A resonant gas sensing detection method based on thermal excitation
By measuring the inherent frequency offset of a nanofilm gas sensor through thermal excitation, the shortcomings of traditional pressure sensors in terms of miniaturization and low power consumption are overcome, achieving high-precision pressure sensing that is suitable for consumer electronics and aerospace fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
- Filing Date
- 2026-03-09
- Publication Date
- 2026-05-29
AI Technical Summary
Existing barometric pressure sensors are inadequate in terms of miniaturization, low power consumption, and high precision. Furthermore, traditional electrical excitation methods cause significant damage to two-dimensional materials and have limited adaptability, failing to meet the needs of consumer electronics and aerospace fields.
A thermal excitation-based method is adopted, which uses ambient white noise to excite the thermal vibration of a nanofilm gas sensor and measures its first-order natural frequency shift to invert the air pressure. Combined with a laser Doppler vibrometer and piezoelectric excitation, air pressure sensing is realized.
It achieves high-precision, low-power air pressure sensing, solves the shortcomings of traditional sensors in miniaturization and adaptability, and reduces the risk of damage to two-dimensional materials.
Smart Images
Figure CN122108432A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of high-precision vibration measurement and gas sensing technology, specifically relating to a resonant gas sensing and detection method based on thermal excitation. Background Technology
[0002] With the rapid development of consumer electronics (such as smartphones and smartwatches), automotive electronics, aerospace, and other fields, higher demands are being placed on barometric pressure measurement, such as miniaturization, low power consumption, high accuracy, and real-time response. However, traditional barometric pressure sensors are large, power-consuming, and expensive, and are difficult to integrate into small electronic devices, failing to meet the needs of portable and intelligent products. For example, early mechanical barometers and electronic barometric pressure sensors had significant shortcomings in size, response speed, and mass production capabilities, limiting their application in emerging fields.
[0003] In recent years, with the rapid development of materials science, two-dimensional nanomaterials such as graphene, hexagonal boron nitride, black phosphorus, and transition metal dichalcogenides have been extensively studied for their unique properties in terms of force, heat, light, and electricity, which distinguish them from macroscopic materials due to scale effects. Their small size, high Young's modulus, and low mass density enable chip-level miniaturization and integration, achieving resonant frequencies in the MHz to GHz range, thus providing a foundation for ultra-sensitive and fast response.
[0004] The resonant two-dimensional material barometric pressure sensor uses a two-dimensional material as its core resonant structure, combining MEMS micromachining with resonant detection principles. It features ultra-high sensitivity, miniaturization, and a wide measurement range. The action of air pressure alters the stress / stiffness of the two-dimensional material resonator, causing a shift in the resonant frequency. The air pressure is retrieved through high-precision frequency measurement, and the frequency signal is digitally processed for strong anti-interference capabilities.
[0005] In resonant two-dimensional material pressure sensors, the vibration of the two-dimensional material is usually caused by electrical excitation. However, this excitation method generally has the disadvantages of extremely high requirements for micro-nano fabrication, low yield, easy to cause structural damage to the two-dimensional material body, nonlinear effects and parasitic interference, limited adaptability, and inability to drive non-conductive two-dimensional materials. Summary of the Invention
[0006] To address the shortcomings of existing technologies, the present invention aims to provide a thermally excited resonant gas sensing method to solve the problems of small size, low power consumption, high accuracy, manufacturing difficulties, and susceptibility to damage in existing pressure sensors. This invention optimizes the excitation method by using ambient white noise to excite the thermal vibration of a nanofilm gas sensor. Under different pressure conditions, the shift in the first-order natural frequency of the nanofilm gas sensor is measured to infer the pressure, thus achieving pressure sensing.
[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0008] This invention provides a resonant gas sensing and detection method based on thermal excitation, comprising the following steps:
[0009] 1) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise;
[0010] 2) Measure the vibration signal of the nanofilm gas sensor to obtain the vibration information of the nanofilm, and then use a piezoelectric element to excite the nanofilm gas sensor at a single frequency to obtain the first natural frequency of the nanofilm.
[0011] 3) Excite the nanofilm gas sensor using thermal vibration method; measure the first natural frequency of the nanofilm under different gas pressures, and calculate the current gas pressure based on the offset of the first natural frequency of the nanofilm to realize gas pressure sensing.
[0012] Furthermore, the nanofilm gas sensor consists of a patterned substrate and a nanofilm;
[0013] The patterned substrate surface has recesses, and a nanofilm is disposed on the recesses, forming an airtight cavity between the recesses and the nanofilm.
[0014] Furthermore, the substrate material is Si or SiO2.
[0015] Furthermore, the material of the nanofilm is a two-dimensional material.
[0016] Furthermore, the thickness of the two-dimensional material does not exceed 100 nanometers.
