Container for aerosol generating substrate

Abstract

The present invention relates to an aerosol generating substrate container for an aerosol generating device (12), comprising: a chamber (22) configured and dimensioned to contain an aerosol generating substrate (14), the chamber (22) comprising an opening (36) which is configured to receive an aerosol generating substrate (14), and a wall (28, 30, 44) extending from the opening (36), and a substrate detector (51) configured to detect a deformation of the wall (28, 30, 44) that is caused by an aerosol generating substrate (14), the substrate detector (51) comprising a detection layer arranged on the wall (28, 30, 44) and configured to deform together with the wall.

Description

[0001] CONTAINER FOR AEROSOL GENERATING SUBSTRATE

[0002] Technical Field

[0003] The present disclosure generally relates to an aerosol generating system, and more particularly to an aerosol generating substrate container and a manufacturing method thereof.

[0004] Technical Background

[0005] The popularity and use of reduced-risk or modified-risk devices (also known as vaporizers) has grown rapidly in recent years as an alternative to the use of traditional tobacco products. Various devices and systems are available that heat or warm, rather than burn, an aerosol generating substrate to generate an aerosol for inhalation by a user.

[0006] A commonly available reduced-risk or modified-risk device is a heated substrate aerosol generating device, or so-called heat-not-burn device. Devices of this type generate an aerosol or vapor by heating an aerosol generating substrate that typically comprises moist leaf tobacco or other suitable vaporizable material, for example comprised in an aerosol generating article, to a temperature typically in the range of 150 °C to 300, 350 °C, in a heating chamber. Heating an aerosol generating substrate to a temperature within this range, without burning or combusting the aerosol generating substrate, generates a vapor which typically cools and condenses to form an aerosol for inhalation by a user of the device.

[0007] Aerosol generating substrates usable with the aerosol generating devices can take various forms, for example that of an elongate cylindrical stick or a flat-shaped cuboid. The form of an aerosol generating substrate is often a trade-off between convenience, aesthetics, and efficiency in heating. The receiver or the container for the aerosol generating substrates of the aerosol generating device is often shaped accordingly.

[0008] In order to ensure the safe operation of the aerosol generating device and to maximize the energy efficiency of the aerosol generating device, there is a need to ensure that the device can recognize the aerosol generating substrate. More specifically, certain functions, such as heating, may be activated only when an aerosol generating substrate is inserted into the aerosol generating device. The present disclosure seeks to address this need. Summary of the Invention

[0009] The present invention provides an aerosol generating system which addresses some or all of the above-mentioned needs.

[0010] According to a first aspect of the present invention, the following disclosure provides an aerosol generating substrate container for an aerosol generating device, comprising: a chamber configured and dimensioned to contain an aerosol generating substrate, the chamber comprising an opening which is configured to receive an aerosol generating substrate, and a wall extending from the opening, and a substrate detector configured to detect a deformation of the wall that is caused by an aerosol generating substrate, the substrate detector comprising a detection layer arranged on the wall and configured to deform together with the wall.

[0011] With this arrangement, the aerosol generating device can easily detect the presence of the aerosol generating substrate. Especially, considering the relatively small size of the substrate and that it may only cause a slight deformation of the chamber, this solution makes the detection more precise and efficient. Additionally, the device remains portable and compact.

[0012] In a second aspect of the invention according to the first aspect of the invention, the detection layer is a strain gauge, preferably comprising and / or made of silver nano particles.

[0013] This solution brings down the cost of production. The solution also guarantees that even a small variation on the wall can be detected and measured. Especially, the solution makes it possible to measure the level of strain / deformation of the chamber, so that it also prevents incorrect detection. As for the preferred material selected for this solution, it makes the strain gauge easy to be deposit onto the chamber (which is typically made of a heat conductive material, e.g. metal). The selection of the material also makes the strain gauge resistive to high temperatures.

[0014] In a third aspect of the invention according to any one of the preceding aspects of the invention, the strain gauge is Rosette type, T-Rosette, or dual parallel strain gauge, and preferably the strain gauge is a linear type strain gauge.

[0015] The selected types of the strain gauge ensures the precision of deformation detection.

[0016] In a fourth aspect of the invention according to any one of the second or third aspects of the invention, the strain gauge is attached to or printed or deposited onto the wall.

[0017] By this arrangement, especially through printing or deposition, the sensor is thinner and more durable. In a fifth aspect of the invention according to any one of the preceding aspects, the strain gauge has been printed or deposited onto the wall by means of a process of flexography, gravure, screen printing, inkjet printing sputter deposition, and / or aerosol jet printing.

[0018] In a sixth aspect of the invention according to any one of the preceding aspects, a thermal insulation layer is arranged between the wall and the substrate detector.

[0019] In a seventh aspect of the invention according to the preceding aspect, the thermal insulation layer comprises or consists of a high temperature insulation material, preferably, a thermal insulation material that can withstand at least 350 °C, more preferably aluminum oxide, silicon dioxide, and / or silicon nitride.

[0020] This arrangement protects the substrate detector, especially during the process of heating the substrate.

[0021] In an eighth aspect of the invention according to any one of the preceding aspects, the wall has an internal surface on one side of the wall and an external surface on the other side of the wall, the internal surface is arranged to face the aerosol generating substrate when it is fully received in the container body, and the substrate detector is arranged on the external surface.

[0022] In a ninth aspect of the invention according to any one of the preceding aspects, the opening has an elongated shape, preferably an oval shape, or a rectangular or polygonal shape, preferably with rounded corners.

[0023] In a tenth aspect of the invention according to any one of the preceding aspects, the wall comprises a first side wall, a second side wall and connection wall sections connecting the first and second side walls.

[0024] In an eleventh aspect of the invention according to any one of the preceding aspects, the substrate detector is at least partially arranged on at least one of the connection wall sections.

