A method for preparing multi-responsive conductive fiber

Abstract

The present invention discloses a method for preparing multi-responsive conductive fibers, which belongs to the field of flexible bioelectronic sensing. The present invention adopts microfluidic technology to continuously prepare multi-responsive conductive fiber materials in situ. The present invention composites a high-strength and high-toughness regenerated silk protein matrix with calcium alginate fiber to form a core-sheath structure, and then adds PEDOT:PSS conductive material to form a composite conductive fiber. The composite conductive fiber has good multi-responsive intelligent conductive fiber functional materials such as humidity, temperature, and stretching. The material can realize intelligent transformation between conductivity and non-conductivity under the stimulation of humidity, temperature, and stretching. Based on the PEDOT:PSS fiber, the present invention further assembles a simple and flexible fiber-based flexible electronic wearable sensing device.

Description

Technical Field

[0001] The present invention relates to the field of bioelectronic flexible sensing, in particular to a method for preparing multi-response conductive fibers. Background Art

[0002] Over the past decade, wearable devices, flexible electronics, and sensor electronics (such as organic / perovskite photovoltaics, organic thin-film transistors, and medical sensors) have been developed. The key to realizing the corresponding functions of these devices is to fabricate conductive electrodes with ideal mechanical properties. Among them, conductive polymers have attracted much attention due to their unique conjugated chain structure and excellent performance.

[0003] Traditional conductive materials are often high molecular polymers, but because high molecular polymers are hydrophobic, do not respond to humidity and are not easily degraded, there are many obstacles in practical applications, so multi-responsive high-performance bio-based conductive composite fibers have emerged. Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is particularly important in conductive materials because it can be dispersed in water or polar organic solvents, while most conductive polymers cannot be heated and melted and cannot be dispersed in solutions, making them difficult to process. In addition, PEDOT:PSS also has excellent thermal stability in the visible light range, and has the advantages of high conductivity and biocompatibility, so it can have important applications in many fields, such as optoelectronic devices such as light-emitting diodes, solar cells and photodetectors, as well as energy storage devices including batteries and supercapacitors.

[0004] Currently, bio-based fibers are primarily produced using wet spinning, dry spinning, and electrospinning. However, these spinning processes all have drawbacks. For example, wet spinning is time-consuming and energy-intensive, and the chemical reagents used require waste disposal. Furthermore, the spinning solution ejected from the spinneret expands at the outlet, ultimately creating undesirable defects in the fibers. Regarding dry spinning, the mechanical properties of regenerated silk fibroin (RSF) fibers produced solely through dry spinning remain insufficient. High-performance materials can only be added in small quantities to meet the required spinning solution concentration and viscosity. Furthermore, the resulting RSF fibers still require complex post-processing (such as dehydration, recrystallization, and post-stretching) to produce fibers with excellent mechanical properties. This drawback has hindered the further promotion of dry spinning. Conventional electrospinning can typically only produce solid fibers, where all components are mixed in a fiber-forming matrix solution. While these can serve as templates for further fabrication of nanofiber films and scaffolds, it is difficult to directly control the internal porosity, morphology, and structure of the fiber material using a single hollow metal capillary spinneret. Emerging applications in catalysis, energy storage and conversion, environment, and biomedicine require fibers that contain not only two or more types of polymers but also non-polymer materials such as metal oxides, ceramics, semiconductors, and pharmaceuticals. Fibers produced by conventional spinnerets generally have limited applications in these areas. Summary of the Invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method for preparing a multi-responsive conductive fiber. The present invention adopts microfluidic technology to continuously prepare a multi-responsive conductive fiber material in situ, wherein a high-toughness RSF matrix is ​​compounded with calcium alginate fiber to form a core-sheath structure, and then a PEDOT:PSS conductive material is added to form a composite conductive fiber. The resulting material is a smart conductive fiber functional material with good multiple responsiveness such as humidity, temperature, and stretching. The material can realize the intelligent transformation between conductivity and non-conductivity under the stimulation of humidity, temperature, and stretching. Due to the excellent electrochemical stability, high flexibility, and high conductivity of PEDOT:PSS conductive material, combined with the biocompatibility, degradability, and high mechanical properties of bio-based RSF fiber, this high-performance bio-based conductive composite fiber is expected to be used as a flexible electronic device, such as electronic skin, health monitors, soft robots, and various medical devices.

