Flexible temperature sensor suitable for extreme high-temperature environment and preparation method thereof

Abstract

The invention discloses a flexible temperature sensor suitable for an extreme high-temperature environment and a preparation method thereof, the sensor structure comprises a high-temperature-resistant flexible substrate, the high-temperature-resistant flexible substrate is made of a flexible heat-insulation composite material, and the flexible heat-insulation composite material comprises a pre-oxidized fiber film, an aerogel felt or transparent mica; the thermocouple temperature sensitive layer is arranged on the surface of the high-temperature-resistant flexible substrate, and the preparation material of the thermocouple sensitive layer comprises indium oxide, indium tin oxide or indium zinc oxide; wherein the thickness of the high-temperature-resistant flexible substrate is 1-3 mm, and the thickness of the thermocouple temperature sensitive layer is 10-30 microns. The flexible heat-insulating composite material has excellent high-temperature resistance and can keep structural stability and integrity in an extremely high-temperature environment, and the high-temperature-resistant flexible substrate made of the flexible heat-insulating composite material has extremely high heat resistance and has no obvious change in physical properties in a high-temperature environment of 1000 DEG C or above. Good flexibility and stability are still realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature sensors, and in particular relates to a flexible temperature sensor suitable for an extreme high temperature environment and a preparation method thereof. Background Art

[0002] Temperature is an important parameter for object characterization and environmental perception. With the rapid development of artificial intelligence and Internet of Things technologies, the large size and poor flexibility of traditional temperature sensors are no longer suitable for the current diversified application scenarios. Flexible temperature sensors, based on the bendability, stretchability and wearability of flexible materials, are made through micro-nano processing technology and have a wider range of application scenarios. They have important application value in medical health monitoring, environmental monitoring, wearable devices, aerospace and other fields.

[0003] The key to flexible temperature sensors lies in the manufacture of temperature-sensitive layers and flexible substrates. In terms of material selection, the sensitive layer materials of flexible temperature sensors are generally made of metal films, and the flexible substrate materials are mostly made of polymer composite materials such as polyimide. Limited by the preparation process and materials, the current contact-type flexible temperature sensors have an upper limit of measuring temperature below 800°C, and the melting point of the flexible substrate is generally below 400°C, which makes them difficult to use at high temperatures, limiting their application in extreme high-temperature environments such as metallurgy, geocentric exploration, and aerospace. Summary of the invention

[0004] The purpose of the present invention is to provide a flexible temperature sensor suitable for extremely high temperature environments and a preparation method thereof, so as to solve the technical defects of the existing contact-type flexible temperature sensor, which is limited by the preparation process and materials, and has an upper limit of measuring temperature below 800°C and a melting point of the flexible substrate generally below 400°C, making it difficult to use at high temperatures, thus limiting its application in extremely high temperature environments such as metallurgy, geocentric exploration, aerospace, etc.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, a flexible temperature sensor suitable for an extreme high temperature environment is provided, characterized in that it comprises: A high temperature resistant flexible substrate, which is made of a flexible thermal insulation composite material, wherein the flexible thermal insulation composite material includes a pre-oxidized silk film, an aerogel felt or transparent mica; A thermocouple temperature sensitive layer is arranged on the surface of the high temperature resistant flexible substrate, and the preparation material of the thermocouple sensitive layer includes indium oxide, indium tin oxide or indium zinc oxide; Wherein, the thickness of the high temperature resistant flexible substrate is 1-3 mm, and the thickness of the thermocouple temperature sensitive layer is 10-30 um.

[0006] Furthermore, the preparation material of the thermocouple sensitive layer also includes cellulose, epoxy resin, pinene alcohol or polyetheramine.

[0007] Furthermore, the thermocouple temperature sensitive layer comprises a heating end and a cooling end, and the heating end is in direct contact with the cooling end.

[0008] Furthermore, the heating end and the cooling end are connected via a honeycomb mortise and tenon structure.

[0009] Furthermore, the heating end and the cooling end are made of different materials.

[0010] Furthermore, the sensitivity of the thermocouple temperature sensitive layer is not less than -200 μV / C.

[0011] Furthermore, the cross section of the high temperature resistant flexible substrate is rectangular.

