Micro-nano multilayer structure-based electrical stimulation and sensing membrane cloth manufacturing method

Abstract

The invention relates to an electrical stimulation and sensing membrane cloth manufacturing method based on a micro-nano multilayer structure. An electrostatic spinning and silk-screen printing composite technology is adopted, a pain relieving gel nanofiber membrane, a first latticed electrode layer, a PVDF / BaTiO3 nanofiber sensing membrane, a second latticed electrode layer, a PAA nanofiber protection membrane and a silk-screen printing silver stimulation electrode are sequentially prepared, and an electrical stimulation function layer, a pain relieving function layer, a sensing function layer and a protection function layer are precisely integrated. And the multi-layer structure membrane cloth with high flexibility and excellent biocompatibility is prepared. The membrane cloth can be tightly attached to the complex curved surface of the human body, the integrated function of nerve-muscle electrical stimulation treatment, far-infrared physical pain relieving and mechanical signal synchronous monitoring is achieved, and the problems that an existing product is poor in function integration compatibility, the performance cannot meet clinical requirements easily, and the technology is complex are solved. The manufacturing process is mature and controllable, the cost is low, large-scale production is facilitated, and wide application prospects are achieved in the fields of rehabilitation medicine, exercise protection, chronic disease management, home health protection and the like.

Description

Technical Field

[0001] This invention belongs to the field of flexible functional membrane fabric manufacturing, biomedical electronics and intelligent rehabilitation interdisciplinary technology, specifically involving a method for manufacturing an electrical stimulation and sensing membrane fabric based on a micro-nano multilayer structure. Background Technology

[0002] With the rapid development of flexible electronics technology, biomedical materials, and the intelligent rehabilitation industry, flexible membrane fabrics that integrate electrical stimulation therapy, pain relief, and sensing monitoring have become one of the important development directions in the field of rehabilitation medicine. These membrane fabrics can closely adhere to the human skin, regulating neuromuscular function and relieving pain through electrical stimulation, while simultaneously collecting real-time biomechanical signals from the body surface. This provides data support for evaluating rehabilitation effects and optimizing treatment plans, making them highly valuable in scenarios such as rehabilitation of facial paralysis, limb paralysis, sports injury recovery, and chronic pain management.

[0003] In the preparation of functional integrated rehabilitation membranes, existing technologies face two major challenges: First, poor compatibility of functional layer integration. Traditional products often employ an "independent functional component splicing" model, bonding electrical stimulation electrodes, sensing elements, and analgesic patches together. This results in insufficient overall flexibility and weak interlayer bonding, making the membrane prone to delamination under bending and stretching deformation caused by human activity. Furthermore, significant signal transmission loss occurs at the interfaces, affecting the accuracy of electrical stimulation and the reliability of sensing data. Second, some integrated design products suffer from problems such as interference between electrical stimulation signals and sensing signals, and corrosion of electrodes by moisture in the analgesic layer due to mismatched material selection and processes, leading to poor product stability.

[0004] Secondly, the performance of the core functional layer is difficult to meet clinical needs. Regarding electrical stimulation, existing electrode layers are mostly prepared using metal foil or sputtering processes. While these offer good conductivity, they lack flexibility and fit, making them unsuitable for the complex curves of the human body. Long-term wear can easily cause skin pressure discomfort, and the biocompatibility of metallic materials is poor, potentially leading to allergic reactions in some patients. Regarding pain relief, traditional pain patches often rely on the sustained release of chemical drugs, posing risks of drug side effects, skin irritation, and drug resistance. Physical pain relief products (such as far-infrared types) suffer from limited and poorly sustained pain relief due to uneven dispersion of functional materials and unreasonable membrane structure design, making it difficult to meet the long-term pain intervention needs in clinical rehabilitation.

[0005] Regarding the integration of sensing functions, existing products do not yet combine electrical stimulation, analgesia, and sensing capabilities. On the one hand, sensing layers are mostly made from a single material, enabling only the detection of a single parameter and failing to provide comprehensive physiological data support for neuromuscular function remodeling. On the other hand, the fabrication process of the sensing layer has poor compatibility with other functional layers. For example, sensing units fabricated using traditional processes such as photolithography and vapor deposition are easily damaged by solvents, temperatures, and other factors during the subsequent fabrication of functional layers, leading to a decline in sensing performance. Furthermore, the protective layer design of existing membrane fabrics is unreasonable. Most focus only on waterproofing while neglecting breathability, or have good breathability but insufficient protective performance. Long-term wear can easily cause skin stuffiness and dampness, affecting not only the patient's wearing experience but also potentially causing aging and failure of the internal functional layers of the membrane fabric, limiting the continuous use time of the product in home rehabilitation scenarios.