[0025] This arrangement makes the detection of the substrate more sensitive.

[0026] In a twelfth aspect of the invention according to any one of the tenth or eleventh aspects, the aerosol generating substrate container is arranged in a way such that, when an aerosol generating substrate is received therein, a deformation takes place at, at least, the connection wall sections.

[0027] In a thirteenth aspect of the invention according to any one of the tenth to twelfth aspects, the connection wall sections have a bent cross section when no aerosol generating substrate is re- ceived in the aerosol generating substrate container, and the connection wall sections are configured to at least partially deform when an aerosol generating substrate is received in the aerosol generating substrate container.

[0028] In a fourteenth aspect of the invention according to any one of the tenth to thirteenth aspects, the connection wall section protrudes into or out from the volume enclosed by the two side walls.

[0029] In a fifteenth aspect of the invention according to any one of the preceding aspects, the cross section of at least one of the connection wall sections has a V-shape with rounded and / or sharp corners, an arc shape, or a wave shape.

[0030] In a sixteenth aspect of the invention according to any one of the preceding aspects, there is a discrete or continuous change of thickness of the wall when going along the perimeter of the wall.

[0031] In a seventeenth aspect of the invention according to any one of the preceding aspects, the aerosol generating substrate container further comprises a heater configured to heat an inserted substrate.

[0032] According to an eighteenth aspect of the present invention, the following disclosure provides a method of manufacturing the aerosol generating substrate container according to any one of the first to the sixteenth aspects, comprising the step of providing the substrate detector on the wall of the container body, preferably by means of a printing or deposition process, and more preferably a process of flexography, gravure, screen printing, inkjet printing sputter deposition, and / or aerosol jet printing.

[0033] In a nineteenth aspect of the invention according to the preceding aspect, the manufacturing method further comprises the step of providing a thermal insulation layer between the wall and the substrate detector before providing the substrate detector on the wall.

[0034] Preferred embodiments are now described, by way of example only, with reference to the accompanying drawings.

[0035] BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1: is a diagrammatic perspective view of an aerosol generating device suitable for using the aerosol generating substrate container according to the invention;

[0037] Figure 2: is a diagrammatic perspective view of a substantially planar aerosol generating substrate for use with the aerosol generating device of Figure 1; Figure 3: is a diagrammatic perspective view of an aerosol generating substrate container according to the invention used in a device of Figure 1;

[0038] Figures 4a and 4b: are a diagrammatic perspective views of part of an aerosol generating substrate container and its partial enlarged view, showing in particular a heating chamber with a strain gauge;

[0039] Figure 5: is a cross section view of an aerosol generating substrate container, showing in particular a heating chamber with a strain gauge and a thermal insulation layer;

[0040] Figures 6a to 6f: are diagrammatic illustrations showing the movement of first and second side walls / the deformation of the connection wall sections of an aerosol generating substrate con- tainer from a resting position (Figure 4a / 4b) to a deflected / deformed position (Figure 4e / 4f) during insertion of an aerosol generating substrate into the aerosol generating substrate container via an opening; and

[0041] Figure 7a to yf: are diagrammatic illustrations of different examples of a connection wall sections between first and second side walls of the heating chamber with a strain gauge of the aero- sol generating substrate container.

[0042] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Preferred embodiments of the present invention are described hereinafter and in conjunction with the accompanying drawings.

[0044] As used herein, the term “aerosol generating device” “vaporizer system”, “inhaler” or “electronic cigarette” may include an electronic cigarette configured to deliver an aerosol or vapor to a user, including an aerosol for smoking. The illustrated embodiments of the aerosol generating system in this invention are schematic, and it is also possible to combine some of the parts into single units, such as aerosol inlet and outlet, operator or computer modules, which is apparent to a person skilled in the art.

[0045] [Aerosol Generating System]

[0046] Figures 1 to 3 show an aerosol generating system 10 comprising an aerosol generating device 12 and an aerosol generating substrate 14. The aerosol generating substrate 14 is substantially planar or flat, meaning that its effective thickness is much smaller than the extensions in the other dimensions. The aerosol generating device 12 is intended to operate with the aerosol generating substrate 14 which is shown in more detail in Figure 2, and in particular to heat or warm the aerosol generating substrate 14 to generate a vapor containing one or more volatile components. The vapor may typically cool and condense to form an aerosol for inhalation by a user of the device 12.

[0047] The aerosol generating device 12 comprises a device body 16 extending along a device axis Y. The device body 16 comprises a mouthpiece 18 and a housing 20 arranged successively along the device axis Y. The mouthpiece 18 has an outlet 19. According to the example of Figure 1, the mouthpiece 18 and the housing 20 form two different pieces. In particular, the mouthpiece 18 is designed to be removably attached to the housing 20, e.g. fixed on or received in an insertion opening 36 formed at one of the ends of the housing 20. In this case, the aerosol generating substrate 14 can be inserted into the device 12 through the insertion opening 36 when the mouthpiece 18 is removed from the housing 20. According to an alternative example (not shown), the mouthpiece 18 maybe displaceable (such as, but not limited to, slidable and / or rotatable) relative to the housing 20 from a closed position to an open position in which the aerosol generating substrate 14 can be inserted inside the device 12. According to another example (not shown), the mouthpiece 18 and the housing 20 could form one single piece, i.e. the mouthpiece 18 is not removable from the housing 20. In this case, the aerosol generating substrate 14 can be inserted into the device 12 through, e.g., the outlet 19, which is the insertion opening 36 of the aerosol generating device 12. The housing 20 delimits an internal space of the aerosol generating device 12 receiving various elements designed to carry out different functionalities of the device 12. This internal space can for example receive a power source, such as a battery (e.g., a rechargeable battery which may be replaceable), for powering the device 12, a controller comprising electronic circuitry for, for example controlling the operation of the device 12, and an aerosol generating substrate container, which comprises a chamber (specifically, a heating chamber) 22 for receiving and containing the aerosol generating substrate 14. The housing 20 may further comprise an air flow path and / or air inlet for introduction of air into the chamber 22.

