Near-zero temperature coefficient flexible high-temperature strain sensor and preparation method thereof
By preparing a near-zero temperature coefficient flexible high-temperature strain sensor, the problem of insufficient temperature drift and stability of the sensor in high-temperature environment is solved, and high-sensitivity strain monitoring is achieved over a wide temperature range, which is suitable for high-temperature environments such as aerospace.
Patent Information
- Application Number
- CN202510489992.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-08-08
AI Technical Summary
Existing high-temperature strain sensors have problems such as significant temperature drift, insufficient stability and high cost in high temperature environments, making it difficult to achieve accurate strain monitoring in aerospace and other fields.
A composite heterogeneous material powder and flexible substrate material are used to prepare a near-zero temperature coefficient flexible high-temperature strain sensor through screen printing process, and a metal precursor salt is reduced at high temperature to form a metal/metal oxide heterostructure. Combined with the surface modification technology of flexible substrate material, the temperature self-compensation effect is achieved.
Maintain excellent temperature stability and mechanical flexibility in the range of -50°C to 400°C, and has fast response and high resolution strain monitoring capabilities, which are suitable for long-term strain monitoring in high-temperature environments.
Smart Images
Figure CN120445022A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of nanomaterials, and in particular relates to a near-zero temperature coefficient flexible high-temperature strain sensor and a preparation method thereof. Background Art
[0002] Strain sensors are sensors that convert changes in an object's strain into electrical signals. They are widely used in a wide range of fields, including aerospace, automotive manufacturing, civil engineering, and health monitoring. With the continuous advancement of technology, the performance requirements for strain sensors are becoming increasingly higher, especially for strain sensors operating in high-temperature environments.
[0003] Traditional strain sensors are mostly made of materials such as metal foil strain gauges or semiconductor strain gauges. These sensors function well at room temperature, but their performance is significantly affected in high-temperature environments. Thermal stress and thermal expansion at high temperatures cause significant signal drift, affecting the accuracy of strain measurements and often requiring the use of complex compensation circuits. Furthermore, these traditional strain sensors are mostly rigid structures, limiting their applicability in applications requiring conformity to complex curved surfaces or flexible substrates.
[0004] In recent years, research on flexible strain sensors has made significant progress. Flexible strain sensors typically utilize a flexible substrate material with a sensitive layer fabricated on top to achieve highly sensitive strain detection. However, the performance of most current flexible strain sensors in high-temperature environments remains unsatisfactory. For one thing, the flexible substrate material may thermally deform or chemically degrade at high temperatures, resulting in structural damage or performance degradation of the sensor. Furthermore, the sensitive layer material also struggles to maintain stable electrical properties at high temperatures, often exhibiting a large temperature coefficient. The temperature coefficient refers to the sensitivity of the sensor's output signal to changes in ambient temperature. A large temperature coefficient means that the sensor's measurements at different temperatures will be significantly affected by temperature fluctuations, making it difficult to accurately reflect the true strain state. Furthermore, high-temperature sensors often rely on vacuum coating, photolithography, or chemical vapor deposition (CVD) processes, which are costly.
[0005] In summary, the performance of strain sensors in the prior art in high-temperature environments has many deficiencies, such as poor measurement accuracy, low reliability, and a large temperature coefficient. These problems limit the widespread application of strain sensors in high-temperature fields, especially in fields such as aerospace and automotive engine monitoring that have extremely high requirements for high-temperature performance. Therefore, developing a method for preparing a strain sensor that can work stably in a high-temperature environment, has a near-zero temperature coefficient, and has good flexibility is of great significance for meeting the needs of modern industrial and technological development. The present invention is based on the above-mentioned deficiencies in the prior art and aims to provide a near-zero temperature coefficient flexible high-temperature strain sensor and a preparation method thereof to effectively solve the above-mentioned problems and meet the growing demand for high-temperature strain measurement. Summary of the Invention
[0006] The purpose of the present invention is to provide a flexible high-temperature strain sensor with a near-zero temperature coefficient and a preparation method thereof, so as to overcome the technical barriers of existing high-temperature strain sensors such as significant temperature drift, insufficient stability and high cost, and provide a reliable solution for precise strain monitoring in extreme environments.