[0017] Further, step 1) specifically includes:
[0018] 11) Place the nanofilm gas sensor on a piezoelectric element and place it in an adjustable vacuum chamber to keep the pressure inside the vacuum chamber consistent with the atmospheric pressure.
[0019] 12) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise.
[0020] Further, step 2) specifically includes:
[0021] 21) Use a laser Doppler vibrometer to measure the thermal vibration signal of the nanofilm gas sensor under atmospheric pressure, obtain the vibration information of the nanofilm, and find the resonance peaks of the nanofilm gas sensor from the spectrum.
[0022] 22) By applying a single-tone signal at the peak frequency to the piezoelectric element to excite the vibration of the nanofilm gas sensor, the vibration signal of the current nanofilm gas sensor is measured with a laser Doppler vibrometer to obtain the vibration information of the nanofilm. The mode shapes under different excitation frequencies are analyzed to determine the first natural frequency of the nanofilm.
[0023] Furthermore, step 3) specifically includes:
[0024] 31) Adjust the air pressure in the vacuum chamber and use a laser Doppler vibration meter to measure the thermal vibration signal of the nanofilm gas sensor under different air pressures;
[0025] 32) The first natural frequency of the nanofilm under the current air pressure is measured, and the current air pressure is calculated based on the offset between the first natural frequency of the nanofilm and the first natural frequency under atmospheric pressure, thus realizing air pressure sensing.
[0026] Furthermore, this invention also provides a method for fabricating a thermally excited nanofilm gas sensor, the steps of which are as follows:
[0027] Design a nanofilm gas sensor structure and fabricate a patterned substrate;
[0028] Nanofilms were prepared by mechanical exfoliation or chemical vapor deposition and then transferred to the surface of blue adhesive.
[0029] A polyvinyl alcohol water-soluble layer is spin-coated onto a silicon wafer and heated on a hot plate. Polymethyl methacrylate is spin-coated onto the heated silicon wafer, and the spin-coated silicon substrate is heated again on a hot plate. Blue adhesive with nanofilm attached is tightly adhered to the surface of the silicon wafer and placed on a hot plate. After heating, the blue adhesive is peeled off to transfer the nanofilm onto the silicon wafer.
[0030] The position of the nanofilm is located using an optical microscope, the water-soluble layer is dissolved, and the nanofilm is transferred to the prepared patterned substrate to form a cavity between the nanofilm and the patterned substrate.
[0031] The fabricated nanofilm gas sensor was vacuum annealed at 400℃.
[0032] The beneficial effects of this invention are:
[0033] The present invention improves the excitation method of the nanofilm gas sensor by using ambient white noise to excite the thermal vibration of the nanofilm gas sensor. Under different air pressure environments, the shift of the first natural frequency of the nanofilm gas sensor is measured to infer the air pressure, thereby realizing air pressure sensing. This solves the problems of existing micro air pressure sensors, such as extremely high requirements for micro-nano processing precision, low yield, easy structural damage to the two-dimensional material body, nonlinear effects and parasitic interference, limited adaptability, and inability to drive non-conductive two-dimensional materials. Attached Figure Description
[0034] Figure 1 This is a flowchart of the method of the present invention.
[0035] Figure 2 This is a schematic diagram of the structure of the nanofilm gas sensor in this invention. Detailed Implementation
[0036] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.
[0037] Reference Figure 1 As shown, this invention provides a resonant gas sensing detection method based on thermal excitation, comprising the following steps:
[0038] 1) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise;
[0039] In the example, refer to Figure 2 As shown, the nanofilm gas sensor consists of a patterned substrate 1 and a nanofilm 2; the nanofilm 2 covers the patterned substrate 1.
[0040] In a preferred embodiment, the patterned substrate surface is provided with recesses, and a nanofilm is disposed on the recesses, forming an airtight cavity between the recesses and the nanofilm.
[0041] In a preferred example, the substrate is made of Si or SiO2.
[0042] In a preferred example, the nanofilm is made of a two-dimensional material with a thickness not exceeding 100 nanometers.
[0043] Specifically, step 1) includes:
[0044] 11) Place the nanofilm gas sensor on a piezoelectric element and place it in an adjustable vacuum chamber to keep the pressure inside the vacuum chamber consistent with the atmospheric pressure.
[0045] 12) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise.
[0046] 2) Measure the vibration signal of the nanofilm gas sensor to obtain the vibration information of the nanofilm, and then use a piezoelectric element to excite the nanofilm gas sensor at a single frequency to obtain the first natural frequency of the nanofilm.
[0047] Specifically, step 2) includes:
[0048] 21) Use a laser Doppler vibrometer to measure the thermal vibration signal of the nanofilm gas sensor under atmospheric pressure, obtain the vibration information of the nanofilm, and find the resonance peaks of the nanofilm gas sensor from the spectrum.
