Determining a type of aerosol-generating article or substrate using a gas sensor

Abstract

An aerosol-generating device (1), comprising control circuitry (18) including at least one controller (5) and / or processor (6), a heating chamber configured to receive an aerosol-generating article or substrate (2), a heating device configured to heat the aerosol-generating article or substrate (2), and a gas sensor (14) configured to determine a sensing profile (S1, S2, S3), wherein the sensing profile (S1, S2, S3) comprises information about an effect of an exposure of at least part of the gas sensor (14) to one or more gases released from the aerosol-generating article or substrate (2), particularly during heating, wherein the control circuitry (18) is configured to determine a type of the aerosol-generating article or substrate (2) from the sensing profile (S1, S2, S3).

Description

[0001] DETERMINING A TYPE OF AEROSOL-GENERATING ARTICLE OR SUBSTRATE USING A GAS SENSOR

[0002] The present disclosure relates to an aerosol-generating device. The present disclosure further relates to a computer-implemented method of determining a type of an aerosol-generating article or substrate inserted into an aerosol-generating device, a computer program and a non-transitory computer-readable medium.

[0003] Aerosol-forming or aerosol-generating devices are typically designed as handheld devices that can be used by a user for consuming or experiencing, for instance in one or more usage sessions, aerosol generated from an aerosol-forming substrate or an aerosol-forming article, for example by heating. The aerosol-forming devices the present disclosure pertains to are mainly directed to the field of tobacco and tobacco-substitute products, as well as e-vapor devices, for example heated tobacco products (HTP), heat-not-burn devices, electronic cigarettes, e-vapor devices, and / or vaporisers. The aerosol-forming devices of the present disclosure may also pertain to other types of inhalers, dispensers, or atomizers, for example inhalers, dispensers, or atomizers for medical applications.

[0004] Typical aerosol-forming systems can be designed as one-part systems or devices including an aerosol-forming device that can be operated by a user to generate aerosol. Alternatively, aerosol-forming systems can be designed as two-part systems or devices comprising an aerosolforming device and a companion device for storing and / or charging the aerosol-forming device. In either design or configuration, the aerosol-forming system or device can be used by a user for consuming or inhaling, for instance in one or more usage sessions, aerosol generated based on heating an aerosol-forming article or substrate couplable to the aerosol-forming system. In the context of the present disclosure, an aerosol-forming device can refer to both a one-part device and a two-part device, unless explicitly specified otherwise.

[0005] The aerosol-forming article, also referred to as aerosol-generating article, can comprise an aerosol-generating or aerosol-forming substrate, such as a tobacco or nicotine-containing substrate. The aerosol-forming article may be configured in shape and size to be inserted at least partially into the aerosol-forming device or system. In conventional systems or devices, the aerosol-forming article is usually formed as a stick that can be at least partly inserted into a cavity or heating chamber of the aerosol-forming device for aerosol consumption. Insertion of the sticklike shaped aerosol-forming article into the cavity, however, can potentially damage the aerosolforming article, which may potentially affect an experience for a user, for example in terms of taste or homogeneity of the experience. Also, inserting the aerosol-forming article into and removing it from the cavity of conventional systems may, at least for some users or in certain scenarios, be cumbersome.Exemplary aerosol-forming substrates can comprise solid substrate material, such as tobacco material or tobacco cast leaves (TCL) material. The substrate material can, for example, be assembled, often with other elements or components, to form a substantially stick-shaped aerosol-forming article. Such a stick or aerosol-forming article can be configured in shape and size to be inserted at least partially into the aerosol-forming device. The aerosol-forming device may comprise a heating element or heater device for heating the aerosol-forming article and / or the aerosol-forming substrate. The heating element or heater device may be part of the aerosolforming article and / or the aerosol-forming device. Alternatively or additionally, aerosol-forming substrates can comprise one or more liquids and / or solids, which can, for example, be supplied to the aerosol-forming device in the form of a cartridge or container. Corresponding exemplary aerosol-forming articles can, for example, comprise a cartridge containing or fillable with the liquid and / or solid substrate, which can be vaporized during aerosol consumption by the user based on heating the substrate and / or liquid. Usually, such cartridge or container can be coupled to, attached to or at least partially inserted into the aerosol-forming device. Alternatively, the cartridge may be fixedly mounted to the aerosol-forming device and refilled by inserting liquid and / or solid into the cartridge. The aerosol generated from the aerosol-forming substrate or article may comprise or include one or more of nicotine, aroma, sugar, moisturising agent, botanicals, preservative, flavouring, for example cocoa, liquorice, menthol and lactic acid or other additives. The aerosol generated from the aerosol-forming substrate or article may additionally or alternatively comprise one or more pharmaceutical agents or drugs and may include one or more adjuvants.

[0006] For generating the aerosol during use or consumption, heat can be supplied by a heating element, heater device or heat source to heat at least a portion or part of the aerosol-forming substrate. The heating element, heater device or heat source can be arranged in the handheld device or a handheld part of the aerosol-forming device. Alternatively or additionally, at least a part of or the entire heating element or heater device or heat source can be fixedly associated with or arranged within an aerosol-forming article, for instance in the form of a stick or cartridge, which can be attached to and / or powered by the handheld device or handheld part of the aerosolforming device.

[0007] Exemplary heating elements or heater devices can be based on one or more of resistive heating, inductive heating and microwave heating using electrical energy supplied via, drawn from or stored in an energy storage or battery of the aerosol-forming device. As used herein, a battery of the aerosol-forming device can generally refer to an energy storage of the aerosol-forming device configured to store electrical energy. Accordingly, the term energy storage can include one or more batteries, one or more capacitors, one or more accumulators or other types of energy storage. Also, any reference to a battery herein can include a plurality of batteries.Typically, aerosol-forming devices comprise an energy storage, for example a battery, providing the electrical energy needed to operate the aerosol-forming device and especially for heating the aerosol-forming substrate and / or article, for example to generate aerosol in one or more usage sessions using one or more aerosol-forming articles. The battery may, for example, be a lithium-ion battery.

[0008] As used herein, a usage session may refer to a period of time, during which a user may use the device to generate, consume, experience or inhale aerosol using the aerosol-forming device. Therein, a usage session may be finite. In other words, a usage session may have a start, an end and a duration. The duration of the usage session as measured by time may be influenced by use during the usage session. The duration of the usage session may have a maximum duration determined by a maximum time from the start of the usage session. The duration of the usage session may be less than the maximum time if one or more monitored parameters reaches a predetermined threshold before the maximum time from the start of the usage session. By way of example, the one or more monitored parameters may comprise one or more of: i) a cumulative puff count of a series of puffs drawn by a user since the start of the usage session, and ii) a cumulative volume of aerosol evolved from the aerosol-forming substrate since the start of the usage session.

[0009] Aerosol-generating articles or substrates are typically mass-produced and need to fulfil strict quality standards to ensure that health risks for the user are at a minimum. At the same time, being one-use consumables, aerosol-generating articles or substrates need to be as cost-effective and environmentally friendly as possible. Therefore, they are typically analogue in design, meaning that they typically do not contain any electronic sensors or features which communicate with the device to provide information and data about them. The reason such a design is generally preferred may be to reduce any risk of contamination or toxicology issues as well as keeping complexity and cost low. Examples of specifically marking aerosol-generating articles or substrates for identification may include special inks, printed ID codes, embossing, and RFID or EEPROM memory chips, among others. Apart from making the consumables more expensive, there may be a risk that the additional substances used could release toxic gases or fumes during use.

[0010] However, when the aerosol-generating device cannot identify what type of consumable is used, the device will typically work with and heat any consumable, regardless of its origin or constituents. Therefore, the manufacturer of the aerosol-generating device may not be able to protect the user from using lower quality consumables. Additionally, since in this case, the device is unaware of exactly which consumable is inserted, performance may not be optimized since settings such as heating profiles to perform optimally with a particular consumable specification cannot be chosen or adjusted.It may therefore be desirable to provide for a possibility of recognizing the type of aerosolgenerating article or substrate being used in an aerosol-generating device. Specifically, it may be desirable to determine whether or not the aerosol-generating article or substrate fulfils a specification or whether unwanted substances are present.

[0011] These advantages may be achieved by the features described herein.

[0012] According to an aspect of the present invention, there is provided an aerosol-generating device, comprising control circuitry including at least one controller and / or processor, a heating chamber configured to at least partly receive an aerosol-generating article or substrate, a heating device configured to heat at least part of the aerosol-generating article or substrate, and a gas sensor configured to determine a sensing profile, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, particularly during heating, wherein the control circuitry is configured to determine a type of the aerosol-generating article or substrate from the sensing profile.

[0013] In other words, the gas sensor, particularly a sensing part, for example a sensing layer, of the gas sensor may be configured to react to the presence and / or concentration of one or more gases released from the aerosol-generating article or substrate. The response of the gas sensor to the presence and / or concentration of one or more of these gases may be recorded in the sensing profile. For example, the sensing profile may comprise and / or represent the evolution in time of a measurable and / or measured parameter of the gas sensor, particularly a sensing part, for example a sensing layer or sensing surface material, of the gas sensor. For instance, the sensing profile may comprise two or more or a plurality of measured values of the parameter at different points in time. The parameter may be determined or measured at discrete intervals or continually. As a specific example, the parameter may be the electrical resistance and / or the electrical conductance of the gas sensor or the sensing part, which may change over time due to the presence or absence of gases released from the aerosol-generating article or substrate. However, other parameters may also be used.

[0014] The gas sensor may be arranged inside the aerosol-generating device at a location in close proximity to and / or fl uidically coupled to the heating chamber and / or the airflow path through the aerosol-generating device. In this way, one or more gases released from the aerosol-generating article or substrate may reach the gas sensor in as high a concentration as possible to ensure reliable detection. The gas sensor, particularly the sensing part, may be configured to react to one or more gases which may typically be released from aerosol-generating articles or substrates. Additionally or alternatively, the gas sensor, particularly the sensing part, may be configured to react to one or more undesirable gases, for example potentially toxic or toxic gases or gases released from potentially toxic or toxic constituents, which may be found in low-quality orcounterfeit aerosol-generating articles or substrates. The gas sensor, particularly the sensing part, may also be configured to detect potentially toxic or toxic gases in concentrations above a predetermined threshold, wherein the predetermined threshold represents a value that is normally considered unproblematic. Such gases may also be released from high-quality aerosolgenerating articles or substrates in small quantities, but their concentration may be increased above the unproblematic threshold in low-quality or counterfeit aerosol-generating articles or substrates.

[0015] By using one or more gases released from the aerosol-generating article or substrate, the aerosol-generating article or substrate does not need to be modified for the determination to work. There is no need to provide the aerosol-generating article or substrate with some kind of identifying tag, which would only increase the cost of the aerosol-generating article or substrate.

[0016] However, it is noted that the gas sensor may not need to be configured to actually identify one or more of the gases released from the aerosol-generating article or substrate. It may be enough that the gas sensor reacts to the relevant gases in a way that enables the control circuitry to determine the type of the aerosol-generating article or substrate from the measurements of the gas sensor. Therefore, an identification of the one or more gases themselves may not be necessary. For example, a manufacturer of the aerosol-generating device may sell a number of different types of aerosol-generating articles or substrates to be used with the device. As an example, a dozen different types of aerosol-generating articles or substrates may be available. Simultaneously, several hundreds of different gases may be released from each of the aerosolgenerating articles or substrates. The collective response of the gas sensor to all of these gases recorded in the sensing profile may be used to identify which one of the previously known aerosolgenerating articles or substrates is being used at the moment without having to identify any one or all of the multitude of gases. The determination of the type of the aerosol-generating article or substrate may therefore comprise determining whether or not the aerosol-generating article or substrate used is one of the original types provided by the manufacturer of the aerosol-generating device. The determination of the type of the aerosol-generating article or substrate may also comprise determining which type of the original types the aerosol-generating article or substrate used belongs to. Also, it may be detected whether the aerosol-generating article or substrate used is not one of the original consumables provided by the manufacturer of the aerosol-generating device and / or whether undesirable gases are present, for example in concentrations above a predetermined threshold.