[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0008] A method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor, the method comprising preparing a printing ink: the raw materials for preparing the printing ink include composite heterogeneous material powder, and the dissolving medium is a mixture of a polymer and an organic solvent; the composite heterogeneous material is obtained by high-temperature treatment of a metal precursor salt, and the high-temperature treatment atmosphere is a mixture of hydrogen and argon in a volume ratio of 1:1; the high-temperature temperature is 700-900°C; the printing ink is printed on the surface of a substrate using a screen printing process to achieve patterning, and the printed pattern is subjected to solvent evaporation and sintering and solidification treatment.
[0009] Optionally, the metal precursor salt is selected from at least one of ammonium molybdate, ammonium tungstate, ammonium niobate and hydrated niobium oxalate.
[0010] Optionally, the polymer is at least one of ethyl cellulose, polyvinyl pyrrolidone and hydroxymethyl cellulose, and the organic solvent is at least one of ethylene glycol, terpineol, ethanol and isopropyl alcohol.
[0011] Optionally, the mass fraction of the composite heterogeneous material powder in the dissolution medium is 60% to 70%.
[0012] Optionally, the particle diameter of the composite heterogeneous material powder is 10 to 50 μm.
[0013] Optionally, the hydrogen flow rate is 40 to 80 sccm, and the argon flow rate is 40 to 80 sccm.
[0014] Optionally, the substrate is mica, polyimide or ceramic; and the substrate is plasma cleaned before screen printing, with a plasma cleaning power of 20 to 90 W and a cleaning time of 100 to 500 s.
[0015] Optionally, the mesh size of the screen printing plate is 100 to 400 meshes, the screen printing scraper pressure is 0.4 MPa, and the scraper speed is 0.5 m / s.
[0016] Optionally, the solvent evaporation and sintering solidification treatment includes: introducing argon as the protective gas and the annealing temperature is 300-600°C.
[0017] A near-zero temperature coefficient flexible high-temperature strain sensor is prepared using any method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor described in the present invention.
[0018] The advantages of the present invention are:
[0019] 1. By employing a unique material combination and fabrication process, this invention successfully achieves a strain sensor with a near-zero temperature coefficient. In high-temperature environments, the sensor's output signal is virtually unaffected by temperature fluctuations, accurately reflecting the true strain state of the object being measured.
[0020] 2. The strain sensor of the present invention has excellent flexibility and can adapt to substrates with various complex shapes and curved surfaces. It can maintain stable electrical performance under deformation conditions such as bending and stretching, greatly expanding its application range.
[0021] 3. The strain sensor of the present invention exhibits high sensitivity over a wide temperature range and can respond quickly to tiny strain changes, thereby achieving high-precision strain measurement.
[0022] 4. The preparation method of the present invention is simple and efficient, and can be used for large-scale production. By adopting mature material preparation technology and process flow, the production cost is reduced and the production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to more clearly illustrate the content of the present invention, it is described in detail below with reference to the accompanying drawings and specific embodiments.
[0024] Figure 1 This is the X-ray diffraction spectrum of the composite heterogeneous material prepared in Example 1;
[0025] Figure 2 This is a graph of the temperature coefficient of resistance of the composite heterogeneous material prepared in Example 1;
[0026] Figure 3 The sensor printing pattern drawn in Example 1;
[0027] Figure 4 This is a physical picture of the flexible high-temperature strain sensor prepared in Example 1;
[0028] Figure 5 This is the room temperature strain response diagram of the flexible high-temperature strain sensor prepared in Example 2;
[0029] Figure 6 This is the high-temperature strain response diagram of the flexible high-temperature strain sensor prepared in Example 2;
[0030] Figure 7 This is the X-ray diffraction spectrum of the pure MoO2 material prepared in Example 3;
[0031] Figure 8 The temperature coefficient of resistance of the materials prepared in Examples 3 and 4 is shown;
[0032] Figure 9 This is the X-ray diffraction spectrum of the pure Mo material prepared in Example 4; DETAILED DESCRIPTION
[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that for ordinary persons in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.
