Flexible anti-freezing self-repairing hydrogel stress sensing optical fiber and high-throughput preparation method thereof

Abstract

The invention relates to a flexible anti-freezing self-repairing hydrogel stress sensing optical fiber and a high-throughput preparation method thereof. The high-flux preparation method comprises the following steps: S0, mixing carboxymethyl cellulose, acrylic acid, conductive metal salt, an initiator and a binary solvent according to a preset proportion to obtain a precursor solution; the preparation method comprises the following steps: S1, carrying out preliminary curing on the precursor solution, so that the precursor solution is converted into semi-solidified hydrogel; and S2, enabling the semi-solidified hydrogel to form filamentous hydrogel fibers, and further solidifying the semi-solidified hydrogel fibers at the same time, so that the semi-solidified hydrogel fibers are converted into completely solidified hydrogel fibers, thereby obtaining the prepared flexible anti-freezing self-repairing hydrogel stress sensing optical fiber. The flexible anti-freezing self-repairing hydrogel stress sensing optical fiber is excellent in performance, and pressure signals can be converted through a resistance value or light intensity loss dual mechanism; and the preparation method is relatively high in efficiency, and meets the requirements of industrial high-throughput preparation.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and in particular to a flexible antifreeze self-repairing hydrogel stress sensing optical fiber and a high-throughput preparation method thereof. Background Art

[0002] Hydrogels are three-dimensional networks formed by physical or chemical crosslinking of hydrophilic polymers. Their core properties include high water content, good biocompatibility, biodegradability, flexibility, and stretchability. Hydrogels are currently widely used in biomedicine, flexible sensing, environmental protection, and other fields. For example, in the biomedical field, hydrogels can mimic the extracellular matrix and promote the regeneration of tissues such as bone, cartilage, and nerves. In the field of flexible sensing, hydrogels can be used as flexible stress sensors in wearable electronic devices to monitor human movement, breathing, and other activities.

[0003] Hydrogel fibers are a common form of hydrogel material. Microscopically, they possess a three-dimensional hydrogel network structure and macroscopically present a fibrous, linear form. The template method is a common method for preparing hydrogel fibers in the prior art, comprising the steps of: injecting a hydrogel precursor solution into a tubular template; applying external stimuli such as light or heat to the hydrogel precursor solution to promote polymerization of the hydrogel molecules; and finally, peeling the polymerized hydrogel material from the template to obtain the prepared hydrogel fibers. It can be seen that the length and diameter of the hydrogel fibers prepared by the template method depend on the shape of the template. Due to the manufacturing process and cost limitations of the template, the template method cannot produce long fibers greater than 10 meters in length. Furthermore, in the template method, the cross-linking process that causes the hydrogel molecules to undergo polymerization takes too long, making it unsuitable for industrial high-throughput production.

[0004] To overcome the template method's inability to produce long fibers, the prior art also offers a wet-spinning method for preparing hydrogel fibers. The method comprises the following steps: injecting a viscous hydrogel precursor solution into a tubular container equipped with a spinneret, extruding the hydrogel precursor solution from the spinneret to form a thin hydrogel stream; and finally, allowing the hydrogel stream to solidify to form hydrogel fibers. While this wet-spinning method can produce long hydrogel fibers, the resulting products typically lack flexibility and have poor mechanical properties. Furthermore, the method requires the hydrogel precursor solution to be a viscous supramolecular or polyelectrolyte solution, making it unsuitable for low-viscosity monomer solutions. This method also cannot produce hydrogel fibers continuously, resulting in low production efficiency and unsuitable for industrial high-throughput production. Summary of the Invention

[0005] Based on this, the object of the present invention is to provide a flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber and a high-throughput preparation method thereof.

