Optical microcavity hydrogen sensor and gas detection equipment

Abstract

The utility model relates to the technical field of gas detection, in particular to an optical microcavity hydrogen sensor and gas detection equipment. The optical microcavity hydrogen sensor comprises an optical fiber sensor, a mounting bracket and a cantilever beam, and the cantilever beam is provided with a deformable structure and a functional film and is combined with an optical microcavity. The functional film with gas concentration can absorb gas to cause the stress change of the film material, the stress can be transmitted to the cantilever beam to enable the cantilever beam to generate mechanical deformation, and then the hydrogen concentration can be indirectly detected by detecting the deformation condition of the cantilever beam. Compared with a traditional sensor, the optical microcavity hydrogen sensor has the advantages that electromagnetic interference is reduced, electrical risks are avoided, and the detection reliability is improved.

Description

Technical Field

[0001] This utility model relates to the field of gas detection technology, specifically to an optical microcavity hydrogen sensor. Background Technology

[0002] Hydrogen is a renewable and clean energy gas and an important industrial raw material, widely used in petroleum, electronics, metallurgy, aerospace, and many other fields. However, hydrogen is flammable and explosive. Effective detection of hydrogen leaks during its production, transportation, storage, and use is crucial for ensuring personnel safety, preventing explosions, and protecting the environment. To prevent these problems, hydrogen sensors are typically used to detect hydrogen concentration to ensure safety. Currently, commercially available hydrogen sensors for detection include electrochemical, electrical, and optical types.

[0003] In the process of realizing this utility model, the inventors discovered that: currently, electrochemical hydrogen sensors are prone to corrosion of equipment, have insufficient gas sensitivity, and require frequent electrolyte replacement; electrical semiconductor oxide hydrogen sensors typically operate at temperatures between 200℃ and 400℃, respond to most combustible gases but have poor selectivity, and also suffer from drawbacks such as complex structure, long response time, and short lifespan; traditional optical hydrogen sensors, such as photoacoustic hydrogen sensors, have high sensitivity and fast response speed, but are greatly affected by the photoacoustic cell and temperature; while fiber optic hydrogen sensors have many advantages, some types suffer from complex manufacturing processes and high costs. Summary of the Invention

[0004] In view of the above problems, this utility model is proposed to provide an optical microcavity hydrogen sensor and gas detection device that overcomes or at least partially solves the above problems.

[0005] In a first aspect, the present invention provides an optical microcavity hydrogen sensor, including an optical fiber sensor;

[0006] Mounting bracket for mounting fiber optic sensors;

[0007] A cantilever beam is provided at one end of the mounting bracket. The cantilever beam includes a fixed part and an extension arm. The fixed part is provided on the mounting bracket. One end of the extension arm is connected to the fixed part, and the extension arm extends from the fixed part toward the center position.

[0008] The end of the extension arm is provided with a gas adsorption layer, and the sensing head of the fiber optic sensor is set at the end of the extension arm to detect the deformation of the cantilever beam.

[0009] Furthermore, the mounting bracket includes: a mounting base for mounting the fiber optic sensor;

[0010] A support member, one end of which is disposed on one side of the mounting base; and,

[0011] The cavity component is located at the other end of the support component.

[0012] Furthermore, a flow cavity is provided in the middle of the cavity component, and the end of the optical fiber sensor is located in the flow cavity.

[0013] Furthermore, the cavity of the flow chamber gradually increases in size from the end closer to the support member to the end farther away from the support member.

[0014] Furthermore, the end of the extension arm is provided with an end portion, the cross-sectional area of ​​the end portion is larger than the area of ​​the end of the extension arm, and the cross-section of the end portion is circular.

[0015] Furthermore, the end portion is provided with a gas adsorption layer, and the gas adsorption layer is disposed close to the support member.

[0016] Furthermore, the gas adsorption layer is a hydrogen-sensitive adsorption film, which is made of Pd / Ag target material.

[0017] Furthermore, the proportion of Ag in the Pd / Ag target is 30-40% of the total.

[0018] In a further embodiment, the extension arm is a silicon wafer, the lateral width of the silicon wafer near the fixing part is 200-220um, and the lateral width of the silicon wafer near the end part is 30-50um.

[0019] The third aspect also discloses a gas detection device, including the optical microcavity hydrogen sensor described in any of the above.

