THC vapor fuel cell

Abstract

A cannabinoid fuel cell is provided. The cannabinoid fuel cell can include a fuel cell housing, a membrane electrode assembly (MEA) comprising an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA comprises an anode side and a cathode side; and a buffer flow plate defining a first serpentine channel. The buffer flow plate can be disposed between the anode side of the MEA and the fuel cell housing.

Description

[0001] PDSD No. 365.0123WOU1

[0002] THC VAPOR FUEL CELL

[0003] This application is being filed as a PCT International Application on July 31, 2025, in the name of Consumer Safety Technology, LLC, a U.S. national corporation, applicant for the designation of all countries, and Di Huang, a Chinese Citizen; Evan R. Darzi, a U.S. Citizen; Christina R. Forbes, a U.S. Citizen; and Randall B. Hellman, a U.S. Citizen; inventors for the designation of all countries, and claims priority to U.S. Provisional Application No. 63 / 682,627, filed August 13, 2024, the contents of which are herein incorporated by reference in its entirety.

[0004] Field

[0005] Embodiments herein relate to fuel cells and devices for the detection of tetrahydrocannabinol (“THC”) in a vapor sample.

[0006] Background

[0007] Breath alcohol detection devices are used to measure an amount of alcohol in a user’s breath. It is known that concentration of alcohol in a user’s breath is closely proportional to the concentration of alcohol in the user’s blood, which is typically the basis upon which intoxication is legally determined. Generally, a user blows into a mouthpiece of an alcohol detection device and a breath path is configured to transport at least a portion of the breath sample to a sensing element of the detection device. The capability to detect an amount of phenolic cannabinoid, such as tetrahydrocannabinol, in a user’s breath, would be valuable for law enforcement, employers, and accountability partners. The concentration of phenolic cannabinoid in a user’s breath typically correlates with recent use of cannabinoid products, such as marijuana.

[0008] Summary

[0009] Various embodiments provide a cannabinoid fuel cell. The fuel cell can include a fuel cell housing, a membrane electrode assembly (MEA), and a buffer flow plate. The MEA can include an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte. The MEA includes an anode side and a cathode side. The buffer flow plate can define a first serpentine channel. The buffer flow plate is disposed between the anode side of the MEA and the PDSD No. 365.0123WOU1 fuel cell housing.

[0010] In an embodiment, the fuel cell can further include an anode flow plate positioned between the anode side of the MEA and the buffer flow plate. The anode flow plate can define an anode flow plate passage.

[0011] In an embodiment, the fuel cell can further include a cathode plate positioned between the cathode side of the MEA and the fuel cell housing. The cathode plate defines cathode plate perforations.

[0012] In an embodiment, the electrolyte is held by the cathode plate and in contact with the membrane electrode assembly to keep the membrane wet.

[0013] In an embodiment, the first serpentine channel includes a plurality of switchbacks. number of switchbacks.

[0014] In an embodiment, the buffer flow plate further defines a second serpentine channel. first serpentine channel.

[0015] In an embodiment, the first serpentine channel and the second serpentine channel share a common inlet.

[0016] In an embodiment, the first serpentine channel and the second serpentine channel share a common outlet.

[0017] In an embodiment, the first serpentine channel and the second serpentine channel each include a plurality of switchbacks.

[0018] In an embodiment, a number of switchbacks in the first serpentine channel is equal to a number of switchbacks in the second serpentine channel.

[0019] In an embodiment, the first serpentine channel has a cross-section that has a width that is at least twice a distance of a height.

[0020] In an embodiment, the first serpentine channel has a rectangular cross-section.

[0021] In an embodiment, the fuel cell can further include a heating element.

[0022] In an embodiment, the heating element is configured to reach at least 80°C.

[0023] In an embodiment, the heating element is configured to reach at least 100°C.

[0024] In an embodiment, the fuel cell housing includes a first end plate and a second end plate and the heating element is disposed on at least one of the first end plate, the second end plate, and the buffer flow plate.

[0025] In an embodiment, the MEA further includes a first gas diffusion layer positioned on an outer side of the anode and a second gas diffusion layer positioned PDSD No. 365.0123WOU1 on an outer side of the cathode.

[0026] In an embodiment, a cannabis breath detection device is included having an input opening to a breath path for receiving breaths from a user, a capture structure in the breath path configured so that the breaths from the user flow over the capture structure, a capture structure heating element configured to heat the capture structure, a cannabis fuel cell, a valve configured to selectively direct the breath path either through the fuel cell and then to an outlet opening, or directly to the outlet opening bypassing the fuel cell, wherein the fuel cell, includes: a fuel cell housing, a membrane electrode assembly (MEA) can include an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA includes an anode side and a cathode side, and a buffer flow plate defining a first serpentine channel, wherein the buffer flow plate is disposed between the anode side of the MEA and the fuel cell housing.

[0027] In an embodiment, a cannabinoid fuel cell, is included having a membrane electrode assembly (MEA) can include an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA includes an anode side and a cathode side, and a heating element configured to reach at least 80°C.

[0028] In an embodiment, the heating element is a conductive wire.

[0029] In an embodiment, the heating element is a conductive sheet.

[0030] In an embodiment, the heating element has at least one axis of symmetry.

[0031] In an embodiment, the heating element has at least two axes of symmetry.

[0032] In an embodiment, the heating element is configured to reach at least 100°C.

[0033] In an embodiment, the fuel cell further includes fuel cell housing. The fuel cell housing can include a first end plate and a second end plate. The MEA can be disposed between the first end plate and the second end plate. The heating element can be embedded within at least one of the first end plate and the second end plate.

[0034] In an embodiment, the heating element includes a first heating element and a second heating element, and wherein the first heating element is embedded within the first end plate and the second heating element is embedded within the second end plate.

