the aerosol-forming substrate.

[0065] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol. For example, the aerosol-generating article may be a smoking article that generates an aerosol that can be inhaled directly through the user's mouth into the user's lungs. The aerosol-generating article may be disposable.

[0066] As used herein, the term "aerosol-forming substrate" relates to a substrate capable of emitting one or more volatile compounds capable of forming an aerosol. Such volatile compounds may be emitted by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoking article.

[0067] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may include both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. The aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may include an aerosol former that facilitates the formation of a dense and stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0068] The aerosol-generating substrate preferably comprises a homogenized tobacco material, an aerosol former, and water. Providing a homogenized tobacco material may improve aerosol generation and the nicotine content and flavor profile of the aerosol generated during heating of the aerosol-generating article. Specifically, the process of making homogenized tobacco involves grinding tobacco leaves, which allows for more efficient release of nicotine and flavor upon heating.

[0069] For simplicity, when only the terms "wrapped" or "wrap" are used for the wrapping or folding process, this also encompasses the options "folded" or "fold."

[0070] Below 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 described above, for example, with any one or more features of other examples, embodiments, or aspects described herein.

[0071] Example 1. A method for manufacturing a 3D sensor for an aerosol generating device, comprising: providing a layer of flexible dielectric substrate; printing or mounting a first sensor component at a first location on a flexible dielectric substrate; printing or mounting a second sensor component at a second location on the flexible dielectric substrate, the second location being different from the first location; printing or mounting a third sensor component at a third location on the flexible dielectric substrate, the third location being different from the second location and different from the first location; and wrapping or folding the flexible dielectric substrate to form three layers of the flexible dielectric substrate, the first location, the second location, and the third location overlapping each other, thereby forming a 3D sensor.

[0072] Example 2. The method according to Example 1, wherein one or more of the first sensor components is an electrical sensor component, the second sensor component is an electrical sensor component, and the third sensor component is an electrical sensor component.

[0073] Example 3. The method according to any of the preceding examples, wherein one or more of the first, second, and third sensor components comprises a controller.

[0074] Example 4. The method according to any of the preceding examples, wherein one or more of the first, second, and third sensor components comprise one or more of a resistor, a capacitor, an inductor, a microprocessor, an electronic circuit, a coupling circuit, a cavity, a stud, and a heat sink.

[0075] Example 5. The method according to any of the preceding examples, wherein the method comprises a further step after the wrapping or folding step, the further step being attaching an electrical component, preferably a conductive track, to the 3D sensor.

[0076] Example 6. The method according to the preceding example, wherein attachment is facilitated using one or more of glue, friction welding, friction bonding, and ultrasonic bonding.

[0077] Example 7. A method according to either of the previous two examples, wherein attachment is facilitated using one or more of glue, epoxy, wire, and solder.

[0078] Example 8. The method according to any of the preceding examples, wherein the 3D sensor comprises a pressure sensor.

[0079] Example 9. The method according to any preceding example, wherein one of the first, second, and third sensor components comprises a sealed cavity, and a different one of the first, second, and third sensor components comprises a pressure sensitive resistor.

[0080] Example 10. The method according to any of the preceding examples, wherein the 3D sensor comprises a spectrometer.

[0081] Example 11. The method according to the preceding example, wherein one of the first, second, and third sensor components comprises a light source, and one of the first, second, and third sensor components comprises a detector.

[0082] Example 12. The method according to any of the preceding examples, wherein the 3D sensor comprises a temperature sensor.

[0083] Example 13. The method according to any preceding example, wherein one of the first, second, and third sensor components comprises a heat-sensitive material, and a different one of the first, second, and third sensor components comprises a pressure-sensitive resistor.

[0084] Example 14. A method according to either of the previous two examples, wherein the temperature sensors comprise at least two, preferably at least three, separate temperature sensors disposed at different locations on the wrapped or folded flexible dielectric substrate.

[0085] Example 15. The method according to any of the preceding examples, wherein the 3D sensor comprises a flow sensor.

[0086] Example 16. The method according to the preceding examples, wherein one of the first, second, and third sensor components comprises a free-standing cantilever structure, and one of the first, second, and third sensor components comprises two separate electrodes in electrical contact with the free-standing cantilever structure.

[0087] Example 17. The method according to any of the preceding examples, wherein the 3D sensor comprises one or more of a humidity sensor, a chemical composition sensor, and a biological signal sensor.

[0088] Example 18. A 3D sensor for use in an aerosol generating device, the 3D sensor being manufactured according to any of the preceding examples.

[0089] Example 19. An aerosol generating device equipped with the 3D sensor of the preceding example.

[0090] Features described with respect to one embodiment may be equally applied to other embodiments of the invention.