[0006] Meanwhile, existing technologies for forming multilayer membrane fabrics suffer from complex processes and high costs. For example, some functional layers employ precision processes such as photolithography and chemical deposition, which require sophisticated equipment and have long production cycles, making large-scale mass production difficult. On the other hand, functional layers prepared using simple coating processes suffer from uneven thickness and poor controllability of microstructure, affecting the stability of electrical stimulation, analgesia, and sensing functions. With the expanding patient population suffering from facial paralysis, limb paralysis, and other conditions, as well as the increasing demand for home rehabilitation due to population aging, the market demand for rehabilitation membrane fabrics that combine high flexibility, biocompatibility, multifunctional integration, and long-term stability is becoming increasingly urgent.

[0007] Therefore, developing a micro-nano multilayer membrane fabric that can precisely integrate electrical stimulation, analgesia, sensing and protective functional layers, has good interlayer compatibility, conforms to the curvature of the human body, has excellent biocompatibility, and is suitable for long-term wear has become a key technical challenge that urgently needs to be overcome in the field of intelligent rehabilitation equipment. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides an electrostimulation and sensing membrane fabric based on a micro-nano multilayer structure, comprising, from one side to the other: a screen-printed silver stimulation electrode, an analgesic gel nanofiber membrane, a first mesh electrode layer, a PVDF / BaTiO3 nanofiber sensing membrane, a second mesh electrode layer, and a PAA nanofiber protective membrane.

[0009] The analgesic gel nanofiber membrane is obtained by electrospinning analgesic gel electrospinning solution;

[0010] The first mesh-like electrode layer is formed by winding silver fiber wires around an analgesic gel nanofiber membrane;

[0011] The PVDF / BaTiO3 nanofiber sensing membrane is formed on the first grid-like electrode layer by adding nano-BaTiO3 particles modified with APTES to a PVDF solution, then adding polyvinylpyrrolidone to obtain a uniform PVDF / BaTiO3 electrospinning solution.

[0012] The second mesh-like electrode layer is formed by winding silver fiber wires onto a PVDF / BaTiO3 nanofiber sensing membrane;

[0013] The PAA nanofiber protective film is formed on the second mesh electrode layer by electrospinning of PAA spinning precursor solution.

[0014] The screen-printed silver stimulation electrode is made by: using a stainless steel screen, creating a screen with electrode patterns using a photosensitive emulsion plate-making process, fixing the membrane cloth on the printing platform, uniformly coating the conductive silver paste onto the surface of the screen, and printing using the screen to uniformly transfer the conductive silver paste from the surface of the screen to the surface of the analgesic gel nanofiber membrane.

[0015] The present invention provides an electrostimulation and sensing membrane fabric based on a micro / nano multilayer structure, which is prepared by the following manufacturing method, comprising the following steps:

[0016] Step 1: Preparation of analgesic gel nanofiber membrane

[0017] (1) Polyvinyl alcohol (PVA), far-infrared ceramic powder, glycerin, carbomer 940, propylene glycol, ethylparaben and deionized water are prepared in a certain weight ratio and stirred thoroughly to form an analgesic gel electrospinning solution. The electrospinning solution is then defoamed.

[0018] (2) The electrospinning solution was electrospinned on a collector to obtain analgesic gel nanofiber membrane;

[0019] Step 2: Preparation of PVDF / BaTiO3 nanofiber sensing membrane

[0020] (1) Silver fiber wires are wound onto the analgesic gel nanofiber membrane to form a first grid-like electrode layer;

[0021] (2) Disperse a certain amount of PVDF particles in a certain amount of mixed solvent consisting of N,N-dimethylformamide (DMF) and ethanol in a volume ratio, stir thoroughly until the PVDF particles are completely dissolved, and obtain a PVDF solution with a mass fraction of 20%.

[0022] (3) A certain amount of nano BaTiO3 particles were dispersed in ethanol and ultrasonically dispersed; a certain amount of 3-aminopropyltriethoxysilane (APTES) was added and stirred to react; after the reaction was completed, the supernatant was discarded, the precipitate was washed with ethanol, and then the washed precipitate was placed in a vacuum drying oven to dry, and nano BaTiO3 particles modified by APTES were obtained.

