Aerosol-generating device with matrix sensor

Abstract

The present invention relates to an aerosol-generating device comprising a cavity for receiving an aerosol-forming substrate. The aerosol-generating device also includes an upstream airflow passage through the cavity. The aerosol-generating device also includes a substrate sensor arranged to fluidly interface with the upstream airflow channel. The substrate sensor is configured to detect a degree of consumption of the aerosol-forming substrate. The invention also relates to an aerosol-generating system comprising an aerosol-generating device and an aerosol-generating article or cartridge. The invention also relates to a method for detecting the degree of consumption of an aerosol-forming substrate of an aerosol-generating article in an aerosol-generating device.

Description

[0001] The present invention relates to an aerosol generating device. The present invention also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article comprising an aerosol-forming substrate. The present invention also relates to a method for detecting the degree of consumption of an aerosol-forming substrate of an aerosol generating article in an aerosol generating device.

[0002] It is known to provide an aerosol generating device for generating an inhalable vapour. Such a device 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 strip shape for inserting the aerosol-generating article into a cavity (e.g., a heating chamber) of the aerosol-generating device. A heating element may be arranged in or around the heating chamber so as to heat the aerosol-forming substrate once the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] It would be desirable to have an aerosol-generating device that enables a user to know when an aerosol-generating article is exhausted. It would be desirable to have an aerosol-generating device that enables a user to know the stage of consumption of an aerosol-generating article.

[0004] According to an embodiment of the present invention, an aerosol generating device is provided, which may include a cavity for receiving an aerosol-forming substrate. The aerosol generating device may also include an airflow channel passing through the cavity. The aerosol generating device may also include a substrate sensor. The substrate sensor may be arranged in the cavity or arranged adjacent to the cavity. The substrate sensor may be configured to detect the degree of consumption of the aerosol-forming substrate.

[0005] According to an embodiment of the present invention, an aerosol generating device is provided, comprising a cavity for receiving an aerosol-forming substrate. The aerosol generating device also comprises an airflow channel passing through the cavity. The aerosol generating device also comprises a substrate sensor. The substrate sensor is arranged in the cavity or arranged adjacent to the cavity. The substrate sensor is configured to detect the degree of consumption of the aerosol-forming substrate.

[0006] According to an embodiment of the present invention, an aerosol generating device is provided, which may include a cavity for receiving an aerosol-forming substrate. The aerosol generating device may also include an upstream airflow channel passing through the cavity. The aerosol generating device may also include a substrate sensor arranged to fluidly interface with the upstream airflow channel. The substrate sensor may be configured to detect the degree of consumption of the aerosol-forming substrate.

[0007] According to an embodiment of the present invention, there is provided an aerosol generating device comprising a cavity for receiving an aerosol-forming substrate. The aerosol generating device further comprises an upstream airflow channel passing through the cavity. The aerosol generating device further comprises a substrate sensor arranged to fluidly interface with the upstream airflow channel. The substrate sensor is configured to detect a degree of consumption of the aerosol-forming substrate.

[0008] Detecting the extent of consumption of the aerosol-forming substrate enables the user to know the stage of consumption of the aerosol-forming substrate. Thus, the user can know when the aerosol-forming substrate is exhausted and when a new aerosol-forming substrate needs to be received in the cavity.

[0009] The matrix sensor may be a pH sensor.

[0010] During continued consumption of the aerosol-forming substrate, the pH value of the aerosol-forming substrate may change. This change in the pH value of the aerosol-forming substrate may be detected by the sensor.

[0011] The matrix sensor may have a measuring range between 2 pH and 10 pH, preferably between 3 pH and 9 pH, most preferably between 5 pH and 8 pH.

[0012] The matrix sensor may have a measurement accuracy of ± 0.02 pH at pH 7. Preferably, the matrix sensor has a measurement accuracy of ± 0.01 pH at pH 7.

[0013] The matrix sensor can have a drift of less than 0.05 pH / day at pH 7.

[0014] The aerosol generating device may be configured to heat the aerosol-forming substrate to a temperature above which the aerosol is generated during and between puffs. Between puffs, vaporizable material from the aerosol-forming substrate may be vaporized due to the temperature to which the aerosol-forming substrate is heated between puffs. When a consumer draws on the aerosol generating device or on the aerosol-forming substrate, the vaporized vaporizable material may be entrained in the airflow to generate an inhalable aerosol.

[0015] The substrate sensor may be configured to measure the rate of consumption of the aerosol-forming substrate between puffs, preferably the pH value.

