Temperature self-compensating two-dimensional material resonant MEMS pressure sensor and measurement and preparation method

Abstract

The present invention discloses a temperature-self-compensating two-dimensional material resonant MEMS pressure sensor, comprising: a silicon pressure-sensitive membrane, a two-dimensional material pressure-sensitive membrane, a two-dimensional material temperature compensation membrane, a glass cover, and a glass capillary. Two blind holes are provided on the upper surface of the silicon pressure-sensitive membrane, one for accommodating the two-dimensional material pressure-sensitive membrane and the other for accommodating the two-dimensional material temperature compensation membrane. A deep cavity is etched on the lower surface to serve as the pressure-sensitive region. The two-dimensional material pressure-sensitive membrane is vacuum-encapsulated, acting as a pressure-sensitive resonator, simultaneously sensitive to pressure and temperature changes and connected to one or more two-dimensional material pressure-sensitive membrane detection optical fibers. The two-dimensional material temperature compensation membrane is disposed at the edge of the upper surface of the silicon pressure-sensitive membrane and connected to one or more two-dimensional material temperature compensation membrane detection optical fibers. The glass cover is used to provide a vacuum environment, and the glass capillary is used to secure the two-dimensional material pressure-sensitive membrane detection optical fibers and the two-dimensional material temperature compensation membrane detection optical fibers. Corresponding measurement methods and preparation methods are also disclosed.

Description

Technical Field

[0001] The present invention relates to the technical field of micro / nano-electromechanical systems, and in particular to a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, a measuring method and a preparation method. Background Art

[0002] Resonant sensors, also known as frequency sensors, utilize resonant elements (such as vibrating wires, vibrating cylinders, vibrating beams, and diaphragms) to convert the measured variable into a frequency signal. Their operating principle is based on the principle of resonance. When the measured variable changes, the natural frequency of the vibrating element changes. This frequency change is converted into an electrical signal by a measuring device, thereby enabling the measurement of the measured variable. Resonant pressure sensors measure the natural frequency of a resonant element as a function of pressure. When external pressure acts on the sensor's sensitive element, the element deforms, causing a change in its equivalent stiffness and, consequently, a shift in the resonant natural frequency. Compared to traditional pressure sensors, resonant pressure sensors offer advantages such as miniaturization, integration, high sensitivity, excellent stability, high resolution, fast response, and digital output. Currently, these sensors typically use metal, quartz, or silicon as resonators, and are excited and detected electrically or optically. Optical methods can photothermally excite the resonator with an intensity-modulated laser beam, and then detect the excited resonance using optical interferometry. Compared with electric resonant sensors, optical fiber resonant sensors have the advantages of miniaturization, high sensitivity, resistance to electromagnetic interference, strong multiplexing capability, and membrane protection.

[0003] Graphene has excellent properties, such as single-atomic layer thickness, high Young's modulus, high thermal conductivity, and excellent fatigue performance. Its overload capacity is far superior to materials such as silicon. Therefore, graphene membranes have good potential as resonant sensitive membranes. Graphene-based nanoelectromechanical systems (NEMS) have been applied to pressure sensors. Graphene can be used as an ultra-sensitive membrane to detect pressure. Replacing traditional silicon membranes in traditional MEMS pressure sensors with graphene membranes will significantly improve their responsiveness and reduce their size. However, current research on graphene resonant pressure sensors is still limited to laboratory environments, and most of the focus is on theoretical discussions of graphene resonant characteristics and their experimental verification. In 2017, Beijing University of Aeronautics and Astronautics produced a dual-graphene resonant beam pressure sensor (CN106918420A) that achieves quasi-differential measurement and eliminates the influence of environmental factors such as temperature. The sensor is entirely based on the principle of electrical excitation and electrical detection, which is different from the optical excitation / pickup method used in the present invention. In 2019, Steeneken et al. from Delft University of Technology in the Netherlands proposed a method to prevent gas leakage between the interface of graphene and SiO2. By using electron beam induced deposition technology to deposit SiO2 on the edge of suspended multilayer graphene sheets, the gas permeability between graphene and SiO2 substrate was reduced by 10%. 4 times. In 2021, Li Cheng and others from Beijing University of Aeronautics and Astronautics disclosed a vacuum-encapsulated graphene resonant fiber pressure sensor and its manufacturing method (CN2021100376236), but the sensor did not include a temperature compensation structure, resulting in low measurement accuracy. In 2022, Wang Yiping's research group at Shenzhen University reported an ultra-high-sensitivity optomechanical Au / graphene film gas pressure sensor. The Au / graphene film was attached to a hollow-core optical fiber to make an FP resonant pressure sensor with a resolution as low as 7.16×10 -9 mbar, but its graphene film is in direct contact with the environment to be measured, resulting in limitations such as low stability. In 2024, More et al. from the Indian Institute of Science fabricated a graphene resonant pressure sensor on a SiO2 diaphragm. They used a monolithic packaging structure to generate a pressure differential across the diaphragm. Compared with a probe structure, the sensor cannot be placed independently in the environment to be measured, which to some extent limits its application range.

[0004] In addition, for graphene resonant pressure sensors, environmental factors such as temperature and air damping can cause changes in the resonant frequency, which will not only reduce the measurement accuracy of the sensor but also have an adverse effect on its working stability. Summary of the Invention

[0005] In order to solve the problem of temperature drift of graphene resonant pressure sensors in the prior art, the present invention provides the following technical solutions: a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, a measurement method, and a preparation method. The differential structure of the dual two-dimensional material resonators used therein can effectively compensate for the influence of temperature, thereby improving the sensitivity, accuracy and stability of the sensor. It has the advantages of small size, strong anti-interference ability and high stability, and has important application value in deep space pressure detection, automotive industry and other fields.