[0012] Furthermore, the thermocouple temperature sensitive layer is a structure with one end open and the other end closed.

[0013] In a second aspect, a method for preparing the flexible temperature sensor suitable for an extreme high temperature environment is provided, comprising: Preparation of high temperature resistant flexible substrate; Prepare slurry, and print a sensitive layer film on the prepared high temperature resistant flexible substrate through a screen printing process to obtain a flexible temperature sensor; The obtained flexible temperature sensor is subjected to a high temperature treatment for 120 minutes to thermally activate the sensitive layer electrode material in the flexible temperature sensor.

[0014] Furthermore, after thermally activating the sensitive layer electrode material in the flexible temperature sensor, the method further comprises: The flexible substrate was heat treated at 700 degrees Celsius for 20 hours, and its macroscopic morphology and microstructure were observed by comparing it with the same flexible substrate at room temperature; Using an alcohol lamp, the flexible temperature sensor is heated at 700 to 800 degrees Celsius, and the airflow of a butane spray gun is used to heat the flexible temperature sensor; The flexible temperature sensor is calibrated and tested using a high and low temperature chamber and a muffle furnace as heat sources.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The flexible thermal insulation composite material itself has excellent high temperature resistance and can maintain structural stability and integrity in extremely high temperature environments. The high temperature resistant flexible substrate made of flexible thermal insulation composite material has extremely strong heat resistance. Its physical properties do not change significantly in high temperature environments above 1000°C, and it still has good flexibility and stability. Secondly, the thermocouple temperature sensitive layer is made of ceramic powders such as indium oxide, indium tin oxide or indium zinc oxide as the main material, and can perform temperature detection in an ultra-wide temperature range of -196°C to 1300°C. The repeatability error is within ±1.72%, and the sensitivity is not less than -200μV / C. The sensitive layer film is prepared on the surface of the high temperature resistant flexible substrate through screen printing technology to prepare an ultra-soft, ultra-thin, and ultra-light flexible temperature sensor, which fills the gap in high temperature detection of flexible temperature sensors. The sensor has a simple structure and can be mass-produced at low cost.

[0016] 2. Cellulose, epoxy resin, pine alcohol or polyether amine can help improve the sensitivity, stability, durability and measurement accuracy of the thermocouple sensitive layer.

[0017] 3. The heating end is in direct contact with the cooling end, so that heat can be quickly transferred from the heating end to the cooling end, thereby speeding up the response speed of the thermocouple.

[0018] 4. The heating end and the cooling end are connected by a honeycomb mortise and tenon structure, which achieves direct contact between the two, thereby providing a more direct and efficient heat conduction path, which helps to improve the response speed and measurement accuracy of the thermocouple.

[0019] 5. The selection of different materials can achieve complementary performance. The high thermal conductivity of the heating end can ensure rapid temperature response, while the high heat dissipation of the cooling end can maintain the long-term stability of the thermocouple.

[0020] 6. High sensitivity helps reduce errors in the measurement process. When the temperature changes, the thermocouple can respond more quickly and output the corresponding electrical signal, thereby improving the accuracy of the measurement.

[0021] 7. The design of rectangular cross-section can be optimized for specific heat conduction requirements. At the same time, by adjusting the size and proportion of the cross-section, more efficient heat conduction or insulation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic diagram of the overall structure of a flexible temperature sensor suitable for an extreme high temperature environment provided by the present invention; Figure 2 A schematic diagram of the planar structure of a flexible temperature sensor suitable for an extreme high temperature environment provided by the present invention; Figure 3 A fitting graph of the temperature-sensitive characteristics of the flexible temperature sensor suitable for extreme high temperature environments provided by the present invention; Figure 4 A flow chart of a method for preparing a flexible temperature sensor suitable for an extreme high temperature environment provided by the present invention; Among them: 1. High temperature resistant flexible substrate; 2. Thermocouple temperature sensitive layer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] Temperature is an important parameter for object characterization and environmental perception. With the rapid development of artificial intelligence and Internet of Things technologies, the large size and poor flexibility of traditional temperature sensors are no longer suitable for the current diversified application scenarios. Flexible temperature sensors, based on the bendability, stretchability and wearability of flexible materials, are made through micro-nano processing technology and have a wider range of application scenarios. They have important application value in medical health monitoring, environmental monitoring, wearable devices, aerospace and other fields.

