Method for producing elastic semiconductor fibers and use thereof

Abstract

The application discloses a preparation method of elastic semiconductor fibers and application thereof, and belongs to the field of flexible electronic materials. In view of the fact that existing semiconductor fibers are difficult to meet the demand of wearable electronics on elasticity and electrical stability, the application proposes a general method containing material compatibility driven synergistic co-spinning, anti-solvent regulated nano-phase separation and swelling induced post-crosslinking, and successfully prepares semiconductor fibers with high elasticity and high electrical performance. The breaking strain of the fiber can be more than 860%, and the fiber still has almost complete elastic recovery ability under a strain of up to 500%. After the introduction of an insulating elastomer, the electrical performance of the composite fiber is even improved. The method is suitable for various conjugated polymer systems, and the obtained elastic semiconductor fibers can be used for constructing biosensors and three-dimensional thermoelectric fabrics, and provides a general elastic semiconductor fiber construction strategy for realizing a wearable electronic system with high performance and strong conformability.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronic materials and fiber electronic devices, specifically relating to a method for preparing conjugated polymer / elastomer composite fibers and their applications, particularly a process for obtaining elastic organic semiconductor functional fibers through synergistic co-spinning, nanophase separation control and post-crosslinking treatment. Background Technology

[0002] Stretchable and intrinsically elastic materials and devices have wide applications in wearable electronics, skin-contact electronics, and personalized health monitoring. Compared to traditional planar devices, fiber-based electronic devices offer advantages such as good breathability, seamless integration with textile structures, and three-dimensional conformability, making them a focus of attention in flexible electronics and wearable systems. In applications involving human movement or other dynamic environments, these devices need to maintain stable electrical performance under cyclic mechanical deformation, thus placing higher demands on the elastic recovery capabilities of the materials.

[0003] Existing fiber-based electronic devices are mostly constructed using silicon, carbon, metals, or conjugated polymer systems. These materials typically fail at low strain (less than 15%) or struggle to recover their initial electrical properties after experiencing significant strain, limiting their applicability in flexible and stretchable applications. Therefore, obtaining fiber materials that maintain structural integrity and electrical stability under repeated mechanical deformation is a pressing problem that needs to be solved.

[0004] Conjugated polymers are widely used in the construction of flexible semiconductor devices due to their excellent flexibility, solution processability, and unique optoelectronic properties. Semiconductor fibers based on these materials have shown application potential in fields such as organic electrochemical transistors (OECT) and organic thermoelectric devices (OTE). However, fiber materials that combine both elasticity and semiconductor properties have not yet been realized, which greatly limits their practical application in wearable electronic textiles that need to withstand large deformation conditions.

[0005] In conjugated polymer film systems, common strategies to improve elasticity or stretchability include embedding active materials into an elastomer matrix or introducing cross-linked networks within it. However, these methods face several challenges when converting to fiber structures: on the one hand, the compatibility between the conjugated polymer and the elastomer affects the spinning stability of the fiber, and the phase separation mechanism during spinning is still unclear; on the other hand, common cross-linking processes are often slow and have fixed reaction conditions, making it difficult to match continuous and dynamic spinning processes. Furthermore, although some studies have reported the preparation of elastic conductive fibers by embedding conductive materials into elastomers, a high content of insulating elastomer is often introduced to ensure spinnability and stretchability, leading to a significant decrease in the fiber's electrical properties.

[0006] To date, there is no universally applicable fiber fabrication method that can simultaneously achieve high mechanical elasticity and maintain semiconductor properties. Therefore, how to construct fiber materials that combine excellent elasticity with stable electrical properties remains a key problem to be solved in this technical field. Summary of the Invention

[0007] This invention addresses the lack of fiber materials possessing both high elasticity and stable semiconductor properties in existing technologies. It proposes a general preparation strategy for constructing elastic semiconductor fibers and, based on this strategy, develops various elastic electronic devices, including but not limited to fiber-based biosensors and three-dimensional thermoelectric fabric devices. Through methods such as material compatibility regulation, nanophase separation regulation, and swelling-induced crosslinking, this invention achieves a synergistic improvement in fiber elasticity and electrical properties. Specifically, it includes the following three parts:

[0008] First aspect: Co-spinning based on solubility parameter matching (ECO)

[0009] Introducing elastomers into thin film systems can improve the elasticity and stretchability of materials. However, when used directly in fiber preparation, the complex interactions between multiple components such as conjugated polymers, elastomers, solvents, and antisolvents can easily lead to difficulties in solution homogeneity and solidification process control, thereby restricting the stability of fiber forming.

[0010] To address this problem, this invention, based on Hansen's solubility theory, calculates the solubility distance between the conjugated polymer and the elastomer, and screens material combinations capable of forming a uniform spinning solution and achieving synchronous phase transitions under the same solidification conditions. By mixing compatible materials in a predetermined ratio and then wet-spinning them, semiconductor composite fibers with uniform morphology and good mechanical properties are successfully obtained.