[0023] (4) Add nano BaTiO3 particles modified with APTES to the obtained PVDF solution and disperse them by ultrasonication. Then add polyvinylpyrrolidone (PVP) to the solution and continue stirring to obtain a uniform PVDF / BaTiO3 electrospinning solution.

[0024] (5) Using the first grid-like electrode layer as the receiving substrate, the PVDF / BaTiO3 electrospinning solution is electrospinned to obtain a PVDF / BaTiO3 nanofiber sensing film on the first grid-like electrode layer.

[0025] Step 3: Preparation of PAA nanofiber protective film

[0026] (1) Silver fiber wires are wound onto the PVDF / BaTiO3 nanofiber sensing membrane to form a second mesh electrode layer;

[0027] (2) Weigh a certain amount of polyamic acid (PAA) powder, disperse it in a certain amount of N,N-dimethylformamide (DMF), stir thoroughly until the PAA powder is completely dissolved, and obtain a PAA spinning precursor solution with a mass fraction of 10%; defoam the PAA spinning precursor solution.

[0028] (3) Using the second mesh electrode layer as the receiving substrate, the defoamed PAA spinning precursor solution is electrospun to obtain a PAA nanofiber protective film on the second mesh electrode layer.

[0029] (4) After spinning, the film with PAA nanofiber protective film deposited is placed in an oven to dry and remove residual solvent. The PAA nanofiber protective film is dense and flexible.

[0030] Step 4: Fabrication of screen-printed silver stimulation electrodes

[0031] (1) Weigh out spherical silver powder, binder, solvent, plasticizer and sintering aid and mix them in a certain weight ratio, stir them thoroughly until a uniform and fine conductive silver paste is formed;

[0032] (2) One side of the analgesic gel nanofiber membrane of the membrane cloth is pretreated with oxygen plasma to remove surface impurities;

[0033] (3) Based on the design pattern of the stimulation electrode, stainless steel wire mesh is selected and a screen printing plate is made using photosensitive emulsion plate making process;

[0034] (4) Fix the pretreated membrane cloth on the printing platform, uniformly coat the conductive silver paste on the screen printing plate, and use the screen printing plate to print, so that the conductive silver paste on the screen printing plate is uniformly transferred to the surface of the membrane cloth to form a silver stimulation electrode layer with a preset pattern.

[0035] (5) The printed film is placed in an oven for pre-drying; after pre-drying, the film is placed in a vacuum drying oven for vacuum drying to remove residual moisture and impurities, and a micro-nano multilayer structure of electrical stimulation and sensing membrane cloth is obtained.

[0036] Further, in step one (1), the weight percentages of polyvinyl alcohol (PVA), far-infrared ceramic powder, glycerin, carbomer 940, propylene glycol and ethylparaben are respectively 20%-25% for polyvinyl alcohol, 10%-15% for far-infrared ceramic powder, 15%-20% for glycerin, 0.5%-1.0% for carbomer, 3%-5% for propylene glycol, and 0.1%-0.2% for ethylparaben, with the remainder made up to 100% with deionized water; the defoaming treatment is carried out in a vacuum oven with the following process parameters: vacuum degree 100-150 Pa, vacuuming time 5-10 minutes.

[0037] Further, in step one (2), the electrospinning solution is loaded into a syringe with a metal needle, the syringe is installed on the electrospinning equipment, the electrospinning equipment is started, and analgesic gel nanofiber membrane is obtained on the collector; the metal needle model is 20G or 21G, and the electrospinning parameters are set as follows: voltage 25-26kV, distance between needle and collector 15-20cm, push speed 0.2-0.5mL / h, ambient temperature 20-25℃, humidity 40%-50%, and roller speed 800-1000r / min.

[0038] Further, in step two (1), the diameter of the silver fiber wire is 0.05 mm; the collector rotation speed is 30 r / min during winding, the axial feed speed of the wire is 5 mm / min, and the wire is wound once in the forward direction and once in the reverse direction.

[0039] Further, in step two (2), the volume ratio of N,N-dimethylformamide (DMF) to ethanol is 3:2; the stirring method is to place the mixture on a magnetic stirrer, and the magnetic stirring parameters are: temperature 55-65℃, stirring time 8-10 hours.