[0016] Measuring the consumption rate of the aerosol-forming substrate between puffs may have the advantage that the consumption rate can be accurately determined. During puffs, air may flow through the device, and the evaporated evaporable substrate of the aerosol-forming substrate may be entrained in the airflow. It may be difficult to measure the accurate consumption rate of the aerosol-forming substrate during puffs. However, between puffs, there is no airflow flowing through the device, so that the consumption rate measurement of the evaporated evaporable material from the aerosol-forming substrate may be more accurate. In addition, due to the lack of airflow through the aerosol generating device, the evaporated evaporable material from the aerosol-forming substrate can reach the substrate sensor to improve the accuracy of the measurement between puffs.

[0017] The substrate sensor may be disposed in or adjacent to the upstream end of the cavity.

[0018] The upstream end of cavity can be the base of cavity.When aerosol forms substrate and is received in cavity, aerosol forms substrate and can be arranged to the upstream end of adjacent cavity.In other words, when aerosol forms substrate and is received in cavity, aerosol forms substrate and can be directly received in the downstream of the upstream end of cavity.By substrate sensor is placed in the upstream end of cavity or is placed into adjacent upstream end, substrate sensor can be placed in the region beside the region where the evaporable material of aerosol-forming substrate in cavity is evaporated.Particularly between suction, because aerosol forms the small distance between substrate and substrate sensor, therefore the evaporable material of the evaporation from aerosol forms substrate can expand slightly and flow towards substrate sensor, to realize accurate measurement.

[0019] The substrate sensor can be arranged in adjacent air flow channel.The air flow channel can be a central air flow channel.The substrate sensor can be in direct contact with the air flow channel.The substrate sensor can be a part for air flow channel.The substrate sensor can comprise one or more air channels as a part for air flow channel.Preferably, the substrate comprises at least two, preferably a plurality of air channels as a part for air flow channel.The air channel can be arranged with an annular arrangement, to allow the lateral airflow from all directions towards the orifice in the upstream end of the chamber.

[0020] The airflow channel may enter the cavity at the upstream end of the cavity. The cavity may include an orifice to allow air to flow into the cavity from the airflow channel. The orifice may be centrally arranged at the upstream end of the cavity. The substrate sensor may be directly adjacent to the orifice arrangement at the upstream end of the cavity. The substrate sensor may partially form the orifice. The orifice may be arranged in the substrate sensor. The orifice may be a part of the substrate sensor.

[0021] The substrate sensor may be configured to detect the nicotine content of an aerosol drawn through the airflow channel.

[0022] The substrate sensor may be configured to detect the nicotine content of the aerosol-forming substrate. The substrate sensor may be configured to detect the nicotine content of the vaporized vaporizable material of the aerosol-forming substrate. The substrate sensor may be configured to detect the nicotine content during puffing. Alternatively, the substrate sensor may be configured to detect the nicotine content between puffs. As another alternative, the substrate sensor may be configured to detect the nicotine content of the aerosol generated during puffing, and the nicotine content of the vaporized vaporizable material of the aerosol-forming substrate between puffs.

[0023] The substrate sensor may be configured to detect the pH of an aerosol drawn through the airflow channel.

[0024] The substrate sensor may be configured to detect the pH value of the aerosol-forming substrate. The substrate sensor may be configured to detect the pH value of the evaporated vaporizable material of the aerosol-forming substrate. The substrate sensor may be configured to detect the pH value during puffing. Alternatively, the substrate sensor may be configured to detect the pH value between puffs. As another alternative, the substrate sensor may be configured to detect the pH value of the aerosol generated during puffing, and the pH value of the evaporated vaporizable material of the aerosol-forming substrate between puffs.

[0025] The aerosol generating device may further comprise a controller.The controller may be configured to generate a signal based on the output of the substrate sensor if the level of consumption of the aerosol-forming substrate falls below a predetermined threshold.

[0026] The signal may indicate the extent of consumption of the aerosol-forming substrate.The aerosol generating device may be configured to output a signal to a consumer.

[0027] The signal may be one or more of a user interface signal, a light signal, a sound signal, and a vibration signal.

[0028] The signal may comprise information provided to the user when the aerosol-forming substrate must be renewed. The signal may comprise information provided to the user when the aerosol-forming substrate is exhausted. The signal may comprise information provided to the user of the replacement interval of the aerosol-forming substrate.

[0029] The controller may be configured to end operation of the aerosol generating device after a predetermined time or a predetermined number of puffs by a user if the extent of consumption of the aerosol-forming substrate may be below a predetermined threshold.

[0030] The controller may be configured to end operation of the aerosol generating device if the level of consumption of the aerosol-forming substrate may be below a predetermined threshold.