[0006] The present invention provides a high-throughput preparation method for a flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber, comprising the following steps: S0, mixing carboxymethyl cellulose, acrylic acid, a conductive metal salt, an initiator, and a binary solvent in a preset proportion to obtain a precursor solution; S1, preliminarily solidifying the precursor solution to convert the precursor solution into a semi-solidified hydrogel; S2, forming the semi-solidified hydrogel into a filamentous hydrogel fiber, and further solidifying the semi-solidified hydrogel fiber to convert the semi-solidified hydrogel fiber into a completely solidified hydrogel fiber, thereby obtaining the prepared flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber.

[0007] The high-throughput preparation method of the flexible, antifreeze, self-repairing hydrogel stress-sensing optical fiber of the present invention has high preparation efficiency. As long as the precursor solution is sufficient, continuous hydrogel fibers of continuous length can be continuously produced, meeting the needs of industrial high-throughput preparation. The flexible, antifreeze, self-repairing hydrogel stress-sensing optical fiber prepared by the present invention has the following advantages: ① Flexibility: It can be bent and stretched to conform to the human body or complex surfaces, and is suitable for wearable devices; ② High mechanical strength: Based on the PAA / CMC long-chain intercalation network and metal-carboxyl coordination, the mechanical strength is approximately three times that of wet-spinning products; ③ Self-repairability: Dynamic chemical bonds achieve self-repair and remain stable after 1,000 stretching cycles; ④ Antifreeze: The binary solvent enables the material to maintain good mechanical and electrical properties at -20°C; ⑤ Piezoelectric properties: The conductive metal salt imparts a resistance-pressure mapping relationship, and its GF value as a piezoelectric sensor is significantly better than that of the product prepared by the template method; ⑥ Fiber properties: It has both light transmission function, and light loss is correlated with pressure, realizing optical / electrical dual-mode sensing. The flexible, antifreeze, self-repairing hydrogel stress sensing optical fiber of the present invention converts pressure signals through a dual mechanism of resistance value or light intensity loss, and has high practical value in the fields of wearable and extreme environment monitoring.

[0008] Furthermore, the preset ratio in step S0 is: 1% wt carboxymethyl cellulose, 40% wt acrylic acid, 5% wt conductive metal salt, 0.5% wt initiator and 53.5% wt binary solvent.

[0009] Furthermore, step S2 allows the semi-solidified hydrogel to form filamentous hydrogel fibers, specifically comprising: applying an extrusion force to the semi-solidified hydrogel to extrude the semi-solidified hydrogel from the container; and then applying a traction force to the extruded semi-solidified hydrogel to form filamentous hydrogel fibers.

[0010] Furthermore, in step S2, the semi-solidified hydrogel is extruded from the container at an extrusion speed of 6 to 12 m / h; and the traction force applied to the semi-solidified hydrogel is 1 to 2 N.

[0011] Furthermore, the initiator is a photoinitiator; step S1 preliminarily solidifies the precursor solution, specifically: preliminarily irradiates the precursor solution with ultraviolet light; step S2 further solidifies the semi-solidified hydrogel fiber, specifically: further irradiates the semi-solidified hydrogel fiber with ultraviolet light.

[0012] Furthermore, in step S1, the precursor solution is initially irradiated with ultraviolet light for a time of 2s to 4s, and the intensity of the ultraviolet light is 20 to 30mw / cm 2 .

[0013] Furthermore, in step S2, the semi-solidified hydrogel fibers are further irradiated with ultraviolet light at an intensity of 10-20 mw / cm 2 .

[0014] Furthermore, after step S2, the method further includes step S3: continuously collecting the completely solidified hydrogel fibers by a rotating roller.

[0015] Based on the same inventive concept, the present invention also provides a flexible antifreeze self-repairing hydrogel stress sensing optical fiber, which is prepared by any of the above-mentioned high-throughput preparation methods of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber.