[0006] The object of the present invention is to provide a method for preparing the above-mentioned multi-responsive smart conductive fiber functional material, which comprises the following steps:

[0007] (1) The natural silk was degummed, dissolved, dialyzed and concentrated to obtain the regenerated silk fibroin solution as the inner phase; sodium alginate powder was added to the PEDOT:PSS aqueous solution as the middle phase with dilute acid and Ca 2+Configure the external phase; 2+ Mix with ethanol, glycerol and water to form a coagulation bath;

[0008] (2) preparing a microfluidic device, wherein the microfluidic device comprises a capillary glass tube with a tapered outlet after stretching as an inner phase tube, a square tube as a middle phase tube, and a round tube as an outer phase tube, wherein the middle phase tube is sheathed in the outer phase tube, and the inner phase tube is sheathed in the middle phase tube; wherein the tapered tip of the inner phase tube is retracted 0.1 cm relative to the outlet end of the middle phase tube, and the outlet end of the middle phase tube is retracted 2 cm relative to the outlet end of the outer phase tube;

[0009] (3) The inner phase, middle phase and outer phase are fed into the inner phase tube, middle phase tube and outer phase tube respectively by a syringe pump. After the regenerated silk fibroin solution flows and shears through the microfluidic device, it is passed into a coagulation bath. The regenerated silk fibroin solution is dehydrated to form a core layer fiber. Ca 2+ The multi-responsive conductive fiber was obtained by complexing and cross-linking with sodium alginate to form a sheath fiber.

[0010] Furthermore, the mass fraction of the regenerated silk fibroin solution is 20-30 wt%.

[0011] Furthermore, the concentration of sodium alginate in the middle phase is 1-3 wt %; and the concentration of PEDOT:PSS is 50-70 wt %.

[0012] Furthermore, the dilute acid in the external phase is dilute sulfuric acid or dilute hydrochloric acid.

[0013] Furthermore, the pH of the dilute acid is 2-4.

[0014] Furthermore, the Ca in the external phase 2+ As a pre-crosslinking agent for sodium alginate; Ca 2+ The external phase is prepared by mixing calcium chloride or calcium lactate with dilute acid. 2+ The solution concentration is 0.01-0.03mol / L.

[0015] Furthermore, the Ca in the coagulation bath 2+ The concentration is 0.8-1.2 mol / L, Ca 2+ Added to the coagulation bath in the form of calcium chloride or calcium lactate.

[0016] Furthermore, the volume ratio of ethanol:glycerol:water in the coagulation bath is (2-6):1:1.

[0017] Another object of the present invention is to provide a multi-responsive intelligent conductive fiber functional material.

[0018] In the present invention, the multiple responses refer to humidity response, temperature response and stretching response.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The present invention utilizes multiphase microfluidic wet spinning technology to produce fibers with a core-sheath structure. The multi-responsive intelligent conductive fiber functional material has good humidity responsiveness, temperature responsiveness, and stretching responsiveness at the same time, overcoming the defect that traditional multi-responsive intelligent materials cannot have good humidity responsiveness, temperature responsiveness, and stretching responsiveness at the same time, and has better stability.

[0021] (2) Using dilute acid such as dilute sulfuric acid instead of traditional strong acid to treat PEDOT:PSS not only removes PSS by protonation, but also enhances the conductivity of PEDOT:PSS fibers, and the conductivity can reach 11000S / m.

[0022] (3) The core-sheath structure of the conductive fiber and the addition of bio-based RSF inside it greatly improve the mechanical properties of the conductive fiber, which is of great significance for the widespread application of multi-responsive intelligent conductive fiber functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the preparation of multi-responsive conductive fiber microfluidics;

[0024] Figure 2 The fluid flow direction and schematic diagram of the multi-responsive conductive fiber. (a) The flow direction of the multiphase fluid entering the microfluidic device, (b) Schematic diagram of the conductive fiber core sheath;

[0025] Figure 3 The humidity responsiveness of conductive fibers. (a) The resistance change when water vapor is present around the fiber, (b) a schematic diagram of the device that shows how humidity affects the conductivity of the fiber, and (c) the fiber lighting an LED after adding mist.

