A high-sensitivity, high-stability fibrous flexible temperature sensor and a preparation method thereof

Abstract

The application relates to the field of sensing devices, and discloses a high-sensitivity and high-stability fiber-like flexible temperature sensor and a preparation method thereof. The temperature sensor comprises, from inside to outside, a hydrophilic fiber-like substrate, a temperature-sensitive layer, a hydrophobic buffer layer and a water-blocking packaging layer; the resistance of the temperature-sensitive layer changes with the change of temperature; the water vapor permeability of the water-blocking packaging layer is lower than 5 g / (m2*24h); and the hydrophilic fiber-like substrate and the temperature-sensitive layer contain water, and the water content is 4-15%. In the temperature sensor, a certain amount of water is contained in the hydrophilic fiber-like substrate and the temperature-sensitive layer, and the hydrophobic buffer layer and the water-blocking packaging layer are arranged outside the temperature-sensitive layer, so that the temperature sensor has higher sensitivity and precision, and has better cold and hot cycle stability.

Description

Technical Field

[0001] This invention relates to the field of sensor devices, and more particularly to a highly sensitive and highly stable fibrous flexible temperature sensor and its fabrication method. Background Technology

[0002] With the introduction and guidance of the "Big Health" concept, the Big Health industry, as a core development industry today, has experienced vigorous growth. Among these developments, the rapid advancement of flexible wearable technology and corresponding electronic devices has provided broad application prospects for fields such as medical diagnosis, assisted medicine, and health monitoring.

[0003] As a daily monitoring device, flexible wearable sensors can monitor, record, analyze, and provide early warnings for various health-related physiological information of the human body (such as blood oxygen, heart rate, and body temperature), thereby helping people achieve danger warnings and health management. Among them, body temperature is one of the most important physiological indicators of the human body. By monitoring and analyzing the temperature of different parts of the body, it is possible to obtain timely information about the body's health status, which has important therapeutic and preventive significance.

[0004] Currently, most wearable temperature sensors are primarily thin-film based. While they exhibit high sensitivity and a wide temperature detection range, their structure is difficult to integrate with other core sensor components and also affects wearability and comfort. Therefore, fabricating temperature sensors into fiber structures and utilizing their small size, flexibility, and weaving properties allows for good integration. Furthermore, through textile processes, these fibers can be woven into the interior or surface of fabrics, resulting in temperature sensors that are skin-friendly, flexible, and breathable.

[0005] Patent applications CN114295238A and CN107022823A disclose a novel fiber-based resistive temperature sensor and a woven flexible temperature sensor integrating temperature-sensitive fibers, respectively. Both patents emphasize that fiber-based temperature sensors are easily compatible with weaving processes and can achieve temperature sensors that fit snugly against human skin. However, existing fiber-based temperature sensors have shortcomings in terms of sensitivity and stability. In real-time and long-term temperature monitoring, sensors not only need excellent sensitivity but also need to ensure long-term stability; otherwise, they will not be able to meet the requirements of long-term body temperature monitoring in various daily life and medical scenarios. Therefore, developing high-sensitivity, high-precision, high-stability, and low-cost fiber temperature sensors will be a major advancement in the field of wearable health monitoring technology, with potential applications in healthcare, sports medicine, and industrial safety. Summary of the Invention

[0006] To address the technical problems of low sensitivity and stability in existing fibrous temperature sensors, this invention provides a highly sensitive and stable fibrous flexible temperature sensor and its fabrication method. This temperature sensor exhibits high sensitivity and accuracy, as well as good stability during thermal cycling.

[0007] The specific technical solution of this invention is as follows:

[0008] In a first aspect, the present invention provides a highly sensitive and highly stable fibrous flexible temperature sensor, comprising, from the inside out, a hydrophilic fibrous substrate, a temperature-sensitive layer, a hydrophobic buffer layer, and a water-resistant encapsulation layer; the resistance of the temperature-sensitive layer changes with temperature; and the water vapor permeability of the water-resistant encapsulation layer is less than 5 g / (m²). 2 •24h); The hydrophilic fibrous substrate and temperature-sensitive layer contain water, with a water content of 4-15%.