[0006] In one aspect, the present invention provides a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, comprising:

[0007] A silicon pressure sensitive film (1), a two-dimensional material pressure sensitive film (2), a two-dimensional material temperature compensation film (3), a glass cover (4) and a glass capillary (5); wherein:

[0008] Two blind holes are provided on the upper surface of the silicon pressure sensitive film (1), and the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are placed in the two blind holes respectively; the lower surface of the silicon pressure sensitive film (1) is etched to form a deep cavity, and the deep cavity is used as a pressure sensitive area, and the structural size of the deep cavity is adjusted according to the pressure environment to be measured and the sensitivity requirement;

[0009] The two-dimensional material pressure sensitive film (2) is arranged at the center of the upper surface of the silicon pressure sensitive film (1); the two-dimensional material pressure sensitive film (2) is vacuum-sealed and acts as a pressure sensitive resonator, and is sensitive to pressure and temperature changes at the same time; the two-dimensional material pressure sensitive film (2) is connected to one or more two-dimensional material pressure sensitive film detection optical fibers (6); under the photothermal excitation of the two-dimensional material pressure sensitive film detection optical fibers (6), the two-dimensional material pressure sensitive film (2) resonates, and the pressure to be measured directly acts on the lower surface of the silicon pressure sensitive film (1) to cause it to deform, thereby causing the equivalent stiffness of the two-dimensional material pressure sensitive film (2) to change, and changing the resonant frequency of the two-dimensional material pressure sensitive film (2); based on the change in the resonant frequency, the relative change of the corresponding pressure to be measured is calculated;

[0010] The two-dimensional material temperature compensation film (3) is arranged at an edge position of the upper surface of the silicon pressure sensitive film (1), and the two-dimensional material temperature compensation film (3) is connected to one or more two-dimensional material temperature compensation film detection optical fibers (7); the two-dimensional material temperature compensation film (3) has the property of being unaffected by the pressure to be measured and only affected by changes in ambient temperature;

[0011] The glass cover (4) is arranged on the upper surface of the silicon pressure sensitive film (1) and is packaged with the silicon pressure sensitive film (1) through an anodic bonding process, and the glass cover (4) is used to provide a vacuum environment for the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3);

[0012] The glass capillary (5) is arranged on the upper surface of the glass cover (4) and is used to fix the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7), so that the optical fiber output light energy of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) can be irradiated onto the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) through the glass cover (4) and reflected back to the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7).

[0013] Preferably, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) have consistent shapes and geometric dimensions and are in a vacuum environment.

[0014] Preferably, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are single-layer or multi-layer, and are in the form of a circular, square, double-end fixed-support vibration beam or patterned structure.

[0015] Preferably, the excitation-detection method adopted by the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) is consistent, and is any one of an optical excitation-optical detection method, an electrical excitation-electrical detection method, an optical excitation-electrical detection method, and an electrical excitation-optical detection method.

[0016] Preferably, the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) are any one of single-mode optical fibers, multi-mode optical fibers, or fusion-spliced ​​components of optical fibers and optical devices.

[0017] Preferably, the materials of the two-dimensional material pressure sensitive film (2), the two-dimensional material temperature compensation film (3), the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) are graphene films, hBN films, MXene films, black phosphorus films or transition metal sulfide films.

[0018] Preferably, the glass used for the glass cover (4) has high optical transmittance and a thermal expansion coefficient close to that of silicon material; the glass is Pyrex7740 glass or glass of the same type.

[0019] Preferably, the glass capillary (5) is any micro-machinable or mechanically processable material with high optical transmittance, including any one of polymethyl methacrylate, polycarbonate and polystyrene.

[0020] A second aspect of the present invention is to provide a pressure measurement method for a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, comprising:

[0021] Silicon pressure sensitive film (1), two-dimensional material pressure sensitive film (2), two-dimensional material temperature compensation film (3), glass cover (4) and glass capillary (5)

[0022] S1, vacuum-sealing a two-dimensional material pressure-sensitive film (2) and arranging it at the center of the upper surface of the silicon pressure-sensitive film (1); arranging the two-dimensional material temperature-compensation film (3) at the edge of the upper surface of the silicon pressure-sensitive film (1); the two-dimensional material pressure-sensitive film (2) acts as a pressure-sensitive resonator, being sensitive to both pressure and temperature changes; and the two-dimensional material temperature-compensation film (3) being sensitive only to temperature changes;

[0023] S2, under the stimulation of the two-dimensional material pressure sensitive film detection optical fiber (6) connected to the two-dimensional material pressure sensitive film (2), the two-dimensional material pressure sensitive film (2) generates resonance, and the initial resonance frequency of the two-dimensional material pressure sensitive film (2) is recorded;

[0024] S3, under the stimulation of a two-dimensional material temperature compensation film detection optical fiber (7) connected to the two-dimensional material temperature compensation film (3), the two-dimensional material temperature compensation film (3) generates resonance; and the initial resonance frequency of the two-dimensional material temperature compensation film (3) is recorded;

[0025] S4, the pressure to be measured directly acts on the lower surface of the silicon pressure sensitive membrane (1) to cause deformation thereof, thereby causing the equivalent stiffness of the two-dimensional material pressure sensitive membrane (2) to change, and changing the resonant frequency of the two-dimensional material pressure sensitive membrane (2);

[0026] S5, the temperature change acts on the two-dimensional material temperature compensation film (3), and changes the resonant frequency of the two-dimensional material temperature compensation film (3);

[0027] S6, eliminating the temperature effect by using the differential resonant frequency between the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); the differential resonant frequency is expressed as the pressure sensitivity and temperature sensitivity of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3);

[0028] S7, based on the change of the resonant frequency and the differential resonant frequency, the corresponding pressure to be measured is calculated and output. The calculation formula of the pressure to be measured p output by the pressure sensor is expressed as formula (1) as follows:

[0029]

[0030] In formula (1), and are the initial resonant frequencies of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively; f r1 and f r2 are the actual resonant frequencies of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively; k1 and k2 are the pressure sensitivities of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively; s1 and s2 are the temperature sensitivities of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively.

[0031] A third aspect of the present invention is to provide a method for preparing a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, comprising: a micromachining process flow and an assembly process flow;

[0032] The micromachining process includes the following steps:

[0033] (A) thermally oxidizing a clean silicon wafer to grow a silicon dioxide layer on the surface of the silicon wafer, and etching two grooves on the surface of the silicon dioxide layer to prevent the glass cover (4) from directly contacting the two-dimensional material resonator after anodic bonding;

[0034] (B) performing secondary etching at the centers of the two grooves using an RIE process to form blind holes as substrates for the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3);

[0035] (C) performing back etching on the lower surface of the silicon wafer to form a cavity as a pressure sensitive area, thereby forming the silicon pressure sensitive film (1);

[0036] (D) transferring polymethyl methacrylate, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) to the surface of the blind holes on the two circular grooves on the surface of the silicon dioxide layer by dry transfer, adsorbing them on the silicon pressure sensitive film (1) under the action of van der Waals force, and placing the silicon, the two-dimensional material film and polymethyl methacrylate in a high-temperature annealing furnace in a nitrogen environment for annealing to remove the polymethyl methacrylate on the graphene surface, thereby forming a fixed-support suspended two-dimensional material structure above the blind hole;