[0035] In an embodiment, the heating element is disposed around a perimeter of the first end plate.

[0036] In an embodiment, the heating element is disposed on an inner surface of the PDSD No. 365.0123WOU1 first end plate.

[0037] In an embodiment, the fuel cell can further include an anode flow plate positioned between the anode side of the MEA and a fuel cell housing, the anode flow plate defining anode flow plate passages, wherein the heating element is disposed on the anode flow plate.

[0038] In an embodiment, the heating element is disposed around a perimeter of the anode flow plate.

[0039] In an embodiment, the anode flow plate is in electrical communication with an anode collector.

[0040] In an embodiment, the fuel cell can further include a cathode plate positioned between the cathode side of the MEA and a fuel cell housing, the cathode plate defining cathode plate perforations, wherein the heating element is disposed on the cathode plate.

[0041] In an embodiment, the heating element is disposed around a perimeter of the cathode plate.

[0042] In an embodiment, the cathode plate is in electrical communication with a cathode collector.

[0043] In an embodiment, a cannabis breath detection device is included having an input opening to a breath path for receiving breaths from a user, a capture structure in the breath path configured so that the breaths from the user flow over the capture structure, a capture structure heating element configured to heat the capture structure, a cannabis fuel cell, and a valve configured to selectively direct the breath path either through the fuel cell and then to an outlet opening, or directly to the outlet opening bypassing the fuel cell, wherein the fuel cell, includes: a fuel cell housing, a membrane electrode assembly (MEA) can include an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA includes an anode side and a cathode side, and a heating element configured to reach at least 80°C.

[0044] This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the PDSD No. 365.0123WOU1 drawings that form a part thereof, each of which is not to be taken in a limiting sense. The scope herein is defined by the appended claims and their legal equivalents.

[0045] Brief Description of the Figures

[0046] Aspects may be more completely understood in connection with the following figures (FIGS.), in which:

[0047] FIG. l is a schematic view of an intoxicant detection device in accordance with various embodiments herein.

[0048] FIG. 2 is a schematic view of a fuel cell for an intoxicant detection device in accordance with various embodiments herein.

[0049] FIG. 3 is a schematic view of a fuel cell for an intoxicant detection device in accordance with various embodiments herein.

[0050] FIG. 4 is a schematic view of a fuel cell for an intoxicant detection device in accordance with various embodiments herein.

[0051] FIG. 5 is a schematic view of a fuel cell for an intoxicant detection device in accordance with various embodiments herein.

[0052] FIG. 6 is an exploded view of the fuel cell shown in FIG. 4 in accordance with various embodiments herein.

[0053] FIG. 7 is a front view of an end plate with a heating element in accordance with various embodiments herein.

[0054] FIG. 8 is a front view of an end plate with multiple heating elements in accordance with various embodiments herein.

[0055] FIG. 9 is a perspective view of an end plate with a heating element in accordance with various embodiments herein.

[0056] FIG. 10 is a front view of an end plate with multiple heating elements in accordance with various embodiments herein.

[0057] FIG. 11 is a front view of an end plate with a channel in accordance with various embodiments herein.

[0058] FIG. 12 is a perspective view of an end plate with a heating element in accordance with various embodiments herein.

[0059] FIG. 13 is a cross-sectional schematic view of a fuel cell with a heating element in accordance with various embodiments herein.

[0060] FIG. 14 is a front view of a plate with a heating element in accordance with various embodiments herein. PDSD No. 365.0123WOU1

[0061] FIG. 15 is a front view of a plate with a heating element in accordance with various embodiments herein.

[0062] FIG. 16 is an exploded view of the fuel cell in accordance with various embodiments herein.

[0063] FIG. 17 is a cross-sectional schematic view of a fuel cell with a flow plate in accordance with various embodiments herein.

[0064] FIG. 18 is a front view of a flow plate in accordance with various embodiments herein.

[0065] FIG. 19 is a perspective view of the flow plate shown in FIG. 18 in accordance with various embodiments herein.

[0066] FIG. 20 is a front view of a flow plate in accordance with various embodiments herein.

[0067] FIG. 21 is a perspective view of the flow plate shown in FIG. 20 in accordance with various embodiments herein.

[0068] FIG. 22 is a front view of a flow plate in accordance with various embodiments herein.

[0069] FIG. 23 is a perspective view of the flow plate shown in FIG. 22 in accordance with various embodiments herein.

[0070] FIG. 24 is a perspective view of the flow plate in accordance with various embodiments herein.

[0071] FIG. 25 is a front view of a serpentine channel in accordance with various embodiments herein.

[0072] FIG. 26 is a cross-sectional view of a portion of a serpentine channel in accordance with various embodiments herein.

[0073] FIG. 27 is a cross-sectional view of a portion of a serpentine channel in accordance with various embodiments herein.

[0074] FIG. 28 is a cross-sectional schematic view of a fuel cell with a flow plate and multiple heating elements in accordance with various embodiments herein.

[0075] FIG. 29 is a front view of a flow plate with a heating element in accordance with various embodiments.

[0076] While embodiments are susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings, and will be described in detail. It should be understood, however, that the scope herein is not PDSD No. 365.0123WOU1 limited to the particular aspects described. On the contrary, the intention is to cover modifications, equivalents, and alternatives falling within the spirit and scope herein.