[0009] The research team discovered that the conductivity or resistance change of the temperature-sensitive layer is closely related to the water molecule content in the material. When the temperature rises, water molecules leave the interior of the temperature-sensitive layer material and move or diffuse towards the hydrophilic substrate. Therefore, to achieve a high-sensitivity and high-accuracy temperature sensor, the temperature-sensitive layer material needs to contain a certain amount of water molecules, and the substrate material must have good hydrophilicity. Furthermore, both excessive and insufficient water content inside the temperature sensor will cause a decrease in sensitivity and accuracy. Based on this, to prevent water molecules from the environment from entering the interior of the temperature-sensitive layer material, or from escaping into the environment, this invention sets a hydrophobic buffer layer and a water-proof encapsulation layer with low water molecule permeability on the sensor surface to ensure a stable water molecule content inside the sensor. During heating and cooling processes, water molecules form a stable internal circulation within the sensor, thereby ensuring the temperature sensor's sensitivity and accuracy, as well as its thermal cycling stability and anti-interference capabilities, making it unaffected by ambient humidity.

[0010] In addition to preventing water molecules from entering and exiting, the hydrophobic buffer layer also provides mechanical protection, reducing damage to the temperature-sensitive layer from external impacts.

[0011] Preferably, the material of the temperature-sensitive layer includes one or more of polyacetylene, poly(p-phenylene), polyaniline, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), poly(3-hexylthiophene), polythiopheneacetylene, and polyphenylacetylene.

[0012] Preferably, the material of the waterproof encapsulation layer includes one or more of the following: polymers of acrylic monomers, polyethylene, epoxy resin, polytetrafluoroethylene, alumina, zinc oxide, and silicon nitride.

[0013] Preferably, the hydrophilic fibrous substrate is a yarn-like hydrophilic fiber bundle woven from multiple hydrophilic fiber filaments.

[0014] Preferably, the hydrophilic fibrous substrate has a moisture regain of more than 4% at a temperature of 20°C and a humidity of 65%.

[0015] Preferably, the diameter of the hydrophilic fibrous substrate is 200-400 micrometers.

[0016] Preferably, the diameter of the hydrophilic fiber is 10-30 micrometers.

[0017] Preferably, the hydrophilic fiber is one or more of hydrophilic natural fibers, hydrophilic synthetic fibers, and hydrophilic regenerated fibers.

[0018] Preferably, the hydrophilic natural fiber is one or more of silk fiber, cotton fiber, hemp fiber, and animal hair fiber; the hydrophilic synthetic fiber is one or more of nylon, vinylon, and highly absorbent polyester; and the hydrophilic regenerated fiber is one or more of viscose fiber, acetate fiber, cuprammonium fiber, and soybean fiber.

[0019] Preferably, the material of the hydrophobic buffer layer includes one or more of polydimethylsiloxane, polyvinylidene fluoride, polyimide, polyurethane, and aliphatic aromatic random copolyester.

[0020] Preferably, the temperature-sensitive layer has lead-out electrodes made of conductive fibers at both ends.

[0021] Preferably, the conductive fiber is one or more of the following: metal fiber, carbon black fiber, conductive metal compound fiber, and conductive polymer fiber.

[0022] Secondly, the present invention provides a method for preparing the aforementioned fibrous flexible temperature sensor, comprising the following steps:

[0023] (1) Coat a layer of temperature-sensitive material on the surface of a hydrophilic fibrous substrate, dry it, and then let it stand for 1-3 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain a fiber coated with a temperature-sensitive layer.

[0024] (2) A layer of hydrophobic buffer material is coated on the surface of the fiber coated with the temperature sensitive layer. After drying, it is left to stand for 2-5 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain the fiber coated with the hydrophobic buffer layer.

[0025] (3) A layer of water-proof encapsulation material is coated on the surface of the fiber covered with a hydrophobic buffer layer. After curing, a fibrous flexible temperature sensor is obtained.

[0026] In steps (1) and (2), after coating the temperature-sensitive layer material and the hydrophobic buffer layer material, drying allows the coated temperature-sensitive layer material and the hydrophobic buffer layer material to tightly coat the surface of the fiber bundle, forming a uniform temperature-sensitive layer and a hydrophobic buffer layer. Then, by leaving it in an environment with a certain temperature and humidity for a certain period of time, a certain amount of water molecules can be adsorbed in the hydrophilic fibrous substrate and the temperature-sensitive layer, thereby improving the sensitivity and accuracy of the temperature sensor.

[0027] Preferably, after step (1), conductive fibers are connected to both ends of the fiber covered with the temperature-sensitive layer, and conductive paste is applied to the connection point, dried, and then step (2) is performed.

[0028] Preferably, the drying process involves natural drying at room temperature for 1-2 hours.

[0029] Preferably, in step (1), the drying temperature is 100-130℃ and the time is 20-40 minutes; in step (2), the drying temperature is 85-130℃ and the time is 20-60 minutes.