[0011] The second aspect: Nanophase separation based on solvent resistance regulation (ARN)

[0012] Antisolvents not only drive polymer precipitation during fiber forming but also affect chain segment arrangement and crystallization behavior, thus directly determining the fiber's microstructure and mechanical properties. Inappropriate antisolvent selection can easily lead to problems such as uneven phase separation, fiber morphology defects, and decreased elasticity.

[0013] Therefore, this invention comprehensively considers the solubility distance and diffusion flux ratio between the solvent and the antisolvent to screen out an antisolvent system capable of achieving rapid and balanced interdiffusion, thereby promoting the formation of a nanoscale phase separation structure in the fiber during solidification. The composite fiber prepared by this method has the characteristics of uniform cross-sectional morphology, stable phase separation structure, and reduced crystallinity, while its elongation at break and elastic recovery properties are significantly improved.

[0014] The third aspect: based on swelling-induced post-crosslinking (SUP-X)

[0015] Crosslinking can restrict chain segment slippage and enhance network stability, making it an important means of improving the elasticity of conjugated polymers. However, traditional crosslinking methods used in film or hydrogel systems are not suitable for fiber systems, due to reasons including the loss of crosslinking agents during spinning and the difficulty in incorporating crosslinking reaction rates with continuous spinning.

[0016] To address this issue, this invention proposes a swelling-induced post-crosslinking strategy: nascent fibers are immersed in a solution containing a crosslinking agent. The swelling of the elastomer promotes the diffusion of the crosslinking agent into the fiber interior. Crosslinking is then triggered by heating, allowing the conjugated polymer and elastomer to form a stable covalent network structure, thereby limiting segment slip and improving the fiber's deformability. Using a solvent with suitable swelling properties can improve crosslinking efficiency and achieve uniform internal crosslinking. By controlling the concentration of the crosslinking agent, the crosslinking density can be further increased, thereby enhancing the mechanical strength, elastic recovery, and microstructural stability of the composite fiber.

[0017] Fourth aspect: Constructing elastic electronic devices based on elastic semiconductor fibers

[0018] The elastic semiconductor fibers prepared by this invention can be used as functional materials in various types of elastic electronic devices. Elastic fiber OECT devices constructed using the fibers of this invention can maintain a stable electrical response during strain loading and unloading processes. Furthermore, three-dimensional thermoelectric fabric devices constructed based on the fibers of this invention can maintain stable output in deformation environments and achieve close-fitting heat collection from the human body.

[0019] Specifically, the present invention provides a method for preparing an elastic semiconductor fiber, comprising the following steps:

[0020] a) Co-spinning (ECO): The compatibility between the conjugated polymer and the elastomer is determined based on the Hansen solubility distance. The elastomer and the conjugated polymer with compatibility that meets the preset conditions are mixed at a preset mass ratio and co-dissolved in an organic solvent. The mixture is stirred under heating conditions to obtain a uniform spinning solution.

[0021] b) Antisolvent-regulated nanophase separation (ARN): The spinning solution obtained in step a) is extruded into an antisolvent coagulation bath at a constant speed. The rapid and balanced interdiffusion of solvent and antisolvent allows the fiber to form a nanoscale phase separation structure during the coagulation process, resulting in composite fiber.

[0022] c) Swelling-induced post-crosslinking (SUP-X): The composite fiber obtained in step b) is immersed in a solution containing a crosslinking agent, causing the fiber to swell and allowing the crosslinking agent to diffuse into the fiber interior, thereby triggering a crosslinking reaction and forming a stable covalent crosslinked network inside the fiber.

[0023] Further, the compatibility condition mentioned in step a) refers to the Hansen solubility distance between the conjugated polymer and the elastomer (…). R a The pressure is less than a first preset threshold. The first preset threshold is preferably 5 MPa. 1 / 2 More preferably 2 MPa 1 / 2 .

[0024] Further, the conjugated polymer in step a) can be selected from various p-type, n-type, or bipolar conjugated polymers, including but not limited to P(PzDPP-2FT), P(gTDPP-2FT), P(bgTDPP-CT2), P(g2T-T), P(TDPP-TQ), P(TDPP-BT), BBL, PBFDO, and PEDOT:PSS. The elastomer can be selected from at least one of styrene block copolymers, polyurethanes, polyisoprene elastomers, and polybutadiene elastomers, including but not limited to SEBS, TPU, IIR, HVPB, and TBIR. The mass ratio of the conjugated polymer to the elastomer is 1:9 to 9:1.

[0025] Further, the antisolvent in the coagulation bath and the solvent in the spinning solution in step b) R a The diffusion flux ratio of the two is less than the second preset threshold. η The second preset threshold is preferably 10 MPa. 1 / 2 , η The value is in the range of 0.85 to 1.