[0077] Detailed Description

[0078] Fuel cells can be used for the detection of an intoxicant in a breath sample. A breath sample can be provided to a detection device. The intoxicants in the breath sample can be held by a capture structure. A heating element associated with the capture structure can heat the intoxicants in the capture structure to know vaporization points. Since different intoxicants or contaminants have different vaporization temperatures, a desired intoxicant or contaminant can be targeted using a known vaporization temperature. However, a temperature difference between a vaporized portion of a sample being analyzed and a detector element itself can result in noise or inaccurate reading from the detector elements. As such, various embodiments provided herein attempt to balance or reduce the temperature differential between a sample being analyzed and the detector element itself.

[0079] Various embodiments of a detector element provided herein can include a heating element. The heating element can be configured to raise the temperature of the fuel resulting in a smaller temperature differential between the sample and the fuel cell.

[0080] Various embodiments of a detector element provided herein can include a buffer flow plate disposed between an end plate and an anode flow plate. The buffer flow plate can be provided within a detector element to allow the vaporized sample further time to cool down resulting in a smaller temperature differential between the sample and the fuel cell. In some embodiments, the buffer flow plate can be provided to equilibrate or reduce the pressure difference between the sample delivery system and the fuel cell sensor. In various scenarios, reducing the pressure differential can further reduce signal noise resulting in a more accurate analysis of the sample.

[0081] Detection Device (FIG. 1)

[0082] Referring now to FIG. 1, a schematic view of a substance detection device 100 is shown in accordance with various embodiments herein. In various examples, the detection device can detect a substance such as cannabis in a sample, such as a breath PDSD No. 365.0123WOU1 sample. The detection device 100 can include a housing 102 and a breath inlet 104. The housing 102 can be a relatively hard durable material that serves to protect the internal components of the detection device 100. The breath inlet 104 can be positioned on a side of the housing 102.

[0083] Detection device 100 can be used to measure an amount of an intoxicant or phenolic cannabinoid, such as tetrahydrocannabinol, in a user’s breath. The concentration of phenolic cannabinoid in a user’s breath typically correlates with recent use of cannabinoid products, such as marijuana. Generally, a user blows into a mouthpiece of a phenolic cannabinoid detection device, and a breath path is configured to transport at least a portion of the breath sample to a detector element of the detection device. The detector element can detect the presence of an intoxicant in the sample. The device can provide an output of concentration of the intoxicant, such as the intoxication level of the user.

[0084] Breath Opening / Mouthpiece

[0085] The breath inlet 104 can define a breath inflow opening 106. The breath inflow opening 106 can be configured to receive a user’s breath. The breath inlet 104 can receive the mouth of the user providing a breath sample to the detection device 100. The breath inlet 104 can be configured to facilitate the user’s mouth sealing against an exterior surface of the breath inlet 104. Alternatively, the breath inlet 104 can be configured to receive a breath sample that is provided where the user is spaced apart from the breath inlet 104 and is directing breath toward the breath inlet 104 from a distance.

[0086] In various embodiments, the breath inlet 104 can be configured to be removably attachable to the detection device 100. In some embodiments, the breath inlet 104 can include a mouthpiece. The mouthpiece can be removable by means of a friction or snap fit, or similar mechanism. This permits each user to have a separate mouthpiece for sanitary reasons, it also permits easy cleaning or replacement of the mouthpiece. In various embodiments, the breath inlet 104 can be formed from a substantially rigid material configured to retain its shape when a breath sample is provided to the detection device 100. Alternatively, the breath inlet 104 can be formed from a compliant material configured to conform to a user’s mouth when a breath sample is provided to the detection device 100. The breath inlet 104 can be made from PDSD No. 365.0123WOU1 any suitable material or materials including but not limited to plastics, rubbers, silicone, metals, or the like.

[0087] In various embodiments, the user’s breath can travel into the breath inflow opening 106 and through a breath conduit path 108. The breath conduit path 108 can define a breath path 110. In some embodiments, the breath conduit path 108 is connected to a capture structure 112 discussed below. In some embodiments, the breath conduit path 108 is connected to a heating element 114, discussed below. The user’s breath can travel into the breath inflow opening 106, through the breath path 110, and into the capture structure 112. It is herein contemplated that the capture structure 112 can capture one or more breaths of the user. In various embodiments, the capture structure 112 can capture one, two, three, four, five, six, seven, eight, nine, or ten breaths. For example, the capture structure 112 can capture one, two, three, four, or five breaths of the user. In various embodiments, a pressure sensor or micro volumetric measurement sensor can be included within the device 100, such as to accurately control how many breath samples are captured and delivered to the detector element 120.

[0088] Capture Structure

[0089] In various embodiments, the capture structure 112 can include a material designed to capture or trap components found in the sample, such as the user’s breath.

[0090] Heating Element

[0091] In various embodiments, after components in the user’s breath are deposited on the capture structure 112, a heating element 114 can provide heat to the capture structure 112. The heating element 114 can be configured to increase the temperature of the capture structure 112 from a starting temperature, such as room temperature (e.g., 20-22 °C), to one or more desired temperatures. In some embodiments, the desired temperature can be a temperature sufficient to vaporize one or more components of the breath sample. In some embodiments, the desired temperature can be at least the boiling point of one or more components in the breath sample. For example, the desired temperature could be at least 78 °C, the boiling point of ethanol. Alternatively, the desired temperature could be at least 100 °C, the boiling point of water. Further, the desired temperature could be at least 157 °C, the boiling point of cannabis, or at least 170 °C. PDSD No. 365.0123WOU1

[0092] Valve

[0093] In various embodiments, the detection device 100 can include a valve 116. It is herein contemplated that the valve 116 can be a variety of different valves. For example, the valve 116 can include a solenoid valve, a butterfly valve, a diaphragm valve, a gauge valve, a check valve, and the like.