[0030] Preferably, in step (3), the curing temperature is 20-30℃.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] (1) The temperature sensor of the present invention has high temperature sensitivity and accuracy, and can detect minute temperature changes. It is expected to be applied in the fields of health monitoring and medical diagnosis.

[0033] (2) The temperature sensor of the present invention has good thermal cycling stability, and its performance will not change significantly after multiple heating and cooling cycles.

[0034] (3) The temperature sensor of the present invention has a simple manufacturing process, low cost, and can be mass-produced;

[0035] (4) The temperature sensor of the present invention can be installed in the fabric through a simple weaving process, making it easy to wear and fit the skin. It has good comfort and breathability and has strong application potential in the fields of smart fabrics, wearable devices, health monitoring equipment, and medical diagnostic instruments. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a fibrous flexible temperature sensor according to the present invention; wherein, the reference numerals are: hydrophilic fibrous substrate 1, temperature sensitive layer 2, hydrophobic buffer layer 3, water-proof encapsulation layer 4, lead electrode 5, and junction point 6.

[0037] Figure 2 This is the temperature-relative resistance change curve of the fibrous flexible temperature sensor in Example 1;

[0038] Figure 3 This is the high-precision temperature-relative resistance change curve of the fibrous flexible temperature sensor in Example 1;

[0039] Figure 4 This is the relative resistance change curve of the thermal cycling stability of the fibrous flexible temperature sensor in Example 1;

[0040] Figure 5 The temperature-relative resistance curve of the fibrous flexible temperature sensor in Comparative Example 1 is shown.

[0041] Figure 6 The temperature-relative resistance curve of the fibrous flexible temperature sensor in Comparative Example 2 is shown.

[0042] Figure 7 This is the temperature-relative resistance change curve of the fibrous flexible temperature sensor in Comparative Example 3. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments. However, it should be noted that the present invention can be implemented through various embodiments, and these equivalent embodiments should also fall within the scope defined by the appended claims. Therefore, the scope of protection of the present invention is not limited to the specific embodiments mentioned herein.

[0044] General Implementation Examples

[0045] A highly sensitive and stable fibrous flexible temperature sensor comprises, from the inside out, a hydrophilic fibrous substrate, a temperature-sensitive layer, a hydrophobic buffer layer, and a water-resistant encapsulation layer; the resistance of the temperature-sensitive layer changes with temperature; and the water vapor permeability of the water-resistant encapsulation layer is less than 5 g / (m²). 2 •24h); The hydrophilic fibrous substrate and temperature-sensitive layer contain water, with a water content of 4-15%.

[0046] As one specific embodiment, the hydrophilic fibrous substrate has a moisture regain of more than 4% at a temperature of 20°C and a humidity of 65%.

[0047] In one specific embodiment, the diameter of the hydrophilic fibrous substrate is 200-400 micrometers.

[0048] In one specific embodiment, the hydrophilic fibrous substrate is a yarn-like hydrophilic fiber bundle woven from multiple hydrophilic fiber filaments with a diameter of 10-30 micrometers. The hydrophilic fiber filaments include, but are not limited to, one or more of hydrophilic natural fibers, hydrophilic synthetic fibers, and hydrophilic regenerated fibers. Specifically, the hydrophilic natural fibers include, but are not limited to, one or more of silk fibers, cotton fibers, hemp fibers, and animal hair fibers; the hydrophilic synthetic fibers include, but are not limited to, one or more of nylon, vinylon, and highly absorbent polyester; and the hydrophilic regenerated fibers include, but are not limited to, one or more of viscose fiber, acetate fiber, cuprammonium fiber, and soybean fiber.

[0049] In one specific embodiment, the material of the temperature-sensitive layer includes one or more of polyacetylene, poly(p-phenylene), polyaniline, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), poly(3-hexylthiophene), polythiophene acetylene, and polyphenylacetylene.

[0050] In one specific embodiment, the hydrophobic buffer layer is made of one or more of polydimethylsiloxane, polyvinylidene fluoride, polyimide, polyurethane, and aliphatic aromatic random copolyester (Ecoflex).

[0051] In one specific embodiment, the material of the waterproof encapsulation layer includes one or more of the following: polymers of acrylic monomers, polyethylene, epoxy resin, polytetrafluoroethylene, alumina, zinc oxide, and silicon nitride.