[0048] Referring to Figure 3, the chamber 22 is adapted to receive the aerosol generating substrate 14. The chamber 22 may form a substantially cuboid shape extending along the device axis Y, complementary to the shape of the aerosol generating substrate 14. In other words, the chamber 22 is dimensioned to contain the aerosol generating substrate 14. The chamber 22 has a proximal end 24, a distal end 26, and a longitudinal axis extending between the proximal and distal ends 24, 26. In the illustrated example, the longitudinal axis of the chamber 22 corresponds to the device axis Y. In other words, the longitudinal axis is substantially parallel to the insertion direction of the aerosol generating substrate 14.

[0049] The chamber 22 comprises a wall 28, 30, 44, which extends along the proximal and distal ends 24, 26 (or the device axis Y). Specifically, the wall 28, 30, 44 comprises first and second side walls 28, 30 extending along the device axis Y. In preferred embodiments, the wall 28, 30, 44 further comprises connection wall sections 44 connecting the first and second side walls 28, 30, which is elaborated below. The chamber 22 defines the (insertion) opening 36 at the proximal end 24. The proximal end 24 is, thus, an open end 38 of the chamber 22, configured to receive the aerosol generating substrate 14 into the heating chamber 22 in a longitudinal direction along the longitudinal axis (or the device axis Y). The wall has an external surface 28a, 30a, 44a and an internal surface 28b, 30b, 44b, which internal surface is on the side of the wall 28, 30, 44 which is opposite to the external surface 28a, 30a, 44a, and the internal surface faces an internal volume of the chamber 22. In other words, as in the illustrated example, the first and second internal surfaces 28b, 30b are arranged opposite each other and facing each other.

[0050] The first side wall 28 has first and second longitudinal edges 28c, 28d, which extend parallel to the longitudinal axis of the chamber 22 (and hence the device axis Y). The second side wall 30 also has first and second longitudinal edges 30c, 3od which extend parallel to the longitudinal axis of the chamber 22 (and hence the device axis Y). The first and second side walls 28, 30 are (indirectly) connected via the respective first longitudinal edges 28c, 30c and second longitudinal edges 28d, 3od as best seen in Figure 3. As mentioned above, the chamber 22 preferably in- eludes the integral connection wall sections 44. The connection wall sections 44 elastically connect and are located between the first longitudinal edges 28c, 30c of the first and second side walls 28, 30 and between the connected second longitudinal edges 28d, 3od of the first and second side walls 28, 30. These connection wall sections 44 are flexible and permit the first and second side walls 28, 30 to move relative to each other in a direction substantially orthogonal to the longitudinal axis (and hence the device axis Y) to vaiy a spacing S between the first and second side walls 29, 30, and in particular between the first and second heating surfaces 28b, 30b. Although two connection wall sections 44 are shown in the illustrated example, a single connection wall sections 44 could be provided between the first longitudinal edges 28c, 30c of the first and second side walls 29, 30 or between the second longitudinal edges 28d, 3od of the first and second side walls 28, 30. The other of the first longitudinal edges 28c, 30c of the first and second side walls 28, 30 and the second longitudinal edges 28d, 3od of the first and second side walls 28, 30 could be connected by a rigid connection.

[0051] In other embodiments, the connection wall sections 44 are sections of (i.e., are integrated with) the first and second side walls 28, 30. In other words, the connection wall sections 44 may be the peripheral parts of the side walls 28, 30 without longitudinal edges 28c, 28d, 30c, 3od. For example, the chamber 22 may have an oval cross section, and the connection wall sections 44 maybe the sharp corners of the oval. Accordingly, when a substrate 14 is inserted into the chamber 22, the entire wall 28, 30 44 elastically deforms, or mainly the connection wall sections (and hence the peripheral part) of the wall 28, 30, 44 deforms.

[0052] The wall 28, 40, 55, and especially the connection wall sections 44, typically comprise or made of thin heat-conductive material, preferably metal, such as stainless steel, so as to allow heat to be conducted to the contained aerosol generating substrate 14. The thickness may be between 25 pm and 200 pm, preferably between 50 pm and 175 pm, and most preferably between 75 pm and 150 pm.

[0053] The aerosol generating device 12 comprises at least one heater 40. In the illustrated example, the aerosol generating device 12 comprises two heaters 40, for example a first planer heater 40a and a second planer heater 40b, although in other (non-illustrated) examples, the heater 40 may comprises a single heater that extends (e.g., is wrapped) around the chamber 22. The heater 40 may be arranged in contact with the external surface 28a, 30a of the corresponding first and second side walls 28, 30. The heater 40 maybe substantially planner, and may comprises a thin film heater, such as a polyimide film heater, extending along substantially the total area of the external surfaces 28a, 30a or along only a part of the external surfaces 28a, 30a. In the latter case, this part may have a width substantially equal to a width of the aerosol generating substrate 14. The heater 40 is preferably a resistive heater that is powered by the power source and controlled by the controller of the aerosol generating device 12. In some examples, the aerosol generating device 12 may comprises a single heater 40 attached to just one of the external surfaces 28a, 30a of one of the first and second side walls 28, 30. With the heat-conductive material of the wall, the heat generated by the heater 40 can be conducted from the external surfaces 28a, 30a to the internal surface 28b, 30b. The aerosol generating substrate 14 is intended to be heated by the heater(s) 40.