[0094] In various embodiments, the valve 116 can be configured to direct the vaporized components coming off the capture structure 112. In a first position, the valve 116 can connect the capture structure 112 with the outlet 118, so that vaporized contaminants, such as water and ethanol, can be drawn out of the detection device 100. In a second position, the valve 116 can connect the capture structure 112 with the detector element 120, so that vaporized components of interest, such as cannabis, can be drawn into the detector element 120. In an optionally third position, the valve 116 can be in a closed position, so that vapors coming from the capture structure 112 are stopped from flowing to either the outlet 118 or the detector element 120. This closed position may be used to allow a sufficient quantity of a vapor sample to accumulate, such as over the course of multiple breaths, before passing the sample to the detector element 120.

[0095] Flow Mechanism

[0096] In various embodiments, the vaporized components of interest can be drawn into the detector element 120 via a flow mechanism 122 or flow mechanism 123, such as a pump. For example, the flow mechanism 123 can provide a vacuum or negative pressure through conduit 124 and draw the vaporized components through the detector element 120. In some embodiments, a flow mechanism 123 can be referred to as a pulling flow mechanism. In other embodiments, such as when the flow mechanism 122 is included, the flow mechanism can generate positive pressure to force or push vaporized components through the detector element 120. In some embodiments, a flow mechanism 122 can be referred to as a pushing mechanism.

[0097] In many embodiments, only one flow mechanism 122, 123 is included. However, some embodiments may include more than one flow mechanism 122, 123. In some embodiments, pressure from the user’s breath can be used to draw the vaporized components through the detector element 120. PDSD No. 365.0123WOU1

[0098] In some embodiments, the device 100 can be configured for continuous flow, such as non-stop flow during sample delivery and analysis. In such embodiments, the flow mechanism 122, flow mechanism 123, or both can be continuously running during sample delivery and analysis. In some embodiments, the device can include a stop flow feature. In such embodiments, after the vapor sample goes into the detector element 120, the flow mechanism 122, flow mechanism 123, or both stop to trap the sample within the detector element 120.

[0099] Detector Element

[0100] In various embodiments, the detector element 120 can include a detector configured to measure vaporized components of interest in the user’s breath. For example, the detector element 120 can be configured to measure the amount or concentration of cannabis in the user’s breath. The detector element 120 can include a fuel cell.

[0101] In various embodiments, a cannabis sensing fuel cell can detect the level of cannabis in the user’s breath. Exemplary phenolic cannabinoid sensing fuel cells are disclosed in US2023 / 0384286, titled “Systems and Methods for Oxidizing Phenolic Cannabinoids with Fuel Cells,” published on November 30, 2023 and assigned to Consumer Safety Technology, LLC, the content of which is hereby incorporated by reference in its entirety.

[0102] Fuel Cell with Heating Element

[0103] FIG. 2 shows a schematic cross-section of a detector element 120 in the form of a fuel cell 226 for an intoxicant detection device in accordance with various embodiments herein. In various embodiments, the fuel cell 226 can be a cannabinoid fuel cell.

[0104] In various embodiments, the fuel cell 226 can include a fuel cell housing 228. In some embodiments, the housing 228 can include a first end plate 230 and a second end plate 232. In some embodiments, the housing 228 can include a single or monolithic element that includes both a first end plate 230 and a second end plate 232.

[0105] In various embodiments, the fuel cell 226 can include anode flow plate 234 and a cathode flow plate 236. The anode flow plate 234 can include an anode current collector 238. The cathode flow plate 236 can include a cathode current collector 240. The anode flow plate 234 can be in electrical communication with the anode current PDSD No. 365.0123WOU1 collector 238. The cathode flow plate 236 can be in electrical communication with the cathode current collector 240.

[0106] In various embodiments, the fuel cell 226 can further include a membrane electrode assembly 242 (MEA). The MEA 242 can include an anode 244, a cathode 248, an ion exchange membrane 246 disposed between the anode 244 and the cathode 248, and an electrolyte. The MEA 242 can include an anode side adjacent to the anode flow plate 234 and a cathode side adjacent to the cathode flow plate 236. In various embodiments, the electrolyte is held by the cathode plate 236 and in contact with the MEA 242 to keep the membrane wet. In various embodiments, the MEA 242 can be a five layer MEA, such that the MEA 242 can further include one or more gas diffusion layers 243, 249. The gas diffusion layers 243, 249 can protect the catalysts. In some embodiments, a gas diffusion layer 243 can be positioned on the outer side of the anode 244 and a gas diffusion layer 249 can be positioned on the outer side of the cathode 248. In various embodiments, the first gas diffusion layer 243 can have a face area of about the same size and same shape as the anode 244. Similarly, in various embodiments, the second gas diffusion layer 249 can have a face area of about the same size and shape as the cathode 248.

[0107] In the embodiments described herein, the anode layer 244 may include an anode gas diffusion layer 243 on its outer side and the cathode layer 248 may include a cathode gas diffusion layer 249 on its outer side, even where that is not specifically identified in the FIGS. It should be understood that the embodiments described herein can include a 3-layer MEA or a 5-layer MEA independent of what is depicted in the figures. As an example, FIGS. 3-5, 13, 17, and 28 show an MEA 242 that only includes three layers; however, it is possible and contemplated for the five-layer MEA 242 depicted in FIG. 2 to be included in the embodiments shown in FIGS. 3-5, 13, 17, and 28. Similarly, in some embodiments, the MEA 242 depicted in FIG. 2 could also include only three layers.