[0037] (E) depositing a layer of SiO2 around the two-dimensional material film by a FI B process, for clamping and fixing the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3);

[0038] (F) using a glass wafer as a sealing material, bonding the glass wafer and the silicon pressure sensitive film (1) through a vacuum anodic bonding process, aligning one side of the silicon wafer with the graphene film and the unprocessed side of the glass wafer for anodic bonding, vacuum packaging the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) under vacuum conditions, and mechanically cutting to obtain independent sensor units;

[0039] (G) respectively fixing the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) in the central and edge holes of the glass capillary (5), aligning them with the centers of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), and fixing them with high-temperature resistant glue to form a complete micro-machined part of the MEMS pressure sensor;

[0040] The assembly process includes:

[0041] (A) Making a fixture for an optical fiber ferrule, comprising: assembling the fixture on a micro-movement stage by screws, so that the micro-movement stage can perform long-distance micro-displacement adjustment;

[0042] (B) respectively fixing the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) to the glass capillary (5), including: cutting the center of the single-mode optical fiber jumper, stripping the bare fiber at one end and cutting the end face flat, inserting the single-mode optical fiber into the fixing hole of the glass capillary (5), and making the optical fiber end face flush with the end face of the glass capillary (5), and then sealing the tail of the optical fiber capillary with high temperature resistant liquid glue to fix the optical fiber and the glass capillary (5);

[0043] (C) adjusting the position of the optical fiber end face, comprising: inserting the glass capillary (5) into the clamping fixture, and adjusting the position of the optical fiber end face by the micro-motion stage so that the optical fiber end face can be clearly seen in the center of the microscope eyepiece, and the optical fiber end face is on the focal plane of the microscope; then adjusting the micro-motion stage to keep the relative positions of the micro-motion stage, the clamping fixture and the optical fiber fixed;

[0044] (D) loading a visible light source, including: connecting an end of an optical fiber jumper to a red visible light laser source, and adjusting the output optical power of the red visible light source so that the clear aperture at the center of the optical fiber can be observed through a microscope;

[0045] (E) coarsely adjusting the distance between the thin film formed by the two-dimensional material and the end face of the optical fiber, comprising: fixing the silicon pressure sensitive film (1) on the bracket of the two-dimensional material resonator packaging structure, so that the upper surface of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are 1 mm away from the end face of the optical fiber, so as to prevent the resonator from contacting the end face of the optical fiber, thereby causing mechanical damage to the optical fiber or the packaged resonator structure; and then adjusting the position of the micro-motion stage so that a clear image of the graphene and the substrate is presented in the field of view;

[0046] (F) finely adjusting the distance between the thin film formed by the two-dimensional material and the end face of the optical fiber, comprising: irradiating the output light of a broadband light source onto the thin film surfaces of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), receiving the reflected light by a spectrometer, and performing real-time detection of the cavity length through the reflection spectrum data of the thin film formed by the two-dimensional material;

[0047] (G) adjusting the position of the glass capillary (5) so that the reflected light spots of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are coaxial with the fiber end faces of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7), and so that the red light spots emitted from the centers of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) are located at the center of the pressure sensitive resonator;

[0048] (H) fixing the assembly formed by the silicon pressure sensitive film (1) and the glass cover plate (4) to the glass capillary (5), including: after completing the alignment of the relative positions of the red light spot, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), fixing the glass cover plate (4) to the glass capillary (5), thereby completing the assembly of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor.

[0049] A fourth aspect of the present invention provides an electronic device, comprising a processor and a memory, wherein the memory stores a plurality of instructions, and the processor is configured to read the instructions and execute the method described in the second aspect.

[0050] A fifth aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a plurality of instructions, and the plurality of instructions can be read by a processor to execute the method described in the second aspect.

[0051] The method, system, and electronic device provided by the present invention have the following beneficial effects:

[0052] (1) The present invention adopts an indirect sensitive structure, and the pressure to be measured does not contact the graphene resonator, which can effectively protect the graphene resonator and improve the long-term stability and reliability of the sensor.

[0053] (2) The present invention can measure pressure scenarios in various environments, including gas pressure and liquid pressure. At the same time, the size of the pressure-sensitive area can be adjusted according to the pressure range to be measured and the sensitivity requirements, and has high flexibility.

[0054] (3) The present invention adopts a dual graphene resonator sensing structure and operates in a differential mode, which can compensate for errors caused by the environment, improve the accuracy of the sensor, and is applicable to pressure measurement in complex temperature environments.

[0055] (4) The test system used in the assembly method of the present invention has a simple structure, small space occupancy, high cost performance, and convenient operation, and can realize the assembly of the pressure-sensitive unit and the optical fiber.

[0056] (5) The thickness of the double graphene resonators used in the present invention is in the nanometer range, which is much lower than that of traditional silicon resonators. This can greatly improve the sensitivity of the pressure sensor and provide the possibility for the small integration of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a schematic diagram of the principle structure of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor described in the present invention.

[0058] Figure 2 This is a schematic diagram of the anodic bonding micromachining process method of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor described in the present invention.

[0059] Figure 3 This is a flow chart of the assembly method of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor described in the present invention.

[0060] Figure 4 FIG. 2 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

[0061] The meanings of the reference numerals in the figures are:

[0062] 1-Silicon pressure sensitive film; 2-Two-dimensional material pressure sensitive film; 3-Two-dimensional material temperature compensation film;

[0063] 4-glass cover; 5-glass capillary; 6-two-dimensional material pressure sensitive film detection optical fiber;

[0064] 7- Two-dimensional material temperature compensation film detection optical fiber. DETAILED DESCRIPTION

[0065] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0066] Example 1

[0067] This embodiment provides a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, including:

[0068] Silicon pressure sensitive film 1, two-dimensional material pressure sensitive film 2, two-dimensional material temperature compensation film 3, glass cover 4 and glass capillary 5; wherein:

[0069] Two blind holes are provided on the upper surface of the silicon pressure-sensitive membrane 1, into which a two-dimensional pressure-sensitive membrane 2 and a two-dimensional temperature-compensation membrane 3 are placed, respectively. A deep cavity is etched on the lower surface of the silicon pressure-sensitive membrane 1 to form a pressure-sensitive area. The structural dimensions of the deep cavity are adjusted according to the pressure environment to be measured and the sensitivity requirements.