[0017] It may therefore be provided that determining the type of the aerosol-generating article or substrate comprises determining whether the aerosol-generating article or substrate is an authentic aerosol-generating article or substrate provided by the manufacturer of the aerosolgenerating device or whether the aerosol-generating article or substrate is provided by a thirdparty. For example, it may be determined which one of the available aerosol-generating articles or substrates, i.e. which specific type, provided by the manufacturer of the aerosol-generating device is being used in the aerosol-generating device at that moment. As aerosol-generating articles or substrates provided by third parties and which may, at least in principle, also be compatible with use in the aerosol-generating device may be known, it may also be determined which one of the available aerosol-generating articles or substrates, i.e. which specific type, provided by a third party is being used in the aerosol-generating device at that moment. Additionally or alternatively, determining the type of the aerosol-generating article or substrate may comprise determining whether the one or more gases released from the aerosol-generating article or substrate comprise potentially toxic or toxic constituents, for example gases, in concentrations above a predetermined threshold.

[0018] For example, determining the type of the aerosol-generating article or substrate may comprise comparing the sensing profile to predetermined reference profiles. The reference profiles may comprise information about the effect of an exposure of at least part of the gas sensor to one or more gases released from the specific type of aerosol-generating article or substrate, particularly during heating. For example, the reference profile may comprise and / or represent the evolution in time of the measurable and / or measured parameter of the gas sensor or the sensing part of the gas sensor when a specific type of aerosol-generating article or substrate is used. For instance, the reference profile may comprise two or more or a plurality of measured values of the parameter at different points in time during use of a specific type of aerosol-generating article or substrate. As all of the aerosol-generating articles or substrates provided by the manufacturer of the aerosol-generating device are known beforehand, reference profiles for each one of them may be created and, for example, stored in a data storage or memory of the aerosol-generating device. Even if new types of aerosol-generating articles or substrates are provided after the production of the aerosol-generating device, reference profiles for these new articles or substrates may be added through software or firmware updates. Additionally, reference profiles may also be provided for aerosol-generating articles or substrates by third parties, as third party consumables compatible with the aerosol-generating device may also be known. There may also be provided reference profiles identifying the additional effect of the presence of specific potentially toxic or toxic gases, for example in concentrations above a predetermined threshold. These reference profiles may identify how sensing profiles of aerosol-generating articles or substrates deviate from normal sensing profiles when the potentially toxic or toxic gases are present. In this way, it may be determined whether or not an authentic aerosol-generating article or substrate is used, specifically which type, or whether or not a non-authentic aerosol-generating article or substrate from a third party is used, specifically which type. The presence of undesirable gases, for example in concentrations above a threshold, or their absence may also be determined.In principle, simply determining the type of the aerosol-generating articles or substrates used in the aerosol-generating device is advantageous on its own. For example, the manufacturer of the aerosol-generating device may collect this information over a period of time and may therefore learn the preferences of the user. This may comprise information about which types of aerosol-generating articles or substrates are used at what times of day and / or what times of year and / or which days of the week, for example. Data about the popularity of third party or counterfeit consumables being used in the aerosol-generating device may also be desirable. However, apart from collecting information for its own merit, the information about which specific type of aerosolgenerating article or substrate is being used may also be directly employed in controlling the aerosol-generating device. For example, the control circuitry may be configured to control the heating device depending upon the determined type of the aerosol-generating article or substrate. For instance, the control circuitry may be configured to control the heating device to provide a specific heating profile. The heating profile may be adjusted or configured specifically for the determined type of aerosol-generating article or substrate. For example, some types of aerosolgenerating article or substrate may need different temperatures, for example peak temperatures, or temperature profiles during the usage session to provide the highest quality aerosol. Such specific necessities and therefore heating profiles may be implemented for each type of aerosolgenerating article or substrate, or such specific heating profiles may only be used for some, for example at least one, type of aerosol-generating article or substrate. For example, different heating profiles may be provided for authentic aerosol-generating articles or substrates provided by the manufacturer of the aerosol-generating device and for aerosol-generating articles or substrates provided by a third party. As the quality and security standards of third parties may be unknown, the heating profiles for third party consumables may correspond to or use lower temperatures than the ones for authentic aerosol-generating articles or substrates.

[0019] As another possible reaction to the determined type of aerosol-generating article or substrate, the control circuitry may be configured to allow or disallow generation of aerosol from the aerosol-generating article or substrate depending upon the determined type of the aerosolgenerating article or substrate. Allowing or disallowing the generation of aerosol may be implemented by controlling the heating device of the aerosol-generating device, for example by controlling a switch allowing or preventing the heating device to be supplied with electrical energy. For example, the control circuitry may be configured to allow generation of aerosol from authentic aerosol-generating articles or substrates. Conversely, the control circuitry may be configured to disallow generation of aerosol from non-authentic aerosol-generating articles or substrates from third parties. However, the control circuitry may also be configured to allow generation of aerosol from non-authentic aerosol-generating articles or substrates. It may even be provided that the control circuitry may be configured to allow generation of aerosol from some types of non-authentic aerosol-generating articles or substrates while disallowing generation of aerosol from other types of non-authentic aerosol-generating articles or substrates. Additionally or alternatively, the control circuitry may be configured to disallow generation of aerosol whenever the presence of a potentially toxic or toxic substance and / or gas, for example above a predetermined threshold, is detected. In this way, safety of the user may be ensured while simultaneously providing the highest quality aerosol possible and even allowing the user to use non-authentic aerosol-generating articles or substrates if their quality is sufficiently high.

[0020] In general, the determination of the type of the aerosol-generating article or substrate used may be performed before or during the usage session. This may mean that the time necessary for the determination may end, and therefore the result of the determination may be available, before or during the usage session. An ongoing usage session in which aerosol is generated from the aerosol-generating article or substrate may be aborted when the type of the aerosolgenerating article or substrate has been determined and indicates that this specific type is flagged for disallowing the generation of aerosol. Also, the heating profile may be adjusted during the usage session in response to the determination result. However, both for reasons of user experience and user security, it may be desirable that the determination of the type of the aerosolgenerating article or substrate is finished before a usage session is started. The determination of the sensing profile and the type of the aerosol-generating article or substrate may therefore be performed during a preheating phase, in which the aerosol-generating article or substrate is heated from an ambient temperature to a maintenance temperature, particularly before an aerosolization temperature of the aerosol-generating article or substrate is reached. The ambient temperature may be the temperature at which the aerosol-generating article or substrate is inserted into the aerosol-generating device. Before a usage session is started, the aerosolgenerating article or substrate may be heated to the maintenance temperature, which may be a temperature at which the aerosol-generating article or substrate is held throughout the usage session. However, the maintenance temperature may be below an aerosolization temperature of the aerosol-generating article or substrate. The aerosolization temperature may be the temperature at which an aerosol is released from the aerosol-generating article or substrate, i.e. at which fine solid particles or liquid droplets are released from the aerosol-generating article or substrate and suspended in the surrounding air. There may also be devices in which the aerosol is created from a vapor coming from the heated aerosol-generating article or substrate being mixed with air from the outside environment, for example air at ambient temperature, which then leads to the formation of droplets and therefore aerosol from the vapor. In this case, the aerosolization temperature may be the temperature at which vapor for creating the aerosol is released from the aerosol-generating article or substrate. Before the aerosolization temperature is reached, the one or more gases detected by the gas sensor according to the present inventionare already released from the aerosol-generating article or substrate. These gases may be released even without any heating, but even more so during preheating the aerosol-generating article or substrate from the ambient temperature to the maintenance temperature. The gas sensor may therefore be configured to sense gases - as described herein - released from the aerosol-generating article or substrate at ambient temperature and / or between the ambient temperature and the maintenance temperature and / or at the maintenance temperature and / or below the aerosolization temperature. After the start of a usage session, whenever a user puffs on the aerosol-generating device, the temperature of the aerosol-generating article or substrate is increased from the maintenance temperature to the aerosolization temperature for the provision of aerosol to the user. After the puff ends, the temperature of the aerosol-generating article or substrate may decrease again, but is held at a minimum at the maintenance temperature until the next puff is detected or the usage session ends. Therefore, when the type of the aerosolgenerating article or substrate is determined in the preheating phase in which the aerosolgenerating article or substrate is heated from the ambient temperature to the maintenance temperature, no usage session has started yet. Simultaneously, the increase of temperature of the aerosol-generating article or substrate during preheating may facilitate and / or increase the amount of gases released from the aerosol-generating article or substrate and may therefore improve detection by the gas sensor.

[0021] For example, the determination of the sensing profile and the type of the aerosol-generating article or substrate may be performed within a maximum of 20 seconds after insertion of the aerosol-generating article or substrate into the heating chamber, for example within a maximum of 15 seconds or within a maximum of 10 seconds or within a maximum of 8 seconds or within a maximum of 6 seconds or within a maximum of 5 seconds after insertion of the aerosol-generating article or substrate into the heating chamber. Typically, the preheating phase may last up to 20 seconds, so that these timespans ensure that the determination of the sensing profile and the type of the aerosol-generating article or substrate is finished before the start of a usage session. The control circuit of the aerosol-generating device may then implement any adjustments depending on the type of the aerosol-generating article or substrate as determined, for example allowing or disallowing the generation of aerosol and / or using a specific heating profile.

[0022] In general, any kind of gas released from the aerosol-generating article or substrate may be used for determining its type according to the present invention. Gases of particular interest in the field of aerosol-generating devices may include volatile organic compounds, VOCs. A VOC may be defined as any organic compound having a boiling point between 50 °C and 260 °C. VOCs may be both intentionally present aroma components and / or flavor components and / or active ingredient components and / or potentially undesirable substances. Because of their universal presence in aerosol-generating articles or substrates, the detection of VOCs may leadto particularly reliable results. The gas sensor may therefore be configured to determine, as part of the sensing profile, an effect of an exposure of at least part of the gas sensor to at least one VOC released from the aerosol-generating article or substrate. The effect of the exposure to these one or more VOCs may be represented in the reference profiles for comparison.

[0023] The gas sensor itself may be of any suitable type. For example, the gas sensor may comprise binding ligands having a specificity for binding to specific gas molecules. A detection may then be implemented by measuring the binding of the gas molecules to the ligands. However, this type of sensor may not be maintenance-free and may therefore be hard to implement cost-effectively in aerosol-generating devices. According to an exemplary embodiment of the present invention, the gas sensor may be or may comprise at least one metal-oxide semiconductor, MOS, sensor. MOS sensors detect the presence and / or concentrations of various types of gases by measuring resistance changes of a metal oxide layer due to the adsorption of gases. For example, when the MOS sensor is surrounded by air, oxygen from the air adsorbs to the metal oxide layer and electrostatically immobilizes electrons in the metal oxide layer. This increases the resistance of the metal oxide layer. On the other hand, when gases released from the aerosol-generating article or substrate are mixed into the air, for example reducing gases, then these gases may electrostatically attract the oxygen molecules and remove them from the position adsorbed to the metal oxide layer. Other gases, for example oxidizing gases, may replace oxygen molecules absorbed to the metal oxide layer and may therefore alter the resistance of the metal oxide layer differently. This may lead to the electrons in the metal oxide layer having an increased mobility and therefore the resistance of the metal oxide layer to decrease. This change in resistance of the metal oxide layer is proportional to the concentration of gases released from the aerosolgenerating article or substrate and may be measured and used as the parameter determined by the gas sensor. MOS sensors are cost effective, have high sensitivity and low power needs and are therefore suitable for aerosol-generating devices. They are also maintenance-free, as typically, the oxygen layer adsorbed to the sensing layer is reestablished when the other gases are gone and the sensing layer is in contact with air. MOS sensors may therefore be used through the entire life of the aerosol-generating device.