[0026] Further, the solvent used in step c) can be any solvent capable of dissolving the crosslinking agent and swelling but not dissolving the composite fibers. The solvent used for swelling and the elastomer... R a The smaller the better, preferably, between the two. R a Less than a third preset threshold, wherein the third preset threshold is preferably 10 MPa 1 / 2 .

[0027] Preferably, the crosslinking agent in step c) is a multifunctional aziridine compound, and the crosslinking reaction is triggered by heating or ultraviolet light.

[0028] The elastic semiconductor fiber prepared by the above-described method is also within the scope of protection of this invention. The elastic semiconductor fiber contains a nanoscale phase-separated structure, wherein the conjugated polymer forms a continuous nanofiber conductive network, the elastomer forms a continuous matrix, and the conjugated polymer nanofiber conductive network is embedded in the elastomer matrix.

[0029] The elastic semiconductor fiber prepared by this invention has an elastic recovery rate of ≥70% under a certain strain, and its electrical properties are comparable to or even improved compared to pure conjugated polymer fibers.

[0030] Based on the aforementioned elastic semiconductor fiber, this invention provides an elastic fiber-type organic electrochemical transistor (OECT), comprising an elastic substrate, a source, a drain, a gate, and an electrolyte solution, wherein the channel material between the source and drain is the aforementioned elastic semiconductor fiber. This organic electrochemical transistor maintains stable electrical performance under a tensile strain of not less than 50%, including but not limited to a material quality factor (…). μC *) and transconductance ( g m )wait.

[0031] Furthermore, the present invention also provides an elastic fiber type OECT sensor, in which the elastic semiconductor fiber is used as the channel material between the source and drain, and the test solution containing biomarkers is used as the electrolyte solution. By modifying the gate or elastic semiconductor fiber for biomarkers, high sensitivity and linear sensing of multiple biomarkers can be achieved.

[0032] Based on the above-mentioned elastic semiconductor fibers, the present invention provides a three-dimensional thermoelectric fabric, including the elastic semiconductor fibers or fiber bundles, wherein p-type and n-type elastic semiconductor fibers or fiber bundles are alternately arranged to form a thermoelectric path, which can output a measurable voltage under a temperature gradient.

[0033] In summary, to address the challenge that existing semiconductor fibers cannot simultaneously meet the elasticity and electrical stability requirements of wearable electronics, this invention achieves this through the synergistic application of three technical solutions: ECO, ARN, and SUP-X.

[0034] (1) Controllable cosolubility of conjugated polymers and elastomers;

[0035] (2) Stable nanophase separation structure inside the fiber;

[0036] (3) Efficient and uniform cross-linking within the fiber;

[0037] (4) Organic semiconductor fibers that combine high elasticity and high electrical properties;

[0038] (5) Stable construction and use of various flexible electronic devices.

[0039] This invention provides a general and scalable technical solution for the fabrication of elastic semiconductor fibers and their electronic devices. The prepared semiconductor fibers possess both high elasticity and high electrical properties, with a fracture strain exceeding 860% and almost complete elastic recovery capability even at strains up to 500%. The electrical properties of the composite fibers are even improved by introducing an insulating elastomer. This method is applicable to various conjugated polymer systems, and the resulting elastic semiconductor fibers can be used to construct biosensors and three-dimensional thermoelectric fabrics, providing a general strategy for constructing elastic semiconductor fibers to achieve high-performance, highly conformable wearable electronic systems. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall construction process of the elastic semiconductor fiber of the present invention, which includes three steps: co-spinning (ECO), solvent-resistant nanophase separation (ARN), and swelling-induced post-crosslinking (SUP-X).

[0041] Figure 2 This is the elastomer screening method in Example 1, where 'a' shows the solubility distance between the conjugated polymer P1 and different elastomers. R a b shows the elastic recovery rate of fibers obtained from different material systems.

[0042] Figure 3 This is the solvent screening method in Example 2, where a shows the solvent ( o The solubility distance between -DCB and different antisolvents (EtOH, DMSO, EA) R a and diffusion flux ratio η b shows the mechanical properties of P1 / SEBS (7:3) fibers prepared under different antisolvent conditions.

[0043] Figure 4 The images show the cross-sectional morphology of P1 / SEBS (7:3) fibers obtained under different antisolvent conditions in Example 2, where a, b, and c correspond to the cross-sectional structures when EtOH, DMSO, and EA are used as antisolvents, respectively.

[0044] Figure 5 The mechanical properties of fibers with different conjugated polymer / elastomer ratios in Example 2 are shown.

[0045] Figure 6 The image shows the nanophase separation structure in the P1 / SEBS (3:7) fiber in Example 2, where the dark area represents the conjugated polymer phase (P1 phase) and the light area represents the elastomer phase (SEBS matrix). a shows the P1 phase that is uniformly distributed in the SEBS matrix inside the fiber, and b shows the randomly oriented but interconnected fibrous network.