[0054] In other embodiments, the aerosol generating device 12 may heat the aerosol generating substrate 14 through providing other forms of power, for example, electric power and electromagnetic Induction heating.

[0055] [Aerosol Generating Substrate]

[0056] Referring to Figure 2, the aerosol generating substrate 14 is, for example, a flat-shaped cuboid extending along a substrate axis X and having external dimensions La x Wa x Da. In a typical example, the length La of the aerosol generating substrate 14 according to the article axis X may be in a range from 20 to 45 mm, preferably from 25 to 40 mm, more preferably from 28 to 36 mm, for example 33 mm. The width Wa may be in the range from 8 to 18 mm, preferably from 10 to 16 mm, more preferably from 10 to 14 mm, for example 12 mm. The thickness Da may be in the range from 1 to 5 mm, preferably from 1 to 3 mm, more preferably from 1 to 2 mm, for example 1.4 mm. According to different examples, the values La, Wa and Da can be selected within a range of + / - 40%. According to other examples, the aerosol generating substrate 14 may have any other suitable flat shape and / or external dimensions.

[0057] When positioned and contained in the chamber 22, the aerosol generating substrate 14 remains substantially flat.

[0058] The aerosol generating substrate 14 typically comprises an aerosol generating material such as tobacco. The aerosol generating substrate 14 may be circumscribed by a wrapper 42 extending around the article axis X. The wrapper 42 may, for example, comprise paper and / or non-woven fabric and / or aluminum foil. The wrapper 42 may be porous or air impermeable.

[0059] When the aerosol generating substrate 14 is positioned or contained in the chamber 22, the major surfaces (the upper and lower surfaces in Figure 2) of the aerosol generating substrate 14 face and contact at least the internal surface 28b, 30b of the wall. A distal end of the aerosol generating substrate 14 is typically positioned at the distal end 26 of the chamber 22.

[0060] In other embodiments, the aerosol generating substrate 14 can be a cartridge-like container containing liquid for aerosol and having an outer casing made of, e.g., plastic and / or metal. The di- mensions thereof can be similar or identical to the above embodiment’s aerosol generating substrate. In other words, the embodiments of the aerosol generating substrate 14 being, for example, a flat-shaped cuboid is equally applicable to the embodiments of the aerosol generating substrate 14 being a liquid container.

[0061] [Substrate Detector]

[0062] In order to recognize the presence / insertion / extraction of the aerosol generating substrate 14, the aerosol generating substrate container comprises a substrate detector (or deformation detector) 51. As shown in Figure 2, the substrate detector 51 is arranged on the chamber 22. The substrate detector 51 is configured to detect the aerosol generating substrate 14, specifically the presence / insertion / extraction of the aerosol generating substrate 14. More specifically, the substrate detector 51 is configured to detect a change, specifically a strain, deformation or displacement, of the wall 28, 30, 44 that is caused by the presence / insertion / extraction of the aerosol generating substrate 14. The substrate detector 51 is connected with the controller, so that once a deformation or displacement of the wall 28, 30, 44 is detected, the controller can recognize a presence / insertion / extraction of the substrate 14 and, for example, switch on the aerosol generating device 12 or activate a specific function of the device 12, such as heating.

[0063] With the application of the substrate detector 51, the aerosol generating device 12 can recognize the presence of the aerosol generating substrate 14. Accordingly, the proper functioning of the aerosol generating device 12 is guaranteed in terms of safety, so that the lifespan of the aerosol generating device 12 is extended. It also maximizes the energy efficiency, as certain functions, e.g., heating, are triggered only when the aerosol generating substrate 14 is positioned or contained in the container.

[0064] Considering the selection of the material of the wall, the shape of the chamber 22 may change and deform permanently as a result of natural wear and tear. Accordingly, this invention provides a detection layer (or detection film), which is comprised by the substrate detector 51, and is preferably configured to sense a change of the wall 28, 30, 44 of the chamber 22, specifically, an elastic deformation or displacement of the wall of the chamber 22. The detection layer is arranged on the wall 28, 30, 44 in a way such that it can deform together with the wall 28, 30, 44. Specifically, the detection layer is arranged on an elastic area of the wall where the deformation takes place when the aerosol generating substrate 14 is inserted. In the preferred embodiment, the detection layer is arranged on at least the connection wall section 44. Because the detection layer is applied where the deformation takes place and is deformed together with the wall, even a minor deformation can be sensed and measured by the detection layer. The detection layer can be disposed on the external surface 28a, 30a, 44a as shown in Figures 4a and 4b, or on the internal surface 28b, 30b, 44b of the chamber 22 (not shown). The detection layer is thus utilized to determine the deformation and thus the force exerted on the wall by the aerosol substrate 14. In a preferred embodiment, the detection layer is applied across the first side wall 28, the connection wall section 44, and the second side wall 30 in this order. In another preferred embodiment, the detection layer is only applied on the connection wall section 44. In yet another preferred embodiment, as shown in Figures 4a and 4b, the detection layer is arranged on and across the connection wall section 44 and one of the first and second side walls 28, 30. This ensures that the force exerted on the wall is transferred to the detection layer. The arrangement of the preferred embodiments ensures that the deformation is timely and accurately measured and that only a relatively small area on the wall 28, 30, 44 is needed for the detection layer. This arrangement also makes it possible to recognize the insertion of the substrate 14 even when it just slightly enters the opening 36 of the chamber 22. The controller can thus quickly determine the presence of the substrate 14, and the substrate detector 51 can be switched off right before the heating begins, which further protects the sensor from high temperature.

[0065] Preferably, as shown in Figure 5, a thermal insulation layer 52 is arranged between the wall and the substrate detector 51. The insulation layer 52 comprises or consists of a high temperature insulation material, preferably an insulation material that can withstand at least 350 °C, for example aluminum oxide, silicon dioxide, Kapton, and / or silicon nitride. The insulation layer 52 protects the detector 51 from overheating.