[0070] The two-dimensional material pressure-sensitive membrane 2 is arranged at the center of the upper surface of the silicon pressure-sensitive membrane 1. After being vacuum-encapsulated, the two-dimensional material pressure-sensitive membrane 2 acts as a pressure-sensitive resonator, and is sensitive to pressure and temperature changes at the same time. The two-dimensional material pressure-sensitive membrane 2 is connected to one or more two-dimensional material pressure-sensitive membrane detection optical fibers 6. Under the photothermal excitation of the two-dimensional material pressure-sensitive membrane detection optical fibers 6, the two-dimensional material pressure-sensitive membrane 2 resonates, and the pressure to be measured directly acts on the lower surface of the silicon pressure-sensitive membrane 1 to cause it to deform, thereby causing the equivalent stiffness of the two-dimensional material pressure-sensitive membrane 2 to change, and changing the resonant frequency of the two-dimensional material pressure-sensitive membrane 2. The relative change of the corresponding pressure to be measured is calculated based on the change in the resonant frequency.

[0071] The two-dimensional material temperature compensation film 3 is disposed at the edge of the upper surface of the silicon pressure sensitive film 1 and is connected to one or more two-dimensional material temperature compensation film detection optical fibers 7. The two-dimensional material temperature compensation film 3 is not affected by the pressure to be measured but only by changes in the ambient temperature. It is only sensitive to temperature changes and eliminates temperature effects by detecting the differential resonant frequency of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3.

[0072] The glass cover 4 is provided on the upper surface of the silicon pressure sensitive film 1 and is encapsulated with the silicon pressure sensitive film 1 through an anodic bonding process. The glass cover 4 is used to provide a vacuum environment for the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3;

[0073] The glass capillary 5 is arranged on the upper surface of the glass cover 4, and is used to fix the two-dimensional material pressure-sensitive film detection optical fiber 6 and the two-dimensional material temperature-compensation film detection optical fiber 7, so that the optical fiber output light energy of the two-dimensional material pressure-sensitive film detection optical fiber 6 and the two-dimensional material temperature-compensation film detection optical fiber 7 can pass through the glass cover 4 and irradiate the two-dimensional material pressure-sensitive film 2 and the two-dimensional material temperature-compensation film 3 respectively, and be reflected back to the two-dimensional material pressure-sensitive film detection optical fiber 6 and the two-dimensional material temperature-compensation film detection optical fiber 7 respectively.

[0074] As a preferred embodiment, the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 have consistent shapes and geometric dimensions and are in a vacuum environment; the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 are single-layer or multi-layer, and are circular, square, double-end fixed-support vibration beam or patterned structural forms.

[0075] As a preferred embodiment, the excitation-detection method adopted by the two-dimensional material pressure-sensitive film 2 and the two-dimensional material temperature compensation film 3 is consistent, which is any one of the optical excitation-optical detection method, the electrical excitation-electrical detection method, the optical excitation-electrical detection method and the electrical excitation-optical detection method.

[0076] As a preferred embodiment, the two-dimensional material pressure sensitive film detection optical fiber 6 and the two-dimensional material temperature compensation film detection optical fiber 7 are either single-mode optical fibers, multi-mode optical fibers or fusion-spliced ​​components of optical fibers and optical devices.

[0077] As a preferred embodiment, the materials of the two-dimensional material pressure sensitive film 2, the two-dimensional material temperature compensation film 3, the two-dimensional material pressure sensitive film detection optical fiber 6 and the two-dimensional material temperature compensation film detection optical fiber 7 are graphene film, hBN film, MXene film, black phosphorus film or transition metal sulfide film.

[0078] As a preferred embodiment, the glass used for the glass cover 4 has high optical transmittance and a thermal expansion coefficient close to that of silicon material; the glass is Pyrex7740 glass or similar glass, and the glass cover 4 can be of any thickness.

[0079] As a preferred embodiment, the glass capillary 5 is any material with high optical transmittance that can be micro-machined or machined, such as polymethyl methacrylate (PMMA), polycarbonate (PC), PS (polystyrene) and other similar light-transmitting materials.

[0080] Example 2

[0081] This embodiment provides a pressure measurement method for a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, comprising:

[0082] Silicon pressure sensitive film 1, two-dimensional material pressure sensitive film 2, two-dimensional material temperature compensation film 3, glass cover 4 and glass capillary 5

[0083] S1, vacuum-encapsulate the two-dimensional material pressure sensitive film 2 and place it at the center of the upper surface of the silicon pressure sensitive film 1; place the two-dimensional material temperature compensation film 3 at the edge of the upper surface of the silicon pressure sensitive film 1; the two-dimensional material pressure sensitive film 2 acts as a pressure sensitive resonator, sensitive to both pressure and temperature changes; the two-dimensional material temperature compensation film 3 is only sensitive to temperature changes;

[0084] S2, under the stimulation of the two-dimensional material pressure sensitive film detection optical fiber 6 connected to the two-dimensional material pressure sensitive film 2, the two-dimensional material pressure sensitive film 2 generates resonance, and the initial resonance frequency of the two-dimensional material pressure sensitive film 2 is recorded;

[0085] S3, under the stimulation of the two-dimensional material temperature compensation film detection optical fiber 7 connected to the two-dimensional material temperature compensation film 3, the two-dimensional material temperature compensation film 3 generates resonance; and the initial resonance frequency of the two-dimensional material temperature compensation film 3 is recorded;

[0086] S4, the pressure to be measured directly acts on the lower surface of the silicon pressure sensitive membrane 1 to cause it to deform, thereby causing the equivalent stiffness of the two-dimensional material pressure sensitive membrane 2 to change and changing the resonant frequency of the two-dimensional material pressure sensitive membrane 2;

[0087] S5, the temperature change acts on the two-dimensional material temperature compensation film 3 and changes the resonant frequency of the two-dimensional material temperature compensation film 3;

[0088] S6, eliminating the temperature effect by using the differential resonant frequency between the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3; the differential resonant frequency is expressed as the pressure sensitivity and temperature sensitivity of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3;

[0089] S7, based on the change of the resonant frequency and the differential resonant frequency, the corresponding pressure to be measured is calculated and output. The calculation formula of the pressure to be measured p output by the pressure sensor is expressed as formula (1) as follows:

[0090]

[0091] In formula (1), and are the initial resonant frequencies of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 respectively; f r1 and f r2 are the actual resonant frequencies of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 respectively; k1 and k2 are the pressure sensitivities of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 respectively; s1 and s2 are the temperature sensitivities of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 respectively.