[0046] Figure 7 The method for screening crosslinking agent solvents in Example 3 shows that 'a' represents the solubility distance between the elastomer SEBS and different solvents (EtOH, Ace, DMSO, EA). R a b shows the mechanical properties of the fiber after immersion and annealing in different solutions.

[0047] Figure 8 The mechanical properties of P1 / SEBS (7:3) fibers in Example 3 after SUP-X treatment include the changes in elastic recovery rate and breaking strain with the concentration of crosslinking agent (0, 0.2, 0.5, 1, 3 mg / mL) (where the crosslinking agent solution is EA).

[0048] Figure 9 The elastic properties of P1, P1 / SEBS (3:7) and cross-linked P1 / SEBS (3:7) (X-P1 / SEBS (3:7)) fibers in Examples 1-3 are compared. In this example, a is the elastic recovery rate under different strains, and b is the cyclic tensile curve of X-P1 / SEBS (3:7) fiber under 500% strain.

[0049] Figure 10 The solubility distance between the conjugated polymers and different elastomers in Examples 4-6 R a a, b, and c correspond to the P2, P3, and P4 systems, respectively.

[0050] Figure 11 The solvent screening methods in Examples 4-6 include the solubility distance between the solvent (HFIP) and different antisolvents (Ace, ACN, EA). R a and diffusion flux ratio η .

[0051] Figure 12 Examples 4-6 show the mechanical properties of conjugated polymer fibers, conjugated polymer / elastomer composite fibers, and fibers treated with SUP-X. a, b, and c correspond to the P2, P3, and P4 systems, respectively.

[0052] Figure 13 This is a schematic diagram of the structure of the elastic fiber organic electrochemical transistor (OECT) of the present invention, including an elastic substrate, an elastic semiconductor fiber channel, a source, a drain, a gate, and an electrolyte.

[0053] Figure 14The OECT performance of P2, P2 / TPU (7:3) and X-P2 / TPU (7:3) fibers in Example 4 is shown, where a is the transfer curve of P2 / TPU (7:3) fiber (where...). I D For source and leakage current, V G Gate voltage, g m (b is transconductance) and (b is the three types of fibers) μC *Value comparison, c represents the P2 / TPU (7:3) fibers in Example 7 under different strain conditions. μC *value.

[0054] Figure 15 The OECT performance of P3 and P3 / TPU (7:3) fibers in Example 5 is shown, where a is the transfer curve of P3 / TPU (7:3) fibers (where...). I D For source and leakage current, V G Gate voltage, g m (b represents transconductance) and (b represents the two types of fibers) μC *Value comparison.

[0055] Figure 16 The OECT performance of P4 and P4 / TPU (7:3) fibers in Example 6 is shown, where a is the transfer curve of P4 / TPU (7:3) fiber (where...). I D For source and leakage current, V G Gate voltage, g m (b represents transconductance) and (b represents the two types of fibers) μC *Value comparison.

[0056] Figure 17 This refers to the fiber-type biosensor constructed from P4 / TPU (7:3) fibers in Example 8, where 'a' represents the real-time reading of the sensor as different concentrations of lactic acid solution are gradually added. I DS Response (of which) I DS For source and leakage current, V G Gate voltage, V D b is the source-drain voltage), and b is the normalized calibration curve (where...). NR (For normalized response).

[0057] Figure 18This is a schematic diagram of the structure of the fiber-type organic thermoelectric device (OTE) of the present invention, including an elastic semiconductor fiber channel, a hot and cold end, and electrodes.

[0058] Figure 19 The electrical conductivity of P1, P1 / SEBS (7:3) and X-P1 / SEBS (7:3) fibers in Example 9 is ( ). σ Seebeck coefficient () S ) and power factor ( PF )contrast.

[0059] Figure 20 The thermoelectric properties of P1 / SEBS (7:3) fibers in Example 9 after different tensile strain releases.

[0060] Figure 21 This is a schematic diagram of the three-dimensional thermoelectric fabric constructed from P1 / SEBS (7:3) fiber bundles and PEDOT:PSS fiber bundles in Example 10.

[0061] Figure 22 The three-dimensional thermoelectric fabric in Example 10 is shown at different temperature differences (Δ). T Output voltage (Δ) under ) V ). Detailed Implementation

[0062] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of the invention is not limited in any way.

[0063] The following are the calculation or testing methods for the relevant performance indicators in each embodiment:

[0064] Solubility distance ( R a The calculation method for Hansen solubility parameters (HSPs) includes diffusion interaction parameters. δ d Polar interaction parameters δ p Hydrogen bond interaction parameters δ h Solubility distance between materials ( R a It can be calculated as:

[0065]

[0066] in, δ d1 , δ p1 , δ h1 These represent the diffusion interaction parameter, polar interaction parameter, and hydrogen bond interaction parameter of the first group of components, respectively. δ d2 , δ p2 , δ h2 These represent the diffusion interaction parameter, polar interaction parameter, and hydrogen bond interaction parameter of the second component, respectively. R a This represents the solubility distance between the two components. R a The smaller the value, the higher the blending ability between components.