[0034] The present invention discloses a flexible high-temperature strain sensor with a near-zero temperature coefficient and a method for preparing the same. To address the technical shortcomings of existing high-temperature strain sensors, such as significant temperature drift and poor flexibility and adaptability, the present invention proposes a method for preparing a flexible strain sensor based on a screen printing patterning process by designing a heterogeneous composite sensitive layer structure with temperature self-compensation properties and combining it with flexible substrate material surface modification technology. Specifically, the method comprises: obtaining a metal / metal oxide heterogeneous composite material through high-temperature reduction of a metal precursor salt, wherein the temperature resistance responses of the material offset each other to achieve a temperature self-compensation effect. A suitable high-temperature-resistant film is selected as the flexible substrate, and the near-zero temperature coefficient material is patterned using a screen printing process to prepare a flexible high-temperature strain sensor. The sensor prepared by this method has a simple structure and low cost, and exhibits excellent temperature stability, mechanical flexibility, and high-temperature durability in the range of -50°C to 400°C. Furthermore, it exhibits rapid strain response and high resolution, making it suitable for long-term strain monitoring in high-temperature environments such as battery thermal failure, aircraft engine blades, and nuclear reactor components.
[0035] To overcome the technical barriers of existing high-temperature strain sensors, such as significant temperature drift, insufficient stability, and high cost, and to provide a reliable solution for precise strain monitoring in extreme environments, this invention provides a near-zero temperature coefficient flexible high-temperature strain sensor and its preparation method. This sensor is resistant to temperature interference and offers advantages such as flexibility, high sensitivity, a wide operating temperature range, a simple preparation process, and low cost.
[0036] Specifically, the near-zero temperature coefficient flexible high-temperature strain sensor and its preparation method include the following processes:
[0037] Step 1: Selection of high temperature resistant metal precursor salt
[0038] High-temperature resistant metal precursor salts are key materials for preparing high-temperature strain sensors. Their selection directly impacts the sensor's conductivity and high-temperature stability. This invention uses one of the high-temperature resistant metal precursor salts, such as ammonium molybdate, ammonium tungstate, ammonium niobate, or hydrated niobium oxalate, as the conductive material precursor.
[0039] Step 2: High temperature reduction of metal precursor salt
[0040] The selected high-temperature resistant metal precursor salt is subjected to high-temperature reduction treatment to obtain a pure metal and metal oxide composite heterogeneous material. The specific operation is as follows:
[0041] The precursor salt is placed in a tube furnace and a mixture of hydrogen and argon is introduced at a 1:1 ratio. The hydrogen flow rate is controlled between 40 and 80 sccm, and the argon flow rate is also controlled between 40 and 80 sccm. The hydrogen acts as a reducing agent, reducing the metal precursor salt to pure metal, while the argon acts as an inert gas, providing a stable reaction environment and preventing oxidation.
[0042] The tube furnace is heated to a high temperature range of 700-900°C to carry out a high-temperature reduction reaction. Within this temperature range, the metal precursor salt gradually decomposes and is reduced to pure metal. Simultaneously, some metal oxides and pure metals form a composite heterostructure. This composite heterostructure exhibits excellent electrical conductivity and high-temperature stability, providing an ideal material foundation for the fabrication of strain sensors.
[0043] Step 3: Substrate surface treatment
[0044] In order to improve the adhesion and compatibility between the strain sensor and the substrate, the substrate surface is processed. The specific operations are as follows:
[0045] Choose high-temperature resistant flexible materials as substrates, such as mica, polyimide, ceramics, etc. These materials have good flexibility and high-temperature stability, which can meet the requirements of strain sensors for use in high-temperature environments.
[0046] The substrate surface was treated with UV / ozone plasma to adjust the surface energy. The plasma cleaning power was set between 20 and 90 W, and the cleaning time was between 100 and 500 seconds. UV / ozone plasma treatment effectively removes organic contaminants and oxide layers from the substrate surface, increasing the number of active sites on the substrate surface. This improves the adhesion and compatibility between the strain sensor and the substrate, ensuring stable sensor adhesion and good performance.
[0047] Step 4: Printing the Design
[0048] Based on the substrate size and the design requirements of the strain sensor, use drawing software to design the conductive path of the strain sensor and make a screen printing plate. The specific steps are as follows:
[0049] Considering the substrate dimensions, use professional drawing software to design the strain sensor's conductive path. The design of the conductive path should fully consider factors such as the sensor's sensitivity, response speed, and stability to ensure that the sensor can accurately and quickly detect strain changes.