[0031] The extent of depletion of the aerosol-forming substrate may be the nicotine content or pH of the aerosol drawn through the airflow channel.

[0032] The extent of consumption of the aerosol-forming substrate may be the nicotine content or pH of the aerosol during a puff by a user. The extent of consumption of the aerosol-forming substrate may be the nicotine content or pH of the vaporized vaporizable material of the aerosol-forming substrate between uses of the aerosol generating device. The extent of consumption of the aerosol-forming substrate may be the nicotine content or pH of both the aerosol during a puff by a user and the vaporized vaporizable material of the aerosol-forming substrate between uses of the aerosol generating device.

[0033] The aerosol generating device may further have an activation button.The substrate sensor may be configured to start detecting the extent of consumption of the aerosol-forming substrate after a predetermined time after pressing the activation button or after a predetermined number of puffs by a user after pressing the activation button.

[0034] Alternatively, the substrate sensor may be configured to detect the rate of consumption of the aerosol-forming substrate immediately after pressing the activation button. As another alternative, the substrate sensor may be configured to perform a consumption rate analysis of the aerosol-forming substrate immediately after pressing the activation button, and only allow activation of the aerosol generating device if the rate of consumption of the aerosol-forming substrate is found to be not below a predetermined threshold.

[0035] The substrate sensor may be configured to continuously detect the extent of consumption of the aerosol-forming substrate during operation of the aerosol generating device or when approaching an estimated consumption of the aerosol-forming substrate. The consumption estimate may be based on a predetermined time after pressing the activation button or on a predetermined number of puffs by a user after pressing the activation button.

[0036] The present invention further relates to an aerosol generating system comprising an aerosol generating device as described herein and an aerosol generating article comprising an aerosol-forming substrate.

[0037] The present invention also relates to a method for detecting the extent of consumption of an aerosol-forming substrate of an aerosol-generating article in an aerosol-generating device as described herein, the method comprising:

[0038] - Detecting the extent of consumption of the aerosol-forming substrate by the substrate sensor.

[0039] As used herein, the terms “proximal”, “distal”, “upstream” and “downstream” are used to describe the relative position of components or parts of components of an aerosol generating device relative to the direction in which a user draws puffs on the aerosol generating device during use.

[0040] The aerosol generating device may include a mouth end, through which the aerosol leaves the aerosol generating device and is delivered to the user when in use. The mouth end may also be referred to as a proximal end. When in use, the user draws on the proximal end or mouth end of the aerosol generating device to inhale the aerosol generated by the aerosol generating device. Alternatively, the user may draw directly on an aerosol generating article inserted into an opening at the proximal end of the aerosol generating device. The opening at the proximal end may be an opening of a cavity. The cavity may be configured to receive the aerosol generating article. The aerosol generating device includes a distal end opposite to the proximal end or mouth end. The proximal end or mouth end of the aerosol generating device may also be referred to as a downstream end, while the distal end of the aerosol generating device may also be referred to as an upstream end. Components or parts of components of the aerosol generating device may be described as upstream or downstream of each other based on their relative positions between the proximal end, downstream end or mouth end and the distal end or upstream end of the aerosol generating device.

[0041] As used herein, an "aerosol generating device" relates to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate may be part of an aerosol-generating article, such as a part of a smoking article. The aerosol generating device may be a smoking device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol that can be inhaled directly into the user's lungs through the user's mouth. The aerosol generating device may be a holder. The device may be an electrically heated smoking device. The aerosol generating device may include a housing, a circuit, a power supply, a heating chamber, and a heating element.

[0042] As used herein with reference to the present invention, the term "smoking" used 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 that is below the combustion temperature of the aerosol-forming substrate but at or above the temperature at which one or more volatile compounds of the aerosol-forming substrate are released to form an inhalable aerosol.

[0043] The aerosol generating device may include an electrical circuit. The electrical circuit system may include a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electrical circuit system may include additional electronic components. The electrical circuit system may be configured to regulate the supply of power to the heating element. Power may be continuously supplied to the heating element after activation of the aerosol generating device, or may be supplied intermittently, such as on a puff-by-puff basis. Power may be supplied to the heating element in the form of current pulses. The electrical circuit may be configured to monitor the resistance of the heating element and preferably control the supply of power to the heating element depending on the resistance of the heating element.

[0044] The aerosol generating device may include a power source, typically a battery, within the 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 such as a lithium-cobalt, lithium-iron-phosphate, lithium titanate, or lithium-polymer battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may need to be recharged and may have a capacity that enables storage of sufficient energy for one or more use experiences; for example, the power source may have sufficient capacity to continuously generate an aerosol for a period of about six minutes or a multiple of six minutes. In another example, the power source may have sufficient capacity to provide a predetermined number of puffs or discontinuous activation of the heating element.