[0066] In a more preferred embodiment, the above-mentioned thermal insulation layer 52 is a part of the substrate detector 51. In other words, the thermal insulation layer 52 is served as the carrier substrate for the substrate detector 51, which will be explained in detail below.

[0067] Preferably, as shown in Figures 3, 4a and 4b, the detection layer is a strain gauge, preferably comprising and / or made of silver nano particles. Strain gauges are thin metal film sensors whose electrical resistance varies with applied force. The strain gauge measures the level of the deformation of the wall based on the change of the applied force or strain thereon.

[0068] With this configuration, the substrate detector 51 can easily detect a temporary deformation of the chamber’s shape. Therefore, even if, due to the time passing and frequent usage of the aerosol generating container, the shape thereof is permanently changed, the substrate detector 51 can still detect the presence of the aerosol generation substrate 14. As mentioned above, this configuration also offers the advantage of being able to measure the degree of the deformation precisely and accurately. Therefore, with the cooperation of the controller, the aerosol generating device 12 can determine the thickness of the aerosol generating substrate 14. This allows the aerosol generating device 12 to detect even a slight difference between different aerosol generating substrates 14. In a preferred embodiment, a specific type or model of the aerosol generating substrate 14 can be recognized by the aerosol generating device 12 based on the thickness that is measured by the detection layer. Then, a specific configuration, such as a heating temperature, corresponding to that type or model of the aerosol generating substrate 14 will be set accordingly. Furthermore, in this preferred embodiment, since the elastic deformation is only measured when the aerosol generating substate 14 is inserted into the heater, i.e., while the heater is at ambient temperature, the strain gauge does not need to operate at high temperatures. This also extends the work lifespan of the strain gauge. The strain gauge further brings the benefits of being inexpensive and small. As it is a veiy thin flat metal film, it can be easily attached to the chamber 22 without occupying further space inside the aerosol generating device 12.

[0069] Although only a strain gauge is explained, any other types of known force or deformation sensors forming a layer can be used.

[0070] [Process of Detecting Aerosol Generating Substrate]

[0071] Hereinafter, together with Figures 6a to 6f, the detection process of the insertion of the aerosol generating substrate 14 is illustrated.

[0072] In the configuration shown in Figures 6a and 6b, there is no aerosol generating substrate 14 positioned in the chamber 22. The connection wall sections 44 are biased to a relaxed configuration, or have a bent cross section. In this relaxed configuration, the first and second side walls 28, 30 and the connection wall section 44 are in a resting position in which there is a first spacing Si between the first and second internal surfaces 28b, 30b. In other words, a height of the bent cross section equals the height of the first spacing Si as shown in Figure 6b. The substrate detector 51 (and hence the detection layer or the strain gauge) is in a first form, and no force is exerted on the substrate detector 51.

[0073] The connection wall sections 44 are configured to transition from the relaxed configuration to a loaded configuration through a transitioning configuration, or at least partially straighten out when an aerosol generating substrate 14 is inserted into the chamber 22 via the opening 36 as shown in Figures 6c and 6d. In the transitioning configuration, the first and second side walls 28, 30 have been slightly pushed apart by the aerosol generating substrate 14 and are in a par- tially deflected position in which there is a second spacing S2 between the first and second heating surfaces 28b, 30b in the A-A line, where the substrate detector 51 is located. In other words, when an outward force is applied to the first and second side walls 28, 30, the force is also applied to the connection wall sections 44. Thus, this force causes a deformation structure to the connection wall sections 44 and the substrate detector 51. The second spacing S2 is greater than the first spacing Si. Accordingly, the substrate detector 51 is in a partially loaded configuration, and a force is exerted on the substrate detector 51. The substrate detector 51 is in a second form as shown in 6d, and continuously senses and measures the strain or the force exerted thereon. In the preferred embodiment, in which the substrate detector 51 is the strain gauge, the strain gauge senses the applied force and transmits the data generated accordingly to the controller.

[0074] In the loaded configuration of Figures 6e and 6f, the first and second side walls 28, 30 have been pushed further apart by the aerosol generating substrate 14 and are in a deflected position, in which there is a third spacing S3 between the first and second heating surfaces 28b, 30b. Accordingly, the connection wall sections 44 are further straightened out, and the height of the straightened-out connection wall sections 44 equals the height of the spacing S3. The third spacing S3 is greater than the second spacing S2 and Si. The substrate detector 51 is in a third form as shown in Figure 6f, and a greater force is thus exerted on the substrate detector 51. Accordingly, the substrate detector 51 senses and measures the strain or the force exerted thereon. Preferably, the substrate detector 51 then transfer the data to the controller. A table may be stored in the controller, and only if the transferred data exceeds a predetermined threshold (e.g., the substrate 14 is fully inserted, and thus the space is S3 or the exerted force exceeds a certain value), the controller may then determine that the aerosol generating substrate 14 is inserted in the chamber 22.