[0050] The designed conductive path pattern is made into a screen printing plate. The mesh size of the screen printing plate is selected to be between 100 and 400. The mesh size of the screen printing plate directly affects the accuracy and resolution of the printed pattern. Choosing the appropriate mesh size ensures accurate printing of the conductive path and improves the performance and reliability of the strain sensor.
[0051] Step 5: Preparation of printing ink ingredients
[0052] Prepare ink suitable for screen printing to achieve precise printing of the conductive path of the strain sensor. The specific steps are as follows:
[0053] The pure metal and metal oxide composite heterogeneous material obtained by high-temperature reduction is ground into powder. The grinding process must ensure uniform powder particle size to ensure ink stability and printing quality. The metal powder particle size is controlled at the micron level, with a particle diameter of 10 to 50 μm.
[0054] The metal powder is dispersed in a mixture of polymer and organic solvent, such as a mixture of ethyl cellulose, polyvinyl pyrrolidone, ethylene glycol, and terpineol. The polymer acts as a binder for the ink, improving its adhesion and stability, while the organic solvent adjusts its viscosity and fluidity.
[0055] Ethanol is used to adjust the viscosity of the ink to meet the requirements for screen printing. The viscosity of the ink directly affects the accuracy and uniformity of the printed pattern. By adjusting the amount of ethanol used, the viscosity of the ink can be precisely controlled to ensure a smooth printing process and the quality of the printed pattern.
[0056] Step 6: Screen Printing
[0057] The prepared ink is printed on the substrate through a screen printing plate to achieve patterning. The specific operation is as follows:
[0058] Place the prepared ink evenly on the screen printing plate, ensuring that the ink can fully cover the conductive path pattern on the plate.
[0059] Screen printing equipment is used for printing. During the printing process, the screen printing scraper pressure is controlled at 0.4MPa and the scraper speed is controlled at 0.5m / s. Precise control of scraper pressure and speed ensures uniform transfer of ink onto the substrate, forming a clear and accurate conductive path pattern.
[0060] After printing is completed, the substrate with the printed conductive path is dried to remove the solvent in the ink and form a stable conductive pattern.
[0061] Step 7: High temperature annealing and sintering of the sensor
[0062] The printed pattern is subjected to high-temperature annealing and sintering treatment to achieve final solidification and performance optimization of the sensor. The specific operations are as follows:
[0063] According to the curing and sintering temperature of the selected material, the appropriate post-processing process parameters are formulated. Argon is used as the protective gas to prevent oxidation of the conductive material during the high-temperature sintering process.
[0064] The substrate printed with the conductive path is placed in a high-temperature furnace and heated to an annealing temperature range of 300-600°C. Within this temperature range, the conductive material undergoes a sintering reaction, forming good conductive contact between the particles and further solidifying and stabilizing the substrate material. After annealing, the sensor is naturally cooled to room temperature, resulting in a flexible, high-temperature strain sensor with a near-zero temperature coefficient and excellent performance.
[0065] The following describes in detail a method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor through specific implementation methods.
[0066] Example 1:
[0067] This embodiment provides a method for preparing a flexible high-temperature strain sensor with a near-zero temperature coefficient. The specific implementation steps are as follows:
[0068] Step 1: High temperature reduction of metal precursor salt
[0069] Weigh 0.5g of ammonium molybdate salt into a quartz boat, place it in a tube furnace, and introduce a mixture of hydrogen and argon at a ratio of 1:1. The hydrogen and argon flow rates are controlled at 60 sccm, and the argon flow rates are also controlled at 60 sccm.
[0070] Heat the tube furnace to 710℃ for high temperature reduction reaction. Within this temperature range, ammonium molybdate gradually decomposes and is reduced to a composite heterostructure of Mo and MoO2. The XRD analysis results are as follows: Figure 1 This composite heterogeneous material has excellent electrical conductivity and an extremely low temperature coefficient, with a resistance change rate of only 0.011 within 300°C. Figure 2 As shown, it provides a material basis for the preparation of strain sensors.
[0071] Step 3: Substrate surface treatment
[0072] A 50 μm thick mica substrate was selected, which has good flexibility and high-temperature stability. The surface of the mica substrate was treated with UV / ozone plasma, with the plasma cleaning power set at 80 W and the cleaning time set at 500 seconds.