[0040] Further, in step two (3), the ultrasonic dispersion time is 30 minutes; the mass ratio of 3-aminopropyltriethoxysilane to nano BaTiO3 particles is 1:10; the stirring reaction temperature is 45-55℃; the stirring time is 5-6 hours; the centrifugation speed of the mixture is 10000-15000r / min; the centrifugation time is 8-12 minutes; the precipitate is washed with ethanol 4-5 times; the vacuum drying temperature is 55-65℃; and the drying time is 10-12 hours.

[0041] Further, in step two (4), the ultrasonic dispersion time is 35-40 minutes, the mass ratio of polyvinylpyrrolidone (PVP) to PVDF particles added to the solution is 1:200, and the stirring time is continued for 3-4 hours.

[0042] Further, in step two (5), the PVDF / BaTiO3 electrospinning solution is loaded into a syringe with a metal needle, the syringe is installed on the electrospinning equipment, the first mesh electrode layer is used as the receiving substrate, the electrospinning equipment is started, and a PVDF / BaTiO3 nanofiber sensing membrane is obtained on the first mesh electrode layer; the metal needle is of model 20G or 21G, and the electrospinning parameters are set as follows: voltage is 30-35kV, distance between needle and collector is 10-15cm, feed speed is 0.5-1mL / h, ambient temperature is 20-25℃, humidity is 40%-50%, and roller speed is 1800-2200r / min.

[0043] Furthermore, in step three (1), the diameter of the silver fiber wire is 0.05 mm; the collector rotation speed is 30 r / min during winding, the axial feed speed of the wire is 5 mm / min, and the wire is wound once in the forward direction and once in the reverse direction.

[0044] Further, in step three (2), the stirring method is to place the mixture on a magnetic stirrer, the magnetic stirring temperature is 60-70℃, and the stirring time is 2-3 hours; the defoaming treatment is carried out in a vacuum oven, and the process parameters are: vacuum degree 200-250 Pa, vacuuming time 6-10 minutes.

[0045] Further, in step three (3), the defoamed PAA spinning precursor solution is loaded into a syringe with a metal needle, the syringe is installed on an electrospinning device, the second mesh electrode layer is used as the receiving substrate, the electrospinning device is started, and a PAA nanofiber protective film is obtained on the second mesh electrode layer; the metal needle is of model 20G or 21G, and the electrospinning parameters are set as follows: voltage is 20-25kV, distance between needle and collector is 15-20cm, feed speed is 0.3-0.5mL / h, ambient temperature is 20-25℃, humidity is 40-50%, and roller speed is 1200-1500r / min.

[0046] Furthermore, in step three (4), the drying temperature of the oven is 120-130℃ and the drying time is 3-5 minutes.

[0047] Further, in step four (1), the binder is preferably ethyl cellulose, the solvent is preferably terpineol, the plasticizer is preferably dibutyl phthalate, the sintering aid is preferably glass powder, and the weight ratio of spherical silver powder, ethyl cellulose, terpineol, dibutyl phthalate and glass powder is 85:5:3:2:5, the particle size of the spherical silver powder is 1-3μm; the stirring method is to place it in a high-speed mixer, the high-speed mixing speed is 1500-2000r / min, and the stirring time is 3-4 hours.

[0048] Furthermore, in step four (2), the oxygen plasma treatment process parameters are: power 50-60 watts, vacuum degree 200-250 Pa, and treatment time 3-4 minutes.

[0049] Furthermore, in step four (3), the design pattern of the stimulation electrode is a grid or strip shape, which is suitable for the rehabilitation target area of ​​facial paralysis and limb paralysis; the stainless steel wire mesh selected is 300-400 mesh, and the electrode pattern resolution should be ≥50μm.

[0050] Furthermore, in step four (4), during the printing process using a screen printing plate, the squeegee angle is 45-60° and the squeegee speed is 5-10cm / s.

[0051] Furthermore, in step four (5), the pre-drying temperature is 100-120℃ and the pre-drying time is 3-5 minutes; the vacuum drying process parameters are: temperature 80-100℃, vacuum degree 200-250 Pa, and drying time 15-20 minutes.