[0030] The key to flexible temperature sensors lies in the manufacture of temperature-sensitive layers and flexible substrates. In terms of material selection, the sensitive layer materials of flexible temperature sensors are generally made of metal films, and the flexible substrate materials are mostly made of polymer composite materials such as polyimide. Limited by the preparation process and materials, the current contact-type flexible temperature sensors have an upper limit of measuring temperature below 800°C, and the melting point of the flexible substrate is generally below 400°C, which makes them difficult to use at high temperatures, limiting their application in extreme high-temperature environments such as metallurgy, geocentric exploration, and aerospace.

[0031] In order to solve the above technical defects, the inventor provides a flexible temperature sensor suitable for extreme high temperature environments and a preparation method thereof.

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1-Figure 3As shown, in an embodiment of the present invention, a first aspect provides a flexible temperature sensor suitable for an extreme high temperature environment, comprising a high temperature resistant flexible substrate 1, which is made of a flexible thermal insulation composite material, the flexible thermal insulation composite material comprises a pre-oxidized silk film, an aerogel felt or a transparent mica, the thickness of the high temperature resistant flexible substrate 1 is 1-3 mm, the high temperature resistant flexible substrate 1 has good flexibility and stability, and its properties do not change significantly at a high temperature of 1000°C, and it can withstand a high temperature of up to 1300°C; a thermocouple temperature sensitive layer 2 is arranged on the surface of the high temperature resistant flexible substrate 1, and the preparation material of the thermocouple sensitive layer 2 comprises ceramic powders such as indium oxide, indium tin oxide or indium zinc oxide; wherein, the thickness of the thermocouple temperature sensitive layer 2 is 10-30 um. In the above structural design, since the flexible thermal insulation composite material itself has excellent high temperature resistance, it can maintain structural stability and integrity in extreme high temperature environments, and the high temperature resistant flexible substrate 1 made of the flexible thermal insulation composite material has extremely strong heat resistance, and its physical properties do not change significantly in a high temperature environment above 1000°C, and it still has good flexibility and stability; secondly, the thermocouple temperature sensitive layer 2 is prepared with ceramic powders such as indium oxide, indium tin oxide or indium zinc oxide as the main material, and can perform temperature detection in an ultra-wide temperature range of -196°C to 1300°C, with a repeatability error within ±1.72%, and a sensitivity of not less than -200μV / C; a sensitive layer film is prepared on the surface of the high temperature resistant flexible substrate 1 by screen printing technology to prepare an ultra-flexible, ultra-thin, and ultra-light flexible temperature sensor, which fills the gap in high temperature detection of flexible temperature sensors, and the sensor has a simple structure, which can be mass-produced at low cost. The preparation materials of the thermocouple sensitive layer 2 also include cellulose, epoxy resin, pine alcohol or polyether amine. The application of these materials helps to improve the sensitivity, stability, durability and measurement accuracy of the thermocouple sensitive layer 2. Figure 1 and Figure 2As shown, the thermocouple temperature sensitive layer 2 includes a heating end and a cooling end, and the heating end is in direct contact with the cooling end; wherein, the heating end is in direct contact with the cooling end, so that heat can be quickly transferred from the heating end to the cooling end, thereby accelerating the response speed of the thermocouple temperature sensitive layer 2. This design enables the thermocouple temperature sensitive layer 2 to sense temperature changes more quickly and improves the real-time performance of the measurement. At the same time, the direct contact design reduces the loss of heat during the conduction process, ensures that the thermocouple temperature sensitive layer 2 can measure the temperature more accurately, and helps to improve the accuracy and reliability of the measurement. Secondly, the heating end of the thermocouple temperature sensitive layer 2 is in direct contact with the cooling end, and no additional heat conduction medium or structure is required, so that the structure of the thermocouple temperature sensitive layer 2 is more compact and simple, which not only reduces the use of materials, but also reduces the manufacturing cost. Finally, the direct contact design reduces the thermal stress caused by the temperature gradient, which helps to improve the long-term stability and reliability of the thermocouple temperature sensitive layer 2. The thermocouple temperature sensitive layer 2 can better adapt to the temperature measurement requirements under extreme environments (such as high temperature, high pressure, strong magnetic field, etc.), and improves the environmental adaptability of the sensor. Furthermore, the heating end and the cooling end are in direct contact through a honeycomb mortise and tenon structure. The honeycomb mortise and tenon structure has a unique geometric shape, which can effectively disperse stress at the connection. When the heating end or the cooling end is subjected to external pressure or tension, this structure can evenly distribute the stress to the entire connection area, thereby improving the overall strength and stability. Through the honeycomb mortise and tenon structure, the direct contact between the heating end and the cooling end is achieved, which helps to reduce the thermal resistance in the heat conduction process, so that the heat can be transferred from the heating end to the cooling end more quickly, thereby improving the heat conduction efficiency. In addition, the geometric shape of the honeycomb mortise and tenon structure helps to optimize the heat conduction path, which can make the heat flow along a more efficient path during the conduction process, thereby further improving the heat conduction efficiency. In addition, the honeycomb mortise and tenon structure does not rely on a specific material combination, so it can adapt to the heating end and the cooling end of different materials, so that the galvanic temperature sensitive layer 2 can be more flexibly applied to various environments and occasions. The honeycomb mortise and tenon structure has the characteristics of easy assembly and maintenance. During the assembly process, the heating end and the cooling end can be fixed by a simple mortise and tenon connection; during the maintenance process, the mortise and tenon structure can also be disassembled to facilitate replacement or repair. Finally, the honeycomb mortise and tenon structure can reduce the impact of thermal stress on the connection to a certain extent. Since this structure can effectively disperse stress and adapt to the expansion and contraction of materials caused by temperature changes, it can reduce the risk of damage to the connection caused by thermal stress; the tight connection achieved by the honeycomb mortise and tenon structure helps to improve the sealing of the thermocouple temperature sensitive layer 2 and prevent external contaminants from entering the thermocouple temperature sensitive layer 2 and affecting the measurement accuracy or causing damage.