[0052] In one specific embodiment, the temperature-sensitive layer is provided with lead-out electrodes made of conductive fibers at both ends. The conductive fibers are one or more of the following: metal fibers, carbon black fibers, conductive metal compound fibers, and conductive polymer fibers, such as conductive copper wire, silver wire, gold wire, platinum wire, nickel-chromium wire, carbon fiber, polyacetylene fiber, polythiophene, polyaniline fiber, polypyrrole fiber, etc.

[0053] A method for fabricating the aforementioned fibrous flexible temperature sensor includes the following steps:

[0054] (1) Coat a layer of temperature-sensitive material on the surface of a hydrophilic fibrous substrate, dry it, and then let it stand for 1-3 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain a fiber coated with a temperature-sensitive layer.

[0055] (2) A layer of hydrophobic buffer material is coated on the surface of the fiber coated with the temperature sensitive layer. After drying, it is left to stand for 2-5 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain the fiber coated with the hydrophobic buffer layer.

[0056] (3) A layer of water-proof encapsulation material is coated on the surface of the fiber covered with a hydrophobic buffer layer. After curing, a fibrous flexible temperature sensor is obtained.

[0057] As one specific implementation, after step (1), conductive fibers are connected to both ends of the fiber covered with the temperature-sensitive layer, and conductive paste is applied to the connection. The fiber is then allowed to dry naturally at room temperature for 1-2 hours before proceeding to step (2).

[0058] In one specific implementation, in step (1), the drying temperature is 100-130℃ and the time is 20-40 minutes; in step (2), the drying temperature is 85-130℃ and the time is 20-60 minutes.

[0059] In one specific implementation, the curing temperature in step (3) is 20-30℃.

[0060] Example 1

[0061] A highly sensitive and stable fiber-like flexible temperature sensor, such as Figure 1 As shown, from the inside out, it includes a hydrophilic fibrous substrate 1, a temperature-sensitive layer 2, a hydrophobic buffer layer 3, and a water-resistant encapsulation layer 4. The temperature-sensitive layer has lead-out electrodes 5 made of conductive fibers at both ends, and a junction point 6 is provided between the lead-out electrodes and the temperature-sensitive layer.

[0062] The hydrophilic fibrous substrate is composed of silkworm silk fiber bundles, a yarn-like structure woven from multiple hydrophilic silkworm fibers. The diameter of the hydrophilic silkworm fibers is 10-20 micrometers, and the diameter of the silkworm silk fiber bundles is 200 micrometers. The equilibrium moisture regain of the silkworm silk fiber bundles is 9% at 20℃ and 65% humidity. The temperature-sensitive layer is made of poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS), which has good solubility in water. Both the hydrophilic fibrous substrate and the temperature-sensitive layer contain water, with a water content of 9%. The hydrophobic buffer layer is made of polydimethylsiloxane (PDMS). The water-proof encapsulation layer is made of acrylic resin with a water vapor permeability of 1 g / (m²). 2 • 24h). The conductive fiber is a metallic silver wire. The bonding material is silver.

[0063] The above-mentioned fibrous flexible temperature sensor is prepared through the following steps:

[0064] (1) Coat the surface of the silk fiber bundle with PEDOT:PSS temperature-sensitive material and anneal and dry at 110°C for 30 minutes to ensure that it is tightly wrapped on the surface of the silk fiber bundle and forms a uniform temperature-sensitive layer. Then, let it stand for 1 hour at 25°C and 70% humidity to ensure that the hydrophilic fibrous base and the temperature-sensitive layer contain a certain amount of water molecules.

[0065] (2) Use metal fiber silver wire to connect to both ends of the fiber coated with PEDOT:PSS material obtained in step (1), and apply conductive silver paste to the connection point, and then let it dry naturally at room temperature for 1 hour.

[0066] (3) The fiber connected to the lead-out electrode in step (2) is coated with PDMS hydrophobic buffer layer material and dried at 100°C for 30 minutes to form a uniform hydrophobic buffer protective layer on the fiber surface. Then, it is left to stand at 25°C and 70% humidity for 3 hours to ensure that there is a certain amount of water molecules inside the hydrophilic fibrous substrate and temperature sensitive layer.

[0067] (4) The fiber surface coated with PDMS material obtained in step (3) is coated with a layer of acrylic resin water-proof encapsulation material with low water molecule permeability, and then naturally cured at room temperature of 25°C to form a uniform film, thus obtaining a fiber-shaped flexible temperature sensor.