[0052] The beneficial effects of this invention are:

[0053] This invention employs a composite process of electrospinning and screen printing to prepare micro / nano multilayered electrostimulation and sensing membrane fabrics. Compared with existing rehabilitation membrane fabric manufacturing methods, this invention offers advantages such as simpler manufacturing processes, easier operation, and lower costs. By precisely controlling the material ratios, spinning parameters, and printing process parameters of each functional layer, a flexible functional membrane fabric meeting the requirements can be prepared. The electrostimulation and sensing membrane fabric prepared by this method exhibits excellent flexibility and biocompatibility, better conforming to the complex curves of the human body, improving wearing comfort and treatment accuracy. Its high integration allows for simultaneous neuromuscular electrical stimulation therapy, far-infrared physical analgesia, and synchronous monitoring of mechanical signals, providing comprehensive rehabilitation data support for neuromuscular function remodeling. This solves the problems of poor functional integration compatibility, difficulty in meeting clinical needs, and complex processes in existing products. The manufacturing process utilizes mature and controllable technology, and all materials are commercially available medical-grade raw materials, resulting in lower costs and facilitating large-scale production. This promotes the application of intelligent rehabilitation membrane fabrics in more fields such as rehabilitation medicine, sports protection, and home health. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the electrostimulation and sensing membrane structure of the micro / nano multilayer structure of the present invention.

[0055] Figure 2 This is a physical image of the electrostimulation and sensing membrane fabric of the micro / nano multilayer structure of the present invention.

[0056] Figure 3 This is an electron microscope image of the PVDF / BaTiO3 nanofiber sensing membrane of the present invention.

[0057] Figure 4 The Fourier transform infrared spectrum of the PVDF / BaTiO3 nanofiber sensing membrane of this invention.

[0058] Figure 5 The piezoelectric curve of the PVDF / BaTiO3 nanofiber sensing membrane of this invention is shown.

[0059] Figure 6 This is an electron microscope image of the PAA nanofiber protective film of the present invention.

[0060] 1. Screen-printed silver stimulation electrode layer; 2. Analgesic gel nanofiber membrane; 3. First mesh electrode layer; 4. PVDF / BaTiO3 nanofiber sensing membrane; 5. Second mesh electrode layer; 6. PAA nanofiber protective membrane. Detailed Implementation

[0061] The electrostimulation and sensing membrane fabric based on a micro-nano multilayer structure provided in this embodiment is prepared by the following manufacturing method, the steps of which include:

[0062] Step 1: Preparation of analgesic gel nanofiber membrane 2

[0063] (1) Polyvinyl alcohol (PVA), far-infrared ceramic powder, glycerin, carbomer 940, propylene glycol, ethylparaben, and deionized water are prepared in a certain weight ratio, with the following weight percentages: polyvinyl alcohol 20%-25%, far-infrared ceramic powder 10%-15%, glycerin 15%-20%, carbomer 0.5%-1.0%, propylene glycol 3%-5%, ethylparaben 0.1%-0.2%, and the remainder is made up to 100% with deionized water. After thorough mixing, an analgesic gel electrospinning solution is formed. The electrospinning solution is then defoamed. The defoaming treatment is carried out in a vacuum oven with the following process parameters: vacuum degree 100-150 Pa, vacuuming time 5-10 minutes.

[0064] In some embodiments, the weight percentage of polyvinyl alcohol can be 20%, 21%, 22%, 23%, 24%, or 25%; the weight percentage of far-infrared ceramic powder can be 10%, 11%, 12%, 13%, 14%, or 15%; the weight percentage of glycerol can be 15%, 16%, 17%, 18%, 19%, or 20%; the weight percentage of carbomer can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1.0%; and the weight percentage of propylene glycol can be 3%, 4%, or 5%.

[0065] (2) Load the electrospinning solution into a syringe with a 20G or 21G metal needle, install the syringe on the electrospinning equipment, and set the electrospinning parameters: voltage 25-26kV, distance between the needle and the collector 15-20cm, push speed 0.2-0.5mL / h, ambient temperature 20-25℃, humidity 40%-50%, roller speed 800-1000r / min, start the electrospinning equipment, and obtain the analgesic gel nanofiber membrane 2 on the collector;

[0066] Step 2: Preparation of PVDF / BaTiO3 nanofiber sensing membrane

[0067] (1) A silver fiber wire with a diameter of 0.05 mm is wound onto the analgesic gel nanofiber membrane. During the winding, the collector rotates at 30 r / min and the axial feed speed of the wire is 5 mm / min. The wire is wound once in the forward direction and once in the reverse direction to form the first grid-like electrode layer 3.