[0033] In this embodiment, each heating end of the thermocouple temperature sensitive layer 2 must undergo a heating stage at 160°C for nearly 20 minutes to ensure that it is completely solidified in the vacuum drying oven. The heating end and the cooling end of the thermocouple temperature sensitive layer 2 are made of different materials. Different materials have different thermoelectric effects, that is, when there is a temperature difference at the junction of two different materials, an electromotive force will be generated. By utilizing the difference in this thermoelectric effect, the thermocouple temperature sensitive layer 2 can measure the temperature difference more accurately. In addition, the temperature response characteristics of different materials are also different. The electromotive force of one material may increase linearly with temperature, while the electromotive force of another may present a nonlinear curve. By reasonably selecting different materials, the thermocouple temperature sensitive layer 2 can have more accurate measurement values ​​within different temperature ranges. In this embodiment, by combining materials with different applicable temperature ranges, a thermocouple temperature sensitive layer 2 suitable for various extreme temperature environments can be made. Finally, the thermocouple temperature sensitive layer 2 made of different materials has different characteristics and applicable scopes, which enables the thermocouple temperature sensitive layer 2 to be applied to more diverse fields and scenarios. For example, some thermocouples are particularly suitable for high temperature and high pressure environments such as aerospace, petrochemical, etc.; while other thermocouples are more suitable for low temperature or special atmosphere environments such as medical and electronics.

[0034] In this embodiment, the thermocouple temperature sensitive layer 2 is a structure with one end open and the other end blocked. The sensitivity of the thermocouple temperature sensitive layer 2 is not less than -200μV / C, which makes the thermocouple temperature sensitive layer 2 highly sensitive to temperature changes, helps to improve the accuracy of temperature measurement, and enables the thermocouple temperature sensitive layer 2 to more accurately reflect the temperature changes of the object being measured. Secondly, the high sensitivity enables the thermocouple temperature sensitive layer 2 to measure smaller temperature changes, thereby broadening its measurement range. In some occasions that require precise temperature control, such as scientific research experiments, medical equipment, etc., this highly sensitive thermocouple temperature sensitive layer 2 can provide more reliable temperature data. Finally, the higher the sensitivity, the faster the thermocouple temperature sensitive layer 2 responds to temperature changes, which helps to capture temperature information in a rapidly changing temperature environment in a timely manner, providing strong support for real-time temperature monitoring and control. The structure of the thermocouple temperature sensitive layer 2 with one end open and the other end blocked helps to enhance the structural stability of the thermocouple temperature sensitive layer 2. The blocked end can protect the inside of the thermocouple temperature sensitive layer 2 from interference and damage from the external environment, thereby improving the durability and reliability of the thermocouple temperature sensitive layer 2. The blocked structural design helps to optimize the heat conduction path and improve the measurement efficiency and accuracy of the thermocouple temperature sensitive layer 2.