[0092] Example 3

[0093] This embodiment provides a method for preparing a temperature self-compensating two-dimensional material resonant MEMS pressure sensor, including: a micromachining process flow and an assembly process flow;

[0094] The micromachining process includes the following steps:

[0095] (A) Thermally oxidizing a clean silicon wafer to grow a silicon dioxide layer on the surface of the silicon wafer, and etching two grooves on the surface of the silicon dioxide layer to prevent direct contact between the glass cover 4 and the two-dimensional material resonator after anodic bonding;

[0096] (B) A secondary etching process is performed at the center of the two grooves using the RIE process to form blind holes as the base of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3;

[0097] (C) Back-etching is performed on the lower surface of the silicon wafer to form a cavity as a pressure-sensitive area, thereby forming a silicon pressure-sensitive membrane 1;

[0098] (D) Using a dry transfer method, polymethyl methacrylate (PMMA), a two-dimensional pressure-sensitive film 2, and a two-dimensional temperature-compensation film 3 are transferred to the blind hole surfaces of the two circular grooves on the surface of the silicon dioxide layer. Under the action of van der Waals forces, they are adsorbed on the silicon pressure-sensitive film 1. The silicon, two-dimensional material film, and polymethyl methacrylate (PMMA) are then placed in a high-temperature annealing furnace in a nitrogen environment and annealed for 3 hours to remove the polymethyl methacrylate (PMMA) from the graphene surface, forming a fixed-support suspended two-dimensional material structure above the blind hole.

[0099] (E) A layer of SiO2 is deposited around the two-dimensional material film by the FI B process to clamp and fix the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3;

[0100] (F) Using a glass wafer as a capping material, the glass wafer and the silicon pressure sensitive film 1 are vacuum anodic bonding, and the side of the silicon wafer with the graphene film is aligned with the unprocessed side of the glass wafer for anodic bonding. The two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 are vacuum packaged under vacuum conditions, and then mechanically cut to obtain independent sensor units;

[0101] (G) Fixing the two-dimensional material pressure sensitive film detection optical fiber 6 and the two-dimensional material temperature compensation film detection optical fiber 7 in the central and edge holes of the glass capillary 5, respectively, and aligning them with the centers of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3, and fixing them with high-temperature resistant glue to form a complete micro-machined part of the MEMS pressure sensor;

[0102] The assembly process includes:

[0103] (A) Making a fixture for an optical fiber ferrule, comprising: assembling the fixture on a micro-movement stage by screws, so that the micro-movement stage can perform long-distance micro-displacement adjustment;

[0104] (B) respectively fixing the two-dimensional material pressure sensitive film detection optical fiber 6 and the two-dimensional material temperature compensation film detection optical fiber 7 to the glass capillary 5, including: cutting the center of the single-mode optical fiber jumper, stripping the bare fiber at one end and cutting the end face flat, inserting the single-mode optical fiber into the fixing hole of the glass capillary 5, and making the optical fiber end face flush with the end face of the glass capillary 5, and then sealing the tail of the optical fiber capillary with high-temperature resistant liquid glue to fix the optical fiber and the glass capillary 5.

[0105] (C) Adjusting the position of the optical fiber end face, including: inserting the glass capillary 5 into the clamp and adjusting the position of the optical fiber end face through the micro-motion stage so that the optical fiber end face can be clearly seen in the center of the microscope eyepiece. At this time, the optical fiber end face is on the focal plane of the microscope; then adjusting the micro-motion stage to keep the relative positions of the micro-motion stage, the clamp and the optical fiber fixed.

[0106] (D) loading a visible light source, including: connecting an end of the optical fiber jumper to a red visible light laser source, and adjusting the output optical power of the red visible light source so that the clear aperture at the center of the optical fiber can be observed through a microscope;

[0107] (E) Coarsely adjusting the distance between the thin film formed by the two-dimensional material and the end face of the optical fiber, including: fixing the silicon pressure sensitive film 1 on the bracket of the two-dimensional material resonator packaging structure so that the upper surface of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3 are about 1 mm away from the end face of the optical fiber to prevent the resonator from contacting the end face of the optical fiber, thereby causing mechanical damage to the optical fiber or the packaged resonator structure; then adjusting the position of the micro-motion stage so that a clear image of the graphene and the substrate is presented in the field of view. At this time, the distance between the upper surface of the glass cover plate of the graphene resonator packaging structure and the end face of the optical fiber from which the laser is emitted is about 50 μm.

[0108] (F) finely adjusting the distance between the thin film formed of the two-dimensional material and the end face of the optical fiber, comprising: irradiating the output light of a broadband light source onto the thin film surfaces of the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3, receiving the reflected light by a spectrometer, and detecting the cavity length in real time based on the reflection spectrum data of the thin film formed of the two-dimensional material;

[0109] (G) Adjust the position of the glass capillary 5 so that the reflected light spot of the two-dimensional material pressure-sensitive film 2 and the two-dimensional material temperature-compensation film 3 is coaxial with the fiber end faces of the two-dimensional material pressure-sensitive film detection optical fiber 6 and the two-dimensional material temperature-compensation film detection optical fiber 7, and the red light spot emitted from the center of the two-dimensional material pressure-sensitive film detection optical fiber 6 and the two-dimensional material temperature-compensation film detection optical fiber 7 is located at the center of the pressure-sensitive resonator;

[0110] (H) fixing the assembly formed by the silicon pressure sensitive film (1) and the glass cover plate 4 to the glass capillary 5, including: after completing the alignment of the relative positions of the red light spot and the two-dimensional material pressure sensitive film 2 and the two-dimensional material temperature compensation film 3, fixing the glass cover plate 4 to the glass capillary 5, thereby completing the assembly of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor.

[0111] In the following examples, graphene is selected as a typical two-dimensional material.

[0112] Figure 1 The figure shows a schematic diagram of the principle structure of the temperature self-compensating graphene resonant MEMS pressure sensor of the present invention, which mainly includes a silicon pressure sensitive membrane 1, a graphene pressure sensitive membrane 2, a graphene temperature compensation membrane 3, a glass cover 4, a glass capillary 5, a detection optical fiber 6 of the graphene pressure sensitive membrane, and a detection optical fiber 7 of the graphene temperature compensation membrane.