[0016] Based on the same inventive concept, the present invention also provides an optical fiber stress sensor system, which includes: the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention, a first optical fiber, a second optical fiber, a light intensity measurement module and a first calculation module; the first optical fiber and the second optical fiber are respectively arranged at the two ends of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber; the laser passes through the first optical fiber, enters the flexible antifreeze self-repairing hydrogel stress sensing optical fiber, and then exits from the second optical fiber; the light intensity measurement module measures the light intensity of the incident laser and the outgoing laser in the first optical fiber and the second optical fiber; the first calculation module calculates the loss light intensity generated by the laser passing through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber by comparing the light intensity of the incident laser and the outgoing laser in the first optical fiber and the second optical fiber, and calculates the pressure exerted on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber based on the loss light intensity.

[0017] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the process for preparing the high-throughput flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention;

[0019] Figure 2Schematic diagram of a preparation device for the high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention under laboratory conditions;

[0020] Figure 3 Schematic diagram of a module of the optical fiber stress sensor system of the present invention;

[0021] Figure 4 Schematic diagram of a module of the piezoelectric sensor system of the present invention. DETAILED DESCRIPTION

[0022] It should be clear that the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the embodiments of the present application.

[0023] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms "a," "the," and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0025] It should be understood that the embodiments of the present application are not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the embodiments of the present application is limited only by the appended claims.

[0026] The present invention optimizes the formula of the precursor solution, not only improving the mechanical and electrical properties of the hydrogel fiber by adding carboxymethyl cellulose and conductive metal salts, but also significantly improving the antifreeze and liquid retention capacity of the hydrogel fiber by replacing the solvent with a binary solvent. The present invention also addresses the defect that the existing template method and wet spinning method cannot prepare hydrogel fibers on a large scale, and divides the curing process of the hydrogel into two stages. As long as the precursor solution is sufficient, hydrogel fibers of continuous length can be continuously produced, which meets the needs of industrial high-throughput preparation. The flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention can be used as an optical fiber stress sensor and a piezoelectric sensor in wearable electronic devices.

[0027] See also Figure 1-Figure 2 , Figure 1 This is a schematic flow chart of the high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention. Figure 2 This is a schematic diagram of a high-throughput preparation method for a flexible, freeze-resistant, self-repairing hydrogel stress-sensing optical fiber under laboratory conditions. The flexible, freeze-resistant, self-repairing hydrogel stress-sensing optical fiber of the present invention is prepared using the high-throughput preparation method of the present invention, which includes the following steps:

[0028] S0, carboxymethyl cellulose (CMC), acrylic acid (AA), conductive metal salt, initiator and binary solvent are mixed in a preset ratio to obtain a precursor solution.

[0029] The initiator is a photoinitiator or a thermal initiator. If the initiator is a photoinitiator, the precursor solution needs to be irradiated with ultraviolet light during subsequent curing; if the initiator is a thermal initiator, the precursor solution needs to be heated during subsequent curing. Preferably, the initiator in this embodiment is a photoinitiator to improve preparation efficiency, considering that the solidification speed of the photocuring reaction is much faster than that of the thermal curing reaction.

[0030] The binary solvent is a binary solvent formed by mixing water and ethylene glycol, which has better antifreeze and liquid retention capabilities than a single solvent.

[0031] S1, preliminarily solidifying the precursor solution to convert the precursor solution into a semi-solidified hydrogel.

[0032] Since the initiator of this embodiment is a photoinitiator, step S1 specifically includes: performing preliminary ultraviolet light irradiation on the precursor solution to convert the precursor solution into a semi-solidified hydrogel. After absorbing the energy of ultraviolet light, the photoinitiator in the precursor solution will decompose into free radicals or cations. These free radicals or cations will promote the polymerization reaction of the acrylic acid (AA) monomer in the precursor solution to generate polyacrylic acid (PAA), thereby converting the precursor solution into a semi-solidified hydrogel. While the acrylic acid monomer is polymerizing, the metal ions in the precursor solution form metal ligand coordination with the carboxyl groups on the polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) chains, thereby improving the mechanical strength of the hydrogel.