[0068] (2) Accurately weigh 20g of PVDF particles and disperse them in 80g of a mixed solvent consisting of N,N-dimethylformamide (DMF) and ethanol in a volume ratio of 3:2. Place the mixture on a magnetic stirrer at 55-65℃ and stir for 8-10 hours until the PVDF particles are completely dissolved to obtain a PVDF solution with a mass fraction of 20%.

[0069] (3) Weigh 5g of nano BaTiO3 particles and disperse them in 400mL of ethanol, and ultrasonically disperse them for 30 minutes; add 0.5g of 3-aminopropyltriethoxysilane (APTES), and stir the mixture at 45-55℃ for 5-6 hours; after the reaction, centrifuge the mixture at 10000-15000r / min for 8-12 minutes, discard the supernatant, wash the precipitate with ethanol 4-5 times, and then place the precipitate in a vacuum drying oven at 55-65℃ for 10-12 hours to obtain nano BaTiO3 particles modified with APTES.

[0070] (4) Add nano BaTiO3 particles modified with APTES to the obtained PVDF solution and ultrasonically disperse for 35-40 minutes. Then add 0.1g of polyvinylpyrrolidone (PVP) to the solution and continue stirring for 3-4 hours to obtain a uniform PVDF / BaTiO3 electrospinning solution.

[0071] (5) Load the PVDF / BaTiO3 electrospinning solution into a syringe with a 20G or 21G metal needle, install the syringe on the electrospinning equipment, use the first mesh electrode layer 3 as the receiving substrate, set the electrospinning parameters: voltage 30-35kV, distance between the needle and the collector 10-15cm, feed speed 0.5-1mL / h, ambient temperature 20-25℃, humidity 40-50%, roller speed 1800-2200r / min, start the electrospinning equipment, and obtain the PVDF / BaTiO3 nanofiber sensing membrane 4 on the first mesh electrode layer 3;

[0072] Step 3: Preparation of PAA nanofiber protective film 6

[0073] (1) A silver fiber wire with a diameter of 0.05 mm is wound onto the PVDF / BaTiO3 nanofiber sensing membrane. During the winding, the collector rotation speed is 30 r / min and the axial feed speed of the wire is 5 mm / min. The wire is wound once in the forward direction and once in the reverse direction to form a second mesh electrode layer 5.

[0074] (2) Accurately weigh 10g of polyamic acid (PAA) powder and disperse it in 90g of N,N-dimethylformamide (DMF). Place the mixture on a magnetic stirrer at 60-70℃ and stir for 2-3 hours until the PAA powder is completely dissolved to obtain a PAA spinning precursor solution with a mass fraction of 10%. Place the PAA spinning precursor solution in a vacuum oven for defoaming treatment. The process parameters are: vacuum degree 200-250 Pa, vacuuming time 6-10 minutes, to ensure that there are no residual bubbles in the solution and to avoid affecting the uniformity of the spinning film.

[0075] (3) The defoamed PAA spinning precursor solution is loaded into a syringe with a 20G or 21G metal needle. The syringe is installed on the electrospinning equipment. The second mesh electrode layer 5 is used as the receiving substrate. The electrospinning parameters are set as follows: voltage is 20-25kV, distance between needle and collector is 15-20cm, feed speed is 0.3-0.5mL / h, ambient temperature is 20-25℃, humidity is 40%-50%, and roller speed is 1200-1500r / min. The electrospinning equipment is started, and a PAA nanofiber protective film 6 is obtained on the second mesh electrode layer 5.

[0076] (4) After spinning, the film with PAA nanofiber protective film 6 deposited is placed in an oven at 120-130℃ and dried for 3-5 minutes to remove residual solvent. The resulting PAA nanofiber protective film is dense and flexible. The protective film is both waterproof and breathable, which can effectively protect the sensing layer and ensure wearing comfort.

[0077] Step 4: Preparation of screen-printed silver stimulation electrode 1

[0078] (1) Accurately weigh 85g of spherical silver powder (particle size 1-3μm), 5g of ethyl cellulose (binder), 3g of terpineol (solvent), 2g of dibutyl phthalate (plasticizer) and 5g of glass powder (sintering aid), place them in a high-speed mixer, and stir at a speed of 1500-2000r / min for 3-4 hours until a uniform and fine conductive silver paste is formed;

[0079] (2) One side of the analgesic gel nanofiber membrane 2 of the membrane cloth is subjected to oxygen plasma pretreatment. The plasma treatment parameters are: power 50-60 watts, vacuum degree 200-250 Pa, treatment time 3-4 minutes to remove surface impurities, ensure that the substrate surface is dry and clean, and improve the adhesion of silver paste.