[0026] Figure 4 The temperature response of the conductive fiber. (a) The resistance change of the conductive fiber when the temperature changes, (b) Schematic diagram of the device that makes the fiber conductive under the influence of temperature, (e) After the temperature changes, the fiber is used to light an LED lamp;

[0027] Figure 5 is the tensile response of the conductive fiber, that is, the resistance change of the conductive fiber when it is stretched.

[0028] Figure 6 The conductive mechanism of the multi-responsive conductive fiber;

[0029] Figure 7 It is the ultraviolet absorption spectrum of whether the external phase contains sulfuric acid treatment. DETAILED DESCRIPTION

[0030] The present invention will be further described and illustrated below in conjunction with specific embodiments. The embodiments are merely illustrative of the present disclosure and do not limit its scope. The technical features of the various embodiments of the present invention may be combined accordingly, provided that there is no conflict between them.

[0031] Example 1: Preparation of microfluidic device:

[0032] One end of a capillary glass tube with an inner diameter of 0.55 μm and an outer diameter of 0.96 μm was stretched to form a tapered outlet. The stretched capillary glass tube was then polished to a tapered outlet diameter of 300 μm, which served as the inner phase tube. A 1.5 mm × 1.01 mm square tube was placed outside the inner phase tube as the middle phase tube, and an unpolished round tube with a diameter of 2000 μm was placed outside the middle phase tube. The distance between the tip of the inner phase tube and the outlet of the middle phase tube was 0.1 cm, and the distance between the outlet of the middle phase tube and the outlet of the outer phase tube was 2 cm. A V-shaped notch was cut into the plastic inlet of a dispensing needle. The starting ends of the three matched tubes were inserted into the center bottom of the dispensing needle and sealed with epoxy resin on a glass slide to form a coaxial microfluidic device.

[0033] Example 2: Preparation of inner, middle and outer phase solutions

[0034] RSF solution is obtained by degumming, dissolving, dialysis, and concentrating natural silk at room temperature. The specific preparation process can be divided into 6 steps. The first step is cocoon processing. The silkworm pupae are removed and the cocoons are cut into small pieces. They are washed with deionized water to remove insoluble impurities. The second step is degumming. One gram of cocoon pieces are placed in 100mL of 0.5wt% sodium carbonate solution and boiled for 30 minutes. Degumming is carried out by utilizing the property of sericin that can be hydrolyzed in alkaline solution. The degummed silk is soaked in deionized water and washed for 30 minutes to remove sodium carbonate and surface sericin. After repeating the boiling and washing process twice, the degummed silk is dried in a 40°C oven to obtain degummed silk. The third step is dissolution. One gram of dried degummed silk is dissolved in 10mL of 9.3mol / L lithium bromide aqueous solution at 40°C for 2 hours. Insoluble impurities are further removed by filtration. The fourth step is dialysis. Use a dialysis bag with a molecular weight cutoff of 14,000 Da to collect the filtered silk fibroin solution and dialyze it in deionized water for 48 hours to remove salt ions and small molecular peptides. Replace the deionized water every 4 hours. Step 5: Concentrate and concentrate. Use a fan to blow the dilute solution after dialyzation to increase its concentration to ~25wt% to obtain a water-soluble RSF solution. Step 6: Freeze-drying and dissolving. The water-soluble RSF solution is freeze-dried to obtain RSF solid, which is dissolved in 95vt% formic acid organic solvent to prepare a 250mg / mL RSF solution.

[0035] Middle phase (Alg / PEDOT:PSS solution): a certain mass of sodium alginate powder is added to a prepared PEDOT:PSS aqueous solution of a certain concentration; the sodium alginate concentration is 1-3 wt%; the PEDOT:PSS concentration is 50-70 wt%.

[0036] Foreign Minister (H + / Ca 2+ Solution): A certain concentration of dilute acid (dilute sulfuric acid or dilute hydrochloric acid, pH = 2-4) is mixed with a low concentration of calcium ion solution (calcium chloride or calcium lactate) to obtain an external phase solution. 2+ The solution concentration is 0.01-0.03mol / L.

[0037] Coagulation bath: a certain amount of Ca 2+ (Calcium chloride or calcium lactate) is added to a mixed solution of ethanol, glycerol, and water to form a coagulation bath. The volume ratio of ethanol: glycerol: water is (2-6): 1: 1. The Ca 2+ The concentration is 0.8-1.2mol / L.