[0073] Step 4: Printing the Design
[0074] Considering the size of the mica substrate, the conductive path of the strain sensor was designed using drawing software, such as Figure 3 As shown in the figure, the designed conductive path pattern is made into a screen printing plate. The mesh count of the screen printing plate is selected to be 200 mesh.
[0075] Step 5: Preparation of printing ink ingredients
[0076] The Mo and MoO2 composite heterogeneous material obtained by high-temperature reduction is ground into a powder. The grinding process ensures uniform powder particle size to ensure ink stability and printing quality. 0.12g of the metal powder is dispersed in a mixed solvent of 0.03g of ethyl cellulose and terpineol (the mass ratio of ethyl cellulose to terpineol is 1:9). 0.02-0.04g of ethanol is used to adjust the ink viscosity to meet screen printing requirements.
[0077] Step 6: Screen Printing
[0078] The prepared ink is evenly applied to the screen printing plate, ensuring that the ink fully covers the conductive path pattern on the plate. Screen printing equipment is used for printing. During the printing process, the screen printing scraper pressure is controlled at 0.4 MPa and the scraper speed is controlled at 0.5 m / s. Precise control of scraper pressure and speed ensures uniform transfer of ink to the substrate, forming a clear and accurate conductive path pattern. After printing, the substrate with the printed conductive path is dried at 80°C for 20 minutes to remove the solvent from the ink and form a stable conductive pattern.
[0079] Step 7: High temperature annealing and sintering of the sensor
[0080] The printed sensor was placed in a high-temperature furnace and heated to 400°C for annealing. After annealing, the sensor was naturally cooled to room temperature to obtain a flexible high-temperature strain sensor with a near-zero temperature coefficient and good performance. Figure 4 shown.
[0081] Example 2:
[0082] This embodiment provides a method for preparing a flexible high-temperature strain sensor with a near-zero temperature coefficient. The specific implementation steps are as follows:
[0083] Step 1: High temperature reduction of metal precursor salt
[0084] Weigh 0.5g of ammonium tungstate salt into a quartz boat, place it in a tube furnace, and introduce a mixture of hydrogen and argon at a ratio of 1:1. The hydrogen flow rate is controlled at 80sccm, and the argon flow rate is also controlled at 80sccm.
[0085] The tube furnace is heated to 850°C for high-temperature reduction. Within this temperature range, ammonium molybdate gradually decomposes and is reduced to a W-WO2 composite heterostructure.
[0086] Step 3: Substrate surface treatment
[0087] A 100-μm-thick polyimide substrate was selected, which has excellent flexibility and high temperature stability. The surface of the polyimide substrate was treated with UV / ozone plasma, with the plasma cleaning power set at 80 W and the cleaning time set at 600 seconds.
[0088] Step 4: Printing the Design
[0089] Considering the dimensions of the polyimide substrate, the conductive path of the strain sensor was designed using drawing software, such as Figure 3 As shown in the figure, the designed conductive path pattern is made into a screen printing plate. The mesh count of the screen printing plate is selected to be 200 mesh.
[0090] Step 5: Preparation of printing ink ingredients
[0091] The W-WO2 composite heterogeneous material obtained by high-temperature reduction is ground into a powder. The grinding process ensures uniform powder particle size to ensure ink stability and printing quality. 0.12g of the metal powder is dispersed in a mixed solvent of 0.03g of polyvinyl pyrrolidone and terpineol (polyvinyl pyrrolidone:terpineol mass ratio of 1:9). 0.02-0.04g of ethanol is used to adjust the ink viscosity to meet screen printing requirements.
[0092] Step 6: Screen Printing
[0093] The prepared ink is evenly applied to the screen printing plate, ensuring that the ink fully covers the conductive path pattern on the plate. Screen printing equipment is used for printing. During the printing process, the screen printing scraper pressure is controlled at 0.4 MPa and the scraper speed is controlled at 0.5 m / s. Precise control of scraper pressure and speed ensures uniform transfer of ink to the substrate, forming a clear and accurate conductive path pattern. After printing, the substrate with the printed conductive path is dried at 80°C for 20 minutes to remove the solvent from the ink and form a stable conductive pattern.