[0020] The beneficial effects of the above-mentioned technical solutions provided by the embodiments of this utility model include at least the following:

[0021] This invention provides an optical microcavity hydrogen sensor, comprising a fiber optic sensor, a mounting bracket, and a cantilever beam. The cantilever beam is equipped with a deformable structure and a functional thin film, combined with an optical microcavity. The functional thin film, when adsorbing gas, experiences stress changes in the film material. This stress is transmitted to the cantilever beam, causing it to deform mechanically. By detecting the deformation of the cantilever beam, the hydrogen concentration can be indirectly determined. Compared to traditional sensors, this optical microcavity hydrogen sensor reduces electromagnetic interference, avoids electrical risks, and increases detection reliability.

[0022] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0023] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0025] Figure 1 This is a schematic diagram of the optical microcavity hydrogen sensor of the first embodiment;

[0026] Figure 2 This is a utility model Figure 1 A diagram from another perspective;

[0027] Figure 3 This is a utility model Figure 2 AA section view;

[0028] Figure 4 This is a schematic diagram of the cantilever beam according to the first embodiment of this utility model;

[0029] Figure 5 This is a utility model Figure 4 A magnified view of part B;

[0030] Figure 6 This is a schematic diagram of a cavity component according to an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of the cantilever beam according to the second embodiment of this utility model;

[0032] Figure 8 This is a schematic diagram of the optical microcavity hydrogen sensor of the second embodiment;

[0033] Figure 9 This is a diagram illustrating the actual usage effect of the optical microcavity hydrogen sensor in this embodiment.

[0034] The image shows:

[0035] 1. Cantilever beam; 2. Mounting bracket;

[0036] 10. Fixing part; 11. Extension arm; 12. End part; 13. Gas adsorption layer;

[0037] 20. Cavity component; 21. Support component; 22. Mounting base;

[0038] 200. Cavity. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any implementation described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other implementations. The following description is provided to enable any person skilled in the art to implement and use this application. Details are set forth in the following description for illustrative purposes. It should be understood that those skilled in the art will recognize that this application can be implemented without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but rather to be consistent with the broadest scope of the principles and features disclosed in this application.

[0042] A gas detector is an instrument used to detect the concentration of leaked gases. These include portable gas detectors, handheld gas detectors, stationary gas detectors, and online gas detectors. They primarily utilize gas sensors to detect the types of gases present in the environment; gas sensors are used to detect the composition and concentration of gases.

[0043] Hydrogen is a renewable and clean energy gas and an important industrial raw material, widely used in petroleum, electronics, metallurgy, aerospace, and many other fields. However, hydrogen is flammable and explosive. Effective detection of hydrogen leaks during its production, transportation, storage, and use is crucial for ensuring personnel safety, preventing explosions, and protecting the environment. Currently, commercially available hydrogen sensors are mainly electrochemical, electrical, and optical types. This application aims to invent a hydrogen detection device combining a fiber optic sensor.

[0044] Before describing the embodiments of this utility model in detail, the design concept of this utility model is first outlined below. (Refer to the appendix.) Figure 8 As shown, this invention designs an optical microcavity hydrogen sensor, which includes a fiber optic sensor, a mounting bracket, and a cantilever beam. The cantilever beam is equipped with a deformable structure and a functional thin film, combined with an optical microcavity. The functional thin film, when adsorbing gas, experiences stress changes in the film material. This stress is transmitted to the cantilever beam, causing it to deform mechanically. By detecting the deformation of the cantilever beam, the hydrogen concentration can be indirectly determined. Compared to traditional sensors, this optical microcavity hydrogen sensor reduces electromagnetic interference, avoids electrical risks, and increases detection reliability.

[0045] The inventors of this utility model have continued their research on how to effectively solve the problems of current gas detection sensors. Their research includes at least the following: how a hydrogen sensor can indirectly detect hydrogen concentration by combining an optical microcavity with a deformable structure to create a functional thin film, and then detecting deformation via optical fiber. After extensive and repeated research, the inventors have proposed the optical microcavity hydrogen sensor and its fabrication method described in this application.

[0046] See attached document Figure 1 As shown, this embodiment of the present invention provides an optical microcavity hydrogen sensor, including an optical fiber sensor 3;

[0047] Mounting bracket 2 is used to mount fiber optic sensor 3;

[0048] A cantilever beam 1 is provided at one end of the mounting bracket 2. The cantilever beam 1 includes a fixed part 10 and an extension arm 11. The fixed part 10 is provided on the mounting bracket 2. One end of the extension arm 11 is connected to the fixed part 10, and the extension arm 11 extends from the fixed part 10 toward the center position.