[0068] The performance of the temperature sensor in this embodiment was tested, and the results are as follows: Figure 2-4 As shown. From Figure 2 It can be seen that the temperature sensor in this embodiment has a good temperature response between 25-50℃, with a temperature sensitivity of 1.89% / ℃, demonstrating good temperature sensitivity performance. From... Figure 3 As can be seen, the temperature sensor in this embodiment has a temperature resolution of 0.1℃, enabling it to detect minute temperature changes. From... Figure 4 It can be seen that the temperature sensor in this embodiment did not show significant performance changes after 300 heating and cooling cycles, which can meet the requirements of long-term temperature detection.

[0069] Comparative Example 1

[0070] A highly sensitive and stable fibrous flexible temperature sensor comprises, from the inside out, a hydrophilic fibrous substrate, a temperature-sensitive layer, and a water-resistant encapsulation layer, without the water-resistant encapsulation layer. The temperature-sensitive layer has lead-out electrodes made of conductive fibers at both ends, with junction points between the lead-out electrodes and the temperature-sensitive layer. In this comparative example 1, except for the absence of the water-resistant encapsulation layer, the structure and composition of the other layers are the same as in Example 1. The preparation process is the same as in Example 1 except that step (4) is omitted.

[0071] The stability performance of the temperature sensor in Example 1 was compared with that of the temperature sensor in Comparative Example 1. The results are as follows: Figure 5 As shown. From Figure 5 It can be seen that the water-proof encapsulation layer has a significant impact on the stability of the sensor under humidity changes of 10-90%. In Example 1, the resistance of the temperature sensor with the water-proof encapsulation layer changed by about 20% in a high humidity environment of 90% compared to the initial resistance, while the resistance of the sensor without the water-proof layer increased by about 1300%.

[0072] Comparative Example 2

[0073] The temperature sensor in Comparative Example 2 has the same structure and composition as in Example 1. The only difference is that the hydrophilic fibrous substrate and temperature-sensitive layer used contain water, with a water content of 3%.

[0074] The fibrous flexible temperature sensor of Comparative Example 2 above was prepared by the following steps:

[0075] (1) Coat the surface of the silk fiber bundle with PEDOT:PSS temperature-sensitive material and anneal and dry at 110°C for 30 minutes to ensure that it is tightly wrapped on the surface of the silk fiber bundle and forms a uniform temperature-sensitive layer. Then, let it stand for 2 hours at 25°C and 9% humidity to ensure that the water molecule content inside the hydrophilic fibrous base and the temperature-sensitive layer is 3%.

[0076] (2) Use metal fiber silver wire to connect to both ends of the fiber coated with PEDOT:PSS material obtained in step (1), and apply conductive silver paste to the connection point, and then let it dry naturally at room temperature for 1 hour.

[0077] (3) The fiber connected to the lead electrode in step (2) is coated with PDMS hydrophobic buffer layer material and dried at 100°C for 30 minutes to form a uniform hydrophobic buffer protective layer on the fiber surface. Then, it is left to stand at 25°C and 9% humidity for 3 hours to ensure that the water molecule content inside the hydrophilic fibrous substrate and temperature sensitive layer is 3%.

[0078] (4) The fiber surface coated with PDMS material obtained in step (3) is coated with a layer of acrylic resin water-proof encapsulation material with low water molecule permeability. Then, it is naturally cured at a temperature of 25°C and a humidity of 9% to form a uniform film, thus obtaining a fibrous flexible temperature sensor.

[0079] The performance of the temperature sensor in Comparative Example 2 was tested, and the results are as follows: Figure 6 As shown. From Figure 6It can be seen that the temperature sensor of Comparative Example 2 has a weak temperature response between 25-50℃, with a temperature sensitivity of 0.36% / ℃, which is poor temperature sensitivity performance. Its sensitivity is less than one-fifth of that of the temperature sensor in Example 1.

[0080] Comparative Example 3

[0081] The temperature sensor in Comparative Example 3 has the same structure and composition as in Example 1. The only difference is that the hydrophilic fibrous substrate and temperature-sensitive layer used contain water, with a water content of 22%.

[0082] The fibrous flexible temperature sensor of Comparative Example 3 above was prepared by the following steps:

[0083] (1) Coat the surface of the silk fiber bundle with PEDOT:PSS temperature-sensitive material and anneal and dry at 110°C for 30 minutes to ensure that it is tightly wrapped on the surface of the silk fiber bundle and forms a uniform temperature-sensitive layer. Then, let it stand for 2 hours at 25°C and 97% humidity to ensure that the water molecule content inside the hydrophilic fibrous base and the temperature-sensitive layer is 22%.