[0045] 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 the base of the cavity. The closed end may be closed except for providing air holes arranged in the base. The base of the cavity may be flat. The base of the cavity may be circular. The base of the cavity may be arranged upstream of the cavity. The open end may be arranged downstream of the cavity. The cavity may have an elongated extension. The cavity may have a longitudinal central axis. The longitudinal direction 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.

[0046] 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 shape of the cavity may correspond 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.

[0047] The airflow channel may pass through the cavity. Ambient air may be drawn into the aerosol generating device through the airflow channel, into the cavity and towards the user. Downstream of the cavity, a mouthpiece may be arranged, or the user may draw directly on the aerosol generating article. The airflow channel may extend through the mouthpiece.

[0048] In any aspect of the present disclosure, the heating element may include a resistive material. Suitable resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, platinum, gold, and silver. Examples of suitable metal alloys include stainless steel, nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, gold-containing alloys, iron-containing alloys, and superalloys based on nickel, iron, cobalt, stainless steel, Timetal®, and iron-manganese-aluminum alloys. In the composite material, the resistive material may be optionally embedded in an insulating material, encapsulated by an insulating material, or coated by an insulating material, or vice versa, depending on the kinetics of energy transfer and the desired external physicochemical properties.

[0049] As described, in any of the aspects of the present disclosure, the heating element can be part of an aerosol generating device. The aerosol generating device may include an internal heating element or an external heating element or both, where "inside" and "outside" are for the aerosol forming substrate. The internal heating element can take any suitable form. For example, the internal heating element can take the form of a heating blade. Alternatively, the internal heater can take the form of a sleeve or substrate with different conductive portions, or a resistive metal tube. Alternatively, the internal heating element can be one or more heating needles or rods extending through the center of the aerosol forming substrate. Other alternatives include heating wires or filaments, for example, Ni-Cr (nickel-chromium), platinum, tungsten or alloy wires or heating plates. Optionally, the internal heating element can be deposited in or on a rigid carrier material. In one such embodiment, the resistive heating element can be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal can 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). A heater formed in this manner may be used to both heat and monitor the temperature of the heating element during operation.

[0050] The external heating element can take any suitable form. For example, the external heating element can take the form of one or more flexible heating foils on a dielectric substrate (e.g., polyimide). The flexible heating foil can be shaped to conform to the periphery of the substrate receiving cavity. Alternatively, the external heating element can take the form of a metal grid, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or can be formed on a suitable shaped substrate using a coating technique (e.g., plasma vapor deposition). The external heating element can also be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal can be formed as a track between two layers of suitable insulating materials. The external heating element formed in this way can be used to heat and monitor the temperature of the external heating element during operation.

[0051] As an alternative to a resistive heating element, the heating element may be configured as an induction heating element. An induction heating element may include an induction coil and a susceptor. Generally speaking, a susceptor is a material that is capable of generating heat when penetrated by an alternating magnetic field. When located in an alternating magnetic field. If the susceptor is conductive, eddy currents are typically induced by the alternating magnetic field. If the susceptor is magnetic, another effect that generally contributes to heating is generally referred to as hysteresis losses. Hysteresis losses are primarily generated by the movement of magnetic domain blocks within the susceptor, as the magnetic orientation of these domain blocks will be aligned with the alternating magnetic induction field. Another effect that contributes to hysteresis losses is when magnetic domains will grow or shrink within the susceptor. Generally, all of these changes in the susceptor that occur at the nanoscale or below are referred to as "hysteresis losses" because they generate heat in the susceptor. Therefore, if the susceptor is both magnetic and conductive, both hysteresis losses and eddy current generation will contribute to the heating of the susceptor. If the susceptor is magnetic, but non-conductive, hysteresis losses will be the only means of heating the susceptor when penetrated by an alternating magnetic field. According to the invention, the susceptor may be conductive or magnetic, or both. The alternating magnetic field generated by the induction coil or coils heats the susceptor, which then transfers heat to the aerosol-forming substrate, causing aerosol formation. The heat transfer may be primarily by thermal conduction. Such heat transfer is optimal if the susceptor is in close thermal contact with the aerosol-forming substrate.

[0052] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of releasing volatile compounds that can form an aerosol. For example, the aerosol-generating article may be a smoking article that generates an aerosol that can be inhaled directly into the user's lungs through the user's mouth. The aerosol-generating article may be disposable.