[0038] Example 3: Preparation of multi-responsive high-performance conductive fibers

[0039] The internal phase of Example 3 is 25 wt% RSF solution; in the coagulation bath, the volume ratio of ethanol, glycerol and water is 3:1:1, Ca 2+ The concentration is 1.0 mol / L; the Alg concentration in the middle phase is 1 wt%, the PEDOT:PSS concentration is 60 wt%, and the Ca 2+ The concentration is 0.01 mol / L, and the pH of dilute sulfuric acid is 2-4.

[0040] As attached Figure 1 As shown, the inner phase RSF solution, the middle phase Alg / PEDOT:PSS solution, and the outer phase H + / Ca 2+ solution into a microfluidic device, wherein the fluid is Figure 2 a flows through the microfluidic device and is sheared, then enters the coagulation bath, where the RSF solution is dehydrated to form core fibers. Ca 2+ Complexation and cross-linking with Alg to form sheath fibers, such as Figure 2b, collected by a collecting roller (6 cm in diameter) for later use. Among them, RSF has excellent mechanical properties due to its own multi-level structure. The unique microscopic multi-level structure of RSF includes the primary structure of the amino acid sequence, including random coils, β-folds, α-helices and β-turns (β-folds form a folded structure at a spatial conformation of 180°), of which the β-crystals formed by the stacking of β-folds are tertiary structures. The component ratio of the secondary structure and the crystallinity of the tertiary structure basically determine the mechanical properties of silk; the β-crystals are embedded in the disordered structure to form silk fibroin nanofibers with a diameter of ≈30nm, forming a quaternary structure; and the network structure formed by the mutual entanglement of silk fibroin nanofibers forms a quinary structure. Therefore, the unique multi-level structure of RSF determines the necessity of the fiber of the present invention to have high strength and high toughness. In addition, since the fiber of the present invention has good humidity ( Figure 3 ),temperature( Figure 4 ), Stretch( Figure 5 ) stimulus responsiveness, the present invention can be widely used in wearable electronic devices, intelligent control and aerospace and other fields. When sensing stimuli such as humidity, temperature (such as fire), stretching, etc., the fiber will realize the intelligent conversion between conductive and non-conductive. The specific stimulus response is as follows:

[0041] When sensing humidity stimulation, the fiber of Example 1 will undergo a significant resistance change, as shown in FIG. Figure 3 a. When exposed to high humidity (such as foggy environment), the LED and the fiber of Example 1 are Figure 3 The connection circuit shown in b will light up, otherwise it will not light up. Figure 3 c. This shows that the fiber of the present invention can generate electrical signals under humidity stimulation.

[0042] When temperature, such as fire, is applied, a significant resistance change signal is generated. Figure 4 a. Example 1 Fiber and LED according to Figure 4 Assembled in b mode, under the condition of temperature change (such as adding fire), the fiber conducts electricity and the LED becomes brighter. When the temperature and other stimuli are removed, the circuit fiber does not conduct electricity and the LED light returns to its initial state, and the LED light becomes dim. Figure 4 e.

[0043] The smart sensing gloves made by sewing the fibers of Example 1 on the joints of the gloves are used for finger joint strain sensing, allowing repeated deformation detection when the finger joints are bent. When the fingers are stretched, the resistance of the fibers of Example 1 will change, such as Figure 5 Therefore, this textile could help humans or robots electronically respond to external environments like water and fire. Furthermore, the combination of fibers and touch-electronic systems enables human-machine interaction for detection and positioning, making it an ideal choice for wearable human-machine interfaces. This sensory textile can not only be used for flexible sensing to achieve a variety of sensing and detection functions, but can also be used for remote control communications.

[0044] Comparative Example 1: Preparation of multi-responsive high-performance conductive fibers

[0045] The internal phase of Comparative Example 1 is 25 wt% RSF solution; in the coagulation bath, the volume ratio of ethanol, glycerol and water is 3:1:1, Ca 2+ The concentration is 1.0 mol / L; the concentration of Alg in the middle phase is 1 wt%, the concentration of PEDOT:PSS is 40 wt%, and the concentration of Ca in the outer phase is 1 wt%. 2+ The concentration is 0.01mol / L and does not contain dilute acid.