[0049] The end of the extension arm 11 is provided with a gas adsorption layer 13, and the sensing head of the fiber optic sensor 3 is provided at the end of the extension arm 11 to detect the deformation of the cantilever beam 1.

[0050] Understandably, the embodiment includes a fixed part 10 and an extension arm 11 in the cantilever beam 1, with the extension arm 11 designed as a structure with its end freely suspended. A gas adsorption layer 13 is provided at the end, which can adsorb the target gas. When the material stress changes, this stress is transmitted to the cantilever beam 1, causing mechanical deformation. This deformation causes changes in the optical parameters of the fiber optic microcavity of the fiber optic sensor 3, such as the length and refractive index, thereby indicating a change in gas concentration. Compared with traditional sensors, the optical microcavity hydrogen sensor has advantages such as reduced electromagnetic interference, avoidance of electrical risks, and increased detection reliability.

[0051] It should be noted that in this embodiment, the gas adsorption layer 13 provided at the end of the extension arm 11 is a hydrogen-sensitive adsorption film that can adsorb hydrogen. In other embodiments, it is not ruled out that by replacing the gas adsorption layer 13, other gases can be detected, such as a film layer that can adsorb carbon monoxide, biogas or other toxic gases.

[0052] In this embodiment, the degree of deformation of the extension arm 11 is related to the amount of hydrogen adsorbed, which in turn is related to the hydrogen concentration in the surrounding environment. Therefore, by detecting the deformation of the cantilever beam 1, the concentration of hydrogen can be indirectly determined.

[0053] In this embodiment, a fiber optic microcavity and cantilever structure are used for hydrogen concentration detection. The fiber optic microcavity is typically composed of a specially designed section of optical fiber with a tiny cavity structure. When a light beam propagates from the fiber into the microcavity, it undergoes multiple reflections and interferences within the microcavity. Due to the deformation of the cantilever beam 1, the optical parameters of the fiber optic microcavity, such as its length and refractive index, change. For example, bending of the cantilever beam 1 may stretch or compress the fiber optic microcavity, thereby changing its length. According to the principle of optical interference, changes in parameters such as the microcavity length will lead to changes in the intensity, phase, or wavelength of the output light. Simultaneously, the characteristics of the fiber optic microcavity can be precisely designed and controlled to give it a unique response mode to optical changes caused by hydrogen, enhancing the sensor's selective recognition capability for hydrogen and effectively achieving high-precision detection.

[0054] An optical microcavity is an optical structure that confines light to undergo multiple reflections and interferences within a tiny space. Optical microcavities possess high optical quality factors and mode-volume ratios, enhancing the interaction between light and matter. In sensor applications, optical microcavities can be used to achieve high-precision measurements of external physical or chemical quantities by detecting changes in the propagation characteristics of light within the microcavity, such as wavelength, intensity, and phase.

[0055] In this embodiment, when the optical microcavity hydrogen sensor is in a hydrogen environment, the adsorption of the gas adsorption layer 13 causes a change in material stress. This stress is transmitted to the cantilever beam 1, causing mechanical deformation of the cantilever beam 1. Since one end of the extension arm 11 is connected to the fixed part 10 and the other end is free, the extension arm 11 will undergo bending or torsion deformation under stress.

[0056] See attached document Figure 1 , 2 As shown in Figure 5, in a further embodiment, the mounting bracket 2 includes: a mounting base 22 for mounting the fiber optic sensor 3;

[0057] Support member 21, one end of which is disposed on one side of the mounting base 22; and,

[0058] The cavity component 20 is located at the other end of the support component 21 and is connected to the cantilever beam 1.

[0059] Understandably, in order to ensure the installation of the fiber optic sensor 3 and the cantilever beam 1, and to accurately relay the deformation of the cantilever beam 1 to the optical microcavity of the fiber, in this embodiment, the mounting bracket 2 is configured as three parts: a mounting base 22, a support member 21, and a cavity member 20. The two ends of the support member 21 are respectively connected to the mounting member and the cavity member 20. The mounting member is used to connect the fiber optic sensor 3, and the cavity member 20 is used to install the cantilever beam, so that the fiber optic sensor 3 can accurately cooperate with the cantilever beam 1, ensuring that when the cantilever beam 1 deforms, it can accurately cause changes in the optical parameters such as the length and refractive index of the fiber optic microcavity.