[0075] The aerosol generating substrate 14 has a thickness Da which is greater than the spacing Si between first and second heating surfaces 28b, 30b when the first and second side walls 28, 30 are in the initial resting position. Thus, when the aerosol generating substrate 14 is initially inserted into the heating chamber 22, it pushes apart the first and second side walls 28, 30 as in the partially deformed position best seen in Figures 6c and 6d, causing them to move from the resting position shown in Figures 6a and 6b to the deflected position shown in Figures 3 and 6e and 6f and, in turn causing the connection wall section 44 to transition from the relaxed configuration to the loaded configuration through a partially loaded configuration. The chamber 22 may have a flared or tapered opening 36 as shown in Figures 6a and 6b, to facilitate insertion of the aerosol generating substrate 14 into the chamber 22. Alternatively or in addition, the transverse leading edge at the distal end of the aerosol generating substrate 14 could be tapered or bevelled to facilitate its insertion into the heating chamber 22. By way of example, for an aerosol generating substrate 14 having a thickness Da between 1 mm and 5 mm, a displacement of the first and second side walls 28, 30 which increases the spacing between them (and more particularly between the first and second heating surfaces 28b, 30b) by up to 1 mm, or more typically up to 0.5 mm, may be sufficient to achieve a good contact between the first and second heating surfaces 28b, 30b and the aerosol generating substrate 14 whilst at the same time allowing a user to insert the aerosol generating substrate 14 into the chamber 22 without failure of the aerosol generating substrate 14, e.g., due to collapse or crushing during insertion due to high compressive forces. In the case of an aerosol generating substrate 14 having a thickness substantially equal to 1.4 mm, a displacement of the first and second side walls 28, 30 which increases the spacing between them (and more particularly between the first and second heating surfaces 28b, 30b) by 0.025 mm to 0.3 mm maybe sufficient to achieve a good contact between the first and second heating surfaces 28b, 30b and the aerosol generating substrate 14 whilst at the same time allowing insertion of the aerosol generating substrate 14 with relative ease.

[0076] Due to the elastic characteristics of the connection wall section 44, section 44 is configured to apply a compression force F, via the first and second side walls 28, 30, to an aerosol generating substrate 14 positioned in the heating chamber 22 when the connection wall section 44 is in the loaded configuration. This compression force F is shown diagrammatically by the arrows in Figure 6e. In particular, when the connection wall section 44 is in the loaded configuration, it is biased to return to the relaxed configuration and, thus, to urge the first and second side walls 28, 30 to move to the resting position. It will be understood that when there is no aerosol generating substrate 14 present in the heating chamber 22, the first and second side walls 28, 30 are free to return to the resting position in which there is a first spacing Si between the first and second heating surfaces 28b, 30b. However, when an aerosol generating substrate 14 is present in the chamber 22, the aerosol generating substrate 14 typically prevents the first and second side walls 28, 30 from returning to the resting position and, thus, a compression force F is applied to the major surfaces of the aerosol generating substrate 14. The compression force F applied to the major surfaces of the aerosol generating substrate 14 is proportional to the distance AS (where AS = S2 - Si) by which the first and second side walls 28, 30 are deflected when they are displaced from the resting position to the deflected position due to insertion of the aerosol generating substrate 14 into the heating chamber 22 via the open end 38. As noted above, the distance AS by which the first and second side walls 28, 30 are deflected does not need to be substantial (not more than 1 mm, and typically not more than 0.5 mm). Accordingly, at least a fraction of reaction force opposite to the compression force from, e.g., the insertion of, the aerosol generation substrate 14 is exerted on the substrate detector 51, which can thus sense and measure the strain applied thereon. Referring now to Figures 7a to yf, the opening 36 has an elongated shape, preferably an oval, or a rectangular or polygonal shape, preferably with rounded corners. The connection wall section 44 protrudes into or out from the volume enclosed by the two side walls 28, 30. The cross section of at least one of the connection wall sections 44 have a V-shape with rounded corners and / or sharp corners, an arc shape, or a wave shape. Specifically, the integrally formed connection wall section 44 can be formed in any suitable manner provided that it adopts a relaxed configuration when it is unbiased (due to the absence of an aerosol generating substrate 14 in the heating chamber 22) and a loaded configuration when it is biased (due to the presence of an aerosol generating substrate 14 in the heating chamber 22). For the sake of clarity, the substrate detector 51 is omitted in Figure 7a to yf, but it should be understood that the substrate detector 51 is applied in the same way on the chamber 22 as described above.

[0077] In first, second and third examples, illustrated in Figures 7a to 7c, the connection wall section 44 is formed by a structural feature or deformation at the first longitudinal edges 28c, 30c and / or the second longitudinal edges 28d, 3od, which urges the first and second chamber walls 28, 30 to the resting position when there is no aerosol generating substrate 14 present in the heating chamber 22.

[0078] In the first and second examples, illustrated in Figures 7a and 7b, the connection wall section 44 is generally V-shaped and projects inwardly into the interior volume of the heating chamber 22. In the first example illustrated in Figure 7a, the V-shaped connection wall section 44 has three sharp edges. In the second example illustrated in Figure 7b, which is the preferred embodiment, the V-shaped connection wall section 44 has three rounded edges. The use of sharp edges or rounded edges may allow the stiffness of the connection wall section 44 to be controlled. E.g., the V-shaped connection wall section 44 with rounded edges may have a lower stiffness than the V- shaped connection wall section 44 with sharp edges. The use of rounded edges may also reduce the stress concentration along the edges of the V-shaped connection wall section 44. The rounded- edge V-shape connection wall section 44 in Figure yd is the preferred embodiment is because it is easier to apply the substrate detector 51 on rounded corners, and it does not so easily break from wear and tear caused by continuous deformation. The measurement of the deformation is also more precise as the change is more linear.

[0079] In the third example, illustrated in Figure 7c, the connection wall section 44 has a first portion that projects outwardly away from the heating chamber 22 and a second portion that projects inwardly into the interior volume of the heating chamber 22. The connection wall section 44 has three rounded edges. A person of ordinary skill in the art will recognize that the shape of the connection wall section 44 illustrated in Figure 7c and, e.g., the radii of curvature of the rounded edges, can be adjusted to achieve an optimal stiffness of the connection wall section 44. In a fourth example, illustrated in Figure d, the connection wall section 44 is formed by a continuous change of thickness of the first and second chamber walls 28, 30, resulting in a semiannular connection wall section 44 with varying thickness that projects outwardly away from the heating chamber 22. The thickness variation can be selected to achieve an optimal stiffness of the connection wall section 44.