[0033] exist Figure 2 In the illustrated embodiment, the reaction vessel for the initial solidification is a transparent syringe. Therefore, before executing step S1, the precursor solution is first injected into the transparent syringe. During step S1, the precursor solution is initially irradiated with ultraviolet light through the transparent syringe to convert the precursor solution in the transparent syringe into a semi-solidified hydrogel.

[0034] S2, forming the semi-solidified hydrogel into a filamentous hydrogel fiber, and further solidifying the semi-solidified hydrogel fiber to convert the semi-solidified hydrogel fiber into a fully solidified hydrogel fiber. The fully solidified hydrogel fiber is the flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber of the present invention.

[0035] Specifically, step S2 forms the semi-solidified hydrogel into filamentous hydrogel fibers, including: applying an extrusion force to the semi-solidified hydrogel to extrude the semi-solidified hydrogel from a container; and then applying a traction force to the extruded semi-solidified hydrogel to form filamentous hydrogel fibers. If only an extrusion force is applied to the semi-solidified hydrogel without a traction force, the semi-solidified hydrogel will adhere to the container surface after being squeezed out of the container, resulting in a spindle-like suspension, and will not form filamentous hydrogel fibers. Therefore, it is necessary to apply a traction force to the hydrogel after it is squeezed out of the container.

[0036] S3, continuously collecting the completely solidified hydrogel fibers by rotating rollers, thereby completing the high-throughput preparation of flexible antifreeze self-repairing hydrogel stress sensing optical fibers.

[0037] The rotating roller rotates, on the one hand winding the completely solidified hydrogel fibers around its outer wall, thereby continuously collecting the hydrogel fibers, and on the other hand generating traction on the semi-solidified hydrogel fibers, thereby guiding the semi-solidified hydrogel squeezed out from the needle of the transparent syringe to form filamentous hydrogel fibers.

[0038] exist Figure 2 In the embodiment shown, the container for accommodating the semi-solidified hydrogel is a transparent syringe, and the force-applying body for applying traction to the extruded semi-solidified hydrogel is a rotating roller. Therefore, step S2 is specifically as follows: by compressing the piston of the transparent syringe, an extrusion force is applied to the semi-solidified hydrogel, so that the semi-solidified hydrogel is squeezed out from the needle in the transparent syringe to form preliminary hydrogel fibers; then the end of the preliminary hydrogel fiber is wound into the rotating roller, and the rotating roller rotates to generate traction on the hydrogel fiber to guide the subsequent semi-solidified hydrogel to form new hydrogel fibers, so that the length of the hydrogel fiber is extended; at the same time, the semi-solidified hydrogel fiber between the needle of the transparent syringe and the rotating roller is further irradiated with ultraviolet light to convert the semi-solidified hydrogel fiber into a completely solidified hydrogel fiber.

[0039] Furthermore, after numerous experiments, the inventors discovered that the preset ratios of the various components used in preparing the precursor solution in step S0, the duration and intensity of the initial UV irradiation of the precursor solution in step S1, the intensity of the further UV irradiation in step S2, the speed at which the semi-solidified hydrogel is extruded from the container in step S2, and the force of the traction applied to the semi-solidified hydrogel significantly impact the performance of the prepared product and the efficiency of the preparation method. For example, if the initial UV irradiation time is too short, the semi-solidified hydrogel will be soft and have low mechanical strength, making it susceptible to breakage when subsequently subjected to the traction of the rotating roller. If the initial UV irradiation time is too long, the hydrogel will become clogged near the outlet of the transparent syringe, making it difficult for the semi-solidified hydrogel to be extruded from the needle in the transparent syringe.