[0084] (2) Use metal fiber silver wire to connect to both ends of the fiber coated with PEDOT:PSS material obtained in step (1), and apply conductive silver paste to the connection point, and then let it dry naturally at room temperature for 1 hour.

[0085] (3) The fiber connected to the lead electrode in step (2) is coated with PDMS hydrophobic buffer layer material and dried at 100°C for 30 minutes to form a uniform hydrophobic buffer protective layer on the fiber surface. Then, it is left to stand at 25°C and 97% humidity for 3 hours to ensure that the water molecule content inside the hydrophilic fibrous substrate and temperature sensitive layer is 22%.

[0086] (4) The fiber surface coated with PDMS material obtained in step (3) is coated with a layer of acrylic resin water-proof encapsulation material with low water molecule permeability. Then, it is naturally cured at a temperature of 25°C and a humidity of 97% to form a uniform film, thus obtaining a fibrous flexible temperature sensor.

[0087] The performance of the temperature sensor in Comparative Example 3 was tested, and the results are as follows: Figure 7 As shown. From Figure 7 It can be seen that the temperature sensor of Comparative Example 3 has a good temperature response between 25-50℃ and a temperature sensitivity of 1.22% / ℃, which is a general temperature sensitivity performance. However, its response fluctuates greatly and its stability is poor. At the same time, its sensitivity is less than that of the temperature sensor in Example 1.

[0088] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A highly sensitive and highly stable fiber-like flexible temperature sensor, characterized in that, From the inside out, it comprises a hydrophilic fibrous substrate, a temperature-sensitive layer, a hydrophobic buffer layer, and a water-proof encapsulation layer; the resistance of the temperature-sensitive layer changes with temperature; the water vapor permeability of the water-proof encapsulation layer is less than 5 g / (m²·24h); the hydrophilic fibrous substrate and the temperature-sensitive layer contain water, with a water content of 4-15%.

2. The fibrous flexible temperature sensor as described in claim 1, characterized in that, The material of the waterproof encapsulation layer includes one or more of the following: polymers of acrylic monomers, polyethylene, epoxy resin, polytetrafluoroethylene, alumina, zinc oxide, and silicon nitride.

3. The fibrous flexible temperature sensor as described in claim 1, characterized in that, The temperature-sensitive layer is made of one or more of the following materials: polyacetylene, poly(p-phenylene), polyaniline, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), poly(3-hexylthiophene), polythiophene acetylene, and polyphenylacetylene.

4. The fibrous flexible temperature sensor as described in claim 1, characterized in that, The hydrophilic fibrous substrate is a bundle of hydrophilic fibers woven from multiple hydrophilic filaments in the shape of yarn.

5. The fibrous flexible temperature sensor as described in claim 1 or 4, characterized in that, The hydrophilic fibrous substrate has a moisture regain of more than 4% at 20°C and 65% humidity.

6. The fibrous flexible temperature sensor as described in claim 1, characterized in that, The hydrophobic buffer layer is made of one or more of the following materials: polydimethylsiloxane, polyvinylidene fluoride, polyimide, polyurethane, and aliphatic aromatic random copolyester.

7. The fibrous flexible temperature sensor as described in claim 1, characterized in that, The temperature-sensitive layer has lead-out electrodes made of conductive fibers at both ends.

8. A method for fabricating a fibrous flexible temperature sensor as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Coat a layer of temperature-sensitive material on the surface of a hydrophilic fibrous substrate, dry it, and then let it stand for 1-3 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain a fiber coated with a temperature-sensitive layer. (2) A layer of hydrophobic buffer material is coated on the surface of the fiber with a temperature-sensitive layer. After drying, the fiber is left to stand for 2-5 hours at a temperature of 20-30℃ and a humidity of 60-90% to obtain the fiber with a hydrophobic buffer layer. (3) A layer of water-proof encapsulation material is coated on the surface of the fiber covered with a hydrophobic buffer layer. After curing, a fibrous flexible temperature sensor is obtained.

9. The method for fabricating the fibrous flexible temperature sensor as described in claim 8, characterized in that, After step (1), conductive fibers are connected to both ends of the fiber covered with the temperature-sensitive layer, and conductive paste is applied to the connection point. After drying, step (2) is then performed.

10. The method for fabricating the fibrous flexible temperature sensor as described in claim 8, characterized in that, In step (1), the drying temperature is 100-130℃ and the time is 20-40 minutes; in step (2), the drying temperature is 85-130℃ and the time is 20-60 minutes.

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