[0080] In fifth and sixth examples, illustrated in Figures ye and yf, the connection wall section 44 can include one or more regions, e.g., edges, where there is a discrete change of thickness to provide for an optimal, and in particular reduced, stiffness of the connection wall section 44.

[0081] In the fifth example, illustrated in Figure ye, the connection wall section 44 is generally V-shaped and projects outwardly away from the heating chamber 22. As can be seen, the outermost edge of the connection wall section 44 has a reduced thickness, which tends to reduce the stiffness of the connection wall section 44 at this point and thereby to reduce the overall stiffness of the connection wall section 44.

[0082] In the sixth example, illustrated in Figure yf, the connection wall section 44 is generally V-shaped and projects inwardly into the interior volume of the heating chamber 22. The V-shaped connection wall section 44 has rounded edges and is, thus, similar to the V-shaped connection wall section 44 described above with reference to Figure yb. In contrast to Figure yb, the two outermost edges of the connection wall section 44 have a reduced thickness, which tends to reduce the stiffness of the connection wall section 44 at these points and thereby to reduce the overall stiffness of the connection wall section 44.

[0083] The examples described above with reference to Figures ya to ye are not mutually exclusive. For example a structural feature or deformation and / or a continuous change of thickness and / or a discrete change of thickness may be used to form the connection wall section 44, and the connection wall section 44 may have any suitable shape or geometry. What is important is that the connection wall section 44 urges the first and second chamber walls 28, 30 to the resting position, in particular so that the first and second chamber walls 28, 30 apply a compression force F to an aerosol generating substrate 14 when inserted into the heating chamber 22 via the open end 38 and so that the first and second chamber walls 28, 30 return to the resting position when there is no aerosol generating substrate 14 present in the heating chamber 22. Consequently, an opposite reaction force or a strain to the first and second chamber walls 28, 30 is correspondingly applied on the detection layer so that the deformation of the chamber 22 can be detected.

[0084] The preferred shape and geometry may also be selected to optimize the airflow through the aerosol generating device 12 when an aerosol generating substrate 14 is positioned in the heating chamber 22, for example taking into account the increase or decrease in the cross-sectional area of the interior volume of the heating chamber 22 as the first and second chamber walls 28, 30 move from the resting position to the deflected position.

[0085] [Method of Providing Strain Gauge]

[0086] Regarding the method of providing the strain gauge on the wall 28, 30, 44, in the preferred embodiment, the substrate detector 51 is placed directly onto the thermal insulation layer 52. Typically, the strain gauge (specifically the substrate carrier) is glued onto the surface of the wall 28, 30, 44 by using adhesive, e.g., X280 cold curing adhesive. However, this method can experience measurement deviations due to aging phenomena.

[0087] Therefore, in the preferred embodiment, the strain gauge is printed or deposited onto the a substrate carrier, preferably the above mentioned thermal insulation layer 52, by means of a process of flexography, gravure, screen printing, inkjet printing sputter deposition, and / or aerosol jet printing.

[0088] The manufacturing method of directly depositing strain gauges may involve the following steps:

[0089] Material preparation step: polishing the wall 28, 30, 44, preferably the external surface 28a, 30a, 44a, so as to reduce a surface roughness thereof.

[0090] This step reduces the layer thickness of the strain gauge for sufficient electrical insulation properties. For example, a polishing technique using a Dremel®4000 multitool is employed with Wolfcraft® 2134000 2 / B polishing paste. The wall 28, 30, 44 is then manually polished with a Hoffmann Group ® Garant 552100ZY1012 polishing head at an angle of approximately 45 °, a speed of 20,000 rpm, and a contact pressure of approximately 1.1 ± 0.1 MPa. The mean roughness depth (Rz) is reduced from 1.43 pm to 0.57 pm, and the average roughness (Ra) is reduced from 0.27 pm to 0.1 pm. After polishing, the walls 28, 30, 44 are cleaned with acetone and isopropanol to remove any organic residues.

[0091] Layer deposition step: sputter depositing an insulation layer, preferably the thermal insulation layer 52 , onto the polished walls 28, 30, 44; and depositing a structured sensor layer on top of the insulation layer.

[0092] The deposition is carried out by using a power of 275 W, an argon flux of 15 seem, and a sputter pressure of approximately 9.2 x io-3mbar. On top of the insulation layer, the sensor preferably comprises or is made of (specifically, fabricated by using) silver (Ag) nanoparticles (NPs).

[0093] Below is a more preferred embodiment explained more specifically. The sensor structure is fabricated using Aerosol Jet printing technology. Specifically, these strain sensors are printed onto the thermal insulation layer 52. The printing process involves the deposition and sintering of silver nanoparticles to create conductive films forming the sensor electrodes. The fabrication process involves the following steps to ensure a clean and robust sensor structure:

[0094] Material preparation step: preparing the wall 28, 30, 44, preferably through cleaning, conditioning and neutralizing.

[0095] Specifically, the wall 28, 30, 44 undergoes a thorough cleaning process, involving degreasing using CSM-2 degreaser to eliminate contaminants, followed by surface abrasion using silicon carbide paper. Additionally, the wall 28, 30, 44 is conditioned and neutralized to prepare the surface for nanoparticle printing.

[0096] H-Cement Application: applying H-cement to a position on the thermal insulation layer 52 for the sensor material.

[0097] Specifically, to define the area where the sensor material will be printed, H-cement is applied to the above mentioned desired position on the wall 28, 30, 44, using Kapton tape as a temporary dam and a blade-tip as a leveler. The H-cement is then preferably air-dried and heat-cured to achieve the desired thickness.

[0098] Atmospheric Plasma Treatment: treating a surface of the H-cement with an atmospheric plasma.