[0113] Two grooves are etched on the upper surface of the silicon wafer to prevent the graphene from adhering to the glass during anodic bonding. Then, blind holes are etched in the centers of the two grooves to serve as the substrate for the graphene pressure sensitive film 2 and the graphene temperature compensation film 3. A cavity is etched back on the silicon wafer to form the silicon pressure sensitive film 1. The graphene pressure sensitive film 2 and the graphene temperature compensation film 3 are transferred to the surface of the blind holes respectively by dry transfer. The graphene pressure sensitive film 2 is located in the center of the silicon pressure sensitive film 1 and is sensitive to pressure and temperature changes. The graphene temperature compensation film 3 is located at the edge of the silicon pressure sensitive film 1. , which is only sensitive to temperature changes and eliminates temperature effects by detecting differential resonant frequencies; the glass wafer 4 and the silicon pressure-sensitive film 1 are anodically bonded under vacuum conditions to complete the vacuum packaging of the graphene pressure-sensitive film 2 and the graphene temperature compensation film 3, and then the pieces are diced to obtain independent sensor units; the detection optical fiber 6 of the graphene pressure-sensitive film and the detection optical fiber 7 of the graphene temperature compensation film are respectively fixed in the central and edge holes of the glass capillary 5, and aligned with the centers of the graphene pressure-sensitive film 2 and the graphene temperature compensation film 3, and fixed with high-temperature resistant glue to form a complete sensor.

[0114] The pressure sensitive measurement principle and working process of this embodiment are as follows:

[0115] The pressure to be measured first acts on the lower surface of the silicon pressure-sensitive membrane 1, causing its upper surface to deform upward. This in turn causes the graphene pressure-sensitive membrane 2, located at the exact center of the silicon pressure-sensitive membrane 1's upper surface, to deform, thereby changing the resonant frequency and amplitude of the graphene pressure-sensitive membrane 2. Simultaneously, the graphene temperature compensation membrane 3, located at the exact center of the silicon pressure-sensitive membrane 1, does not deform. Because the detection optical fibers 6 and 7 of the graphene pressure-sensitive membrane and the graphene temperature compensation membrane form a Fabry-Perot interferometer cavity between the graphene pressure-sensitive membrane 2 and the graphene temperature compensation membrane 3, respectively, the amplitude changes of the graphene membranes cause changes in the intensity of the interference light. The pressure to be measured is measured by demodulating the interference light intensity.

[0116] The temperature compensation principle and working process of this embodiment are:

[0117] The graphene pressure sensitive film 2 and the graphene temperature compensation film 3 have the same shape and structural dimensions. The graphene pressure sensitive film 2 is sensitive to both pressure and ambient temperature, while the graphene temperature compensation film 3 is only sensitive to ambient temperature. Under different ambient temperatures, the temperature effect is eliminated by detecting the differential resonant frequency.

[0118] This embodiment provides a set of process flows for manufacturing a temperature self-compensated graphene resonant MEMS pressure sensor, wherein the micromachining process consists of Figure 2 Shown, including the following steps:

[0119] In step 1, a clean 500 μm thick silicon wafer 100 is thermally oxidized to grow a silicon dioxide layer with a thickness of about 10 μm on the surface of the silicon wafer, and two circular grooves are etched on the surface of the silicon dioxide layer only from the first etching. The circular shallow grooves have a diameter of 200 μm and a depth of about 10 μm to avoid direct contact between the glass cover and the graphene resonator after bonding.

[0120] Step 2: Perform secondary etching in the two circular grooves on the surface of the silicon dioxide layer using an RIE process to form a substrate for the graphene pressure sensitive film 2 and the graphene temperature compensation film 3.

[0121] Step 3: A pressure-sensitive area with a diameter of 5 mm and a thickness of 100 μm is etched from the back of the lower surface of the silicon wafer to form a silicon pressure-sensitive membrane 1 .

[0122] In step 4, the PMMA / graphene film is transferred to the two circular grooves on the surface of the silicon dioxide layer and adsorbed on the silicon pressure sensitive film 1 under the action of van der Waals force. The silicon / graphene / PMMA is placed in a high-temperature annealing furnace in a nitrogen environment and annealed at 350°C for 3 hours to remove the PMMA on the graphene surface and form a fixed suspended graphene structure above the blind hole.

[0123] In step 5, a layer of SiO2 is deposited around the graphene film by the FIB process to clamp and fix the graphene pressure sensitive film 2 and the graphene temperature compensation film 3.

[0124] In step 6, a 100 μm thick Pyrex7740 glass wafer 4 is selected as the capping material. Through a vacuum anodic bonding process, one side of the silicon wafer with the graphene film is aligned and bonded to the unprocessed side of the glass wafer to achieve vacuum packaging of the graphene pressure sensitive film 2 and the graphene temperature compensation film 3.

[0125] In step 7, the detection optical fiber 6 of the graphene pressure sensitive film and the detection optical fiber 7 of the graphene temperature compensation film are fixed in the central and edge holes of the glass capillary 5, respectively, and aligned with the center of the graphene pressure sensitive film 2 and the graphene temperature compensation film 3, and fixed with high-temperature resistant glue to form a complete sensor.

[0126] This embodiment provides a method for assembling a set of temperature self-compensating graphene resonant MEMS pressure sensors. The assembly method flow chart is as follows: Figure 3 Shown, including the following steps:

[0127] Step 1: Make a holder for the optical fiber ferrule: Assemble the holder on the micro-movement stage with screws so that the micro-movement stage can perform long-distance micro-displacement adjustment.

[0128] Step 2, respectively fix the detection optical fiber 6 of the graphene pressure sensitive film and the detection optical fiber 7 of the graphene temperature compensation film to the glass capillary 5: cut the center of the single-mode optical fiber jumper, strip the bare fiber at one end and cut the end face flat, insert the single-mode optical fiber into the fixing hole of the glass capillary, and make the optical fiber end face flush with the end face of the glass capillary, then seal the tail of the optical fiber capillary with high-temperature resistant liquid glue, and fix the detection optical fiber 6 of the graphene pressure sensitive film and the detection optical fiber 7 of the graphene temperature compensation film to the glass capillary 5.

[0129] Step 3: Adjust the fiber end face position: Insert the glass capillary into the fixture and use the micro-motion stage to adjust the fiber end face position so that the fiber end face can be clearly seen in the center of the microscope eyepiece and is in the focal plane of the microscope. Then adjust the micro-motion stage to keep the relative positions of the micro-motion stage, fixture, and fiber fixed.

[0130] Step 4: Load the visible light source: Connect the fiber jumper end to the red visible light laser source and adjust the output optical power of the light source appropriately so that the clear aperture at the center of the fiber can be observed through a microscope.