[0024] As mentioned, the working principle of a MOS sensor is to determine the change in electrical resistance due to the adsorption of different gases, for example oxygen, on a metal oxide layer or the removal of gases, for example oxygen, from the adsorption layer. The response of a MOS sensor to a specific type of gas therefore depends on the specific metal oxide used. In other words, by using different metal oxides as sensing surface materials or sensing layers, MOS sensors may be configured to detect specific gases or combinations of gases. In this way, MOS sensors may be configured to be particularly sensitive to gases typically released or releasable from aerosol-generating articles or substrates. Such MOS sensors may then be particularly usefulin differentiating between different types of aerosol-generating articles or substrates. However, differentiation between a plurality of different types of aerosol-generating articles or substrates may still be hard using one single MOS sensor using one single sensing surface material, i.e. metal oxide. Therefore, the gas sensor may comprise at least two MOS sensors, for example three or more MOS sensors. The MOS sensors comprised by the gas sensor may include different sensing surface materials. In a specific example, three MOS sensors may be used, each MOS sensor using and / or including a different sensing surface material as the metal oxide. The resistance of the metal oxide layer of each MOS sensor may be measured separately. In this way, the specificity of the gas sensor may be greatly increased, as the effect of the gases released from the aerosol-generating article or substrate create three different measured data values per point in time, each data value coming from a different sensing surface material or sensing layer and therefore providing a different magnitude of response to the presence of the gas or gas mixture.

[0025] In general, any kind of metal oxide may be used in the MOS sensor as long as it is suitable for detecting the gases released or releasable from the aerosol-generating article or substrate. Particularly, at least one of the MOS sensors comprised in the gas sensor may comprise a sensing surface material selected from the group consisting of tin(IV) oxide, SnO2, catalysed with palladium, Pd, tin(IV) oxide, SnO2, tin(IV) oxide, SnO2, catalysed with gold, Au, zinc(ll) oxide, ZnO, tungsten(VI) oxide, WO3, indium(lll) oxide, ln2O3, molybdenum(VI) oxide, MoO3, titanium(IV) oxide, TiO2, copper(ll) oxide, CuO, niobium(V) oxide, Nb2O5, graphene, carbon nanotubes, perovskite oxides, e.g., barium titanate, strontium titanate, and mixed metal oxides. These have all been identified as suitable metal oxide materials for MOS sensors for the differentiation of types of aerosol-generating articles or substrates. In the context of this invention, the term “catalysed with” a substance may mean that small amounts of the substance are provided in or on the sensing surface material as a catalyst, for example as nanoparticles, for example obtained by sputtering techniques.

[0026] In a particular embodiment, the gas sensor may comprise at least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with palladium, Pd, as sensing surface material, at least one MOS sensor comprising tin(IV) oxide, SnO2, as sensing surface material, and at least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with gold, Au, as sensing surface material. For example, the gas sensor may comprise exactly one MOS sensor of each of the three types mentioned. Using this combination, a reliable differentiation between types of aerosol-generating articles or substrates has been achieved.

[0027] To be suitable for use in aerosol-generating devices, the gas sensor needs to be cost-effective. It is therefore preferred that the gas sensor is produced using cost-effective procedures of mass production. For example, the gas sensor may be obtained by screen printing. Inparticular, the sensing surface material of the gas sensor may be deposited, for example on a substrate material such as a non-conductive substrate, by screen printing. However, as also mentioned below, further components of the gas sensor may also be obtained or deposited by screen printing, for example electrodes for connecting the sensing surface material and / or heating tracks of a sensor heating device. In particular, the gas sensor may comprise a heating and sensing element, which may include all of the sensing layers of all of the MOS sensors included in the gas sensor, electrodes or electrical leads for electrically connecting the sensing layers, a sensor heating device including one or more resistive heating tracks and electrodes or electrical leads for electrically connecting the heating device. All of the mentioned components may be arranged on a common sensor substrate and / or all of the mentioned components may be obtained or deposited by screen printing. In this way, the core components of the gas sensor may be mass-produced in a cost-effective manner. The common substrate may be made of or may comprise a non-conductive material, for example quartz, oxidized silicon or oxidated aluminium.

[0028] As already mentioned, the gas sensor may be configured to measure an electrical resistance change of the sensing layer of the gas sensor due to the presence of one or more gases released from the aerosol-generating article or substrate. The electrical resistance change may be measured by measuring the electrical resistance of the sensing layer at one or more or a plurality of different points in time. If only one measurement is taken, a reference value may be used to determine the change. Any suitable procedure for measuring the electrical resistance may be used. For example, the electrical resistance may be measured using ratiometric resistance measurement. In other words, the gas sensor may be configured to measure a resistance change effected by the exposure of at least part of the gas sensor to the one or more gases released from the aerosol-generating article or substrate using ratiometric resistance measurement. In ratiometric resistance measurement, the gas sensor and a reference resistor may be arranged in series so that the same current passes through both the gas sensor and the reference resistor. The electrical resistance of the gas sensor may then be determined using an analog to digital converter which measures the ratio of the voltage drops over the gas sensor and the reference resistor. The only quantity which needs to be previously known may therefore be the resistance value of the reference resistor, which needs to be suitably stable under the conditions prevalent during measurement in the aerosol-generating device. Ratiometric resistance measurement is therefore comparatively cheap and easy to implement with low complexity, but provides sufficient accuracy for the present purposes.

[0029] To achieve accurate measurements, the gas sensor may comprise a sensor heating device configured to heat the gas sensor, particularly the sensing surface material or sensing layer of the gas sensor, during the determination of the sensing profile. For example, the sensor heating device may be configured to heat the gas sensor to a temperature between 250 °C and 450 °Cor between 280 °C and 400 °C or between 310 °C and 380 °C, for example to a temperature of 350 °C. In these temperature ranges or at this temperature, the sensitivity of the gas sensor may be particularly high for the gases of interest in the present invention. To ensure that the one or more sensing layers of the gas sensor are heated to these temperatures, the sensor heating device may be arranged in close proximity to the sensor layers. For example, the sensor layers and the sensor heating device may be arranged together on a common substrate forming a heating and sensing element as explained herein.

[0030] The sensor heating device can be configured to heat the gas sensor before, after or during the actual determination of the sensing profile and / or the determination of VOCs. In particular, the sensor heating device can be configured to heat the gas sensor after the actual determination of the sensing profile and / or the determination of VOCs, for example during a user inhalation, during a puff, during use for aerosol consumption, during an experience and / or during a usage session. This can avoid or reduce recondensation of VOCs or other substances on the gas sensor.

[0031] Any suitable technique for heating the gas sensor, particularly the sensing layer of the gas sensor, may be employed. In an exemplary embodiment, the sensor heating device may comprise a resistive heater, for example including a resistive heating track. The resistive heating track may comprise a platinum, Pt, layer, for example. The sensor heating device may therefore employ ohmic losses for heating.

[0032] The gas sensor may comprise electrical leads for electrically connecting the gas sensor, particularly the sensing layer(s), to the control circuitry. In one embodiment, the electrical leads may comprise a common electrode connecting all of the sensing layers used in the gas sensor in parallel to a power source. Additionally, the electrical leads may comprise a sensor electrical lead for each sensing layer of the gas sensor, connecting the sensing layer of the gas sensor to the control circuitry and, for example, to the resistance measurement components. The electrical leads may be made of the same material, and particularly the same layer thickness, as the resistive heater, i.e. for example Pt. The resistive heater and the electrical leads may be obtained and / or deposited in the same screen printing step during manufacturing. In other words, a resistive heating track of the sensor heating device, the common electrode for all of the sensing layers and the sensor electrical leads for each of the sensing layers may all be made from the same material, i.e. Pt, in the same layer thickness, for example between 10 and 20 micrometers or between 12.5 and 17.5 micrometers, for example 15 micrometers. They may also all be obtained and / or deposited in the same screen printing step during manufacturing. Such thick films of Pt as both heating element, common electrode and the electrodes may be made in the same print with screen printing both to reduce costs and because the same thickness is suitable for the two different applications of heating and electrical connection. Pt both as a heating element and for contacts may be a suitable choice due to high electrical conductivity coupled with chemicalstability, which are both important properties given its use to detect gases released from the aerosol-generating article or substrate, for example VOCs. The thickness of the heating element, for example the Pt heating track, may be chosen to achieve a sufficiently fast response time and to provide correct communication to the control circuitry of the device within the preheating or warm-up phase as described herein. This exemplary design as described herein may allow for three MOS sensors or sensing elements and the heating element or heating device all on one substrate.

[0033] Additionally, the resistive track of the sensor heating device, for example the Pt film, may also be used to correctly measure the temperature itself, thereby allowing the temperature of the sensor to remain constant through feedback. The temperature of the sensor may be determined from a measured resistance of the resistive track, which may change slightly depending on the temperature. The resistive track of the sensor heating device may be configured or designed to have an electrical resistance of approximately 10-18 ohm, for example 11-17 ohm or 12-15 ohm. This may ensure that electrical current is kept low enough to safely use wires of between 15 to 25 micrometers, for example of 20 micrometers, in diameter. Increasing the diameter of the wire in comparison to the thickness of the heating track and / or sensing layer decreases its resistance relative to the heating track. This may ensure that the resistance effect of the wires is negligible when measuring the resistance of the sensor, thereby minimizing the complexity of the measurement circuitry and keeping component cost low. The gas sensor may be designed to be compact in size, for example approximately 4 mm x 4 mm x 0.25 mm or 3 mm x 3 mm x 0.25 mm. Other dimensions are also possible. This may ensure that minimal power is required to heat the MOS sensors to operating temperature. In the example given, approximately 650 mW may be needed to heat the element to 350 °C. In keeping power consumption to a minimum, battery life can be conserved.

[0034] The gas sensor may be arranged on a printed circuit board, PCB. The gas sensor may be connected to the PCB by rigid or inflexible connections, for example base pins. These rigid or inflexible connections may also serve for electrically connecting the different electrodes and / or components of the gas sensor to the control circuitry. Alternatively, the gas sensor may be connected to the PCB by a flexible connection. The flexible connection may, for example, comprise a flexible substrate material, such as Kapton, and electrical leads for electrically connecting the different electrodes and / or components of the gas sensor to the control circuitry. The electrical leads may be printed directly on the flexible substrate material. By using the flexible connection, the gas sensor may be more freely positioned inside the aerosol-generating device. The gas sensor may be arranged on the main PCB of the aerosol-generating device or may be arranged on a separate, dedicated PCB. In other words, the gas sensor may be arranged on the same PCB as the control circuitry, particularly the controller and / or the processor of the controlcircuitry, or the gas sensor may be arranged on a different PCB than the control circuitry, particularly the controller and / or the processor of the control circuitry. Arranging the gas sensor on a separate PCB, different from the one comprising the control circuitry, makes it possible to more freely position the gas sensor inside the aerosol-generating device.

[0035] As mentioned above, the gas sensor may comprise a sensor heating device which may heat at least parts of the gas sensor to several hundred degrees Celsius. Therefore, the gas sensor may be arranged at a distance from the PCB and may be connected to the PCB by electrical connection pins. By distancing the gas sensor from the PCB, heat transfer to the PCB may be reduced or avoided. For example, the distance of the gas sensor to the PCB may be at least 1 mm or at least 2 mm or at least 3 mm or at least 5 mm or at least 7.5 mm or at least 10 mm. This distance may, for example, be measured between the substrate material of the PCB and the sensor heating device, for example the resistive heating track, of the gas sensor. For example, the gas sensor may be distanced from the PCB using base pins, for example electrode rods used for electrically connecting the gas sensor to the PCB and / or the control circuitry. In another example, the gas sensor may be distanced from the PCB using a non-conductive substrate comprising electrical leads for electrically connecting the gas sensor to the PCB and / or the control circuitry. The base pins and / or the substrate may be arranged perpendicularly, for example orthogonally, to the PCB.