[0099] Specifically, the surface of the H-cement is treated with an atmospheric plasma to improve adhesion and ensure proper printing.

[0100] Sensor Printing: printing the sensor material onto the thermal insulation layer 52, preferably using 3D printing, more preferably using aerosol Jet micro-additive printer.

[0101] 3-D printing technique, specifically, the Aerosol Jet (AJ) method has been particularly useful for printing various materials. Silver nanoparticle films significantly enhance stability and oxidation resistance at high temperatures. The porous geometry of sintered nanoparticle films is believed to provide a high Poisson ratio and a high gauge factor, leading to improved sensor performance and measurement accuracy even at elevated temperatures.

[0102] The Aerosol Jet micro-additive printer is utilized to deposit silver nanoparticle ink onto the prepared substrate. The printer's atomizer creates a mist of the ink solution, guided by a carrier gas, and focused to form a micro-jet that exits the nozzle. The printing process involves multiple lateral passes to form individual electrodes using at least three layers of deposited ink.

[0103] Sensor Printing: sintering the printed sensor material. Specifically, the printed film of silver nanoparticles is sintered at 200 °C for 6.5 hours in a programmable oven. This process creates conductive films, constituting the strain sensor electrodes, ensuring stable electrical performance with minimal microstructural changes even under temperatures up to 500 °C.

[0104] The fabrication process described herein results in strain sensors with improved performance, making them suitable for various applications requiring accurate and reliable strain measurements.

[0105] [Reference Signs] aerosol generating device 12 aerosol generating substrate 14 device body 16 mouthpiece 18 outlet 19 housing 20 chamber 22 proximal and distal ends 24, 26 first and second side walls 28, 30 first and second longitudinal edges 28c, 28d, 30c, 3od opening 36 open end 38 heater 40 first and second planer heaters 40a 40b wrapper 42 connection wall sections 44 external surface 28a, 30a, 44a internal surface 28b, 30b, 44b substrate detector 51 insulation layer 52

Claims

Claims1. An aerosol generating substrate container for an aerosol generating device (12), comprising: a chamber (22) configured and dimensioned to contain an aerosol generating substrate (14), the chamber (22) comprising an opening (36) which is configured to receive an aerosol generating substrate (14), and a wall (28, 30, 44) extending from the opening (36), and a substrate detector (51) configured to detect a deformation of the wall (28, 30, 44) that is caused by an aerosol generating substrate (14), the substrate detector (51) comprising a detection layer arranged on the wall (28, 30, 44) and configured to deform together with the wall (28, 30, 44)-2. The aerosol generating substrate container according to the preceding claim, wherein the detection layer is a strain gauge, preferably comprising and / or made of silver nano particles; preferably, the strain gauge is a linear, Rosette type, T-Rosette, or dual parallel strain gauge.

3. The aerosol generating substrate container according to the preceding claim, wherein the strain gauge is attached to or printed or deposited onto the wall.

4. The aerosol generating substrate container according to the preceding claim, wherein the strain gauge has been printed or deposited onto the wall by means of a process of flexography, gravure process, screen printing, inkjet printing sputter deposition, and / or aerosol jet printing.

5. The aerosol generating substrate container according to any one of the preceding claims, wherein a thermal insulation layer (52) is arranged between the wall and the substrate detector (51); preferably, the insulation layer comprises or consists of a high temperature insulation material, preferably, an insulation material that can withstand at least 350 °C, more preferably aluminum oxide, silicon dioxide, and / or silicon nitride.

6. The aerosol generating substrate container according to any one of the preceding claims, wherein the wall (28, 30, 44) has an internal surface on one side of the wall and an external surface on the other side of the wall, the internal surface is arranged to face the aerosol generating substrate when it is fully received in the container body, and the substrate detector (51) is arranged on the external surface.

7. The aerosol generating substrate container according to any one of the preceding claims, wherein the opening has an elongated shape, preferably an oval shape or a rectangular or polygonal shape, preferably with rounded corners.

8. The aerosol generating substrate container according to any one of the preceding claims, wherein the wall comprises a first side wall (28), a second side wall (30) and connection wall sections connecting the first and second side walls (28, 30); preferably, the substrate detector (51) is at least partially arranged on at least one of the connection wall sections; and / or the aerosol generating substrate container is arranged in a way such that, when an aerosol generating substrate is received therein, a deformation takes place at, at least, the connection wall sections.

9. The aerosol generating substrate container according to the preceding claim, wherein the connection wall sections have a bent cross-section when no aerosol generating substrate is received in the aerosol generating substrate container, and the connection wall sections are configured to at least partially deform when an aerosol generating substrate is received in the aerosol generating substrate container.

10. The aerosol generating substrate container according to claims 8 or 9, wherein the connection wall section protrudes into or out from the volume enclosed by the two side walls.

11. The aerosol generating substrate container according to any one of claims 8 to 10, wherein the cross section of at least one of the connection wall sections have a V-shape with rounded and / or sharp corners, an arc shape, or a wave shape.

12. The aerosol generating substrate container according to any one of the preceding claims, wherein there is a discrete or continuous change of thickness of the wall when going along the perimeter of the wall.

13. The aerosol generating substrate container according to any one of the preceding claims, further comprising a heater configured to heat an inserted substrate.

14. A method of manufacturing the aerosol generating substrate container according to any one of claims 1 to 13, comprising the step of: providing the substrate detector (51) on the wall of the container body, preferably by means of a printing or deposition process, and more preferably a process of flexography, gravure, screen printing, inkjet printing sputter deposition, and / or aerosol jet printing.

15. The method of manufacturing the aerosol generating substrate container according to the preceding claim, further comprising the step of:providing a thermal insulation layer between the wall and the substrate detector (51) before providing the substrate detector (51) on the wall.

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