[0040] After repeated experiments, the present invention has obtained the following preferred ranges of the above parameters: when preparing the precursor solution in step S0, the preset proportions of the components are preferably: 1% wt carboxymethyl cellulose, 40% wt acrylic acid, 5% wt conductive metal salt, 0.5% wt initiator and 53.5% wt binary solvent; in step S1, the precursor solution is subjected to preliminary ultraviolet light irradiation for a time of preferably 2s to 4s, and the ultraviolet light intensity is preferably 20 to 30 mw / cm 2 In step S2, the semi-solidified hydrogel fibers are further irradiated with ultraviolet light, and the intensity of the ultraviolet light is preferably 10-20 mw / cm 2 In step S2, the extrusion speed of the semi-solidified hydrogel from the container is preferably 6 to 12 m / h; the force of the traction force applied to the semi-solidified hydrogel is preferably 1 to 2 N.

[0041] The flexible, antifreeze, self-repairing hydrogel stress sensing optical fiber of the present invention has the following advantages:

[0042] ① Flexibility: The flexible, antifreeze, self-repairing hydrogel stress-sensing optical fiber of the present invention can be bent and stretched, and can be highly conformed to the human body or complex curved surfaces. It is suitable for application in wearable devices to improve wearing comfort.

[0043] ② High Mechanical Strength: The long chains of polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) within the flexible, frost-resistant, self-healing hydrogel stress-sensing optical fiber of this invention interpenetrate each other, forming a relatively strong polymer network through hydrogen bonding between the long chains. Metal ions form metal-carboxyl coordination with the carboxyl groups on the long chains of PAA and CMC, further enhancing the material's mechanical strength. Experimental studies have shown that the mechanical strength of the flexible, frost-resistant, self-healing hydrogel stress-sensing optical fiber of this invention is three times that of products prepared by the wet spinning method.

[0044] ③ Self-repairability: After being damaged, the flexible, frost-resistant, self-repairing hydrogel stress-sensing optical fiber of the present invention can autonomously restore its structural integrity and functional properties through the reorganization of dynamic chemical bonds or intermolecular forces. This not only allows it to withstand extreme deformation but also offers excellent service life and durability. Experiments have shown that the flexible, frost-resistant, self-repairing hydrogel stress-sensing optical fiber of the present invention remains stable after enduring 1,000 stretching and release cycles, demonstrating its excellent service life and durability.

[0045] ④ Antifreeze property: The binary solvent used in the preparation of the precursor solution of the present invention gives the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention excellent antifreeze property. Even at a low temperature of -20°C, the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention can maintain good mechanical and electrical properties.

[0046] ⑤ Piezoelectric properties: The conductive metal salt used in the preparation of the precursor solution of the present invention gives the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention good electrical conductivity. There is a definite mapping relationship between the resistance value of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention in the circuit and the pressure it is subjected to. Therefore, by measuring the resistance value of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention in the circuit, the pressure it is subjected to can be inferred. Based on this, the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention can be used as a piezoelectric sensor to convert pressure into an electrical signal. Experiments have shown that when the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention is used as a piezoelectric sensor, its sensitivity coefficient (Gage Factor, GF) under normal conditions reaches 1.83 to 3.85; its sensitivity coefficient under 40% to 75% humidity conditions is also 0.94, and its sensitivity is about three times that of the product prepared by the template method under the same conditions.

[0047] ⑥ Fiber characteristics: The flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention can transmit light, so it can be set as an optical fiber in the optical path. After the laser passes through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention, there is a definite mapping relationship between the loss light intensity generated and the pressure exerted on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention. Therefore, by measuring the loss light intensity generated after the laser passes through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention, the pressure exerted on it can also be inferred. Based on this, the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention can be used as an optical fiber stress sensor to convert pressure into an optical signal.

[0048] The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention has the following technical effects:

[0049] ① The preparation method of the present invention is a continuous high-throughput preparation method. As long as the precursor solution is sufficient, hydrogel fibers of continuous length can be continuously produced, which meets the needs of industrial high-throughput preparation. In an industrial production scenario, the transparent syringe in this embodiment can be replaced with a liquid storage tank, a continuous liquid supply device, and an automated liquid pushing device; a sufficient amount of precursor solution is pre-stored in the liquid storage tank, and the continuous liquid supply device is instructed to automatically transfer the precursor solution in the liquid storage tank to the automated liquid pushing device. The automated liquid pushing device replaces the transparent syringe in this embodiment as the polymerization reaction container and the hydrogel fine stream extrusion device.