[0046] As attached Figure 1 As shown, the inner phase RSF solution, the middle phase Alg / PEDOT:PSS solution, and the outer phase Ca 2+ solution into a microfluidic device, wherein the fluid is Figure 2 After the flow shear of the microfluidic device, the RSF solution is passed into the coagulation bath, and the RSF solution is dehydrated to form the core layer fiber. 2+ It is complexed and cross-linked with Alg to form sheath fibers, which are collected by a collecting roller for later use.

[0047] Comparison between Example 3 and Comparative Example 1 shows that the addition of H + When the water in the PEDOT:PSS solution evaporates, the adjacent microgels in the PEDOT:PSS solution hydrogen bond with each other to form a gel network. + When fibrous PEDOT:PSS solids are formed in the coagulation bath, the two ions H generated by the dissociation of PEDOT oligomers and PSS chains with sulfuric acid in water are + and SO4 2- reaction. In particular, when the positively charged H + When the negative charge of the PSS chain is reacted and neutralized, the electrostatic interaction between the PEDOT oligomer and the PSS chain is weakened. As a result, free PSS chains that are not affected by the PEDOT oligomer are removed from the fibrous PEDOT:PSS solid, such as Figure 6 And whether the external phase contains sulfuric acid can be measured by UV spectrophotometer. Figure 7 During this process, the proportion of conductive PEDOT oligomers increases above the proportion of insulating PSS chains in the fibrous PEDOT:PSS solid, and the PEDOT network with strong π-π stacking properties becomes dense. As a result, highly crystalline and conductive PEDOT:PSS fibers can be obtained.

[0048] Comparative Example 2: Preparation of Conductive Fiber without Pre-crosslinking

[0049] The inner phase of Comparative Example 2 is 25wt% RSF solution; the Alg concentration in the middle phase is 1wt%, the PEDOT:PSS concentration is 60wt%, and the outer phase contains only dilute sulfuric acid with a pH of 2-4 and no Ca 2+ In the coagulation bath, the volume ratio of ethanol, glycerol and water is 3:1:1, Ca 2 + The concentration was 1.0 mol / L. The inner, middle and outer phases were all flowed into the microfluidic device of Example 1 according to the method of Example 3, and finally formed core-sheath fibers.

[0050] Comparison between Example 3 and Comparative Example 2 shows that adding a small amount of Ca 2+ It is beneficial to the formation of conductive fibers. A pre-crosslinking strategy is used to establish covalent bonds between the middle phase and the outer phase. Alg and Ca 2+ Pre-crosslinking, initially forming a small amount of chelating network structure. Add a small amount of Ca 2+ Can realize Alg and Ca 2+ Pre-crosslinking, but because of Ca 2+ At lower concentrations, the fibers can be initially formed, with a rudimentary morphology and an incomplete cross-linked network. After passing through the coagulation bath, the fibers are fully formed. The pre-crosslinking strategy improves the dispersion of PEDOT:PSS in the fibers, thereby enhancing the conductivity of the fibers.

[0051] Comparative Example 3: Preparation of Conductive Fiber without Secondary Crosslinking

[0052] The inner phase of Comparative Example 3 is 25wt% RSF solution; the Alg concentration in the middle phase is 1wt%, the PEDOT:PSS concentration is 60wt%, and the Ca 2+ The concentration is 1.94 mol / L, and the pH of dilute sulfuric acid is 2-4. In the coagulation bath, the volume ratio of ethanol, glycerol, and water is 3:1:1, and there is no Ca 2+ The inner, middle and outer phases were respectively flowed into the microfluidic device of Example 1 according to the method of Example 3, and finally formed core-sheath fibers.

[0053] Comparison between Example 3 and Comparative Example 3 shows that only low concentration of Ca is added to the external phase. 2+ , the fiber is not easy to form; high concentration of Ca is added to the external phase 2+ Therefore, only Ca is added to the external phase. 2+ , no Ca added to the coagulation bath 2+ Fiber molding is difficult to control. Preparation without secondary crosslinking is difficult to control fiber preparation.