[0131] Step 5: Coarsely adjust the distance between the graphene and the fiber end face: Customize the bracket for the graphene resonator packaging structure and secure the silicon pressure-sensitive film 1 to it, ensuring that the upper surfaces of the graphene pressure-sensitive film 2 and the graphene temperature-compensation film 3 are approximately 1-2 mm from the fiber end face. This prevents contact between the resonator and the fiber end face, potentially causing mechanical damage to the fiber or the packaged resonator structure. The position of the micro-motion stage is then adjusted to ensure a clear image of the graphene and substrate within the field of view. At this point, the upper surface of the glass cover plate of the graphene resonator packaging structure is approximately 50 μm from the fiber end face where the laser is emitted.

[0132] Step 6, fine-tuning the distance between graphene and the optical fiber end face: irradiate the output light of the broadband light source to the surface of the graphene pressure sensitive film 2 and the graphene temperature compensation film 3, and the reflected light is received by the spectrometer. The cavity length can be detected in real time through the reflection spectrum data of the graphene.

[0133] Step 7: Adjust the position of the glass capillary 5 so that the reflected light spot on the graphene pressure sensitive film 2 and the graphene temperature compensation film 3 is coaxial with the fiber end faces of the detection fiber 6 of the graphene pressure sensitive film and the detection fiber 7 of the graphene temperature compensation film, and the red light spot emitted from the center of the fiber is located at the center of the graphene resonator.

[0134] Step 8, fixing the silicon pressure-sensitive membrane 1 / glass cover plate 4 assembly to the glass capillary 5: After completing the alignment of the light spot with the relative positions of the graphene pressure-sensitive membrane 2 and the graphene temperature compensation membrane 3, fix the glass cover plate 4 to the glass capillary 5 to complete the assembly of the temperature-self-compensating graphene resonant MEMS pressure sensor.

[0135] The dimensions of the present invention may be larger or smaller than those given in the embodiments.

[0136] The contents not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

[0137] The present invention also provides a memory storing a plurality of instructions, wherein the instructions are used to implement the pressure measurement method and the preparation method.

[0138] like Figure 4 As shown, the present invention also provides an electronic device, including a processor 301 and a memory 302 connected to the processor 301, the memory 302 stores multiple instructions, and the instructions can be loaded and executed by the processor to enable the processor to execute the method as in embodiment 1.

[0139] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A temperature self-compensating two-dimensional material resonant MEMS pressure sensor, characterized in that: include: Silicon pressure sensitive film (1), two-dimensional material pressure sensitive film (2), two-dimensional material temperature compensation film (3), glass cover (4) and glass capillary (5); wherein: Two blind holes are provided on the upper surface of the silicon pressure sensitive film (1), and the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are placed in the two blind holes respectively; the lower surface of the silicon pressure sensitive film (1) is etched to form a deep cavity, and the deep cavity is used as a pressure sensitive area, and the structural size of the deep cavity is adjusted according to the pressure environment to be measured and the sensitivity requirement; The two-dimensional material pressure sensitive film (2) is arranged at the center of the upper surface of the silicon pressure sensitive film (1), and the two-dimensional material pressure sensitive film (2) is vacuum-sealed and acts as a pressure sensitive resonator, and is sensitive to pressure and temperature changes at the same time; the two-dimensional material pressure sensitive film (2) is connected to one or more two-dimensional material pressure sensitive film detection optical fibers (6); under the photothermal excitation of the two-dimensional material pressure sensitive film detection optical fibers (6), the two-dimensional material pressure sensitive film (2) resonates, and the pressure to be measured directly acts on the lower surface of the silicon pressure sensitive film (1) to cause it to deform, thereby causing the equivalent stiffness of the two-dimensional material pressure sensitive film (2) to change, and changing the resonant frequency of the two-dimensional material pressure sensitive film (2); based on the change in the resonant frequency, the relative change of the corresponding pressure to be measured is calculated; The two-dimensional material temperature compensation film (3) is arranged at an edge position of the upper surface of the silicon pressure sensitive film (1), and the two-dimensional material temperature compensation film (3) is connected to one or more two-dimensional material temperature compensation film detection optical fibers (7); the two-dimensional material temperature compensation film (3) has the property of being unaffected by the pressure to be measured and only affected by changes in ambient temperature; The glass cover (4) is arranged on the upper surface of the silicon pressure sensitive film (1) and is packaged with the silicon pressure sensitive film (1) through an anodic bonding process. The glass cover (4) is used to provide a vacuum environment for the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); The glass capillary (5) is arranged on the upper surface of the glass cover (4) and is used to fix the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7), so that the optical fiber output light energy of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) can be irradiated onto the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) through the glass cover (4) and reflected back to the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7).

2. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 1, characterized in that: The two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) have consistent shapes and geometric dimensions and are in a vacuum environment.

3. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 2, characterized in that: The two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are single-layer or multi-layer, and are in the form of a circular, square, double-end fixed-support vibration beam or patterned structure.

4. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 3, characterized in that: The excitation-detection method adopted by the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) is consistent, and is any one of an optical excitation-optical detection method, an electrical excitation-electrical detection method, an optical excitation-electrical detection method, and an electrical excitation-optical detection method.

5. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 4, characterized in that: The two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) are any one of single-mode optical fibers, multi-mode optical fibers, or fusion-spliced ​​components of optical fibers and optical devices.

6. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 5, characterized in that: The materials of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are graphene film, hBN film, MXene film, black phosphorus film or transition metal sulfide film.

7. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 6, characterized in that: The glass used in the glass cover (4) has high optical transmittance and a thermal expansion coefficient close to that of silicon material; the glass is Pyrex7740 glass or glass of the same type.

8. The temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to claim 7, characterized in that: The glass capillary (5) is any material that can be micro-processed or machined and has high optical transmittance, including any one of polymethyl methacrylate, polycarbonate and polystyrene.