[0036] To further reduce the transfer of heat to the PCB, a thermal insulation layer and / or a heat sink may be arranged between the gas sensor and the PCB. The thermal insulation layer and / or the heat sink may, for example, comprise a metal or a ceramic material. In one embodiment, the thermal insulation layer may be arranged on the side of the heating and sensing element of the gas sensor oriented towards the PCB. The thermal insulation layer may therefore be arranged on the opposite side of the common substrate of the heating and sensing element as the sensing layers of the MOS sensors.

[0037] The gas sensor, particularly a sensing surface material or sensing layer of the gas sensor, may be arranged inside a sensing chamber. The sensing chamber may provide an open volume, i.e. an empty space, for receiving the one or more gases released from the aerosol-generating article or substrate. The open volume may be of from 100 mm3to 600 mm3, for example from 125 mm3to 500 mm3or from 150 mm3to 450 mm3. The sensing layer of the gas sensor may be arranged inside the sensing chamber such that gas in the sensing chamber may come into contact with the sensing layer. In the sensing chamber, gases released from the aerosolgenerating article or substrate may accumulate and freely mix with the air in the sensing chamber so that the sensing layer may reliably come into contact with enough gas molecules to be able to determine the type of the aerosol-generating article or substrate used.The sensing chamber may comprise a sensing chamber housing. The sensing chamber housing may house or surround the sensing chamber and / or the gas sensor, for example such that the heating and sensing element of the gas sensor is arranged inside the sensing chamber housing. The sensing chamber housing may comprise a heat insulating material, for example a heat insulating plastic, ceramic, aerogel, glass fiber, and / or aerated foam material. Particularly, the bottom wall of the sensing chamber housing, which may be the wall of the sensing chamber housing oriented towards the PCB, may be made of or may comprise such a heat insulating material. In one embodiment, all walls constituting the sensing chamber housing are made of or comprise such a heat insulating material.

[0038] The sensing chamber housing may be configured to be hermetically sealed towards the outside, with the exception of towards the heating chamber and / or the airflow path through the aerosol-generating device. This may prevent gases from leaking into interior spaces of the aerosol-generating device, thereby diluting the concentration of gases available for testing by the gas sensor. To make sure that gases released from the aerosol-generating article or substrate may enter the sensing chamber, the sensing chamber housing may comprise an opening towards the heating chamber and / or the airflow path through the aerosol-generating device. The opening may comprise a hydrophobic filter to prevent liquid particles or steam from entering the sensing chamber. In summary, therefore, the sensing chamber may be fluidical ly connected to the heating chamber and / or the airflow path through the aerosol-generating device and / or the aerosolgenerating article or substrate via a hydrophobic filter, for example a hydrophobic gauze filter. The hydrophobic filter may comprise polyethylene, PE, polypropylene, PP, polyvinylidene fluoride, PVDF, silicone, and / or polytetrafluoroethylene, PTFE.

[0039] As mentioned, the sensing chamber may be hermetically sealed to the outside except for the opening through which the gases released from the aerosol-generating article or substrate are supposed to enter the chamber. To prevent gases from leaking at the connection of the sensing chamber to the heating chamber and / or the airflow path through the aerosol-generating device, the sensing chamber may be fluidically connected to the heating chamber and / or the airflow path through the aerosol-generating device by a hermetic seal, for example a gasket seal, particularly wherein the hermetic seal comprises silicone and / or polytetrafluoroethylene, PTFE. For example, the hermetic seal may be arranged at the circumference of the opening of the sensing chamber containing the hydrophobic filter. The hermetic seal may be in contact both with the sensing chamber housing and a housing of the heating chamber and / or the airflow path through the aerosol-generating device.

[0040] The gas sensor may be arranged in relation to the heating chamber such that the gas sensor, particularly a sensing surface material or sensing layer of the gas sensor, is distanced from the heating chamber and / or the aerosol-generating article or substrate by between 0.5 mmand 8 mm, for example by between 1 mm and 5 mm or by between 2.5 mm and 4 mm. Particularly when the opening of the sensing chamber is directly adjacent to the aerosol-generating article or substrate in the heating chamber, there may be only little room in which the gases released from the aerosol-generating article or substrate may accumulate for detection by the gas sensor. Therefore, the sensing layer of the gas sensor may be arranged inside the sensing chamber at the mentioned distances from the opening towards the heating chamber and / or at the airflow path through the aerosol-generating device, wherein an open space is arranged between the opening and the sensing layer. Gas released from the aerosol-generating article or substrate may therefore accumulate and mix in this open space, thereby facilitating reliable detection by the gas sensor.

[0041] In general, the position of the gas sensor inside the aerosol-generating device may be chosen so that gases released from the aerosol-generating article or substrate, particularly during the preheating phase, may reach the sensing surface material or sensing layer of the gas sensor in sufficiently high concentrations for reliable detection. According to the present invention, the type of the aerosol-generating article or substrate is determined through the gas sensor before a usage session is started. Therefore, the gases released from the aerosol-generating article or substrate and used for this determination are not transported through the airflow path in a stream induced by the user, for example by puffing on the device. In contrast, the gases released from the aerosol-generating article or substrate and used for the determination according to the present invention spread or disperse through the airflow path and / or the sensing chamber by diffusion only. Therefore, the gas sensor, particularly the sensing chamber of the gas sensor, should be connected to the airflow path through the aerosol-generating device and / or the heating chamber in a position close to where the aerosol-generating article or substrate inserted into the aerosolgenerating device is positioned and / or arranged. In one example, the gas sensor may be fluidically connected to the heating chamber of the aerosol-generating device. In this position, very high concentrations of the relevant gases released from the aerosol-generating article or substrate may be brought into proximity of the gas sensor. However, it may not be practical to connect the gas sensor in this position for space limitations in the heating chamber, for example caused by the heating device or heating element of the heating chamber, which needs to be in close contact with the aerosol-generating article device over large areas. Therefore, the connection of the gas sensor or sensing chamber to the airflow path through the aerosolgenerating device may be arranged in close proximity of the heating chamber but upstream or downstream thereof. The terms upstream or downstream as used herein may relate to the flow direction of air and / or aerosol in the airflow path through the aerosol-generating device. For example, parts upstream of the heating chamber are reached by the air flowing through the aerosol-generating device before the heating chamber. Conversely, parts downstream of theheating chamber are reached by the air flowing through the aerosol-generating device after the air has flown through the heating chamber. Thus, the gas sensor may be fluidically connected to the airflow path through the aerosol-generating device and / or the aerosol-generating article or substrate upstream of the heating chamber or downstream of the heating chamber.

[0042] In one example, the gas sensor may be fluidically connected to a cooling section of the airflow path through the aerosol-generating device and / or the aerosol-generating article or substrate. Such a cooling section may be arranged downstream of the heating chamber. It may comprise a bigger cross-section than parts of the airflow path upstream of the cooling section. The cooling section may also comprise an aerosolization or nucleation chamber in which aerosol and / or vapor coming out of the heating chamber may be mixed with ambient air from the outside environment to increase aerosol quality and / or to form aerosol. Depending on the type and build of the aerosol-generating device, such a cooling section may be part of an airflow path through the device or may be part of the aerosol-generating article or substrate itself. In other words, the cooling section may be arranged inside or outside of the aerosol-generating article or substrate. In the case that the cooling section is arranged inside of the aerosol-generating article or substrate, the aerosol-generating article or substrate may comprise at least one opening or perforation connecting the cooling section and airflow path providing ambient air from the outside environment. For example, the aerosol-generating article or substrate may comprise a line of perforations, for example around the whole circumference of the aerosol-generating article or substrate. The gas sensor may be arranged directly opposite or and / or adjacent to these perforations. For example, the opening of the sensing chamber may be arranged such that it overlaps one or more of the perforations in the aerosol-generating article or substrate, for example in a radial direction of a longitudinal axis of the aerosol-generating article or substrate and / or the heating chamber.

[0043] The gas sensor may be arranged on a longitudinal axis of the heating chamber and / or the aerosol-generating article or substrate or the gas sensor may be arranged radially offset from the longitudinal axis of the heating chamber and / or the aerosol-generating article or substrate. The longitudinal axis may be the longitudinal middle axis of the heating chamber and / or the aerosolgenerating article or substrate. In case of a cylindrical stick-formed aerosol-generating article or substrate, the longitudinal axis may, for example, be the cylinder axis. With respect to an aerosolgenerating article or substrate arranged in the heating chamber, the gas sensor may therefore be arranged either adjacent to one of its face sides or adjacent to one of its lateral sides.

[0044] To make sure that gases released from the aerosol-generating article or substrate reach the gas sensor in sufficient concentrations for the determination of the type of the aerosolgenerating article or substrate used, the gas sensor may be provided with a fluidic interconnection element for establishing a fluidic connection between the gas sensor, particularly the sensingchamber, and the aerosol-generating article or substrate, particularly an airflow path inside the aerosol-generating article or substrate. In a specific example, the gas sensor may comprise a perforation device or piercing device, for example a needle or needle-like device, configured to perforate and / or enter the aerosol-generating article or substrate in the heating chamber. The perforation device may be hollow so that gases released from the aerosol-generating article or substrate may be transported through the perforation device to the gas sensor, particularly into the sensing chamber of the gas sensor. The perforation device may be configured and / or arranged so that the perforation device enters the aerosol-generating article or substrate when the aerosol-generating article or substrate is inserted into the heating chamber. For example, the perforation device may extend into the hollow space or chamber into which the aerosol-generating article or substrate is inserted by the user so that the perforation device enters the aerosolgenerating article or substrate driven by the movement of the aerosol-generating article or substrate when it is being inserted into the aerosol-generating device.

[0045] The perforation device may also be configured to enter the aerosol-generating article or substrate on one of its lateral sides, i.e. in a direction perpendicular to the longitudinal axis of the aerosol-generating article or substrate. For example, the perforation device may be configured to enter a cooling section of the aerosol-generating article or substrate. To facilitate this, the perforation device may be movable between an extended position, in which the perforation device may perforate and / or enter the aerosol-generating article or substrate and / or be arranged at least partly inside the aerosol-generating article or substrate, and a retracted position, in which the perforation device is arranged outside the aerosol-generating article or substrate. The gas sensor may comprise an actuator configured to move the perforation device between the extended position and the retracted position. For example, the actuator may comprise a solenoid or any other linear-moving actuator. The actuator may be configured to move the perforation device into the extended position whenever a preheating of an aerosol-generating article or substrate is started. Also, the actuator may be configured to move the perforation device into the retracted position whenever a usage session is started and / or whenever preheating of the aerosolgenerating article or substrate ends and / or when the type of the aerosol-generating article or substrate being used has been determined. In this way, the perforation device is not in the extended position during the usage session anymore, which may avoid contamination of the perforation device by liquid droplets and / or solid particles from the aerosol. Also, the perforation device is retracted a sufficient time before the user removes the aerosol-generating article or substrate from the aerosol-generating device, which ensures that the perforation device is not damaged by the user removing or trying to remove the aerosol-generating article or substrate while the perforation device is in the extended position. By providing the perforation device and positioning the open end of the perforation device on the inside of the aerosol-generating articleor substrate, a sufficiently high concentration of gases released from the aerosol-generating article or substrate may be achieved in the sensing chamber.