[0108] In various embodiments, the anode flow plate 234 can define one or more anode flow plate passages. In various embodiments, the cathode flow plate 236 can define one or more cathode flow plate passages. In some embodiments, a flow plate passage can include one or more perforations. In some embodiments, a flow plate passage can include one or more channels. Various flow plate passages can be seen in FIGS. 14-16. PDSD No. 365.0123WOU1

[0109] Heating Element (FIGS. 3-15)

[0110] In various embodiments, the fuel cell 226 can include a heating element 350. The heating element 350 can be configured to heat the fuel cell 226, such as to decrease the temperature differential between the sample being analyzed and the fuel cell 226 itself. As discussed above, a smaller temperature differential can result in a more accurate analysis of the sample.

[0111] In various embodiments, the heating element 350 is configured to reach a temperature of at least 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, 155 °C, or 160 °C. In various embodiments, the heating element 350 can be electrically connected to a power source (not shown), such as a power source of the detection device 100. In some embodiments, the fuel cell heating element 350 can be electrically coupled to a control board. In some embodiments, the control board can be integrated with a control board for the heating element 114.

[0112] In various embodiments, the heating element 350 can include a conductive wire, such as shown in FIGS. 9, 12, 14, and 15. In various embodiments, the heating element 350 can include a conductive sheet, such as shown in FIGS. 3-4 and 6-7. In various embodiments, the heating element 350 can include both a conductive sheet and a conductive wire, such as shown in FIGS. 8 and 10.

[0113] FIGS. 3-5 show schematic cross-sections of fuel cells 226 in accordance with various embodiments herein.

[0114] In various embodiments, a heating element 350 can be wrapped around one or more plates within the housing 102, such as shown in FIG. 3. In some embodiments, the heating element 350 can be disposed between the first end plate 230 and the second end plate 232. In some embodiments, a portion of the heating element 350 can be disposed between the first end plate 230 and the anode flow plate 234. In some embodiments, a portion of the heating element 350 can be disposed between the second end plate 232 and the cathode flow plate 236.

[0115] In some embodiments, there can be multiple heating elements, such as one disposed on the first end plate 230 and a separate heating element disposed on the second end plate 232. In various embodiments, a single heating element can be partially disposed on the first end plate 230 and partially disposed on the second end plate 232. PDSD No. 365.0123WOU1

[0116] In some embodiments, a heating element 350 can be embedded within a plate. FIG. 4 shows a cross-section of a fuel cell 226 with a heating element 350 embedded within the first end plate 230 and a second heating element 350 embedded within the second end plate 232. In some embodiments, the fuel cell 226 can include one heating element disposed in one of the end plates 230, 232. In some embodiments, embedded can mean that a plate defines a through hole or an aperture that is at least partially occupied by a heating element, such as shown in FIG. 4. In some embodiments, embedded can mean that the heating element is disposed within channel defined by the plate, such as shown in FIGS. 11-13.

[0117] In some embodiments, the heating element 350 can be at least partially disposed within a plate and partially not disposed within a plate, such that a portion of the heating element 350 extends beyond the surface of the plate. In some embodiments, the heating element 350 can be disposed on a surface of a plate, such as shown in FIG. 5.

[0118] In various embodiments, a heating element 350 can be disposed on the surface of a plate. In various embodiments, a heating element 350 can be on one or more of the first end plate 230, the second end plate 232, the anode flow plate 234, and the cathode flow plate 236.

[0119] FIG. 5 shows a fuel cell with multiple heating elements. The embodiment shown in FIG. 5 includes a heating element on an internal surface of both end plates. The embodiment shown in FIG. 5 also includes a heating element on an inner surface of the both anode flow plate 234 and the cathode flow plate 236. It should be understood that heating elements can be disposed on internal or inner surfaces as well as external or outer surfaces of each of the plates. All disclosure relating to one of the surface is also applicable to the opposite surface.

[0120] FIG. 6 shows an exploded view of the fuel cell 226 shown in FIG. 4. In various embodiments, the fuel cell 226 can include a first end plate 230, a second end plate 232, an anode flow plate 234, a cathode flow plate 236, and a MEA 242. The first end plate 230 can include an embedded heating element 350. The anode flow plate 234 can define an anode flow plate passage 652. The cathode flow plate 236 can define a cathode flow plate passage 654.

[0121] In various embodiments, a plate can refer to an element that has a width that is at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or 30 times greater than the thickness. In various embodiments, a plate can refer to an element that has a length that is at least PDSD No. 365.0123WOU1

[0122] 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25 or 30 times greater than the thickness. In various embodiments, the plates can be generally rectangular.

[0123] FIG. 7 shows a front view of a heating element wrapped around an end plate in accordance with various embodiments herein. In various embodiments, the heating element 350 can be wrapped around a plate, similar to how it can be wrapped around multiple plates as shown in FIG. 3. In various embodiments, the heating element 350 can contact an inner surface and an outer surface of a plate, such as to provide heating on both sides of the plate.

[0124] FIG. 8 shows a front view of an end plate with multiple heating elements in accordance with various embodiments herein. In some embodiments, multiple heating elements can be disposed on, embedded in, or otherwise connected to a single plate. FIG. 8 shows two heating elements 350 for a single end plate 230.

[0125] In some embodiments, a heating element 350 can be centered on an end plate. In some embodiments, a heating element 350 can be disposed around the perimeter of the end plate. In some embodiments, a heating element 350 follows the perimeter of the end plate, such that the perimeter of the end plate and the heating element 350 define a similar shape. The heating element 350 can be inset from the perimeter of the end plate.

[0126] In some embodiments, a heating element can be symmetric. In some embodiments, the heating element can have at least one axis of symmetry. In some embodiments, the heating element can have at least two, three, or four axes of symmetry.