[0053] As used herein, the term "aerosol-forming substrate" relates to a substrate capable of releasing one or more volatile compounds that can form an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may suitably be part of an aerosol-generating article or a smoking article.

[0054] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may be a liquid aerosol-forming substrate contained in a replaceable cartridge connectable to an aerosol generating device or contained in a refillable liquid storage portion of an aerosol generating device. The aerosol-forming substrate may include both solid and liquid components.

[0055] Aerosol formation substrate can comprise tobacco-containing material, and described tobacco-containing material contains the volatile tobacco flavor compound that releases from substrate when heating.Aerosol formation substrate can comprise non-tobacco material.Aerosol formation substrate can comprise the aerosol forming agent that helps dense and stable aerosol to form.The example of suitable aerosol forming agent is glycerol and propylene glycol.

[0056] The aerosol-generating substrate preferably comprises: homogenized tobacco material, an aerosol-forming agent and water. Providing a homogenized tobacco material can improve aerosol generation, nicotine content and flavor characteristics of the aerosol generated during heating of the aerosol-generating article. Specifically, the process of making homogenized tobacco involves grinding tobacco leaves, which more effectively achieves the release of nicotine and flavor when heated.

[0057] A non-exhaustive list of non-limiting examples is provided below.Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0058] Example ex1. An aerosol generating device, the aerosol generating device comprising:

[0059] a cavity for receiving the aerosol-forming substrate,

[0060] an airflow passage through the cavity, and

[0061] Matrix sensor,

[0062] Wherein the substrate sensor is arranged in or adjacent to the cavity, and wherein the substrate sensor is configured to detect the extent of consumption of the aerosol-forming substrate.

[0063] Example ex2. An aerosol generating device according to example ex1, wherein the substrate sensor is a pH sensor.

[0064] Example ex3. An aerosol generating device according to the preceding example, wherein the substrate sensor has a measurement range between 2 pH and 10 pH, preferably between 3 pH and 9 pH, most preferably between 5 pH and 8 pH.

[0065] Example ex4. An aerosol generating device according to any one of the two preceding examples, wherein the substrate sensor has a measurement accuracy of ± 0.02 pH at pH 7, preferably wherein the substrate sensor has a measurement accuracy of ± 0.01 pH at pH 7.

[0066] Example ex5. An aerosol generating device according to any one of the three preceding examples, wherein the substrate sensor has a drift of less than 0.05 pH / day at pH 7.

[0067] Example ex6. An aerosol generating device according to any preceding example, wherein the substrate sensor is arranged in or adjacent to the upstream end of the cavity.

[0068] Example ex7. An aerosol generating device according to any preceding example, wherein the substrate sensor is configured to detect a nicotine content of an aerosol drawn through the airflow channel.

[0069] Example ex8. An aerosol generating device according to any preceding example, wherein the substrate sensor is configured to detect a pH value of an aerosol drawn through the airflow channel.

[0070] Example ex9. An aerosol generating device according to any preceding example, wherein the aerosol generating device further comprises a controller, and wherein the controller is configured to generate a signal based on the output of the substrate sensor if the degree of consumption of the aerosol-forming substrate falls below a predetermined threshold.

[0071] Example ex10. The aerosol generating device according to the previous example, wherein the signal is one or more of a signal of a user interface, a light signal, a sound signal, and a vibration signal.

[0072] Example ex11. An aerosol generating device according to any one of the two preceding examples, wherein the controller is configured to end the operation of the aerosol generating device after a predetermined time or a predetermined number of puffs by a user if the degree of consumption of the aerosol-forming substrate is below the predetermined threshold.

[0073] Example ex12. An aerosol generating device according to any preceding example, wherein the extent of consumption of the aerosol-forming substrate is the nicotine content or pH value of the aerosol drawn through the airflow channel.

[0074] Example ex13. An aerosol generating device according to any of the preceding examples, wherein the aerosol generating device also has an activation button, and wherein the substrate sensor is configured to start detecting the degree of consumption of the aerosol-forming substrate after a predetermined time after pressing the activation button or after a predetermined number of puffs by the user after pressing the activation button.

[0075] Example ex14. An aerosol generating device according to the previous example, wherein the substrate sensor is configured to continuously detect the degree of consumption of the aerosol-forming substrate during operation of the aerosol generating device or when approaching the estimated consumption of the aerosol-forming substrate, wherein the consumption estimate is preferably based on a predetermined time after pressing the activation button or based on a predetermined number of puffs by the user after pressing the activation button.