9. A pressure measurement method for a temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to any one of claims 1 to 8, characterized in that: include: Silicon pressure sensitive film (1), two-dimensional material pressure sensitive film (2), two-dimensional material temperature compensation film (3), glass cover (4) and glass capillary (5) S1, vacuum-sealing a two-dimensional material pressure-sensitive film (2) and arranging it at the center of the upper surface of the silicon pressure-sensitive film (1); arranging the two-dimensional material temperature-compensation film (3) at the edge of the upper surface of the silicon pressure-sensitive film (1); the two-dimensional material pressure-sensitive film (2) acts as a pressure-sensitive resonator, being sensitive to both pressure and temperature changes; the two-dimensional material temperature-compensation film (3) being sensitive only to temperature changes; S2, under the stimulation of the two-dimensional material pressure sensitive film detection optical fiber (6) connected to the two-dimensional material pressure sensitive film (2), the two-dimensional material pressure sensitive film (2) generates resonance, and the initial resonance frequency of the two-dimensional material pressure sensitive film (2) is recorded; S3, under the excitation of the two-dimensional material temperature compensation film detection optical fiber (7) connected to the two-dimensional material temperature compensation film (3), the two-dimensional material temperature compensation film (3) generates resonance; and the initial resonance frequency of the two-dimensional material temperature compensation film (3) is recorded; S4, the pressure to be measured directly acts on the lower surface of the silicon pressure sensitive membrane (1) to cause deformation thereof, thereby causing the equivalent stiffness of the two-dimensional material pressure sensitive membrane (2) to change, and changing the resonant frequency of the two-dimensional material pressure sensitive membrane (2); S5, the temperature change acts on the two-dimensional material temperature compensation film (3), and changes the resonant frequency of the two-dimensional material temperature compensation film (3); S6, eliminating the temperature effect by using the differential resonant frequency between the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); the differential resonant frequency is expressed as the pressure sensitivity and temperature sensitivity of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); S7, based on the change of the resonant frequency and the differential resonant frequency, the corresponding pressure to be measured is calculated and output. The calculation formula of the pressure to be measured p output by the pressure sensor is expressed as formula (1) as follows （1）； In formula (1), and are the initial resonant frequencies of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively; and are the actual resonant frequencies of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), respectively; k1 and k2 are respectively the pressure sensitivities of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); s1 and s2 are respectively the temperature sensitivities of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3).

10. A method for preparing a temperature self-compensating two-dimensional material resonant MEMS pressure sensor according to any one of claims 1 to 8, characterized in that: include: Micromachining process flow and assembly process flow; The micromachining process includes the following steps: (A) thermally oxidizing a clean silicon wafer to grow a silicon dioxide layer on the surface of the silicon wafer, and etching two grooves on the surface of the silicon dioxide layer to prevent the glass cover (4) from directly contacting the two-dimensional material resonator after anodic bonding; (B) performing secondary etching in the centers of the two grooves using an RIE process to form blind holes as substrates for the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); (C) performing back etching on the lower surface of the silicon wafer to form a cavity as a pressure sensitive area, thereby forming the silicon pressure sensitive film (1); (D) using a dry transfer method to transfer polymethyl methacrylate, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) to the surface of the blind hole on the two circular grooves on the surface of the silicon dioxide layer, adsorbing them on the silicon pressure sensitive film (1) under the action of van der Waals force, and placing the silicon, two-dimensional material film and polymethyl methacrylate in a high-temperature annealing furnace in a nitrogen environment for annealing to remove the polymethyl methacrylate on the graphene surface, thereby forming a fixed-support suspended two-dimensional material structure above the blind hole; (E) depositing a layer of SiO2 around the two-dimensional material film by a FIB process, for clamping and fixing the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3); (F) using a glass wafer as a sealing material, bonding the glass wafer and the silicon pressure sensitive film (1) through a vacuum anodic bonding process, aligning one side of the silicon wafer with the graphene film and the unprocessed side of the glass wafer for anodic bonding, vacuum packaging the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) under vacuum conditions, and mechanically cutting to obtain independent sensor units; (G) respectively fixing the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) in the central and edge holes of the glass capillary (5), aligning them with the centers of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), and fixing them with high-temperature resistant glue to form a complete micro-machined part of the MEMS pressure sensor; The assembly process includes: (A) Making a fixture for an optical fiber ferrule, comprising: assembling the fixture on a micro-movement stage via screws, so that the micro-movement stage can perform long-distance micro-displacement adjustment; (B) respectively fixing the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) to the glass capillary (5), including: cutting the center of the single-mode optical fiber jumper, stripping the bare fiber at one end and cutting the end face flat, inserting the single-mode optical fiber into the fixing hole of the glass capillary (5), and making the optical fiber end face flush with the end face of the glass capillary (5), and then sealing the tail of the optical fiber capillary with high temperature resistant liquid glue to fix the optical fiber and the glass capillary (5); (C) adjusting the position of the optical fiber end face, comprising: inserting the glass capillary (5) into the clamp, and adjusting the position of the optical fiber end face by the micro-motion stage so that the optical fiber end face can be clearly seen at the center of the microscope eyepiece, and the optical fiber end face is on the focal plane of the microscope; then adjusting the micro-motion stage to keep the relative positions of the micro-motion stage, the clamp and the optical fiber fixed; (D) loading a visible light source, including: connecting an end of an optical fiber jumper to a red visible light laser source, and adjusting the output optical power of the red visible light source so that the clear aperture at the center of the optical fiber can be observed through a microscope; (E) coarsely adjusting the distance between the thin film formed by the two-dimensional material and the end face of the optical fiber, comprising: fixing the silicon pressure sensitive film (1) on the bracket of the two-dimensional material resonator packaging structure, so that the upper surface of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are 1 mm away from the end face of the optical fiber, so as to prevent the resonator from contacting the end face of the optical fiber, thereby causing mechanical damage to the optical fiber or the packaged resonator structure; and then adjusting the position of the micro-motion stage so that a clear image of the graphene and the substrate is presented in the field of view; (F) finely adjusting the distance between the thin film formed by the two-dimensional material and the end face of the optical fiber, comprising: irradiating the output light of a broadband light source onto the thin film surfaces of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), receiving the reflected light by a spectrometer, and performing real-time detection of the cavity length through the reflection spectrum data of the thin film formed by the two-dimensional material; (G) adjusting the position of the glass capillary (5) so that the reflected light spots of the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3) are coaxial with the fiber end faces of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7), and so that the red light spots emitted from the centers of the two-dimensional material pressure sensitive film detection optical fiber (6) and the two-dimensional material temperature compensation film detection optical fiber (7) are located at the center of the pressure sensitive resonator; (H) fixing the assembly formed by the silicon pressure sensitive film (1) and the glass cover (4) to the glass capillary (5), including: after completing the alignment of the relative positions of the red light spot, the two-dimensional material pressure sensitive film (2) and the two-dimensional material temperature compensation film (3), fixing the glass cover (4) to the glass capillary (5), thereby completing the assembly of the temperature self-compensating two-dimensional material resonant MEMS pressure sensor.

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