[0127] FIGS. 9 and 10 show front views of an end plate with an unorganized heating element 350. FIG. 9 shows a plate with an unorganized or randomly oriented heating element 350, such as a heating element 350 that does not follow a set pattern or layout. In some embodiments, the heating element 350 can be in an unorganized or random configuration, such as shown in FIG. 9 as well as in FIG. 10. The heating element 350 can be random, such as having varying lengths, shapes, and positions of switchbacks or portions of the heating element 350. The heating element 350 can be applied to the plate without a specific pattern, such that the density of which the heating element is disposed on the plate can vary over the face of the plate.

[0128] FIG. 10 shows a front view of an end plate with a central heating element 350 as well as an unorganized heating element disposed between the central heating PDSD No. 365.0123WOU1 element and the perimeter of the plate. In various embodiments, the plate can include a central heating element and a randomly disposed heating element. The randomly disposed heating element can be disposed between the perimeter of the plate and the central heating element.

[0129] Heating Element in a Channel (FIGS. 11-13)

[0130] In some embodiments, a heating element 350 can be embedded or disposed within a trench or channel 1156. FIG. 11 shows an end plate the defines an open channel 1156. The open channel 1156 can be configured to receive the heating element 350. FIG. 12 shows a front view of the end plate with a heating element 350 disposed in the channel 1156. In some embodiments, the heating element 350 can be within the channel 1156, such that the heating element 350 does not extend beyond the surface of the plate. In some embodiments, the heating element 350 is partially disposed within the channel 1156 and partially extends beyond the surface of the plate.

[0131] FIG. 13 shows a cross-section view of a fuel cell 226 that includes an embedded heating element 350 on the inner surface of the first end plate 230 and the second end plate 232. The fuel cell shown in FIG. 13 has end plates 230, 232 with a heating element disposed in a channel according to the embodiment shown in FIGS. 11-12.

[0132] Heating Element on a Cathode or Anode Flow Plate (FIG. 14-15)

[0133] In some embodiments, a heating element 350 can be applied to an anode flow plate 234 or a cathode flow plate 236. FIG. 14 shows a front view of a plate with a uniform heating element 350 around the perimeter in accordance with various embodiments herein. FIG. 15 is a front view of a plate with a random heating element 350 in accordance with various embodiments herein. As mentioned above, all of the disclosure related to the end plates and heating element is also applicable to an anode flow plate or a cathode flow plate.

[0134] Buffer Flow Plate

[0135] Various embodiments provided herein can include a buffer flow plate within a fuel cell. A fuel cell can include a buffer flow plate between the first end plate and the anode flow plate. In various embodiments, a sample can enter the fuel cell through the PDSD No. 365.0123WOU1 first end plate and then travel through the buffer flow plate before traveling through the anode flow plate. While the sample is flowing along and / or through the buffer flow plate, the sample can be cooled down. As the sample decreases in temperature, the temperature differential between the sample and the fuel cell decreases resulting in a more accurate analysis of the sample. In various embodiments, the buffer flow plate can also equilibrate the pressure difference between the sample delivery system and the fuel cell sensor. Reducing the pressure difference can improve the accuracy of an analysis by reducing signal noise.

[0136] FIG. 16 shows an exploded view of a fuel cell 226 in accordance with various embodiments. In various embodiments, the fuel cell 226 can include a first end plate 230, a second end plate 232, an anode flow plate 234, a cathode flow plate 236, a MEA 242, and a buffer flow plate 1658. In various embodiments, the buffer flow plate 1658 is disposed between the anode side of the MEA and the fuel cell housing 102. In various embodiments, the buffer flow plate 1658 is disposed between the anode flow plate 234 and the first end plate 230.

[0137] The anode flow plate 234 can define an anode flow plate passage 652, such as a channel. The cathode flow plate 236 can define a cathode flow plate passage 654, such as perforations 1654. The buffer flow plate 1658 can define a buffer flow plate passage 1660, such as a trench or a channel on a surface of the buffer flow plate 1658. In some embodiments a flow plate passage can include a serpentine channel.

[0138] In various embodiments, a flow plate passage can be defined in an inner surface of the flow plate, such as the surface facing the MEA 242. In various embodiments, a flow plate passage can be defined in an outer surface of the flow plate, such as the surface facing outwards or away from the MEA 242.

[0139] FIG. 17 shows a schematic cross-section of a fuel cell 226 in accordance with various embodiments herein. In various embodiments, the fuel cell 226 can be a cannabinoid fuel cell.

[0140] In various embodiments, the fuel cell 226 can include a fuel cell housing 228. In some embodiments, the housing 228 can include a first end plate 230 and a second end plate 232.

[0141] In various embodiments, the fuel cell 226 can include a buffer flow plate 1658. In various embodiments, the buffer flow plate 1658 can be disposed within the housing 228. In various embodiments, the buffer flow plate 1658 can be disposed between the first end plate 230 and the anode flow plate 234. PDSD No. 365.0123WOU1

[0142] Similar to the embodiments above, in various embodiments, the fuel cell 226 can include anode flow plate 234 and a cathode flow plate 236. The anode flow plate 234 can include an anode current collector 238. The cathode flow plate 236 can include a cathode current collector 240. The anode flow plate 234 can be in electrical communication with the anode current collector 238. The cathode flow plate 236 can be in electrical communication with the cathode current collector 240.

[0143] In various embodiments, the fuel cell 226 can further include a membrane electrode assembly 242 (MEA). The MEA 242 can include an anode 244, a cathode 248, an ion exchange membrane 246 disposed between the anode 244 and the cathode 248, and an electrolyte. The MEA 242 can include an anode side adjacent to the anode flow plate 234 and a cathode side adjacent to the cathode flow plate 236. In various embodiments, the electrolyte is held by the cathode flow plate 236 and in contact with the MEA 242 to keep the membrane wet. In various embodiments, the MEA 242 can further include one or more gas diffusion layers which can be an outer layer of the anode and cathode layers to protect the catalysts.