[0067] Diffusion flux ratio ( η The calculation method for ( ) is as follows: Fiber formation in wet spinning mainly depends on the interdiffusion behavior between the solvent in the spinning solution and the antisolvent in the coagulation bath. At their interface, the diffusion flux of the solvent towards the antisolvent is... J A The diffusion flux of the antisolvent towards the solvent is J B their ratio η The calculation is as follows:

[0068]

[0069] in, ρ A , ρ B These are the densities of the solvent and the antisolvent, respectively. M A , M B These represent their molar molecular weights. η The closer the value is to 1, the more balanced the interfacial solvent-antisolvent exchange is.

[0070] Fiber fracture strain and elastic recovery rate testing: An Instron 68SC-05 universal testing machine was used. The fiber was fixed and clamped onto a aperture card. In the tensile test, the fiber was... The load rate is applied until fracture. In the tensile-release test, the load rate is... The loading rate stretches the fiber to a gradually increasing strain or five times consecutively to a fixed strain, then releases it to its initial length. Elastic recovery rate ( ER It can be calculated as:

[0071]

[0072] in, ε and ε R These represent the applied strain and the residual strain after release, respectively.

[0073] Electrical performance of a fiber-type organic electrochemical transistor (OECT): A fiber was placed on a clean silicon dioxide (SiO2) substrate, covered with a metal mask, and then a metal adhesion layer (Ti, 2 nm) and a metal conductive layer (Au, 5 nm) were sequentially deposited by magnetron sputtering to form the source and drain electrodes. Using an Ag / AgCl electrode as the gate, a 0.1 M sodium chloride aqueous solution was added dropwise at the channel as the electrolyte. The gate voltage and source-drain voltage were applied using a semiconductor parameter analyzer, and the transfer curve was measured. The device… μC * The calculation was performed according to the steps in the literature (Adv. Mater. 2024, 36, 2400287).

[0074] Example 1: Preparation of P1 / SEBS composite fibers (ECO synergistic co-spinning)

[0075] The laboratory-synthesized n-type conjugated polymer P1 (P(PzDPP-2FT)) was selected. The specific synthesis method is described in the reference (Nat. Commun. 2021, 12, 5723). Its chemical structure is as follows:

[0076]

[0077] The selected commercially available elastomers included polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) and thermoplastic polyurethane (TPU), as well as laboratory-synthesized butyl rubber (IIR), high vinyl polybutadiene rubber (HVPB), and trans-1,4-poly(butadiene-co-isoprene) rubber. trans -1,4-poly(butadiene- co (-isoprene)rubber, TBIR), for specific synthesis methods, please refer to the reference (Nature 2025, 644, 920-926), its chemical structure is as follows:

[0078]

[0079] Where m, n and w, x, y, z all represent the number of different repeating units.

[0080] Based on Hansen's solubility theory, the relationship between P1 and each elastomer was calculated. R a value( Figure 2 (a) Select representative elastomers SEBS, HVPB, and TPU, and weigh P1 and the above three elastomers at a mass ratio of 7:3 respectively, and add o-dichlorobenzene ( o Using DCB as a solvent, the concentration of P1 was controlled at 10 mg / mL. The mixture was magnetically stirred overnight at 70°C to obtain a homogeneous spinning solution.

[0081] The spinning solution is loaded into a syringe and extruded through a metal needle (30 G or 34 G) into an ethanol (EtOH) coagulation bath at a constant speed (0.04 or 0.06 mL / min), causing the fiber to solidify rapidly. The formed fiber is then drawn and collected by a winding device to obtain continuous P1 / elastomer (7:3) composite fiber.

[0082] Mechanical property test results show that the elastic recovery rate of composite fibers obtained by adding different elastomers varies, among which... R a The smallest combination (P1 / SEBS) exhibits the highest elastic recovery rate. Figure 2 (b) verified the feasibility of using Hansen solubility theory to screen materials for compatibility in order to achieve synergistic co-spinning.

[0083] Example 2: Composite fibers under different solvent resistance conditions (ARN nanophase separation control)

[0084] The spinning solution obtained in Example 1 was extruded into an EtOH, ethyl acetate (EA), or dimethyl sulfoxide (DMSO) coagulation bath at a rate of 0.04 or 0.06 mL / min to form fibers.

[0085] Solvent calculations based on Hansen's solubility theory o - Between DCB and different antisolvents R a and η Value discovery, o -The lowest value exists between DCB and EA. R a and closer to equilibrium η This indicates that it has relatively fast and balanced interdiffusion characteristics, which is conducive to the formation of composite fibers with uniform structure and better mechanical properties. Figure 3 , Figure 4 ).