[0050] ② Compared to the existing template method, the preparation method of the present invention can produce hydrogel fibers of any length, overcoming the defect that the template method cannot produce long fibers. Compared to the existing wet spinning method, the preparation method of the present invention does not require the precursor solution to be a viscous supramolecular or polyelectrolyte solution, has a wider range of applications, and the product performance is significantly better than that of the products prepared by the wet spinning method. The reason why the existing wet spinning method requires the precursor solution to be a viscous supramolecular or polyelectrolyte solution is that only the hydrogel streams formed by the viscous supramolecular or polyelectrolyte solution during extrusion can be smoothly solidified into hydrogel fibers; if the precursor solution is a low-viscosity monomer solution, the hydrogel stream will deform before solidification, resulting in the inability to form hydrogel fibers. The preparation method of the present invention, however, preliminarily solidifies the precursor solution before extruding it, converting the precursor solution into a semi-solidified hydrogel. This greatly shortens the time required for the hydrogel streams to completely solidify and form hydrogel fibers after extrusion, thereby ensuring that the hydrogel fibers can be smoothly formed. The products prepared by the existing wet spinning method have poor mechanical properties and can usually only be used in the biomedical field. However, the products prepared by the present invention have relatively excellent mechanical and electrical properties and can be used as stress sensors in wearable devices, with a wide range of applications.

[0051] Based on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber of the present invention, the present invention also provides an optical fiber stress sensor system and a piezoelectric sensor system.

[0052] See also Figure 3 , Figure 3 Schematic diagram of the modules of the optical fiber stress sensor system of the present invention. The optical fiber stress sensor system of the present invention comprises: the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10 of the present invention, a first optical fiber 11, a second optical fiber 12, a laser light source 13, a light intensity measurement module 14 and a first calculation module 15. The first optical fiber 11 and the second optical fiber 12 are respectively arranged at the two ends of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10. The laser light source 13 emits laser light; the laser light passes through the first optical fiber 11 and enters the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10, and then passes through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10 and is emitted from the second optical fiber 12. The light intensity measurement module 14 is used to measure the light intensity of the incident laser and the outgoing laser in the first optical fiber 11 and the second optical fiber 12. The first calculation module 15 calculates the loss light intensity generated by the laser passing through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10 by comparing the light intensities of the incident laser and the outgoing laser in the first optical fiber 11 and the second optical fiber 12, and calculates the pressure exerted on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 10 based on the loss light intensity, thereby realizing the function of measuring pressure.

[0053] Furthermore, the optical fiber stress sensor system also includes a signal conditioning circuit 141, which is used to pre-process the original light intensity signal obtained by the light intensity measurement module 14 by amplification, filtering, isolation, analog-to-digital conversion, etc., and then transmit the pre-processed light intensity signal to the first calculation module 15.

[0054] See also Figure 4 , Figure 4 Schematic diagram of the module of the piezoelectric sensor system of the present invention. The piezoelectric sensor system of the present invention comprises: the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 20 of the present invention, a first electrode 21, a second electrode 22, a resistance measurement module 23 and a second calculation module 24. The first electrode 21 and the second electrode 22 are respectively arranged at the two ends of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 20. The resistance measurement module 23 is used to measure the resistance value between the first electrode 21 and the second electrode 22, that is, the resistance value of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 20. The second calculation module 24 is used to calculate the pressure exerted on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 20 according to the resistance value of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber 20, thereby realizing the function of measuring pressure.

[0055] Furthermore, the first electrode 21 and the second electrode 22 may be printed conductors. In this case, the flexible, frost-resistant, self-repairing hydrogel stress sensing optical fiber 20 of the present invention is fixed to an insulating substrate, and conductive silver paste is printed on both ends of the flexible, frost-resistant, self-repairing hydrogel stress sensing optical fiber 20 to form the first electrode 21 and the second electrode 22.