[0144] Serpentine Channel Characteristics

[0145] A flow plate passage can include a serpentine channel. A serpentine channel can provide a path from an inlet to an outlet in an indirect manner, such that it does not extend straight and directly from the inlet to the outlet. A serpentine channel can include a plurality of switchbacks, such as portions of the channel that turn the direction of the channel 180°. In various embodiments, at least a portion or length of the channel is parallel with a different portion or length of the channel. The two portions or lengths of the channel that are parallel can be separated by a portion of the channel that creates a 180° turn in the channel. Various different widths and depths of the channel are possible. Various numbers of channels are possible, such as one channel as shown in FIGS. 18-23, two channels as shown in FIG. 25, three channels, four channels, five channels, or more.

[0146] FIGS. 18-23 show front and perspective views of three different serpentine channels each with a different radius, which can result in different sized gaps between adjacent lengths of the channel that are joined by 180° transitions in the channel. In some embodiments, the 180° transitions can be curved or rounded, such as shown in FIGS. 18-23. In some embodiments, the 180° transitions can be straight and 90° intersections between connecting sections, such as shown in FIG. 16. PDSD No. 365.0123WOU1

[0147] The adjacent lengths of channel can be separated by ribs 1810. Various different embodiments can have different rib width-to-channel width ratios. As an example, FIG. 18 shows a front view of a first embodiment and FIG. 19 shows a perspective view of the first embodiment. The first embodiment has a channel width of 1.4 mm and a rib width of 0.3 mm. As a result, the first embodiment can have a ratio of about 0.2.

[0148] FIG. 20 shows a front view of a second embodiment and FIG. 21 shows a perspective view of the second embodiment. The second embodiment can have a ratio of about 0.35. FIG. 22 shows a front view of a third embodiment and FIG. 23 shows a perspective view of the third embodiment. The third embodiment can have a radius of curvature of 0.5.

[0149] In various embodiments, the rib width-to-channel width ratio can be at least 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5. In various embodiments, the rib width-to-channel width ratio can be no more than 1, 0.9, 0.8, 0.7. 0.6, 0.5, 0.4, or 0.3. In various embodiments, the rib width-to-channel width ratio can fall within a range of any of the values listed above.

[0150] Double Serpentine Channel

[0151] FIGS. 24-25 show a buffer flow plate 1658 with a flow plate passage 1660. In various embodiments a flow plate passage can include a first serpentine channel and a second serpentine channel. The flow plate passage 1660 can include a first serpentine channel 2470 and a second serpentine channel 2472 as shown in FIGS. 24-25. In various embodiments, the first and second serpentine channels follow each other, such that they have the same length and similar shapes.

[0152] In various embodiments, the first serpentine channel can be isolated from the second serpentine channel, such that a portion of the sample that enters the first serpentine channel does not enter the second serpentine channel. In some embodiments, the first serpentine channel and the second serpentine channel share a common inlet 2474, such that both the portion of the sample that will travel through the first serpentine channel and the portion of the sample that will travel through the second serpentine channel are not separated from each other. Similarly, the first serpentine channel and the second serpentine channel can share a common outlet 2476. PDSD No. 365.0123WOU1

[0153] In various embodiments, the first serpentine channel and the second serpentine channel can each comprise a plurality of switchbacks. In some embodiments, the first serpentine channel and the second serpentine channel alternate being on the inside and on the outside of between each 180° transitions, such that the first serpentine channel can be on the outside for the first, third, and fifth transitions and the second serpentine channel can be on the outside for the second, fourth, and sixth transitions. In various embodiments, the first serpentine channel and the second serpentine channel have the same number of switchbacks or the same number of 180° transitions.

[0154] Channel Characteristics

[0155] FIGS. 26 and 27 show a portion of a plate 2680 and the plate defines a flow plate passage or channel 2682. Specifically, FIGS. 26 and 27 show cross-sectional views of a flow plate passage or channel 2682 defined by a plate 2680 in accordance with various embodiments herein. In various embodiments, the channel can have a rectangular cross-section, such as shown in FIG. 26. In some embodiments, the channel can have a curved cross-section, such as shown in FIG. 27. The channel can have a width 2684 and a depth 2686. In various embodiments, the width 2684 can be at least two, three, four, five, six, seven, eight, nine, or ten times larger than the depth 2686.

[0156] Buffer Plate and Heating

[0157] In various embodiments, a fuel cell 226 can include a buffer flow plate 1658 and one or more heating elements 350. It should be understood that the heating element embodiments described above are also applicable to an embodiment that includes a buffer flow plate. In some embodiments, a heating element 350 can be disposed on or embedded in a buffer flow plate 1658.

[0158] In various embodiments, a heating element 350 can be disposed on the surface of a plate, such as the buffer flow plate 1658. In various embodiments, a heating element 350 can be on one or more of the first end plate 230, the second end plate 232, the anode flow plate 234, the cathode flow plate 236, and a buffer flow plate 1658.

[0159] FIG. 28 shows a fuel cell with multiple heating elements 350. The embodiment shown in FIG. 28 includes a heating element on an internal surface of both end plates or alternatively an outer surface of the buffer flow plate 1658 and PDSD No. 365.0123WOU1 cathode flow plate 236. It should be understood that heating elements can be disposed on internal or inner surfaces as well as external or outer surfaces of each of the plates. All disclosure relating to a heating element on or in one of the surfaces is also applicable to the opposite surface.

[0160] FIG. 29 shows a front view of a buffer flow plate 1658 that includes a heating element 350. The heating element 350 can be disposed in an area of the plate 1658 that is between the buffer flow plate passage 1660 and the outer perimeter of the buffer flow plate 1658.