[0091] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief explanation of the drawings]

[0092] [Figures 1A-1C] 1A to 1C show a 3D sensor that includes a pressure sensor. [Figures 2A-2C] 2A-2C show a 3D sensor comprising a spectrometer. [Figure 3A-3C] 3A to 3C show a 3D sensor that includes a temperature sensor. [Figures 4A-4C] 4A-4C show a 3D sensor comprising multiple temperature sensors. [Figures 5A-5C] 5A-5C show a 3D sensor comprising a flow sensor. DETAILED DESCRIPTION OF THE INVENTION

[0093] 1A shows the 3D sensor after it has been wrapped. The 3D sensor comprises a flexible dielectric substrate 10. The flexible dielectric substrate 10 is wrapped such that three layers A-A', C-C', and E-E' of the flexible dielectric substrate 10 are disposed on top of each other in the area where the 3D sensor will be formed.

[0094] 1A-1C includes a pressure sensor 12. The pressure sensor 12 is formed by a first sensor component 14, a second sensor component 16, and a third sensor component 20.

[0095] The first sensor component 14 is disposed at a first location on a flexible dielectric substrate 20. The second sensor component 16 is disposed at a second location on a flexible dielectric substrate 22. The third sensor component 20 is disposed at a third location on a flexible dielectric substrate 24.

[0096] 1 is a base 26 of a sealed cavity 28. The second sensor component 16 comprises walls 30, particularly side walls 30, of the sealed cavity 28. The third sensor component 20 comprises a flexible diaphragm 32 forming a top wall of the sealed cavity 28, a pressure sensitive resistor 34 on the flexible diaphragm 32, the walls 30 of the sealed cavity 28, a controller 36, and conductive tracks 38 electrically connecting the pressure sensitive resistor 34 to the controller 36.

[0097] FIG. 1A shows the final 3D sensor. FIG. 1B shows a top view of the third sensor component 20 or the wrapped 3D sensor, and FIG. 1C shows the 3D sensor prior to the wrapping process. The arrangement in this figure is consistent with FIGS. 1-5. FIG. 1C shows the individual first sensor component 14, second sensor component 16, and third sensor component 20 disposed on a flexible dielectric substrate 10. A functional pressure sensor 12 is formed solely by wrapping the flexible dielectric substrate 10. Changes in the pressure of the air drawn through the aerosol generation system, particularly negative pressure, then lead to deformation of the internal volume of the sealed cavity 28. This deformation leads to outward bulging of the flexible diaphragm 32, which in turn leads to a resistance change in the pressure-sensitive resistor 34. This resistance change is detected by the controller 36 and indicates the user's inhalation.

[0098] 2A-2C show a 3D sensor comprising a spectrometer 40. The embodiment shown in Figures 2A-2C has many similar components to the embodiment shown in Figures 1A-1C, such as the flexible dielectric substrate 10, the wrapping and layering of the flexible dielectric substrate 10, and the controller 36. For brevity, the description of this embodiment and the following embodiments will focus on the differences while not describing similar elements, and similar elements will have the same reference numbers in the figures.

[0099] The spectrometer 40 of Figures 2A-2C includes a spectrometer cavity 42 having a wall 30. The first sensor component 14 at a first location on the flexible dielectric substrate 20 includes the wall 30, preferably the base 26, of the spectrometer cavity 42, and the second sensor component 16 at a second location on the flexible dielectric substrate 22 includes the wall 30, preferably the sidewall 30, of the spectrometer cavity 42. The first sensor component 14 further includes a light source 44 and a detector 46, both of which are disposed on the base 26 of the spectrometer cavity 42 such that they are inside the spectrometer cavity 42 after wrapping of the flexible dielectric substrate 10. The first sensor component 14 further includes a first shutter 48 disposed over a base hole 50 disposed in the base 26 of the flexible dielectric substrate 10. The first sensor component 14 further includes a controller 36, a first through-substrate connector 52, and a second through-substrate connector 54. The first through-substrate connector 52 and the second through-substrate connector 54 are arranged to establish an electrical connection with the conductive tracks 38 between the detector 46 and the controller 36 .

[0100] The third sensor component 18 further comprises a second shutter 56 disposed over an upper hole 58 disposed at a third location in the flexible dielectric substrate 24 .

[0101] 2A, after wrapping of the flexible dielectric substrate 10, the spectrometer cavity 42 is fully formed. The first shutter 48 and the second shutter 56 are arranged to allow air to enter the spectrometer cavity 42. The first shutter 48 and the second shutter 56 are arranged to allow air to enter the spectrometer cavity 42 during a pressure change, preferably during a negative pressure outside the spectrometer cavity 42. Gas entering the spectrometer cavity 42 may be detected by the detector 46, for example, because scattering of light from the light source 44 affects the light reaching the detector 46.