[0080] (3) According to the design pattern of the stimulation electrode, a 300-400 mesh stainless steel wire mesh is selected, and a photosensitive emulsion plate-making process is used to make the screen plate to ensure that the electrode pattern resolution is ≥50μm and the line width is uniform; the design pattern of the stimulation electrode is grid-shaped or strip-shaped, which is suitable for the rehabilitation target area of ​​facial paralysis and limb paralysis.

[0081] (4) Fix the pretreated membrane on the printing platform, coat the conductive silver paste evenly on the screen, and print using parameters of 45°-60° squeegee angle and 5-10cm / s squeegee speed. Transfer the conductive silver paste on the screen to the surface of the analgesic gel nanofiber membrane 2 evenly to form a silver stimulation electrode with a preset pattern.

[0082] (5) The printed membrane is pre-baked in an oven at 100-120℃ for 3-5 minutes to remove the solvent and perform curing treatment to enhance the bonding force between the silver electrode and the membrane cloth. After pre-baking, the membrane is placed in a vacuum drying oven and dried at 80-100℃ and 200-250 Pa for 15-20 minutes to remove residual moisture and impurities, and finally obtains a micro-nano multilayer structure of electrical stimulation and sensing membrane cloth with good biocompatibility and stable conductivity. The silver stimulation electrode is closely attached to the analgesic gel nanofiber layer 2 to achieve stable transmission of 2-6KHz multi-band electrical stimulation.

Claims

1. An electrostimulation and sensing membrane fabric based on a micro / nano multilayer structure, characterized in that: From one side to the other, the layers are as follows: screen-printed silver stimulation electrode, analgesic gel nanofiber membrane, first mesh electrode layer, PVDF / BaTiO3 nanofiber sensing membrane, second mesh electrode layer, and PAA nanofiber protective membrane. The analgesic gel nanofiber membrane is obtained by electrospinning analgesic gel electrospinning solution; The first mesh-like electrode layer is formed by winding silver fiber wires around an analgesic gel nanofiber membrane; The PVDF / BaTiO3 nanofiber sensing membrane is formed on the first grid-like electrode layer by adding nano-BaTiO3 particles modified with APTES to a PVDF solution, then adding polyvinylpyrrolidone to obtain a uniform PVDF / BaTiO3 electrospinning solution. The second mesh-like electrode layer is formed by winding silver fiber wires onto a PVDF / BaTiO3 nanofiber sensing membrane; The PAA nanofiber protective film is formed on the second mesh electrode layer by electrospinning of PAA spinning precursor solution. The screen-printed silver stimulation electrode is made by: using a stainless steel screen, creating a screen with electrode patterns using a photosensitive emulsion plate-making process, fixing the membrane cloth on the printing platform, uniformly coating the conductive silver paste onto the surface of the screen, and printing using the screen to uniformly transfer the conductive silver paste from the surface of the screen to the surface of the analgesic gel nanofiber membrane.