[0076] Example ex15. An aerosol generating system comprising an aerosol generating device according to any preceding example and an aerosol generating article comprising an aerosol-forming substrate.

[0077] Example ex16. A method for detecting the extent of consumption of an aerosol-forming substrate of an aerosol-generating article in an aerosol-generating device according to any one of examples 1 to 14, the method comprising:

[0078] - Detecting the extent of consumption of the aerosol-forming substrate by the substrate sensor.

[0079] Features described with respect to one embodiment may be equally applicable to other embodiments of the invention.

[0080] The present invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0081] Figure 1 A, 1B and 1C show an aerosol generating device with a substrate sensor;

[0082] Figure 2 A and 2B show more detailed views of the interaction between an aerosol-generating article comprising an aerosol-forming substrate and a substrate sensor;

[0083] Figure 3 A and 3B show more detailed views of the matrix sensor;

[0084] Figure 4 Another embodiment of an aerosol generating device utilizing a liquid aerosol-forming substrate is shown; and

[0085] Figure 5 Shows Figure 4 Alternative positioning of the matrix sensor in the embodiments.

[0086] Figure 1A shows an aerosol generating device 10. The aerosol generating device 10 comprises a cavity 12 for receiving an aerosol-forming substrate 14. The aerosol-forming substrate 14 is part of an aerosol generating article 16 which is partially received in the cavity 12 of the aerosol generating device 10. A consumer may draw directly on the proximal end of the aerosol generating article 16 during use.

[0087] Figure 1 B shows a view of the aerosol generating device 10 in which the aerosol generating article 16 is not received in the cavity 12. The heating element 18 is arranged at least partially around the cavity 12. The heating element 18 can be arranged in a distal portion or an upstream portion of the cavity 12. More specifically, the heating element 18 includes an induction coil surrounding the distal portion of the cavity 12. In addition, a susceptor is arranged within the aerosol-forming substrate 14 of the aerosol generating article 16. When the aerosol generating article 16 is received in the cavity 12, the induction coil generates an alternating magnetic field that heats the susceptor within the aerosol-forming substrate 14 in the aerosol generating article 16.

[0088] The substrate sensor 22 is arranged adjacent the upstream end 20 of the cavity 12. The substrate sensor 22 is configured to detect a consumption rate of the aerosol-forming substrate 14 when the aerosol-forming substrate 14 is received in the cavity 12.

[0089] The aerosol generating device 10 also includes a controller 24 , and a power source in the form of a battery 26 .

[0090] Figure 1 C shows that Figure 1 B, but with an aerosol-generating article 16 received in the cavity 12. As can be seen, the aerosol-forming substrate 14 of the aerosol-generating article 16 is placed proximate to the substrate sensor 22. Thus, the substrate sensor 22 can detect the rate of consumption of the aerosol-forming substrate 14. The substrate sensor 22 may be configured to detect the rate of consumption of the aerosol-forming substrate 14 during use, between uses, or both during and between uses.

[0091] The substrate sensor 22 is configured as a pH sensor or a nicotine content sensor.

[0092] During use, air is drawn by a user through the aerosol-forming substrate 14 disposed in the cavity 12. Therefore, during use, the substrate sensor 22 may be configured to detect the rate of consumption of the aerosol-forming substrate 14 by measuring the pH value or nicotine content of the aerosol drawn through the cavity 12. To this end, the substrate sensor 22 may also be placed at different locations in the cavity 12, such as at a downstream portion of the cavity 12. Preferably, the substrate sensor 22 is placed upstream of the aerosol-generating article 16. Preferably, the substrate sensor 22 is placed facing the upstream end of the aerosol-generating article 16.

[0093] Between uses, the heating element 18 is configured to heat the aerosol-forming substrate 14 of the aerosol-generating article 16 to a temperature above the vaporization temperature of the vaporizable material of the aerosol-forming substrate 14. The vaporized vaporizable material of the aerosol-forming substrate 14 will expand slightly and reach the substrate sensor 22. Therefore, the substrate sensor 22 can optimally detect the consumption rate of the aerosol-forming substrate 14 between puffs. Alternatively, the substrate sensor 22 can be configured to detect the consumption rate of the aerosol-forming substrate 14 from a distance. Exemplarily, the substrate sensor 22 may include a light source and a detector to detect the consumption rate of the aerosol-forming substrate from a distance.

[0094] The substrate sensor 22 may be a pH sensor. Silica fiber based electrodes having high accuracy and small size may be used.