[0035] In this embodiment, the cross section of the high temperature resistant flexible substrate 1 is rectangular. The rectangular cross section design enables the high temperature resistant flexible substrate 1 to distribute these forces more evenly when subjected to external pressure or stress, thereby enhancing the stability of the high temperature resistant flexible substrate 1. This stability is particularly important for flexible temperature sensors working in extreme high temperature environments, because high temperature may cause thermal expansion and contraction of the material, increasing the risk of stress concentration. Secondly, the rectangular cross section design usually has higher strength than the circular or other irregular shapes. Under the same material thickness, the high temperature resistant flexible substrate 1 can withstand greater tensile, compressive or bending forces, thereby improving the durability and reliability of the entire flexible temperature sensor. In addition, the rectangular cross section design helps to optimize the heat conduction path, so that heat can be more efficiently transferred to the outside of the high temperature resistant flexible substrate 1 or dissipated through other heat dissipation mechanisms, which can effectively reduce the temperature of the high temperature resistant flexible substrate 1 and the entire flexible temperature sensor, thereby extending the service life of the flexible temperature sensor.

[0036] In this embodiment, in one implementation, the thickness of the high temperature resistant flexible substrate 1 is 1-3 mm; in another implementation, the thickness of the high temperature resistant flexible substrate 1 is 1.5-2.5 mm.

[0037] In this embodiment, the flexible temperature sensor is a sensor with linear temperature-sensitive characteristics, wherein, in one implementation, the thickness of the thermocouple temperature-sensitive layer 2 is 10-30 um; in another implementation, the thickness of the thermocouple temperature-sensitive layer 2 is 13-25 um; in yet another implementation, the thickness of the thermocouple temperature-sensitive layer 2 is 15-20 um.

[0038] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned flexible temperature sensor suitable for an extreme high temperature environment, such as Figure 4 As shown, including: S101. Prepare a flexible thermal insulation composite material substrate; illustratively, select a flexible thermal insulation composite material to prepare a high temperature resistant flexible substrate 1, wherein the flexible thermal insulation composite material includes pre-oxidized silk film, aerogel felt and transparent mica, but is not limited to these three materials; after the high temperature resistant flexible substrate 1 is prepared, the prepared high temperature resistant flexible substrate 1 is cut to a size that meets the use requirements; at the same time, since the high temperature resistant flexible substrate 1 is prepared using the above-mentioned materials, the high temperature resistant flexible substrate 1 has no obvious change in properties at high temperatures above 1000°C, has good flexibility and stability, and can still return to its original shape after repeated bending.

[0039] S102, prepare slurry, and print a sensitive layer film on the flexible thermal insulation composite material substrate through a screen printing process to obtain a flexible temperature sensor; illustratively, ceramic powders such as indium oxide (In2O3), indium tin oxide (ITO) or indium zinc oxide (IZO) are selected as main materials, and a binder and a curing agent (including but not limited to epoxy resin, cellulose and polyether amine) are added to mix and formulate the slurry; then based on the screen printing process, a thermocouple sensitive layer film is prepared on the rough surface of the high-temperature resistant flexible substrate 1 prepared with the thermal insulation composite material, and printed 1 to 2 times, so that the thermocouple temperature sensitive layer 2 is tightly attached to the high-temperature resistant flexible substrate 1; wherein, after each application, a heat treatment is performed at 160°C for 20 minutes to ensure that it is completely solidified in a vacuum drying oven, thereby obtaining a flexible temperature sensor.