[0049] 22) By applying a single-tone signal at the peak frequency to the piezoelectric element to excite the vibration of the nanofilm gas sensor, the vibration signal of the current nanofilm gas sensor is measured with a laser Doppler vibrometer to obtain the vibration information of the nanofilm. The mode shapes under different excitation frequencies are analyzed to determine the first natural frequency of the nanofilm.
[0050] 3) Excite the nanofilm gas sensor using thermal vibration method; measure the first natural frequency of the nanofilm under different gas pressures, and calculate the current gas pressure based on the offset of the first natural frequency of the nanofilm to realize gas pressure sensing.
[0051] Specifically, step 3) includes:
[0052] 31) Adjust the air pressure in the vacuum chamber and use a laser Doppler vibration meter to measure the thermal vibration signal of the nanofilm gas sensor under different air pressures;
[0053] 32) The first natural frequency of the nanofilm under the current air pressure is measured, and the current air pressure is calculated based on the offset between the first natural frequency of the nanofilm and the first natural frequency under atmospheric pressure, thus realizing air pressure sensing.
[0054] This invention achieves air pressure sensing by using a simpler sensor structure, optimizing the excitation method, and using ambient white noise to excite the thermal vibration of the nanofilm gas sensor. Under different air pressure environments, the shift of the first-order natural frequency of the nanofilm gas sensor is measured to infer the air pressure.
[0055] Furthermore, this invention also provides a method for fabricating a thermally excited nanofilm gas sensor, the steps of which are as follows:
[0056] Design a nanofilm gas sensor structure and fabricate a patterned substrate;
[0057] Nanofilms were prepared by mechanical exfoliation or chemical vapor deposition and then transferred to the surface of blue adhesive.
[0058] A polyvinyl alcohol water-soluble layer is spin-coated onto a silicon wafer and heated on a hot plate. Polymethyl methacrylate is spin-coated onto the heated silicon wafer, and the spin-coated silicon substrate is heated again on a hot plate. Blue adhesive with nanofilm attached is tightly adhered to the surface of the silicon wafer and placed on a hot plate. After heating, the blue adhesive is peeled off to transfer the nanofilm onto the silicon wafer.
[0059] The position of the nanofilm is located using an optical microscope, the water-soluble layer is dissolved, and the nanofilm is transferred to the prepared patterned substrate to form a cavity between the nanofilm and the patterned substrate.
[0060] The fabricated nanofilm gas sensor was vacuum annealed at 400℃.
[0061] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.
Claims
1. A resonant gas sensing and detection method based on thermal excitation, characterized in that, Includes the following steps: 1) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise; 2) Measure the vibration signal of the nanofilm gas sensor to obtain the vibration information of the nanofilm, and then use a piezoelectric element to excite the nanofilm gas sensor at a single frequency to obtain the first natural frequency of the nanofilm. 3) Excite the nanofilm gas sensor using thermal vibration method; measure the first natural frequency of the nanofilm under different gas pressures, and calculate the current gas pressure based on the offset of the first natural frequency of the nanofilm to realize gas pressure sensing.
2. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, The nanofilm gas sensor consists of a patterned substrate and a nanofilm, with the nanofilm covering the patterned substrate.
3. The resonant gas sensing and detection method based on thermal excitation according to claim 2, characterized in that, The patterned substrate surface has recesses, and a nanofilm is disposed on the recesses, forming an airtight cavity between the recesses and the nanofilm.
4. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, The patterned substrate is made of Si or SiO2.
5. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, The nanofilm is made of a two-dimensional material, and the thickness of the two-dimensional material does not exceed 100 nanometers.
6. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, Step 1) specifically includes: 11) Place the nanofilm gas sensor on a piezoelectric element and place it in an adjustable vacuum chamber to keep the pressure inside the vacuum chamber consistent with the atmospheric pressure. 12) Excite the nanofilm gas sensor by using thermal vibrations excited by ambient white noise.
7. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, Step 2) specifically includes: 21) Use a laser Doppler vibrometer to measure the thermal vibration signal of the nanofilm gas sensor under atmospheric pressure, obtain the vibration information of the nanofilm, and find the resonance peaks of the nanofilm gas sensor from the spectrum. 22) By applying a single-tone signal at the peak frequency to the piezoelectric element to excite the vibration of the nanofilm gas sensor, the vibration signal of the current nanofilm gas sensor is measured with a laser Doppler vibrometer to obtain the vibration information of the nanofilm. The mode shapes under different excitation frequencies are analyzed to determine the first natural frequency of the nanofilm.
8. The resonant gas sensing and detection method based on thermal excitation according to claim 1, characterized in that, Step 3) specifically includes: 31) Adjust the air pressure in the vacuum chamber and use a laser Doppler vibration meter to measure the thermal vibration signal of the nanofilm gas sensor under different air pressures; 32) The first natural frequency of the nanofilm under the current air pressure is measured, and the current air pressure is calculated based on the offset between the first natural frequency of the nanofilm and the first natural frequency under atmospheric pressure, thus realizing air pressure sensing.