[0060] See attached document Figure 3 As shown in the embodiment, in a further embodiment, a cavity 200 is provided in the middle position of the cavity component 20, and the end of the optical fiber sensor 3 is located in the cavity 200.

[0061] See attached document Figure 6 As shown in the embodiment, in a further embodiment, the cavity 200 of the flow cavity gradually increases in size from the end near the support member 21 to the end away from the support member 21.

[0062] Understandably, in order to allow gas to flow within the cavity component 20, in this embodiment, a flow cavity is provided within the cavity component 20, and the cross-section of the flow cavity is set such that the area near the cantilever beam 1 is larger than the area away from the cantilever beam 1, and has a gradually changing structure. This effectively ensures smoother gas flow, thereby ensuring that the light field directly acts on the sensitive membrane, increasing the interaction between light and the gas adsorbed on the sensitive membrane, and improving sensitivity.

[0063] See attached document Figure 4 As shown in the embodiment, in a further embodiment, the end of the extension arm 11 is provided with an end portion 12, the cross-sectional area of ​​the end portion 12 is larger than the end area of ​​the extension arm 11, and the cross-section of the end portion 12 is circular.

[0064] Understandably, in order to ensure the contact area between the gas adsorption layer 13 and the gas and to ensure accuracy, the embodiment is to increase the area of ​​the end portion 12 and then ensure that the area of ​​the gas adsorption layer 13 deposited on the end portion 12 is large enough, that is, to increase the area of ​​the gas adsorption layer 13.

[0065] Meanwhile, to improve the accuracy of the deformation of the extension arm 11 after the gas adsorption layer 13 adsorbs gas, in this embodiment, by reducing the lateral area of ​​the extension arm 11, the deformation of the extension arm 11 after the gas adsorption layer 13 adsorbs gas is made more accurate. Furthermore, to ensure the stability of the extension arm 11, in this embodiment, the lateral width of the extension arm 11 gradually decreases from the fixed portion 10 to the end portion 12, thereby ensuring the accuracy of gas detection.

[0066] See attached document Figure 4 and 5 As shown in the embodiment, the thickness of the gas adsorption layer 13 of the end portion 12 is controlled to be 120-670 nm, and the gas adsorption layer 13 is disposed close to the support member 21.

[0067] In this embodiment, by controlling the thickness of the gas adsorption layer 13 to a certain thickness, it is ensured that the gas to be detected can fully contact the gas adsorption layer 13.

[0068] In some embodiments, a gas adsorption layer 13 is deposited at the end portion 12 of the extension arm 11 by magnetron sputtering, and the thickness of the deposited layer is 300 nm; in other embodiments, a gas adsorption layer 13 is deposited at the end portion 12 of the extension arm 11 by magnetron sputtering, and the thickness of the deposited layer is 120 nm; in still other embodiments, a gas adsorption layer 13 is deposited at the end portion 12 of the extension arm 11 by magnetron sputtering, and the thickness of the deposited layer is 600 nm.

[0069] See attached document Figure 5As shown in the embodiment, the gas adsorption layer 13 is a hydrogen-sensitive adsorption film, which is made of a Pd / Ag target. The proportion of Ag in the Pd / Ag target is 30-40% of the total content.

[0070] Understandably, this is for the purpose of detecting hydrogen, so the gas adsorption layer 13 is a thin film made of a hydrogen-sensitive material. At the same time, the hydrogen-sensitive material here is a Pd / Ag target, that is, a sputtering target containing an alloy of Pd and Ag, and in order to provide the sensitivity of hydrogen detection, the proportion of Ag is 30-40% of the whole.

[0071] In some embodiments, the hydrogen-sensitive material is a Pd / Ag target, i.e., sputtered from an alloy containing Pd and Ag, with Ag comprising 1 / 3 of the total to provide hydrogen detection sensitivity; in other embodiments, the hydrogen-sensitive material is a Pd / Ag target, i.e., sputtered from an alloy containing Pd and Ag, with Ag comprising 30% of the total to provide hydrogen detection sensitivity; and in still other embodiments, the hydrogen-sensitive material is a Pd / Ag target, i.e., sputtered from an alloy containing Pd and Ag, with Ag comprising 40% of the total to provide hydrogen detection sensitivity.