[0046] The perforation device may comprise a sharpened tip to facilitate perforation of the aerosolgenerating article or substrate. To make sure that gases released from the aerosol-generating article or substrate may easily flow into the sensing chamber in an unobstructed way through the perforation device, the perforation device may comprise a bevelled tip, like an injection needle. The free end of the bevel of the perforation device may therefore be arranged on the circumference of the opening of the perforation device. The perforation device may be configured to perforate and / or enter the aerosol-generating article or substrate in a direction transverse, for example perpendicular, to a longitudinal axis of the heating chamber and / or the aerosolgenerating article or substrate, wherein the free end of the bevel of the tip may be arranged on the downstream side of the perforation device. In other words, the bevel of the perforation device may cause the opening of the perforation device, through which the gases need to pass to flow into the sensing chamber, to lie in a plane which is angled in relation to the longitudinal axis of the heating chamber and / or the aerosol-generating article or substrate. The perforation device may be arranged so that the opening of the perforation device may be oriented towards the heating chamber. In this way, gases released from the aerosol-generating article or substrate, for example gases coming from the heating chamber, may flow into the perforation device and therefore into the sensing chamber without obstacles.

[0047] Despite the repeated mention of the aerosol-generating article or substrate herein, an aspect of the present invention may be the aerosol-generating device alone, without the aerosolgenerating article or substrate. However, as the aerosol-generating device may be configured, designed, and built to be used with the aerosol-generating article or substrate, references to the aerosol-generating article or substrate may merely illustrate the configuration of the aerosolgenerating device itself. However, the aerosol-generating device according to the present invention may also further comprise the aerosol-generating article or substrate. For example, the aerosol-generating device may be configured to generate aerosol from the aerosol-generating article or substrate. Any of the aerosol-generating articles or substrates as described herein may be used.

[0048] According to another aspect of the present invention, there is provided a computer-implemented method of determining a type of an aerosol-generating article or substrate inserted into an aerosol-generating device, for example an aerosol-generating device according to the invention, the method comprising: determining a sensing profile by a gas sensor, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, and determining the type of the aerosol-generating article or substrate from the sensing profile. All ofthe features, functions and advantages described herein for the aerosol-generating device are also applicable to the computer-implemented method and vice versa.

[0049] The method may comprise detecting the insertion of the aerosol-generating article or substrate into the aerosol-generating device. This may be accomplished by any suitable sensor, such as contact sensors or laser sensors. However, the detection may also be accomplished by user input, for example by the user starting a preheating session in preparation of a usage session.

[0050] The method may also comprise heating the aerosol-generating article or substrate, for example preheating the aerosol-generating article or substrate from an ambient temperature to a maintenance temperature, and determining the sensing profile during heating or preheating of the aerosol-generating article or substrate.

[0051] As explained further, the method may further comprise allowing, disallowing or adjusting the operation of a heater device of the aerosol-generating device depending on the determined type of the aerosol-generating article or substrate. To avoid repetitions, reference to the previous explanations is made.

[0052] According to another aspect of the present invention, there is provided a computer program, which when executed by processing circuitry of an aerosol-generating device, for example an aerosol-generating device according to the present invention, or a companion device configured to charge an aerosol-generating device with electrical energy, causes the aerosol-generating device or the companion device to perform the steps of the method according to the present invention. All of the features, functions and advantages described herein for the aerosolgenerating device and / or the method are also applicable to the computer program and vice versa.

[0053] According to another aspect of the present invention, there is provided a non-transitory computer-readable medium storing a computer program according to the present invention. All of the features, functions and advantages described herein for the aerosol-generating device and / or the method and / or the computer program are also applicable to the computer-readable medium and vice versa.

[0054] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0055] Example 1. An aerosol-generating device, comprising

[0056] control circuitry including at least one controller and / or processor,

[0057] a heating chamber configured to receive an aerosol-generating article or substrate, a heating device configured to heat the aerosol-generating article or substrate, anda gas sensor configured to determine a sensing profile, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, particularly during heating, wherein the control circuitry is configured to determine a type of the aerosol-generating article or substrate from the sensing profile.

[0058] Example 2. The aerosol-generating device according to Example 1,

[0059] wherein determining the type of the aerosol-generating article or substrate comprises determining whether the aerosol-generating article or substrate is an authentic aerosolgenerating article or substrate provided by the manufacturer of the aerosol-generating device or whether the aerosol-generating article or substrate is provided by a third party, and / or determining whether the one or more gases released from the aerosol-generating article or substrate comprise potentially toxic constituents in concentrations above a predetermined threshold.

[0060] Example 3. The aerosol-generating device according to any one of the previous Examples,

[0061] wherein determining the type of the aerosol-generating article or substrate comprises comparing the sensing profile to predetermined reference profiles.

[0062] Example 4. The aerosol-generating device according to any one of the previous Examples,

[0063] wherein the control circuitry is configured to control the heating device, particularly to provide a specific heating profile, depending upon the determined type of the aerosol-generating article or substrate.

[0064] Example 5. The aerosol-generating device according to any one of the previous Examples,

[0065] wherein the control circuitry is configured to allow or disallow generation of aerosol from the aerosol-generating article or substrate depending upon the determined type of the aerosolgenerating article or substrate.

[0066] Example 6. The aerosol-generating device according to any one of the previous Examples,

[0067] wherein the determination of the sensing profile and the type of the aerosol-generating article or substrate is performed during a preheating phase, in which the aerosol-generating article or substrate is heated from an ambient temperature to a maintenance temperature, particularly before an aerosolization temperature of the aerosol-generating article or substrate is reached.

[0068] Example 7. The aerosol-generating device according to any one of the previous Examples,wherein the determination of the sensing profile and the type of the aerosol-generating article or substrate is performed within a maximum of 20 seconds after insertion of the aerosolgenerating article or substrate into the heating chamber, for example within a maximum of 15 seconds or within a maximum of 10 seconds or within a maximum of 8 seconds or within a maximum of 6 seconds or within a maximum of 5 seconds after insertion of the aerosol-generating article or substrate into the heating chamber.

[0069] Example 8. The aerosol-generating device according to any one of the previous Examples,

[0070] wherein the gas sensor is configured to determine, as part of the sensing profile, an effect of an exposure of at least part of the gas sensor to at least one volatile organic compound, VOC, released from the aerosol-generating article or substrate.

[0071] Example 9. The aerosol-generating device according to any one of the previous Examples,

[0072] wherein the gas sensor is or comprises at least one metal-oxide-semiconductor, MOS, sensor.

[0073] Example 10. The aerosol-generating device according to any one of the previous Examples,

[0074] wherein the gas sensor comprises at least two metal-oxide-semiconductor, MOS, sensors, for example three or more MOS sensors, particularly wherein the MOS sensors comprised by the gas sensor include different sensing surface materials.

[0075] Example 11. The aerosol-generating device according to any one of previous Examples 9-10,

[0076] wherein at least one of the MOS sensors comprised in the gas sensor comprises a sensing surface material selected from the group consisting of

[0077] - tin(IV) oxide, SnO2, catalysed with palladium, Pd,

[0078] - tin(IV) oxide, SnO2,

[0079] - tin(IV) oxide, SnO2, catalysed with gold, Au,

[0080] - zinc(ll) oxide, ZnO,

[0081] - tungsten(VI) oxide, WO3,

[0082] - indium(lll) oxide, ln2O3,

[0083] - molybdenum(VI) oxide, MoO3,

[0084] - titanium(IV) oxide, TiO2,

[0085] - copper(ll) oxide, CuO,

[0086] - niobium(V) oxide, Nb2O5,

[0087] - graphene,

[0088] - carbon nanotubes,- perovskite oxides, e.g., barium titanate, strontium titanate, and

[0089] - mixed metal oxides.

[0090] Example 12. The aerosol-generating device according to any one of Examples 9-11 , wherein the gas sensor comprises

[0091] at least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with palladium, Pd, as sensing surface material,

[0092] at least one MOS sensor comprising tin(IV) oxide, SnO2, as sensing surface material, and at least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with gold, Au, as sensing surface material.

[0093] Example 13. The aerosol-generating device according to any one of the previous Examples,

[0094] wherein the gas sensor is obtained by screen printing.

[0095] Example 14. The aerosol-generating device according to any one of the previous Examples,

[0096] wherein the gas sensor is configured to measure a resistance change effected by the exposure of at least part of the gas sensor to the one or more gases released from the aerosolgenerating article or substrate using ratiometric resistance measurement.

[0097] Example 15. The aerosol-generating device according to any one of the previous Examples,

[0098] wherein the gas sensor comprises a sensor heating device configured to heat the gas sensor, particularly a sensing surface material of the gas sensor, during the determination of the sensing profile, for example to a temperature between 250 °C and 450 °C or between 280 °C and 400 °C or between 310 °C and 380 °C, for example to a temperature of 350 °C.

[0099] Example 16. The aerosol-generating device according to the previous Example, wherein the sensor heating device comprises a resistive heater, for example a resistive heating track, particularly wherein the resistive heating track comprises a platinum, Pt, layer.

[0100] Example 17. The aerosol-generating device according to the previous Example, wherein the gas sensor comprises electrical leads for electrically connecting the gas sensor to the control circuitry, and wherein the electrical leads are made of the same material, and particularly the same layer thickness, as the resistive heater, particularly wherein the resistive heater and the electrical leads are obtained in the same screen printing step during manufacturing.

[0101] Example 18. The aerosol-generating device according to any one of the previous Examples,

[0102] wherein the gas sensor is arranged on a printed circuit board, PCB, andwherein the gas sensor is arranged on the same PCB as the control circuitry, particularly the controller and / or the processor of the control circuitry, or

[0103] wherein the gas sensor is arranged on a different PCB than the control circuitry, particularly the controller and / or the processor of the control circuitry.

[0104] Example 19. The aerosol-generating device according to the previous Example, wherein the gas sensor is arranged at a distance from the PCB and connected to the PCB by electrical connection pins, wherein the distance of the gas sensor to the PCB is at least 1 mm or at least 2 mm or at least 3 mm or at least 5 mm or at least 7.5 mm or at least 10 mm.

[0105] Example 20. The aerosol-generating device according to any one of Examples 18-19, wherein a thermal insulation layer and / or a heat sink is arranged between the gas sensor and the PCB, for example comprising a metal or a ceramic material.

[0106] Example 21. The aerosol-generating device according to any one of the previous Examples,

[0107] wherein the gas sensor, particularly a sensing surface material of the gas sensor, is arranged inside a sensing chamber, particularly wherein the sensing chamber provides an open volume for receiving the one or more gases released from the aerosol-generating article or substrate of from 100 mm3 to 600 mm3, for example from 125 mm3 to 500 mm3 or from 150 mm3 to 450 mm3.

[0108] Example 22. The aerosol-generating device according to the previous Example, wherein the sensing chamber comprises a sensing chamber housing, wherein the sensing chamber housing comprises a heat insulating material, for example a heat insulating plastic, ceramic, aerogel, glass fiber, and / or aerated foam material.

[0109] Example 23. The aerosol-generating device according to any one of Examples 21-22, wherein the sensing chamber is fluidically connected to the heating chamber and / or an airflow path through the aerosol-generating device and / or the aerosol-generating article or substrate via a hydrophobic filter, for example a hydrophobic gauze filter, particularly wherein the hydrophobic filter comprises polyethylene, PE, polypropylene, PP, polyvinylidene fluoride, PVDF, silicone, and / or polytetrafluoroethylene, PTFE.

[0110] Example 24. The aerosol-generating device according to any one of Examples 21-23, wherein the sensing chamber is fluidically connected to the heating chamber by a hermetic seal, for example a gasket seal, particularly wherein the hermetic seal comprises silicone and / or polytetrafluoroethylene, PTFE.

[0111] Example 25. The aerosol-generating device according to any one of the previous Examples,

[0112] wherein the gas sensor is arranged in relation to the heating chamber such that the gas sensor, particularly a sensing surface material of the gas sensor, is distanced from the aerosol-generating article or substrate by between 0.5 mm and 8 mm, for example by between 1 mm and 5 mm or by between 2.5 mm and 4 mm.