[0102] Figure 2B shows a first location of the first sensor component 14 and the flexible dielectric substrate 20. Figure 2C shows the first sensor component 14, the second sensor component 16, and the third sensor component 20 disposed on the flexible dielectric substrate 10 prior to the wrapping process. Alternatively, Figure 2C shows a top view of the wrapped 3D sensor.

[0103] 3A-3C show a 3D sensor comprising a temperature sensor 60. Only the elements that differ from the previous embodiment are described below. The first sensor component 14 of the temperature sensor 60 comprises a pressure sensitive resistor 62 and a mounting plate 64 at a first location on the flexible dielectric substrate 20.

[0104] The second sensor component 16 includes a through hole 66, and the third sensor component 20 includes a heat-sensitive material 68. A mounting pin 70 attaches the heat-sensitive material 68 to the mounting plate 64, as shown in Figure 3A.

[0105] After wrapping the flexible dielectric substrate 10, the heat-sensitive material 68 is disposed adjacent to or in contact with the pressure-sensitive resistor 62. A temperature change, particularly an increase in temperature, of the heat-sensitive material 68 leads to an expansion of the heat-sensitive material 68. The expansion of the heat-sensitive material 68 leads to pressure being applied by the heat-sensitive material 68 to the pressure-sensitive resistor 62. This leads to a change in the resistance of the pressure-sensitive resistor 62 that can be detected by the controller 36.

[0106] Figures 4A-4C show a 3D sensor comprising multiple temperature sensors 60. Each of the temperature sensors 60 is configured similarly to the temperature sensor 60 shown in Figures 3A-3C. Exemplarily, all three temperature sensors 60 shown in Figures 4A-4C are connected to a common controller 36 via conductive tracks 38.

[0107] 5A-5C illustrate a 3D sensor comprising a flow sensor 72 or flow meter. The flow sensor 72 comprises a free-standing cantilever structure 74 having a first electrode 76 and a second electrode 78. The free-standing cantilever structure 74 is disposed above a cantilever cavity 80. The cantilever cavity 80 is formed by a first sensor component 14 and a second sensor component 16. The first sensor component 14 comprises the free-standing cantilever structure 74, a first electrode 76, and a second electrode 78. When air flows across the first electrode 76 and the second electrode 78, the resistance across the first electrode 76 and the second electrode 78 changes, which can be detected by the controller 36, which is connected to the first electrode 76 and the second electrode 78 via conductive tracks 38.

Claims

1. 1. A method for manufacturing a sensor for an aerosol generating device, the sensor being formed from at least three sensor components, the method comprising: providing a layer of flexible dielectric substrate; printing or mounting a first sensor component at a first location on said flexible dielectric substrate; printing or mounting a second sensor component at a second location on the flexible dielectric substrate, the second location being different from the first location; printing or mounting a third sensor component at a third location on the flexible dielectric substrate, the third location being different from the second location and different from the first location; and wrapping or folding the flexible dielectric substrate so as to form three layers of the flexible dielectric substrate, the first location, the second location, and the third location overlapping one another, thereby forming the sensor.

2. 10. The method of claim 1, wherein one or more of the first sensor components is an electrical sensor component, the second sensor component is an electrical sensor component, and the third sensor component is an electrical sensor component.

3. The method of claim 1 , wherein one or more of the first, second, and third sensor components comprises a controller.

4. The method of claim 1 , wherein the sensor comprises a pressure sensor.

5. 5. The method of claim 4, wherein one of the first, second, and third sensor components comprises a sealed cavity, and a different one of the first, second, and third sensor components comprises a pressure sensitive resistor.

6. The method of claim 1 , wherein the sensor comprises a spectrometer.

7. 7. The method of claim 6, wherein one of the first, second, and third sensor components comprises a light source, and a different one of the first, second, and third sensor components comprises a detector.

8. The method of claim 1 , wherein the sensor comprises a temperature sensor.

9. 9. The method of claim 8, wherein one of the first, second, and third sensor components comprises a heat-sensitive material, and a different one of the first, second, and third sensor components comprises a pressure-sensitive resistor.

10. 9. The method of claim 8, wherein the temperature sensor comprises at least two, preferably at least three, separate temperature sensors disposed at different locations on the wrapped or folded flexible dielectric substrate.

11. The method of claim 1 , wherein the sensor comprises a flow sensor.

12. 12. The method of claim 11 , wherein one of the first, second, and third sensor components comprises a free-standing cantilever structure, and one of the first, second, and third sensor components comprises two separate electrodes in electrical contact with the free-standing cantilever structure.

13. The method of claim 1 , wherein the sensor comprises one or more of a humidity sensor, a chemical composition sensor, and a biosignal sensor.

14. The method of claim 1 , wherein the sensor is a 3D sensor.

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