[0040] S103. The obtained flexible temperature sensor is subjected to a high-temperature treatment for one hundred and twenty minutes to thermally activate the electrode material of the sensitive layer in the flexible temperature sensor. Exemplarily, the obtained flexible temperature sensor is subjected to a heat treatment at 700°C for 120 minutes to thermally activate the electrode material of the thermocouple temperature sensitive layer 2; then, the high-temperature resistant flexible substrate 1 is heat-treated at 700°C for 20 hours, and compared with the same flexible substrate at room temperature, its macroscopic morphology and microstructure are observed to ensure that its properties have not changed significantly; secondly, the flexible temperature sensor is heated at 700-800°C using an alcohol lamp, and then the flexible temperature sensor is heated at 1050°C-1250°C using the airflow of a butane spray gun, and then the flexible temperature sensor is repeatedly bent with tweezers. The flexible temperature sensor is intact in a high-temperature environment and exhibits good flexibility. Finally, a high and low temperature chamber and a muffle furnace are used as heat sources to calibrate and test the flexible temperature sensor, such as Figure 3 As shown, the relationship curve between the temperature and the voltage output value of the flexible temperature sensor is obtained, ensuring the temperature measurement accuracy in the ultra-wide temperature range of -196~1300℃.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A flexible temperature sensor suitable for extreme high temperature environments, characterized in that: include: A high temperature resistant flexible substrate (1), which is made of a flexible heat insulation composite material, wherein the flexible heat insulation composite material comprises a pre-oxidized silk film, an aerogel felt or transparent mica; A thermocouple temperature sensitive layer (2) is arranged on the surface of the high temperature resistant flexible substrate (1), wherein the preparation material of the thermocouple sensitive layer (2) includes indium oxide, indium tin oxide or indium zinc oxide; The thickness of the high temperature resistant flexible substrate (1) is 1-3 mm, and the thickness of the thermocouple temperature sensitive layer (2) is 10-30 μm.

2. The flexible temperature sensor suitable for extreme high temperature environment according to claim 1, characterized in that: The materials used to prepare the thermocouple sensitive layer (2) also include cellulose, epoxy resin, pinene alcohol or polyetheramine.

3. The flexible temperature sensor suitable for extreme high temperature environment according to claim 1, characterized in that: The thermocouple temperature sensitive layer (2) comprises a heating end and a cooling end, and the heating end is in direct contact with the cooling end.

4. The flexible temperature sensor suitable for extreme high temperature environment according to claim 3, characterized in that: The heating end and the cooling end are connected via a honeycomb mortise and tenon structure.

5. The flexible temperature sensor suitable for extreme high temperature environment according to claim 3 or 4, characterized in that: The heating end and the cooling end are made of different materials.

6. The flexible temperature sensor suitable for extreme high temperature environment according to claim 1, characterized in that: The sensitivity of the thermocouple temperature sensitive layer (2) is not less than -200 μV / C.

7. The flexible temperature sensor suitable for extreme high temperature environment according to claim 1, characterized in that: The cross section of the high temperature resistant flexible substrate (1) is rectangular.

8. The flexible temperature sensor suitable for extreme high temperature environment according to claim 1, characterized in that: The thermocouple temperature sensitive layer (2) is a structure with one end open and the other end closed.

9. A method for preparing a flexible temperature sensor suitable for an extreme high temperature environment as claimed in any one of claims 1 to 8, characterized in that: include: Preparation of high temperature resistant flexible substrate; Prepare slurry, and print a sensitive layer film on the prepared high temperature resistant flexible substrate through a screen printing process to obtain a flexible temperature sensor; The obtained flexible temperature sensor is subjected to a high temperature treatment for 120 minutes to thermally activate the sensitive layer electrode material in the flexible temperature sensor.

10. The method for preparing a flexible temperature sensor suitable for an extreme high temperature environment according to claim 9, characterized in that: After thermally activating the sensitive layer electrode material in the flexible temperature sensor, the method further comprises: The flexible substrate was heat treated at 700 degrees Celsius for 20 hours, and its macroscopic morphology and microstructure were observed by comparing it with the same flexible substrate at room temperature; Using an alcohol lamp, the flexible temperature sensor is heated at 700 to 800 degrees Celsius, and the airflow of a butane spray gun is used to heat the flexible temperature sensor; The flexible temperature sensor is calibrated and tested using a high and low temperature chamber and a muffle furnace as heat sources.

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