[0113] Example 26. The aerosol-generating device according to any one of the previous Examples,

[0114] wherein the gas sensor is fluidically connected to an airflow path through the aerosolgenerating device and / or the aerosol-generating article or substrate upstream of the heating chamber or downstream of the heating chamber.

[0115] Example 27. The aerosol-generating device according to the previous Example, wherein the gas sensor is fluidically connected to a cooling section of the airflow path through the aerosol-generating device and / or the aerosol-generating article or substrate.

[0116] Example 28. The aerosol-generating device according to any one of the previous Examples,

[0117] wherein the gas sensor is arranged on a longitudinal axis of the heating chamber or radially offset from the longitudinal axis of the heating chamber.

[0118] Example 29. The aerosol-generating device according to any one of the previous Examples,

[0119] wherein the gas sensor comprises a perforation device, for example a needle, configured to perforate and / or enter the aerosol-generating article or substrate in the heating chamber.

[0120] Example 30. The aerosol-generating device according to the previous Example, wherein the perforation device is movable between an extended position, in which the perforation device may perforate and / or enter the aerosol-generating article or substrate, and a retracted position, in which the perforation device is arranged outside the aerosol-generating article or substrate.

[0121] Example 31. The aerosol-generating device according to any one of Examples 29-30, wherein the perforation device comprises a bevelled tip, and wherein the perforation device is configured to perforate and / or enter the aerosol-generating article or substrate in a direction transverse, for example perpendicular, to a longitudinal axis of the heating chamber, and wherein the free end of the bevel of the tip is arranged on the downstream side of the perforation device.

[0122] Example 32. The aerosol-generating device according to any one of the previous Examples, further comprising

[0123] an aerosol-generating article or substrate, preferably wherein the aerosol-generating device is configured to generate aerosol from the aerosol-generating article or substrate.

[0124] Example 33. A computer-implemented method of determining a type of an aerosolgenerating article or substrate inserted into an aerosol-generating device, for example an aerosolgenerating device according to any one of the previous Examples, the method comprising:determining a sensing profile by a gas sensor, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, and

[0125] determining the type of the aerosol-generating article or substrate from the sensing profile. Example 34. The method according to the previous Example, further comprising detecting the insertion of the aerosol-generating article or substrate into the aerosolgenerating device.

[0126] Example 35. The method according to any one of the previous Examples 33-34, further comprising

[0127] heating the aerosol-generating article or substrate and determining the sensing profile during heating of the aerosol-generating article or substrate.

[0128] Example 36. The method according to any one of the previous Examples 33-35, further comprising

[0129] allowing, disallowing or adjusting the operation of a heater device of the aerosol-generating device depending on the determined type of the aerosol-generating article or substrate.

[0130] Example 37. A computer program, which when executed by processing circuitry of an aerosol-generating device or a companion device configured to charge an aerosol-generating device with electrical energy, causes the aerosol-generating device or the companion device to perform the steps of the method according to any one of the previous Examples 33-36.

[0131] Example 38. A non-transitory computer-readable medium storing a computer program according to the previous Example.

[0132] Examples will now be further described with reference to the figures in which:

[0133] Figure 1 shows two examples of aerosol-generating devices;

[0134] Figure 2 shows a magnified view of a heating and sensing element of a gas sensor;

[0135] Figure 3 shows a gas sensor;

[0136] Figure 4 shows a top view of a gas sensor;

[0137] Figure 5 shows a side view of a gas sensor;

[0138] Figure 6 shows a circuit diagram of the wiring of the gas sensor for ratiometric resistance measurement;

[0139] Figure 7 shows three exemplary sensing profiles;

[0140] Figure 8 shows a first embodiment of a gas sensor mounted in an aerosol-generating device;

[0141] Figure 9 shows a second embodiment of a gas sensor mounted in an aerosol-generating device;

[0142] Figure 10 shows a third embodiment of a gas sensor mounted in an aerosol-generating device;Figure 11 shows a front and a back view of another gas sensor;

[0143] Figure 12 shows a back view of another gas sensor; and

[0144] Figure 13 shows a flowchart of the method.

[0145] The figures are schematic only and not to scale.

[0146] Figure 1 shows two examples of aerosol-forming or aerosol-generating devices 1 for forming or generating aerosol, for example for consumption or inhalation by a user in one or more usage sessions. On the left side of Figure 1 , an aerosol-generating device 1 is shown which may be configured to at least partly receive an aerosol-forming article or substrate 2 into an insertion opening 3, which may lead into the heating chamber of the aerosol-generating device 1. Part of the aerosol-forming article or substrate 2 may protrude from the aerosol-generating device 1 and may be directly used as mouthpiece for a user to puff on. Typically, the aerosol-forming article or substrate 2 used in this type of aerosol-generating device 1 may be formed like cylindrical sticks, as exemplarily shown, but other shapes and / or forms may also be used. The aerosol-generating article 2 may comprise an aerosol-generating substrate, such as a tobacco containing substrate, and / or a cartridge comprising a liquid, for example a liquid that can be aerosolized for inhalation. On the right side of Figure 1, another type of aerosol-generating device 1 is shown. The aerosolgenerating device 1 may comprise a mouthpiece 4, which may be part of the housing of the device, through which a user may inhale aerosol provided by the aerosol-generating device 1 for consumption during a usage session. The aerosol may be provided from an aerosol-generating article or substrate 2 provided inside the aerosol-generating device 1 and therefore not visible in Figure 1.

[0147] The aerosol-generating device 1 may further include processing circuitry or control circuitry 18 with at least one controller 5 and one or more processors 6. For generating the aerosol during use or consumption of the aerosol-generating article 2, the aerosol-generating device 1 may comprise at least one heating element 7 or heater device for applying heat to at least a portion of the aerosol-generating article 2. Instead of the heating element 7, an ultrasonic device (not shown) may also be used to generate aerosol from the aerosol-generating article. The processing circuitry 18 and / or the controller 5 and / or the processor 6 may be configured to control actuation, activation and / or deactivation of at least one heating element 7 or ultrasonic device.

[0148] For powering the at least one heating element 7 with electrical power, the aerosolgenerating device 1 may further comprise the at least one energy storage 15, for example in the form of a battery, for storing electrical energy or power. Energy storage 15 may be removably couplable to the aerosol-generating device 1. In other words, energy storage 15 may be a replaceable energy storage or battery. The connection between the energy storage 15 and the aerosol-generating device 1 may be configured so that the device 1 may be run by electrical energy provided by the energy storage 15.The aerosol-generating device 1 may further comprise at least one electrical connector 12 for coupling to a corresponding electrical connector on a companion device (not shown) for the aerosol-generating device 1 and / or an electrical connector of an external power supply (not shown), e.g., a USB charger.

[0149] The aerosol-generating device 1 may further comprise a communications arrangement 9 or communication circuitry 9 with one or more communications interfaces 10 for communicatively coupling the aerosol-generating device 1 with a companion device or other devices, for example, via an Internet connection, a wireless LAN connection, a WiFi connection, a Bluetooth connection, a mobile phone network, a mobile data connection for example but not limited to a 3G / 4G / 5G connection, an edge connection, an LTE connection, a BUS connection, a wireless connection, a wired connection, an optical data connection such as but not limited to IrDa, a radio connection, a near field connection, and / or an loT connection.

[0150] The aerosol-generating device 1 may further comprise a data storage 11 or memory for storing information, program code or data. Data storage 11 may also store collected values of sensors and / or one or more mathematical functions or formulas, software and computer instructions that can be executed by the processing circuitry 18, particularly controller 5 and / or processor 6. One or more sensors 16 may be arranged on, at or in the aerosol-generating device 1 to collect data. One or more of the sensors 16 may for example be temperature sensors, strain sensors, accelerometers or any other suitable sensors.

[0151] The aerosol-generating device 1 may further comprise user interface components, for example comprising an input element or input device 8, for example in the form of a pushbutton or a capacitive button. The input device 8 may be used as a power button to activate or deactivate the heating element 7 or ultrasonic device for aerosol generation thereby to activate or deactivate the aerosol-generating device 1. Upon activation of the aerosol-generating device 1, the heating element 7 may be activated and heat may be applied to at least a part of the aerosol-generating article or substrate 2, such that aerosol can be generated for consumption or inhalation by the user, for example in a usage session. The aerosol-generating device 1 may comprise one or more output elements, such as a display device 17 and / or one or more LEDs, for outputting a signal and / or displaying information to a user, for example a user interface such as a GUI, or haptic and acoustic data output devices. The display device 17 may be, for example, a touchscreen and may therefore be configured as both an output and an input element.

[0152] The aerosol-generating device 1 may further comprise a gas sensor 14 for determining the type of the aerosol-generating article or substrate 2 inserted into the device 1 by a user. A central component of the gas sensor 14, specifically a heating and sensing element 24 is shown in Figure 2. As shown in Figure 2, the heating and sensing element 24 of the gas sensor 14 may be a flat component. It may comprise a sensor substrate 19, which may be or may comprise a non-conductive material, for example quartz, oxidized silicon or oxidated aluminium. Deposited on the sensor substrate 19, the heating and sensing element 24 of the gas sensor 14 may comprise a sensor heating device 20, which may be a resistive heater, and which may comprise a resistive heating track 13 as well as heater contacts 50 or heater electrodes for electrically connecting the resistive heating track 13 to a power supply. The sensor heating device 20 may be configured to heat the entire heating and sensing element 24 in order to heat the sensing surface material of the gas sensor 14, which is the material reacting to the presence or absence of one or more gases released from the aerosol-generating article or substrate 2, and which is therefore the material used for the actual measurement. In Figure 2, the sensing surface material of the gas sensor 14 is represented by three sensing layers 22, which may be different from each other and which may each constitute the sensing surface material of a MOS sensor. In one example, one of the sensing layers 22 may be or may comprise tin(IV) oxide, SnO2, catalysed with palladium, Pd, another of the sensing layers 22 may be or may comprise tin(IV) oxide, SnO2, without catalyst, and another of the sensing layers 22 may be or may comprise tin(IV) oxide, SnO2, catalysed with gold, Au. However, other materials or other combinations of materials in the different sensing layers 22 may also be used. The sensing layers 22 may be connected to a power supply and / or the control circuitry 18 through a common electrode 21, connecting the sensing layers 22 in parallel, and through sensor electrical leads 23, wherein each sensing layer 22 is connected using a separate, dedicated sensor electrical lead 23, so that the electrical resistance of each sensing layer 22 may be separately measured and determined.