[0086] Furthermore, the fiber's breaking strain and elastic recovery rate increase with increasing SEBS content. When the mass ratio of P1 to SEBS is 3:7, the breaking strain can reach 866%, and the instantaneous elastic recovery rate at 50% strain is approximately 86.9%. Figure 5 ).

[0087] Transmission electron microscopy (TEM) results showed that the P1 phase (arbitrarily oriented but interconnected fibrous network) was uniformly distributed within the SEBS matrix inside the P1 / SEBS (3:7) fibers, forming a nanoscale phase-separated structure. Figure 6 ).

[0088] Example 3: Swelling-induced crosslinking of composite fibers (post-SUP-X swelling crosslinking)

[0089] The fibers obtained in Example 2 were immersed in a solution containing a crosslinking agent for 24 hours to allow the fibers to swell moderately and promote the penetration of the crosslinking agent into the fiber interior. The crosslinking agent used in this example is a tetrazolium-based crosslinking agent. The specific synthesis method can be found in the references (Nature 2025, 644, 920-926, Science 2019, 366, 875-878), and its chemical structure is as follows:

[0090]

[0091] After the fibers are retrieved, they are placed on a hot table and heated at 130°C for 30 minutes to trigger chemical cross-linking and form a stable covalent network structure, thereby improving the elastic recovery rate of the fibers.

[0092] The crosslinking agent solvent and concentration are crucial for SUP-X. EA and SEBS... R a Minimum value ( Figure 7 (a) indicates that it has the best swelling compatibility. Therefore, at the same crosslinking agent concentration (1 mg / mL), EA shows higher crosslinking efficiency and exhibits a higher elastic recovery rate. Figure 7 (b)

[0093] Increasing the crosslinking agent can improve the crosslinking density, thereby increasing the elastic recovery rate of the fiber and decreasing the breaking strain. Figure 8 By selecting appropriate crosslinking agent solvents and concentrations, X-P1 / SEBS (3:7) fibers can achieve an instantaneous elastic recovery rate of over 82%, even at 500% strain. Figure 9 ).

[0094] Example 4: Preparation of P2 / TPU elastic semiconductor fibers

[0095] The laboratory-synthesized n-type conjugated polymer P2 (P(gTDPP-2FT)) was selected. The specific synthesis method is described in the reference (Nat. Commun. 2022, 13, 5970). Its chemical structure is as follows:

[0096]

[0097] The appropriate TPU elastomer for P2 was selected according to the method in Example 1. Figure 10 (a) P2 and TPU were mixed at a mass ratio of 7:3, and hexafluoroisopropanol (HFIP) was added as a solvent. The concentration of P2 was controlled at 10 mg / mL, and the mixture was magnetically stirred overnight at 40°C to form a uniform spinning solution.

[0098] Preferred antisolvents EA were screened according to the method in Example 2. Figure 11 Following the spinning process of Example 1, the spinning solution was extruded and shaped, and then crosslinked with SUP-X according to Example 3 to obtain X-P2 / TPU (7:3) fibers.

[0099] Mechanical property test results show that the elastic recovery rate of the fiber under 50% strain conditions increased from 27.5% in the uncrosslinked state to 89.9% in the crosslinked state. Figure 12 (a). OECT device test results show that, compared with P2 fiber ( Compared to P2 / TPU (7:3) fibers, μC *achieve After cross-linking, the fiber μC *Slight decrease ( Figure 14 (a, b). It can be seen that this strategy achieves a synergistic enhancement of elasticity and electrical performance.

[0100] Example 5: Preparation of P3 / TPU elastic semiconductor fibers

[0101] The chemical structure of the laboratory-synthesized n-type conjugated polymer P3 (P(bgTDPP-CT2)) is as follows:

[0102]

[0103] The appropriate TPU elastomer for P3 was screened according to the method in Example 1. Figure 10 (b) P3 and TPU were mixed at a mass ratio of 7:3, HFIP was added as a solvent, the concentration of P3 was controlled at 3 mg / mL, and the mixture was magnetically stirred overnight at 40°C to form a uniform spinning solution.

[0104] Preferred antisolvents EA were screened according to the method in Example 2. Figure 11 Following the spinning process of Example 1, the spinning solution was extruded and shaped, and then crosslinked with SUP-X according to Example 3 to obtain X-P3 / TPU (7:3) fibers.

[0105] Mechanical property test results show that the elastic recovery rate of P3 fiber under 50% strain condition increased from 29% to 81.5% of that of X-P3 / TPU (7:3) fiber. Figure 12(b) OECT test results show that, compared with P3 fiber, P3 / TPU (7:3) fiber has... μC *There was also an improvement ( Figure 15 This example also verifies that the present invention can achieve synergistic enhancement of the elasticity and electrical properties of elastic semiconductor fibers.