[0095] The measurement range of the substrate sensor 22 can be between about 2 pH and 10 pH, preferably between about 3 pH and 9 pH, and most preferably between 5 pH and 8 pH. The accuracy of the substrate sensor 22 can have a resolution of ± 0.02 pH at pH = 7. Generally, the accuracy can be ± 0.1 pH at pH = 7. The substrate sensor 22 can utilize an automatic sensor calibration performed by a controller. The substrate sensor 22 can have a drift of < 0.05 pH / day at pH = 7 (with a sampling interval of 1 minute). The substrate sensor 22 can have a measurement temperature in the range of + 5 to + 50°C. The substrate sensor 22 can have a response time (t90) of < 30 seconds, preferably < 20 seconds, and most preferably < 10 seconds at a standard ISO room temperature range of 25°C.

[0096] The sensor should monitor the pH value and, depending on this value, send a signal such that when the experience is about to end, a different light signal is switched on, ie for example a green light or a red light.

[0097] Figure 2 Shown in Figure 2 During the use of A and Figure 2 A more detailed view of an aerosol-generating article 16 comprising an aerosol-forming substrate 14 in an airflow, as shown in FIG. Figure 2As can be seen in Figure 1, during use, air is drawn into the aerosol generating article 16 at the upstream end 20 of the aerosol generating article 16. The air travels through the aerosol generating article in the downstream direction 28, and the evaporated evaporable material of the aerosol forming substrate 14 is entrained in the airflow. Downstream, the evaporated evaporable material of the aerosol forming material forms droplets, so that the aerosol is ultimately delivered to the consumer. Due to the proximity of the substrate sensor 22 at the upstream end 20 of the aerosol generating article 16, the air flowing through the substrate sensor 22 can be checked by the substrate sensor 22 for pH or nicotine content. Therefore, the substrate sensor 22 can detect the consumption rate of the aerosol forming substrate 14.

[0098] exist Figure 2 In depiction B, a situation between uses is shown. In this case, no air flows through the aerosol-generating article 16. However, since the heating element 18 still heats the aerosol-forming substrate 14 to a temperature above the vaporization temperature of the vaporizable material of the aerosol-forming substrate 14, vaporizable material of the aerosol-forming substrate 14 is produced. This vaporized vaporizable material of the aerosol-forming substrate 14 may reach the substrate sensor 22. Additionally or alternatively, the substrate sensor 22 may be able to detect the consumption rate of the vaporized vaporizable material of the aerosol-forming substrate 14 from a distance.

[0099] Figure 2 Further details about the aerosol generating article 16 are also shown. Downstream of the aerosol-forming substrate 14, a hollow tubular section 30 of the aerosol generating article 16 is provided. Downstream of the hollow tubular section 30, a filter element 32 is arranged. The filter element 32 is configured to cool the airflow for aerosol generation. A downstream filter segment 34 is arranged downstream of the filter element 32 and forms the most downstream section of the aerosol generating article 16.

[0100] Figure 3 A more detailed view of the configuration of the substrate sensor 22 is shown. The substrate sensor 22 comprises a plurality of laterally arranged and annular air channels 36. All of these air channels 36 lead to a central part of the substrate sensor 22 where the actual detection takes place. The air then flows downstream into the cavity 12. The central part of the substrate sensor 22 may be part of an orifice 38 leading to the cavity 12 or may form an orifice 38 leading to the cavity 12. The substrate sensor 22 is centrally arranged at the longitudinal axis of the aerosol generating device 10. The longitudinal axis of the aerosol generating device 10 is simultaneously the longitudinal axis of the cavity 12.

[0101] Figure 4 An alternative aerosol generating device is shown. Elements similar to elements from previously described embodiments will be denoted by the same reference numerals and will not be described again.

[0102] Figure 4 The aerosol generating device 10 of the embodiment is configured to utilize a liquid aerosol-forming substrate 14. The liquid aerosol-forming substrate 14 is disposed in a cartridge 40. The cartridge 40 may be configured to be replaceable or refillable. In the case of a refillable cartridge 40, the cartridge 40 may be a part of the aerosol generating device 10 and is represented as a liquid storage portion. The cartridge 40 or the liquid storage portion may be received in the cavity 12. A mouthpiece 42 is disposed downstream of the cartridge 40. The mouthpiece 42 includes an air outlet 44 at a downstream end through which an inhalable aerosol may leave the mouthpiece 42. An air flow channel 46 fluidly connects the air inlet 48 to the aerosolization zone 50.

[0103] The heating element 18 is arranged adjacent to the aerosolization zone 50. The heating element 18 is arranged in fluid connection with the aerosolization zone 50. The heating element 18 can be configured as a resistive heating element 18, preferably a mesh heater, or as an inductive heating element 18. The heating element 18 is electrically connected to the controller 24 via a heating connection 52.