[0094] Step 7: High temperature annealing and sintering of the sensor
[0095] The printed sensor was placed in a high-temperature furnace and heated to an annealing temperature of 450°C. After annealing, the sensor was naturally cooled to room temperature to obtain a flexible high-temperature strain sensor with a near-zero temperature coefficient and good performance. The room-temperature strain performance was as follows: Figure 5 As shown in Figure 2, the high temperature strain properties are as follows: Figure 6 At room temperature and high temperature, as the strain increases, the resistance decreases regularly, and the monitoring results are accurate and the response is rapid.
[0096] Example 3 (comparative example):
[0097] This embodiment provides a method for preparing a flexible high-temperature strain sensor with a near-zero temperature coefficient. The specific implementation steps are as follows:
[0098] Weigh 0.5g of ammonium molybdate salt into a quartz boat, place it in a tube furnace, and introduce a mixture of hydrogen and argon at a ratio of 1:1. The hydrogen and argon flow rates are controlled at 60 sccm, and the argon flow rates are also controlled at 60 sccm.
[0099] Heat the tube furnace to 600°C to perform high-temperature reduction reaction. (Other conditions are the same as in Example 1)
[0100] Within this temperature range, ammonium molybdate gradually decomposes and is reduced to pure MoO2 material. The XRD analysis results are as follows: Figure 7 This material has a high temperature coefficient, and its resistance change rate reaches more than 0.3 within 400℃, as shown in Figure 8 As shown, it cannot be used as a near-zero temperature coefficient material.
[0101] Example 4 (comparative example):
[0102] This embodiment provides a method for preparing a flexible high-temperature strain sensor with a near-zero temperature coefficient. The specific implementation steps are as follows:
[0103] Weigh 0.5g of ammonium molybdate salt into a quartz boat, place it in a tube furnace, and introduce a mixture of hydrogen and argon at a ratio of 1:1. The hydrogen and argon flow rates are controlled at 60 sccm, and the argon flow rates are also controlled at 60 sccm.
[0104] Heat the tube furnace to 1000°C to perform high-temperature reduction reaction. (Other conditions are the same as in Example 1)
[0105] Within this temperature range, ammonium molybdate gradually decomposes and is reduced to pure Mo material. The XRD analysis results are as follows: Figure 9 This material has a high temperature coefficient, and its resistance change rate is below -0.3 within 400℃, as shown in Figure 8 As shown, it cannot be used as a near-zero temperature coefficient material.
[0106] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor, characterized in that: The method comprises preparing a printing ink: the raw materials for preparing the printing ink include composite heterogeneous material powder, and the dissolving medium is a mixture of a polymer and an organic solvent; The composite heterogeneous material is obtained by treating a metal precursor salt at a high temperature in an atmosphere of a mixture of hydrogen and argon with a volume ratio of 1:1; the high temperature temperature is 700-900°C; The printing ink is printed on the surface of the substrate by using a screen printing process to achieve patterning, and the printed pattern is subjected to solvent evaporation and sintering curing treatment.
2. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1, characterized in that: The metal precursor salt is selected from at least one of ammonium molybdate, ammonium tungstate, ammonium niobate and hydrated niobium oxalate.
3. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The polymer is at least one of ethyl cellulose, polyvinyl pyrrolidone and hydroxymethyl cellulose, and the organic solvent is at least one of ethylene glycol, terpineol, ethanol and isopropyl alcohol.
4. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The mass fraction of the composite heterogeneous material powder in the dissolving medium is 60% to 70%.
5. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The particle diameter of the composite heterogeneous material powder is 10 to 50 μm.
6. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The hydrogen flow rate is 40 to 80 sccm, and the argon flow rate is 40 to 80 sccm.
7. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The substrate is mica, polyimide or ceramic; Before screen printing, the substrate is also plasma cleaned, with a plasma cleaning power of 20 to 90 W and a cleaning time of 100 to 500 seconds.
8. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The mesh number of the screen printing plate is 100 to 400 meshes, the screen printing scraper pressure is 0.4 MPa, and the scraper speed is 0.5 m / s.
9. The method for preparing a near-zero temperature coefficient flexible high-temperature strain sensor according to claim 1 or 2, characterized in that: The solvent evaporation and sintering solidification process includes: The protective gas introduced is argon, and the annealing temperature is 300-600°C.
10. A near-zero temperature coefficient flexible high-temperature strain sensor, characterized in that: The sensor is prepared by the preparation method of the near-zero temperature coefficient flexible high-temperature strain sensor according to any one of claims 1 to 9.