[0106] Example 6: Preparation of P4 / TPU elastic semiconductor fibers

[0107] The p-type conjugated polymer P4 (P(g2T-T)) synthesized in the laboratory was selected. The specific synthesis method can be found in the literature (J. Am. Chem. Soc. 2016, 138, 10252-10259), and its chemical structure is as follows:

[0108]

[0109] The appropriate TPU elastomer for P4 was selected according to the method in Example 1. Figure 10 c). P4 and TPU were mixed at a mass ratio of 7:3, HFIP was added as a solvent, and the concentration of P4 was controlled at 10 mg / mL. The mixture was magnetically stirred overnight at 40°C to form a uniform spinning solution.

[0110] Preferred antisolvents EA were screened according to the method in Example 2. Figure 11 Following the spinning process of Example 1, the spinning solution was extruded and shaped, and then crosslinked with SUP-X according to Example 3 to obtain X-P4 / TPU (7:3) fibers.

[0111] Mechanical property test results show that the elastic recovery rate of P4 fiber under 20% strain condition increased from 58.3% to 87.1% of X-P4 / TPU (7:3) fiber. Figure 12 c). OECT device test results show that, compared with P4 fiber, P4 / TPU (7:3) fiber has... μC *There was also an improvement ( Figure 16 This example also verifies that the present invention can achieve synergistic enhancement of the elasticity and electrical properties of elastic semiconductor fibers.

[0112] Example 7: Construction and Testing of Elastic Fiber OECT Devices

[0113] A sacrificial layer was formed by spin-coating a 3% polyvinyl alcohol (PVA) aqueous solution onto a silicon wafer, followed by drop-coating of a SEBS / toluene solution. After standing overnight, the substrate was pre-stretched by 60% along the fiber direction for fixation. A stretchable source / drain electrode (Au, 50 nm) was then formed by thermal evaporation after covering with a metal mask.

[0114] The device is constructed by placing wet-spun fibers on electrodes. Figure 13Using an Ag / AgCl electrode as the gate, and adding a 0.1 M sodium chloride aqueous solution as the electrolyte at the channel, the transfer curves of the same device under strains of 0%, 10%, 20%, 30%, 30%, and 50% were measured using a semiconductor parameter analyzer, and the results were calculated. μC *

[0115] The results show that μC *A slight decrease after 20% or 50% strain release reflects the stability of the electrical properties of the elastic semiconductor fiber under cyclic strain. Figure 14 (c)

[0116] Example 8: Construction and Testing of a Fiber-Based OECT Lactic Acid Sensor

[0117] P4 / TPU (7:3) fibers were used as the OECT channel material to construct the source and drain electrodes according to Example 7. The gate electrode was a PEDOT:PSS coated gold electrode, and lactate oxidase was dropped onto the gate surface.

[0118] Lactic acid was prepared into lactic acid / PBS solutions of different concentrations at concentrations of 10 μM–10 mM.

[0119] After stabilizing the device in PBS, the baseline current was recorded. Subsequently, different concentrations of lactic acid / PBS solutions were added sequentially, and the current changes were recorded. Figure 17 (a) This lactate sensor exhibits good linearity (R0) over a wide dynamic range of 10 μM–10 mM. 2 = 0.9807) Figure 17 (b) highlights the strong potential of flexible semiconductor fibers for health monitoring and biomedical applications when seamlessly integrated into wearable bioelectronic systems.

[0120] Example 9: Construction and Testing of Fiber-Type Thermoelectric Devices

[0121] The P1, P1 / SEBS (7:3), and X-P1 / SEBS (7:3) fibers from Examples 1-3 were placed on the surface of a glass substrate, covered with a stainless steel mask, and then subjected to thermal evaporation to obtain the electrode (Au, 50 nm) and the channel region ( Figure 18 ).

[0122] The resulting device was immersed in an EA solution containing dopant (TDAE) in a glove box for an appropriate time, then removed and dried.

[0123] The electrical conductivity of the fiber was tested using the two-probe method. σ ), and apply a temperature difference (Δ) at both ends of the fiber. T ), measuring voltage difference (Δ V To calculate the Seebeck coefficient (S = Δ) V / ΔT ).based on σ and S Calculate the power factor ( PF = σS 2 The results show that P1 / SEBS (7:3) and X-P1 / SEBS (7:3) fibers exhibit thermoelectric properties almost equivalent to those of P1 fibers after doping. Figure 19 ).

[0124] Following the above method, thermoelectric fiber devices were fabricated from P1 / SEBS (7:3) fibers that were stretched to 20%, 40%, and 60% strain, respectively, and tests revealed that their… σ , S and PF The changes are small, exhibiting strain insensitivity. Figure 20 ).

[0125] Example 10: Construction and Testing of Three-Dimensional PN-Type Thermoelectric Fabrics

[0126] The PEDOT:PSS dispersion was heated and concentrated, then extruded through a spinning needle into an isopropanol (IPA) coagulation bath containing 10 vol.% DMSO. After washing and drying, it was treated with ethylene glycol (EG).