[0072] Meanwhile, in other embodiments, it is not ruled out that the gas adsorption layer 13 may be made of a thin film of other sensitive materials for detecting other gases, such as a mixture of Ag-doped Al2O3, La2O3 and CuO nanopowders for detecting carbon monoxide, or a Pd-SnO2 composite material for detecting methane.

[0073] See attached document Figure 7 As shown in the embodiment, the extension arm 11 is a silicon wafer, the lateral width of the silicon wafer near the fixing part 10 is 200-220um, and the lateral width of the silicon wafer near the end part 12 is 30-50um.

[0074] In this embodiment, a cantilever beam 1 is fabricated using a silicon wafer. The silicon-based cantilever beam 1 possesses excellent optical and mechanical properties and is easy to process and integrate. Thus, the cantilever beam 1 provides a stable support structure, and its surface properties can be controlled through various surface treatment techniques to meet different application requirements. In this embodiment, by depositing different functional thin films on the surface of the cantilever beam 1, functions such as adsorption, reaction, or optical modulation of specific gases can be achieved. The thickness of the silicon wafer is controlled to be 30-50 μm.

[0075] In some embodiments, the thickness of the silicon wafer is controlled to be 40 μm, the lateral width of the silicon wafer near the fixing portion 10 is 220 μm, and the lateral width of the silicon wafer near the end portion 12 is 50 μm, thus making the cross-section of the silicon wafer gradually smaller. In other embodiments, the thickness of the silicon wafer is controlled to be 30 μm, the lateral width of the silicon wafer near the fixing portion 10 is 200 μm, and the lateral width of the silicon wafer near the end portion 12 is 30 μm, thus making the cross-section of the silicon wafer gradually smaller. In still other embodiments, the thickness of the silicon wafer is controlled to be 30 μm, the lateral width of the silicon wafer near the fixing portion 10 is 210 μm, and the lateral width of the silicon wafer near the end portion 12 is 45 μm, thus making the cross-section of the silicon wafer gradually smaller.

[0076] Based on the same inventive concept, a second aspect discloses a method for fabricating an optical microcavity hydrogen sensor, comprising the following steps:

[0077] Step 001: Print out the mounting bracket 2 using a printer.

[0078] 3D Printed Optical Microcavity Mold Structure: A 3D optical microcavity mold is directly printed using a photopolymer 3D printer. The printed layer thickness is 0.025 micrometers, and the material used is High Temp V2, a high-temperature 3D printing material.

[0079] Step 002: Cut the silicon wafer into the shape of a cantilever beam 1 using a slicing machine. The cantilever beam 1 includes a fixing part 10 and an extension arm 11.

[0080] In this embodiment, a 365nm ultraviolet laser slicing machine is used to cut silicon into thin-film silicon wafers. During the slicing process, the cutting power is controlled at 25W and the frequency at 80kHz. The thin-film silicon wafer has a cantilever beam structure 1, which includes a fixing part 10 and an extension arm 11. One end of the extension arm 11 is fixed to the fixing part 10, and the end of the extension arm 11 has a circular end portion 12 with a diameter controlled at 50-70µm. The length of the extension arm 11 is controlled at 1-1.5mm. The width of the extension arm 11 near the fixing part 10 is controlled at 200-220µm, and the width near the circular structure is controlled at 30-50µm. The overall thickness of the thin-film silicon wafer is controlled at 30-50µm. This is how the thin-film silicon wafer is obtained.

[0081] Step 003: Cover the cantilever beam with a mask and deposit a hydrogen-sensitive adsorption film on the circular structure at the end of the extension arm 11.

[0082] In this embodiment, firstly, a mask is used to cover the cantilever beam, but the end portion 12 of the extension arm 11 is not covered by a mask. Next, a hydrogen-sensitive adsorption film is deposited using a magnetron sputtering process, so that the end of the extension arm 11 has a circular structure forming a coating layer. The hydrogen-sensitive adsorption film is a Pd / Ag target film. In order to improve the sensitivity, the ratio of Ag in the Pd / Ag target is set to account for 30-40% of the total. The thickness of the hydrogen-sensitive adsorption film is controlled between 120-670 nm.