[0153] All of the components of the heating and sensing element 24 of the gas sensor 14 as shown in Figure 2 and / or as explained herein may be obtained and / or deposited on the sensor substrate 19 by screen printing. All of the components of the sensor heating device 20, i.e. the heater contacts 50 and the resistive heating track 13, as well as all of the components of the MOS sensors, i.e. the common electrode 21, the sensing layers 22 and the sensor electrical leads 23, may be obtained and / or deposited on the sensor substrate 19 by screen printing. Particularly, the heater contacts 50 and / or the resistive heating track 13 and / or the common electrode 21 and / or the sensor electrical leads 23 may be made of or comprise the same material, for example Pt, and / or may have the same layer thickness on the sensor substrate 19. Any combination of these elements may be obtained and / or deposited on the sensor substrate 19 in the same screen printing step. In a particular embodiment, all of the heater contacts 50, the resistive heating track 13, the common electrode 21, and the sensor electrical leads 23 may be obtained and / or deposited on the sensor substrate 19 in the same screen printing step. This may make the gas sensor 14, in the example shown in Figure 2 comprising three MOS sensors, very cost-effective to manufacture.Figure 3 shows an exemplary overview of a complete gas sensor 14 comprising the heating and sensing element 24. In the example shown, the heating and sensing element 24 may be connected to base pins 26 via lead wires 27. The lead wires 27 may each connect one of the electrodes or contacts of the sensor heating device 20 and the sensing layers 22 to one base pin 26. The base pins 26 may be used to connect the gas sensor 14 to a PCB 25, and, for example, to the control circuitry 18. Also, the base pins 26 may be used to distance the heating and sensing element 24 from the PCB 25 to prevent heat transfer to the PCB 25. In this embodiment, the heating and sensing element 24 is connected to the PCB 25 exclusively through the base pins 26. No substrate material, neither from the heating and sensing element 24 or the PCB 25, may span the distance between the heating and sensing element 24 and the PCB 25. The heating and sensing element 24 may be arranged inside a sensing chamber 29, which may be defined by a sensor cap or sensing chamber housing 28. The sensing chamber 29 may provide an open space in which only the heating and sensing elements 24 along with parts of the base pins 26 is arranged. The sensing chamber 29 may be hermetically sealed towards the outside except for an opening 51 configured to let the one or more gases released from the aerosol-generating article or substrate 2 into the sensing chamber 29. The sensing chamber 29 may therefore allow gases entering the sensing chamber 29 to freely mix with the air inside the chamber and therefore come into contact with the sensing layers 22 of the gas sensor 14. To prevent liquid droplets or other contaminants from entering the sensing chamber and from contaminating the gas sensor, the opening 51 may comprise a filter 31 , for example a hydrophobic filter 31 , which may be configured to allow gases to pass freely, but which may prevent contaminants from entering. The gas sensor 14 as shown in Figure 3 may be arranged and / or positioned inside the aerosol-generating device 1 so that the opening 51 is fluidically connected to the heating chamber and / or an airflow path through the aerosol-generating device 1. One or more gases being released from the aerosolgenerating article or substrate 2 may therefore diffuse through the heating chamber and / or the airflow path and into the sensing chamber 29 through the opening 51. To prevent gases from leaking into areas of the aerosol-generating device 1 where they do not belong and where they cannot be detected by the gas sensor 14, the sensing chamber housing 28 may comprise a sealing device 49, for example a hermetic seal, which may, for example, be arranged around opening 51 and which may be configured to hermetically seal the sensing chamber housing 28 to the heating chamber and / or the airflow path.

[0154] Figure 4 shows a top view of the heating and sensing element 24 and its connection to the base pins 26 via lead wires 27. In the example shown comprising three MOS sensors, i.e. three sensing layers 22, a total of six lead wires 27 and six base pins 26 may be needed. Two of them may be used to connect the sensor heating device 20, one may be used to connect the common electrode 21, and three may be used to connect the sensing layers 22 and / or the sensing layerleads 23. As further shown in Figure 5, the base pins 26 may be used to distance the heating and sensing element 24, particularly the sensor heating device 20, from the PCB 25, for instance by a distance D. Distance D may be measured between the heating and sensing element 24 or the sensor heating device 20 and the PCB 25 and may be, for example, at least 1 mm or at least 2 mm or at least 3 mm or at least 5 mm or at least 7.5 mm or at least 10 mm. In this way, less heat from the heating and sensing element 24 and particularly from the sensor heating device 20 may be transferred to the PCB 25. Additionally, an insulation layer 43, which may be made of or may comprise a thermally insulating material, may be arranged on the side of the heating and sensing element 24 directed to the PCB 25. Additionally or alternatively, the chamber base 30, which may be the part of the sensing chamber housing 28 facing the PCB 25, may also be made of or may comprise a thermally insulating material to reduce heat transfer from the gas sensor 14 to the PCB 25.

[0155] Figure 6 shows an exemplary circuitry for ratiometric resistance measurement. The resistance of the gas sensor 14 may be used as the measured parameter for determining the sensing profile used for determining the type of the aerosol-generating article or substrate 2. The gas sensor 14, particularly one of the sensing layers 22 of the gas sensor 14, may have a resistance RSENS, which may be the resistance to be measured in the shown circuit. It may be arranged in series with a reference resistor having the resistance RREF. A reference current IREF may pass through the gas sensor 14 and the reference resistor, i.e. through RSENS and RREF. Through the input pins +IN and -IN, an analog to digital converter ADC may measure the voltage drop over RSENS- Similarly, through the input pins +REF and -REF, the ADC may measure the voltage drop over RREF. The voltage over RSENS may be calculated by multiplying RSENS with the reference current lREF. The voltage over RREFmay be calculated by multiplying RREFwith the reference current lREF. Therefore, as lREFis the same in both calculations, the voltage over RSENS divided by the voltage over RREFequals RSENS divided by RREF. In other words, the resistance to be measured RSENS can be calculated by multiplying the voltage over RSENS by RREFand dividing by the voltage over RREF. The actual value of the reference current lREFmay be variable, as it is the same for both the sensing layer 22 and the reference resistor and thereby eliminated from the equations anyway. Therefore, only the voltage drops over RSENS and RREFneed to be measured. As long as RREFis known and sufficiently stable, the resistance RSENS of the gas sensor 14, particularly of each of the sensing layers 22 of the gas sensor 14, may be calculated from this measurement.

[0156] Figure 7 shows exemplary sensing profiles measured for an exemplary type of aerosolgenerating article or substrate 2 by three MOS sensors comprised in the gas sensor 14. Specifically, the abscissa or x-axis shows the time t elapsed during the measurement in seconds, whereas the ordinate or y-axis shows the measured resistance R in ohm. The sensing profiledetermined by the first MOS sensor is denoted by S1, the sensing profile determined by the second MOS sensor is denoted by S2 and the sensing profile determined by the third MOS sensor is denoted by S3. The three exemplary MOS sensors may be the three sensors comprising the different sensing layers 22 as already mentioned. At around second 40 of the measurement, an aerosol-generating article or substrate 2 was inserted into the aerosol-generating device 1. At around second 60, a usage session was started. Therefore, the period of 20 seconds between second 40 and second 60 comprises the preheating phase in which the temperature of the aerosol-generating article or substrate 2 was increased from ambient temperature to the maintenance temperature. As can be seen from the three sensing profiles S1, S2, S3, the resistance of the different MOS sensors changes differently, but distinctively, in this period of time. The changes of the resistance as measured in the sensing profiles S1, S2, S3 represent the effects of the exposure of part of the gas sensor 14, specifically the sensing layer 22, to one or more gases released from the aerosol-generating article or substrate 2. The differences in the three sensing profiles S1, S2, S3 are due to the different materials of the sensing layers 22 implemented in the specific MOS sensors. From the combination of these three sensing profiles S1, S2, S3, the type of an aerosol-generating article or substrate 2 may be determined by the control circuitry, for example by comparing all three sensing profiles S1, S2, S3 with reference profiles specific for the sensing surface materials or sensing layers 22 used in the MOS sensors and respective types of aerosol-generating articles or substrates 2. The determination of the type of aerosol-generating article or substrate 2 may also be implemented by an artificial intelligence based or machine-learning based process which may, for example, have been trained using reference profiles from known types of aerosol-generating articles or substrates 2.

[0157] Figure 8 shows a cross-sectional side view of an aerosol-generating device 1. An aerosolgenerating article or substrate 2 has been inserted into a heating chamber 38 inside the housing 32 of the aerosol-generating device 1. As shown, the aerosol-generating article or substrate 2 may be positioned in the heating chamber 38 in such a way that the aerosol-generating material 34 may be arranged between one or more heating elements 7. The heating elements 7 may, for example, be resistive heating elements, or they may be dielectric heating elements or they may be part of a resonant cavity for microwave heating. Also, the heating elements 7 may, for example, be part of an inductive heater and the aerosol-generating article or substrate 2 may comprise an internal heating element 33, for example a susceptor configured to be heated by inductive heating elements 7. Further, the aerosol-generating article or substrate 2 may comprise an end filter 35 and / or one or more cooling sections 36, which may be sections downstream of the heating chamber 38, in which the internal diameter or clearance constituting the airflow path may be increased in comparison to an upstream section. One of the cooling sections 36 may comprise a perforation 37, which may be or comprise a series of perforations arranged around a part of thecircumference or the whole circumference of the aerosol-generating article or substrate 2. The perforation 37 may be fl uidical ly connected to the outside environment so that ambient air is drawn into the cooling section 36 when a user puffs on the mouthpiece 4 and / or the aerosol-generating article or substrate 2. Therefore, perforation 37 constitutes a connection between the inside of the cooling section 36, which is part of the airflow path through the aerosol-generating device 1 and the aerosol-generating article or substrate 2, and an outside of the aerosol-generating article or substrate 2.

[0158] As also shown in Figure 8, the gas sensor 14, for example along with its PCB 25, may be arranged laterally offset from the aerosol-generating article or substrate 2. In other words, the gas sensor 14 may be radially offset from the aerosol-generating article or substrate 2 in relation to a longitudinal axis 52 of the aerosol-generating device 1 and / or the aerosol-generating article or substrate 2 and / or the heating chamber 38. The opening 51 of the sensing chamber 29 and / or the sensing chamber housing 28 may be directed towards the aerosol-generating article or substrate 2. For example, the gas sensor 14 may be arranged and / or positioned such that the opening 51 of the sensing chamber 29 and / or the sensing chamber housing 28 is fluidically connected to the perforation 37 and / or an ambient air channel configured to guide air from the outside environment to the perforation 37 and into the cooling section 36. In this arrangement, one or more gases released from the aerosol-generating article or substrate 2, for example from the aerosol-generating material 34, may diffuse through the cooling section 36 and through perforation 37 into the sensing chamber 29, where it may come in contact with the gas sensor 14, specifically the one or more sensing layers 22, thereby facilitating the determination of the sensing profile as explained herein. In this embodiment, therefore, the gas sensor 14 may be arranged and / or positioned so that one or more gases released from the aerosol-generating article or substrate 2 may diffuse to the gas sensor 14 downstream of the heating chamber 38, for example through the perforation 37.

[0159] An alternative embodiment is shown in Figure 9. In Figure 9, the gas sensor 14 may be arranged on a side of the aerosol-generating article or substrate 2 opposite of the mouthpiece 4. In other words, the gas sensor 14, and for instance also the PCB 25 of the gas sensor 14, may be arranged on an extension of the longitudinal axis 52 and / or may be arranged upstream of heating chamber 38. In this embodiment, therefore, the gas sensor 14 may be arranged and / or positioned so that one or more gases released from the aerosol-generating article or substrate 2 may diffuse to the gas sensor 14 upstream of the heating chamber 38, for example through the end filter 35. In this area, there may be enough space for the provision of an exposure chamber 39, which may be an open space in which the gas sensor 14 may be housed. The one or more gases released from the aerosol-generating article or substrate 2 may therefore diffuse into the exposure chamber 39 and from there into the sensing chamber 29. Alternatively, when anexposure chamber 39 arranged in the housing 32 of the aerosol-generating device 1 is available, the sensing chamber housing 28 may be dispensed with. In other words, the gas sensor 14 may only comprise the heating and sensing element 24 and the respective connections without the sensor cap or sensing chamber housing 28.

[0160] Figure 10 shows another alternative embodiment of the aerosol-generating device 1. In this embodiment, the gas sensor 14 may be positioned and / or arranged similarly to the embodiment of Figure 8, however, other positions and / or arrangements are also possible. The main difference of the embodiments according to Figure 10 to the previously described embodiments is that the gas sensor 14 may comprise a perforation device 40, for example shaped like a hollow needle with a sharp, particularly beveled, tip. The perforation device 40 may be movable, for example movable between an extended position, in which the perforation device 40, particularly the tip, may be arranged inside the aerosol-generating article or substrate 2, as shown in Figure 10, and a retracted position, in which the perforation device 40 is, particularly completely, arranged outside of the aerosol-generating article or substrate 2. When the perforation device 40 is moved from the retracted position into the extended position, it may be configured to pierce the aerosolgenerating article or substrate 2 using its tip. The movement may, for example, be effected by an actuator 42, for example a solenoid. When the perforation device 40 is in the retracted position, the aerosol-generating article or substrate 2 may be freely inserted into or removed from the aerosol-generating device 1 and the heating chamber 38. However, the perforation device 40 should not be in the extended position during insertion or removal of the aerosol-generating article or substrate 2. For this reason, the movement of the perforation device 40 from the retracted position into the extended position may be coupled to a function of the aerosol-generating device 1 indicating that an aerosol-generating article or substrate 2 is present in the device 1 and a removal is highly unlikely, for example, when preheating is initiated. Additionally, the perforation device 40 may be moved into the retracted position immediately after the determination of the type of the aerosol-generating article or substrate 2 is finished. In this way, the perforation device 40 may already be in the retracted position when a usage session is started, which also protects the perforation device 40 from contamination by the aerosol.