[0127] The above-mentioned PEDOT:PSS fiber bundles and the P1 / SEBS (7:3) fiber bundles obtained in Example 2 were alternately sewn into a three-dimensional spacer fabric and connected by conductive silver paste to form a continuous thermoelectric path. Figure 21 ).

[0128] The open-circuit voltage was measured using a multimeter by applying a temperature difference between the two ends of the fabric. Clearly, the open-circuit voltage (ΔV) V With the temperature gradient (Δ) applied to the fabric T ) increases linearly, in Δ T = Reaches 60.5 mV at 70℃ ( Figure 22 )

[0129] The above embodiments illustrate the preparation process of composite fibers under different conjugated polymer systems, different elastomers, different solvents, and post-crosslinking treatment conditions. Those skilled in the art can adjust the type of conjugated polymer, elastomer, conjugated polymer / elastomer mass ratio, solvent type, coagulation bath composition, spinning speed, and crosslinking conditions according to specific application requirements; all such adjustments fall within the scope of this invention.

Claims

1. A method for producing an elastic semiconductor fiber, characterized by, Comprising the steps of: a) Synergistic co-spinning: judging the compatibility between the conjugated polymer and the elastomer according to the Hansen solubility distance, selecting the elastomer and the conjugated polymer with compatibility meeting the preset condition, mixing them according to the preset mass ratio, and co-dissolving in an organic solvent to obtain a uniform spinning solution under stirring with heating; wherein the compatibility meeting the preset condition means that the Hansen solubility distance between the conjugated polymer and the elastomer is less than a first preset threshold, the first preset threshold is 5 MPa 1 / 2 ; the conjugated polymer is selected from p-type, n-type or bipolar conjugated polymer, the elastomer is selected from styrene-based block copolymer, polyurethane, polyisoprene and polybutadiene elastomer, and the mass ratio of the conjugated polymer and the elastomer is 1:9~9:1; b) Anti-solvent regulated nanophase separation: extruding the spinning solution obtained in step a) into an anti-solvent coagulation bath at a constant speed, using the rapid and balanced interdiffusion between the solvent and the anti-solvent to form a nanoscale phase separation structure in the fiber during the coagulation process to obtain a composite fiber; wherein the Hansen solubility distance between the anti-solvent in the coagulation bath and the solvent of the spinning solution is less than a second preset threshold value, the second preset threshold value is 10 MPa 1 / 2 , and the diffusion flux ratio of the two is 0.85~1; at the interface between the solvent and the anti-solvent, the diffusion flux of the solvent in the direction of the anti-solvent is J A , the diffusion flux of the anti-solvent in the direction of the solvent is J B , and the ratio η of the two is the diffusion flux ratio, the calculation method is as follows: wherein, p A , p B are the densities of the solvent and the anti-solvent, respectively, M A , M B are their molar molecular weights; c) Swelling-induced post-crosslinking: the composite fiber obtained from step b) is immersed in a solution containing a crosslinking agent, so that the fiber swells and the crosslinking agent diffuses into the interior of the fiber, and then triggers a crosslinking reaction to form a stable covalent crosslinking network in the interior of the fiber; wherein the Hansen solubility distance between the solvent used for swelling and the elastomer is less than a third preset threshold value, the third preset threshold value being 10 MPa 1 / 2 ; the crosslinking agent is a multi-functional aziridine compound, and the crosslinking reaction is triggered by heating or ultraviolet light.

2. An elastic semiconductor fiber, characterized by, The elastic semiconductive fiber internally containing nanoscale phase separation structure prepared by the preparation method of the elastic semiconductive fiber of claim 1, wherein the conjugated polymer forms a continuous nanofiber conductive network, the elastomer forms a continuous matrix, and the nanofiber conductive network is embedded in the elastomer matrix.

3. An elastic fiber type organic electrochemical transistor comprising an elastic substrate, a source electrode, a drain electrode, a gate electrode, and an electrolyte solution, characterized in that, The elastic semiconductive fiber of claim 2 as a channel material between a source electrode and a drain electrode.

4. An elastic fiber type organic electrochemical transistor sensor comprising an elastic substrate, a source electrode, a drain electrode, a gate electrode, and an electrolyte solution, characterized in that, The elastic semiconductive fiber of claim 2 as a channel material between a source electrode and a drain electrode, with a to-be-tested solution as an electrolyte solution, and high-sensitivity linear sensing of a biomarker in the to-be-tested solution is realized by surface modification of a gate electrode or the elastic semiconductive fiber for the biomarker.

5. A three-dimensional thermoelectric fabric, characterized by, Comprising the elastic semiconductive fiber or fiber bundle of claim 2, wherein p-type and n-type elastic semiconductive fibers or fiber bundles are alternately arranged to form a thermoelectric path.

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