[0104] The mouthpiece 42 is arranged downstream of the aerosolization zone 50. The airflow channel 46 fluidly connects the aerosolization zone 50 with the mouthpiece 42. The substrate sensor 22 is arranged adjacent to, preferably adjacent to, the aerosolization zone 50. The substrate sensor 22 is arranged in fluid connection with the aerosolization zone 50. The substrate sensor 22 can be part of the cartridge 40 or separate from the cartridge 50 as part of the aerosol generating device 10. The substrate sensor 22 is electrically connected to the controller 24 via a sensor connection 54.

[0105] Alternatively, if Figure 5 As shown, the substrate sensor 22 may be disposed downstream of the aerosolization zone 50. In other words, the substrate sensor 22 may be disposed downstream of the cartridge 40. In this case, the substrate sensor 22 is disposed downstream of one or both of the aerosolization zone 50 and the cartridge 40 to be fluidically connected to the airflow channel 46.

Claims

1. An aerosol generating device, comprising: a cavity for receiving the aerosol-forming substrate, an upstream airflow passage through the cavity, and a substrate sensor arranged to fluidly interface with the upstream gas flow channel, Wherein the substrate sensor is configured to detect the extent of consumption of the aerosol-forming substrate.

2. An aerosol generating device according to claim 1, wherein the substrate sensor is a pH sensor.

3. An aerosol generating device according to the preceding claim, wherein the substrate sensor has a measurement range between 2 pH and 10 pH, preferably between 3 pH and 9 pH, most preferably between 5 pH and 8 pH.

4. An aerosol generating device according to any of the two preceding claims, wherein the substrate sensor has a measurement accuracy of ± 0.02 pH at pH 7, preferably wherein the substrate sensor has a measurement accuracy of ± 0.01 pH at pH 7.

5. An aerosol generating device according to any one of the three preceding claims, wherein the substrate sensor has a drift of less than 0.05 pH / day at pH 7.

6. An aerosol generating device according to any preceding claim, wherein the substrate sensor is arranged in or adjacent an upstream end of the cavity.

7. An aerosol generating device according to any preceding claim, wherein the substrate sensor is configured to detect the nicotine content of an aerosol drawn through the airflow channel.

8. An aerosol generating device according to any preceding claim, wherein the substrate sensor is configured to detect the pH of an aerosol drawn through the airflow channel.

9. An aerosol generating device according to any preceding claim, wherein the aerosol generating device further comprises a controller, and wherein the controller is configured to generate a signal based on the output of the substrate sensor if the degree of consumption of the aerosol-forming substrate falls below a predetermined threshold, preferably wherein the signal is one or more of a user interface signal, a light signal, a sound signal and a vibration signal.

10. An aerosol generating device according to the preceding claim, wherein the controller is configured to end operation of the aerosol generating device after a predetermined time or a predetermined number of puffs by a user if the degree of consumption of the aerosol-forming substrate is below the predetermined threshold.

11. An aerosol generating device according to any preceding claim, wherein the extent of depletion of the aerosol-forming substrate is the nicotine content or pH of an aerosol drawn through the airflow channel.

12. An aerosol generating device according to any preceding claim, wherein the aerosol generating device also has an activation button, and wherein the substrate sensor is configured to start detecting the degree of consumption of the aerosol-forming substrate after a predetermined time after pressing the activation button or after a predetermined number of puffs by the user after pressing the activation button.

13. An aerosol generating device according to the preceding claim, wherein the substrate sensor is configured to continuously detect the degree of consumption of the aerosol forming substrate during operation of the aerosol generating device or when approaching an estimated consumption of the aerosol forming substrate, wherein the consumption estimate is preferably based on a predetermined time after pressing the activation button or on a predetermined number of puffs by the user after pressing the activation button.

14. An aerosol generating device according to any preceding claim, wherein the upstream airflow channel passes between a side wall of the aerosol-forming substrate and a side wall defining the cavity.

15. An aerosol generating device according to any preceding claim, wherein the substrate sensor is arranged facing an upstream end of the aerosol-forming substrate.

16. An aerosol generating system comprising an aerosol generating device according to any preceding claim, and one of an aerosol generating article comprising an aerosol-forming substrate and a cartridge comprising a liquid aerosol-forming substrate.

17. A method for detecting the extent of consumption of an aerosol-forming substrate of an aerosol-generating article or cartridge in an aerosol-generating device according to any one of claims 1 to 13, the method comprising: - Detecting the extent of consumption of the aerosol-forming substrate by the substrate sensor.

Images