[0083] In some embodiments, a thin film layer is formed on the circular structure using a Pd / Ag target, and the Ag content in the Pd / Ag target is set to 30% of the total content, with the thickness of the hydrogen-sensitive adsorption film controlled at 130 nm; in another embodiment, a thin film layer is formed on the circular structure using a Pd / Ag target, and the Ag content in the Pd / Ag target is set to 40% of the total content, with the thickness of the hydrogen-sensitive adsorption film controlled at 670 nm; in yet another embodiment, a thin film layer is formed on the circular structure using a Pd / Ag target, and the Ag content in the Pd / Ag target is set to 35% of the total content, with the thickness of the hydrogen-sensitive adsorption film controlled at 500 nm.

[0084] Furthermore, before coating, the sputtering chamber needs to be evacuated to a high vacuum level, generally on the order of 10^-4 Pa to 10^-5 Pa, to reduce the scattering of sputtered particles by gas molecules within the chamber and ensure the purity and quality of the film. The working gas for sputtering is argon (Ar), with a purity higher than 99.99%. The gas flow rate is generally controlled between 10 sccm and 30 sccm (standard cubic centimeters per minute). Sputtering power: dual-target sputtering, with the Pd target power controlled between 60 W and 120 W, and the Ag target power correspondingly between approximately 40 W and 80 W.

[0085] Step 004: Use a high-temperature resistant polymer colloid to bond the cantilever beam to the mounting bracket 2.

[0086] In this embodiment, a waterproof, moisture-proof, and high-temperature resistant polymer colloid is selected to bond the fiber optic sensor 3 to the mounting bracket 2. The cantilever beam is bonded to the mounting bracket 2, and the side coated with the hydrogen-sensitive adsorption film faces the end face of the fiber optic sensor 3. The end face of the fiber optic sensor 3, the mounting bracket 2, and the circular structure respectively form an optical microcavity.

[0087] Based on the same utility model concept, a method for using an optical microcavity hydrogen sensor is also disclosed, wherein the optical microcavity hydrogen sensor is used to detect the concentration of hydrogen and to issue an alarm when the concentration reaches a set threshold, indicating a safety problem.

[0088] For specific examples and explanations of the beneficial effects of the method described in this embodiment, please refer to the description of the optical microcavity hydrogen sensor above, which will not be repeated here.

[0089] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. This disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of this utility model fall within the scope of the claims of this utility model and their equivalents, this utility model is also intended to include these modifications and variations.

Claims

1. An optical microcavity hydrogen sensor, characterized in that, Including fiber optic sensors; Mounting bracket for mounting fiber optic sensors; A cantilever beam is provided at one end of the mounting bracket. The cantilever beam includes a fixed part and an extension arm. The fixed part is provided on the mounting bracket. One end of the extension arm is connected to the fixed part, and the extension arm extends from the fixed part toward the center position. The end of the extension arm is provided with a gas adsorption layer, and the sensing head of the fiber optic sensor is set at the end of the extension arm to detect the deformation of the cantilever beam.

2. The optical microcavity hydrogen sensor according to claim 1, characterized in that, The mounting bracket includes: a mounting base for mounting the fiber optic sensor; A support member, one end of which is disposed on one side of the mounting base; and, The cavity component is located at the other end of the support component.

3. The optical microcavity hydrogen sensor according to claim 2, characterized in that, A flow cavity is provided in the middle of the cavity component, and the end of the optical fiber sensor is located in the flow cavity.

4. The optical microcavity hydrogen sensor according to claim 3, characterized in that, The cavity of the flow chamber gradually increases in size from the end closer to the support member to the end farther away from the support member.

5. The optical microcavity hydrogen sensor according to claim 1, characterized in that, The extension arm has an end portion at its end, the cross-sectional area of ​​which is larger than the area of ​​the extension arm end, and the cross-section of the end portion is circular.

6. The optical microcavity hydrogen sensor according to claim 5, characterized in that, The thickness of the gas adsorption layer at the end is controlled to be 120-670 nm, and the gas adsorption layer is disposed close to the support.

7. The optical microcavity hydrogen sensor according to claim 6, characterized in that, The gas adsorption layer is a hydrogen-sensitive adsorption film, which is made of Pd / Ag target material.

8. The optical microcavity hydrogen sensor according to claim 7, characterized in that, The proportion of Ag in the Pd / Ag target is 30-40% of the total.

9. The optical microcavity hydrogen sensor according to claim 5, characterized in that, The extension arm is a silicon wafer, the lateral width of the silicon wafer near the fixing part is 200-220um, and the lateral width of the silicon wafer near the end part is 30-50um.

10. A gas detection device, characterized in that, Including the optical microcavity hydrogen sensor according to any one of claims 1-9.

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