[0054] Comparative Example 4: Preparation of non-crosslinked conductive fibers

[0055] The internal phase of Comparative Example 4 is 25 wt% RSF solution; in the coagulation bath, the volume ratio of ethanol, glycerol and water is 5:1:1, Ca 2+ The concentration is 1.0 mol / L; the concentration of PEDOT:PSS in the middle phase is 60 wt%, and there is no Alg. The Ca 2+ The concentration is 0.01 mol / L, and the pH of dilute sulfuric acid is 2-4.

[0056] As attached Figure 1 As shown, the inner phase RSF solution, the middle phase PEDOT:PSS solution, and the outer phase H + / Ca 2 + The solution was added to the microfluidic device of Example 1. The RSF solution flowed through the microfluidic device and sheared, and then passed into a coagulation bath. The RSF solution was dehydrated to form fibers, which were collected by a collection roller (with a diameter of 6 cm) for later use.

[0057] Comparison of Example 3 with Comparative Example 4 shows that the addition of a calcium alginate sheath layer can make the core-sheath fiber more responsive to humidity stimulation. This is attributed to the change in the strength of hydrogen bonds between the Alg in the sheath layer. Since PEDOT is a hole-conducting polymer and PSS blocks hole transport, the PSS matrix around the PEDOT-enriched domain represents an obstacle for charge carriers. Alg, as a highly hygroscopic material, when the fiber absorbs moisture from the surrounding humid environment, then expands and hydrogen bonds weaken due to the hygroscopicity of hydrophilic Alg and PSS, synergistically increasing carrier mobility and carrier concentration, thereby significantly improving conductivity.

[0058] The above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or imagined by a person skilled in the art from the disclosure of the present invention should be considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a multi-responsive conductive fiber, characterized in that: The following steps are involved: (1) Natural silk is degummed, dissolved, dialyzed, and concentrated to obtain a regenerated silk fibroin solution as the internal phase; Sodium alginate powder was added to the PEDOT:PSS aqueous solution as the middle phase; dilute acid and Ca 2+ Configure the external phase; 2+ Mix with ethanol, glycerol and water to form a coagulation bath; (2) preparing a microfluidic device, wherein the microfluidic device comprises a capillary glass tube with a tapered outlet after stretching as an inner phase tube, a square tube as a middle phase tube, and a round tube as an outer phase tube, wherein the middle phase tube is sheathed in the outer phase tube, and the inner phase tube is sheathed in the middle phase tube; wherein the tapered tip of the inner phase tube is retracted 0.1 cm relative to the outlet end of the middle phase tube, and the outlet end of the middle phase tube is retracted 2 cm relative to the outlet end of the outer phase tube; (3) The inner phase, middle phase and outer phase are fed into the inner phase tube, middle phase tube and outer phase tube respectively by a syringe pump. After the regenerated silk fibroin solution flows and shears through the microfluidic device, it is passed into a coagulation bath. The regenerated silk fibroin solution is dehydrated to form a core layer fiber. Ca 2+ The multi-responsive conductive fiber was obtained by complexing and cross-linking with sodium alginate to form a sheath fiber.

2. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The mass fraction of the regenerated silk fibroin solution is 20-30 wt%.

3. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The concentration of sodium alginate in the middle phase is 1-3 wt %; the concentration of PEDOT:PSS is 50-70 wt %.

4. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The dilute acid in the external phase is dilute sulfuric acid or dilute hydrochloric acid.

5. The method for preparing a multi-responsive conductive fiber according to claim 1 or 4, characterized in that: The pH of the dilute acid is 2-4.

6. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The Ca in the external phase 2+ As a pre-crosslinking agent for sodium alginate; Ca 2+ The external phase is prepared by mixing calcium chloride or calcium lactate with dilute acid.

7. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The Ca in the external phase 2+ The concentration is 0.01-0.03mol / L.

8. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The Ca in the coagulation bath 2+ The concentration is 0.8-1.2 mol / L, Ca 2+ Added to the coagulation bath in the form of calcium chloride or calcium lactate.

9. The method for preparing a multi-responsive conductive fiber according to claim 1, wherein: The volume ratio of ethanol:glycerol:water in the coagulation bath is (2-6):1:

1.

10. The multi-responsive conductive fiber prepared by the method according to any one of claims 1 to 9, characterized in that: The multiple responses are humidity response, temperature response and stretch response.

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