[0161] Compounds of Interest

[0162] Components of a sample can include compounds of interest which the detector element is designed to detect, such as cannabis. It is herein contemplated that cannabis, including a variety of cannabis metabolites or compounds, can be compounds of interest. Cannabis metabolites and cannabis compounds can include, but are not limited to, cannabinoids, phenolic cannabinoids, A9-tetrahydrocannabinol (A9-THC), A8-tetrahydrocannabinol (A8-THC), cannabinol (CBN), cannabidiol (CBD), 11-hydroxy- A9-THC (11-OH-THC), anandamide (arachidonylethanolamide), cannabichromene, and (-)A8-THC-11-oic acid).

[0163] Components of the sample can include contaminants such as alcohol, ethanol, acetone, nitric oxide, carbon monoxide, isoprene, ethane, pentane, water, and the like.

[0164] Sample and Compounds of Interest

[0165] Throughout the application, breath is described as a sample that is analyzed for the presence of a substance such as an intoxicant. It is also possible for the embodiments of the application to be used to process a sample different than breath, such as another gas sample, such as environmental or ambient air or vapor from skin, or another biological sample, such as saliva, mucous, or urine.

[0166] Throughout the application, cannabis is described as a substance of interest or compounds of interest that is detected by a detector element. It is also possible for other substances and compounds to be detected by a detector element in the various embodiments described here in, such as different intoxicants, prescription drugs, cocaine, heroin, nicotine, methamphetamine, amphetamines, hallucinogens, or other substances. PDSD No. 365.0123WOU1

[0167] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0168] It should also be noted that, as used in this specification and the appended claims, the phrase “configured” describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a particular configuration. The phrase "configured" can be used interchangeably with other similar phrases such as arranged and configured, constructed and arranged, constructed, manufactured and arranged, and the like.

[0169] All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference.

[0170] As used herein, the recitation of numerical ranges by endpoints shall include all numbers subsumed within that range (e.g., 2 to 8 includes 2.1, 2.8, 5.3, 7, etc.).

[0171] The headings used herein are provided for consistency with suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not be viewed to limit or characterize the invention(s) set out in any claims that may issue from this disclosure. As an example, although the headings refer to a “Field,” such claims should not be limited by the language chosen under this heading to describe the so-called technical field. Further, a description of a technology in the “Background” is not an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Summary” to be considered as a characterization of the invention(s) set forth in issued claims.

[0172] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices. As such, aspects have been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope herein.

Claims

PDSD No. 365.0123WOU1Claims:

1. A cannabinoid fuel cell, comprising: a fuel cell housing; a membrane electrode assembly (MEA) comprising an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA comprises an anode side and a cathode side; and a buffer flow plate defining a first serpentine channel; wherein the buffer flow plate is disposed between the anode side of the MEA and the fuel cell housing.

2. The fuel cell of any of claims 1 and 3-14, further comprising an anode flow plate positioned between the anode side of the MEA and the buffer flow plate, wherein the anode flow plate defining anode flow plate passages.

3. The fuel cell of any of claims 1-2 and 4-14, further comprising a cathode plate positioned between the cathode side of the MEA and the fuel cell housing, wherein the cathode plate defines cathode plate perforations.

4. The fuel cell of any of claims 1-3 and 5-14, wherein the electrolyte is held by the cathode plate and in contact with the membrane electrode assembly to keep the membrane wet.

5. The fuel cell of any of claims 1-4 and 6-14, wherein the first serpentine channel comprises a plurality of switchbacks.

6. The fuel cell of any of claims 1-5 and 7-14, wherein the buffer flow plate further defines a second serpentine channel.

7. The fuel cell of any of claims 1-6 and 8-14, wherein the second serpentine channel is isolated from the first serpentine channel.PDSD No. 365.0123WOU18. The fuel cell of any of claims 1-7 and 9-14, wherein the first serpentine channel and the second serpentine channel share a common inlet.

9. The fuel cell of any of claims 1-8 and 10-14, wherein the first serpentine channel and the second serpentine channel share a common outlet.

10. The fuel cell of any of claims 1-9 and 11-14, wherein the first serpentine channel and the second serpentine channel each comprise a plurality of switchbacks.

11. The fuel cell of any of claims 1-10 and 12-14, wherein a number of switchbacks in the first serpentine channel is equal to a number of switchbacks in the second serpentine channel.

12. The fuel cell of any of claims 1-11 and 13-14, wherein the first serpentine channel has a cross-section that has a width that is at least twice a distance of a height.

13. The fuel cell of any of claims 1-12 and 14, wherein the first serpentine channel has a rectangular cross-section.

14. The fuel cell of any of claims 1-13, further comprising a heating element, wherein the heating element is configured to reach at least 80°C; wherein the fuel cell housing comprises a first end plate and a second end plate; and wherein the heating element is disposed on at least one of the first end plate, the second end plate, and the buffer flow plate.

15. A cannabis breath detection device comprising: an input opening to a breath path for receiving breaths from a user; a capture structure in the breath path configured so that the breaths from the user flow over the capture structure;PDSD No. 365.0123WOU1 a capture structure heating element configured to heat the capture structure; a cannabis fuel cell; a valve configured to selectively direct the breath path either through the fuel cell and then to an outlet opening, or directly to the outlet opening bypassing the fuel cell; wherein the fuel cell, comprises: a fuel cell housing, a membrane electrode assembly (MEA) comprising an anode, a cathode, an ion exchange membrane disposed between the anode and the cathode, and an electrolyte, wherein the MEA comprises an anode side and a cathode side; and a buffer flow plate defining a first serpentine channel; wherein the buffer flow plate is disposed between the anode side of the MEA and the fuel cell housing.

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