[0056] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to encompass such modifications and variations.

Claims

1. A high-throughput preparation method for a flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber, characterized in that: Including steps: S0, mixing carboxymethyl cellulose, acrylic acid, conductive metal salt, initiator and binary solvent in a preset ratio to obtain a precursor solution; S1, preliminarily solidifying the precursor solution to convert the precursor solution into a semi-solidified hydrogel; S2, allowing the semi-solidified hydrogel to form a filamentous hydrogel fiber, and further solidifying the semi-solidified hydrogel fiber to convert the semi-solidified hydrogel fiber into a completely solidified hydrogel fiber, thereby obtaining the prepared flexible antifreeze self-repairing hydrogel stress sensing optical fiber.

2. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 1 is characterized in that: The preset ratio in step S0 is: 1% wt carboxymethyl cellulose, 40% wt acrylic acid, 5% wt conductive metal salt, 0.5% wt initiator and 53.5% wt binary solvent.

3. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 1 is characterized by: Step S2 forms the semi-solidified hydrogel into filamentous hydrogel fibers, specifically comprising: applying an extrusion force to the semi-solidified hydrogel to squeeze the semi-solidified hydrogel out of the container; Then, a pulling force is applied to the extruded semi-solidified hydrogel to form a filamentous hydrogel fiber.

4. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 3 is characterized by: In step S2, the semi-solidified hydrogel is extruded from the container at an extrusion speed of 6 to 12 m / h; and the pulling force applied to the semi-solidified hydrogel is 1 to 2 N.

5. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 1 is characterized in that: The initiator is a photoinitiator; step S1 performs preliminary curing on the precursor solution, specifically: performs preliminary ultraviolet light irradiation on the precursor solution; step S2 further cures the semi-solidified hydrogel fiber, specifically: performs further ultraviolet light irradiation on the semi-solidified hydrogel fiber.

6. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 5, characterized in that: In step S1, the precursor solution is initially irradiated with ultraviolet light for 2s to 4s, and the intensity of the ultraviolet light is 20 to 30 mw / cm 2 .

7. The high-throughput preparation method of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber according to claim 6, characterized in that: In step S2, the semi-solidified hydrogel fibers are further irradiated with ultraviolet light at an intensity of 10-20 mw / cm 2 .

8. The high-throughput preparation method of the flexible, freeze-resistant, self-repairing hydrogel stress sensing optical fiber according to any one of claims 1 to 7, characterized in that: After step S2, the method further includes step S3: continuously collecting the completely solidified hydrogel fibers by a rotating roller.

9. A flexible, antifreeze, self-repairing hydrogel stress sensing optical fiber, characterized in that: The flexible antifreeze self-repairing hydrogel stress sensing optical fiber is prepared by the high-throughput preparation method according to any one of claims 1 to 8.

10. An optical fiber stress sensor system, characterized in that: include: The flexible antifreeze self-repairing hydrogel stress sensing optical fiber, the first optical fiber, the second optical fiber, the light intensity measurement module and the first calculation module according to claim 9; The first optical fiber and the second optical fiber are respectively arranged at two ends of the flexible antifreeze self-repairing hydrogel stress sensing optical fiber; The laser passes through the first optical fiber, enters the flexible antifreeze self-repairing hydrogel stress sensing optical fiber, and then exits from the second optical fiber; The light intensity measurement module measures the light intensity of the incident laser and the outgoing laser in the first optical fiber and the second optical fiber; The first calculation module calculates the loss light intensity generated by the laser passing through the flexible antifreeze self-repairing hydrogel stress sensing optical fiber by comparing the light intensities of the incident laser and the outgoing laser in the first optical fiber and the second optical fiber, and calculates the pressure exerted on the flexible antifreeze self-repairing hydrogel stress sensing optical fiber based on the loss light intensity.

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