[0161] The perforation device 40 may be configured so that, when it is in the extended position, one or more gases released from the aerosol-generating article or substrate 2 may diffuse through the hollow interior of the perforation device 40 into the sensing chamber 29 for detection by the gas sensor 14. The beveled tip of the perforation device 40 may be configured to assist the diffusion of gases from the interior of the aerosol-generating article or substrate 2 into the sensing chamber 29. For example, the perforation device 40 may be oriented such that the opening of the beveled tip, the circumference of which is defined by the bevel, is oriented towards the heating chamber 38, for example when the perforation device 40 is in the extended position. Therefore,gases released from the aerosol-generating article or substrate 2 may travel in the flow direction marked by arrow 41 in Figure 10 and may freely enter the beveled tip of the perforation device 40. By the provision of the perforation device 40, the concentration of the one or more gases released from the aerosol-article or substrate 2 in the sensing chamber 29 may be increased, and thereby the quality of the measurement may be improved. By providing the perforation device 40 as hollow, needle-like structure, diffusion of the gases into the sensing chamber 29 may also be accelerated so that the determination of the type of the aerosol-generating article or substrate 2 used may be finished more quickly.

[0162] Figures 11 and 12 show another possible embodiment of the gas sensor 14. In this embodiment, the sensor heating device 20 and its electrical connections may be arranged on one side of the substrate 19, which may be a non-conductive substrate as described before, whereas the sensing layers 22 and their respective electrical connections may be arranged on the other, opposite, side of the substrate 19. In Figure 11, the same substrate 19 is shown on the left side and on the right side. On the left side, the side of the substrate 19 comprising the sensor layers 22 and their respective electrical connections is shown. On the right side of Figure 11, the side of the substrate 19 comprising the sensor heating device 20 and its respective electrical connections is shown. Again, both the sensor heating device 20, its electrical connections, the sensing layers 22, and their electrical connections, may be deposited on the substrate 19 by screen printing as described herein. However, instead of the base pins 26, the common electrode 21, the sensor electrical leads 23 and the heater contacts 50 as well as an extension of the substrate 19 may extend over the distance D (see Figure 12) over a lead guide 48. The lead guide 48 may comprise substrate 19 and the common electrode 21, the sensor electrical leads 23 as well as the heater contacts 50. In this way, the common electrode 21, the sensor electrical leads 23 as well as the heater contacts 50 extend over distance D to heater connection pins 44 connecting to the heater contacts 50 and sensor connection pins 45 connecting to the common electrode 21 and the sensor electrical leads 23. Specifically, the substrate 19 as well as the heater connection pins 44 and the sensor connection pins 45 may be configured to directly be slotted into PCB 25 and establish a connection between the heater connection pins 44 or the sensor connection pins 45 with the respective control circuitry 18 and / or power supply circuitry. In one example, the lead guide 48 may comprise a rigid substrate 19, for example the same substrate as used for the heating and sensing element 24. However, alternatively, the lead guide 48 may comprise a flexible substrate 19 on which the sensor electrical leads 23 and the heater contacts 50 are deposited, for example also using a flexible conductive ink. For example, the lead guide 48 may comprise a flexible Kapton substrate 19. This may enable the position and / or arrangement of the heating and sensing element 24 to be chosen more freely, for example in relation to the PCB 25.As exemplarily shown in Figure 11, right side, for the lead guide 48 comprising the heater contacts 50, the lead guide 48 may be at least partly covered by a dielectric or electrically insulating layer 46. Also, the side of the lead guide 48 comprising the sensor electrical leads 23 as well as the common electrode 21 may be at least partly covered by a dielectric layer 46 or electrically insulating layer. As shown in Figure 12, the side of the heating and sensing element 24 comprising the sensor heating device 20 may be covered by a thermally insulating layer 47, which may be configured to prevent heat transfer from the sensor heating device 22 other parts of the aerosol-generating device 1. Furthermore, thermally insulating layer 47 may decrease power consumption of the sensor heating device 24 necessary for keeping the sensing layers 22 at the necessary temperature for sensing the one or more gases.

[0163] Figure 13 shows a flowchart of method 60 according to the present disclosure. The method 60 may be performed by control circuitry 18, for example the controller 5 and / or processor 6, of the aerosol-generating device 1, for example using the other components of the aerosolgenerating device 1. Method 60 may start in step 61 by determining a sensing profile by the gas sensor 14, wherein the sensing profile may comprise information about an effect of an exposure of at least part of the gas sensor 14, for example the sensing surface material or sensing layer 22, to one or more gases released from the aerosol-generating article or substrate 2. For example, two or more sensing profiles may be determined by two or more sensing layers 22. In step 62, the method 60 may comprise determining the type of the aerosol-generating article or substrate 2 from the sensing profile, for example from all sensing profiles determined by the sensing layers 22. This may comprise comparing the sensing profiles to predetermined reference profiles, wherein the reference profiles may represent expected profiles from known types of aerosolgenerating articles or substrates 2. Additionally or alternatively, an artificial intelligence-based or machine learning-based analysis of the sensing profiles may be employed to determine the type of aerosol-generating article or substrate 2 inserted into the aerosol-generating device 1.

[0164] Optionally, method 60 may comprise step 63 of detecting the insertion of an aerosolgenerating article or substrate 2 into the aerosol-generating device 1. For example, a detected insertion may trigger the start of the determination of one or more sensing profiles as described herein. Also, the method 60 may comprise step 64 of heating the aerosol-generating article or substrate 2, for example of pre-heating the aerosol-generating article or substrate 2 from an ambient temperature to the maintenance temperature. This may cause sufficient concentrations of the one or more gases to be released from the aerosol-generating article or substrate 2 for the gas sensor 14 to reliably determine the type of the aerosol-generating article or substrate 2 used.

[0165] After the type of the aerosol-generating article or substrate 2 has been determined, method 60 may comprise step 65 of allowing, disallowing or adjusting the operation of the heater device or heating elements 7 of the aerosol-generating device 1. For example, heating may be allowedand a suitable heating profile may be selected for a known and authorized or original type of aerosol-generating article or substrate 2. Similarly, heating may be allowed and a suitable heating profile may be selected for a known and unauthorized or non-original type of aerosol-generating article or substrate 2, for example for an aerosol-generating article or substrate 2 provided by a third party. As suitable heating profile for an unauthorized or non-original type of aerosolgenerating article or substrate 2 may comprise lower heating temperatures than a heating profile for an authorized or original type of aerosol-generating article or substrate 2. Alternatively, heating may be disallowed for known and / or unknown unauthorized or non-original types of aerosolgenerating article or substrate 2. Heating may also be disallowed when the presence of a potentially toxic gas is detected in the sensing profiles, for example in a concentration above a predetermined threshold.

[0166] In summary, therefore, the present disclosure provides for the determination of a type of the aerosol-generating article or substrate 2 used in the aerosol-generating device 1 without the need for specifically marking the aerosol-generating article or substrate 2. In this way, control of the aerosol-generating device 1 may be adjusted to the specific type as determined, improving both user safety and user experience. The production costs of the aerosol-generating articles or substrates 2 are also kept low.

[0167] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 10 % of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

39 / 42CLAIMS1. An aerosol-generating device, comprisingcontrol circuitry including at least one controller and / or processor,a heating chamber configured to receive an aerosol-generating article or substrate, a heating device configured to heat the aerosol-generating article or substrate, and a gas sensor configured to determine a sensing profile, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, particularly during heating, wherein the control circuitry is configured to determine a type of the aerosol-generating article or substrate from the sensing profile.

2. The aerosol-generating device according to claim 1 ,wherein determining the type of the aerosol-generating article or substrate comprises determining whether the aerosol-generating article or substrate is an authentic aerosolgenerating article or substrate provided by the manufacturer of the aerosol-generating device or whether the aerosol-generating article or substrate is provided by a third party.

3. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor is obtained by screen printing.

4. The aerosol-generating device according to any one of the previous claims, wherein the determination of the sensing profile and the type of the aerosol-generating article or substrate is performed during a preheating phase, in which the aerosol-generating article or substrate is heated from an ambient temperature to a maintenance temperature, particularly before an aerosolization temperature of the aerosol-generating article or substrate is reached.

5. The aerosol-generating device according to any one of the previous claims, wherein the determination of the sensing profile and the type of the aerosol-generating article or substrate is performed within a maximum of 20 seconds after insertion of the aerosolgenerating article or substrate into the heating chamber, for example within a maximum of 15 seconds or within a maximum of 10 seconds or within a maximum of 8 seconds or within a maximum of 6 seconds or within a maximum of 5 seconds after insertion of the aerosol-generating article or substrate into the heating chamber.

6. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor is configured to determine, as part of the sensing profile, an effect of an exposure of at least part of the gas sensor to at least one volatile organic compound, VOC, released from the aerosol-generating article or substrate.

7. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor comprisesat least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with palladium, Pd, as sensing surface material,at least one MOS sensor comprising tin(IV) oxide, SnO2, as sensing surface material, and at least one MOS sensor comprising tin(IV) oxide, SnO2, catalysed with gold, Au, as sensing surface material.

8. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor is configured to measure a resistance change effected by the exposure of at least part of the gas sensor to the one or more gases released from the aerosolgenerating article or substrate using ratiometric resistance measurement.

9. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor comprises a sensor heating device configured to heat the gas sensor,wherein the sensor heating device comprises a resistive heater,wherein the gas sensor comprises electrical leads for electrically connecting the gas sensor to the control circuitry, and wherein the electrical leads are made of the same material, and particularly the same layer thickness, as the resistive heater.

10. The aerosol-generating device according to any one of the previous claims, wherein the gas sensor, particularly a sensing surface material of the gas sensor, is arranged inside a sensing chamber, wherein the sensing chamber is fluidically connected to the heating chamber and / or an airflow path through the aerosol-generating device and / or the aerosolgenerating article or substrate via a hydrophobic filter.

11. The aerosol-generating device according to any one of the previous claims,wherein the gas sensor comprises a hollow perforation device, for example a needle, configured to perforate and / or enter the aerosol-generating article or substrate in the heating chamber so that gases released from the aerosol-generating article or substrate are transported through the perforation device to the gas sensor.

12. The aerosol-generating device according to any one of the previous claims, further comprisingan aerosol-generating article or substrate, preferably wherein the aerosol-generating device is configured to generate aerosol from the aerosol-generating article or substrate.

13. A computer-implemented method of determining a type of an aerosol-generating article or substrate inserted into an aerosol-generating device according to any one of the previous claims, the method comprising:determining a sensing profile by a gas sensor, wherein the sensing profile comprises information about an effect of an exposure of at least part of the gas sensor to one or more gases released from the aerosol-generating article or substrate, anddetermining the type of the aerosol-generating article or substrate from the sensing profile.

14. A computer program, which when executed by processing circuitry of an aerosolgenerating device or a companion device configured to charge an aerosol-generating device with electrical energy, causes the aerosol-generating device or the companion device to perform the steps of the method according to the previous claim.

15. A non-transitory computer-readable medium storing a computer program according to the previous claim.

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