2. The method for manufacturing an electrostimulation and sensing membrane fabric based on a micro / nano multilayer structure as described in claim 1, characterized in that: step include: Step 1: Preparation of analgesic gel nanofiber membrane: (1) Polyvinyl alcohol, far-infrared ceramic powder, glycerin, carbomer 940, propylene glycol, ethylparaben and deionized water are prepared in a certain weight ratio and stirred thoroughly to form an analgesic gel electrospinning solution. The electrospinning solution is then defoamed. (2) The analgesic gel electrospinning solution was electrospinned on a collector to obtain analgesic gel nanofiber membrane; Step 2: Preparation of PVDF / BaTiO3 nanofiber sensing membrane: (1) Silver fiber wires are wound onto the analgesic gel nanofiber membrane to form a first grid-like electrode layer; (2) Disperse a certain amount of PVDF particles in a certain amount of mixed solvent consisting of N,N-dimethylformamide and ethanol in a volume ratio, stir thoroughly until the PVDF particles are completely dissolved, and obtain a PVDF solution with a mass fraction of 20%. (3) A certain amount of nano BaTiO3 particles were dispersed in ethanol and ultrasonically dispersed. A certain amount of 3-aminopropyltriethoxysilane was added and the mixture was stirred to react. After the reaction was completed, the mixture was centrifuged, the supernatant was discarded, the precipitate was washed with ethanol, and then the washed precipitate was dried in a vacuum drying oven to obtain nano BaTiO3 particles modified with APTES. (4) Add nano BaTiO3 particles modified with APTES to the obtained PVDF solution and disperse them by ultrasonication. Then add polyvinylpyrrolidone to the solution and continue stirring to obtain a uniform PVDF / BaTiO3 electrospinning solution. (5) Using the first grid-like electrode layer as the receiving substrate, the PVDF / BaTiO3 electrospinning solution is electrospinned to obtain a PVDF / BaTiO3 nanofiber sensing film on the first grid-like electrode layer. Step 3: Preparation of PAA nanofiber protective film: (1) Silver fiber wires are wound onto the PVDF / BaTiO3 nanofiber sensing membrane to form a second mesh electrode layer; (2) Weigh a certain amount of polyamic acid powder, disperse it in a certain amount of N,N-dimethylformamide, stir it thoroughly until the PAA powder is completely dissolved, and obtain a PAA spinning precursor solution with a mass fraction of 10%; defoam the PAA spinning precursor solution. (3) Using the second mesh electrode layer as the receiving substrate, the defoamed PAA spinning precursor solution is electrospun to obtain a PAA nanofiber protective film on the second mesh electrode layer. (4) After spinning, the film with PAA nanofiber protective film deposited is placed in an oven to dry and remove residual solvent. The PAA nanofiber protective film is dense and flexible. Step 4: Fabrication of screen-printed silver stimulation electrodes: (1) Weigh out spherical silver powder, binder, solvent, plasticizer and sintering aid and mix them in a certain weight ratio, stir them thoroughly until a uniform and fine conductive silver paste is formed; (2) One side of the analgesic gel nanofiber membrane of the membrane cloth is pretreated with oxygen plasma to remove surface impurities; (3) Based on the design pattern of the stimulation electrode, stainless steel wire mesh is selected and a screen printing plate is made using photosensitive emulsion plate making process; (4) Fix the pretreated membrane cloth on the printing platform, uniformly coat the conductive silver paste on the screen printing plate, and use the screen printing plate to print, so that the conductive silver paste on the screen printing plate is uniformly transferred to the surface of the membrane cloth to form a silver stimulation electrode layer with a preset pattern. (5) Arrange the printed film in an oven for pre-drying; After pre-baking, the membrane is placed in a vacuum drying oven for vacuum drying to remove residual moisture and impurities, resulting in a micro-nano multilayer structure of electrostimulation and sensing membrane cloth.

3. The manufacturing method according to claim 2, characterized in that: In step one (1), the weight percentages of polyvinyl alcohol, far-infrared ceramic powder, glycerin, carbomer 940, propylene glycol and ethylparaben are 20%-25% polyvinyl alcohol, 10%-15% far-infrared ceramic powder, 15%-20% glycerin, 0.5%-1.0% carbomer, 3%-5% propylene glycol and 0.1%-0.2% ethylparaben, with the remainder made up to 100% with deionized water; the defoaming treatment is carried out in a vacuum oven with the following process parameters: vacuum degree 100-150 Pa and vacuuming time 5-10 minutes.

4. The manufacturing method according to claim 2, characterized in that: In step one (2), the electrospinning solution is loaded into a syringe with a metal needle, the syringe is installed on the electrospinning equipment, the electrospinning equipment is started, and analgesic gel nanofiber membrane is obtained on the collector; the metal needle model is 20G or 21G, and the electrospinning parameters are set as follows: voltage 25-26kV, distance between needle and collector 15-20cm, push speed 0.2-0.5mL / h, ambient temperature 20-25℃, humidity 40%-50%, and roller speed 800-1000r / min.

5. The manufacturing method according to claim 2, characterized in that: In step two (1), the diameter of the silver fiber wire is 0.05 mm; the collector rotation speed is 30 r / min during winding, the axial feed speed of the wire is 5 mm / min, and the wire is wound once in the forward direction and once in the reverse direction. In step 2 (2), the volume ratio of N,N-dimethylformamide (DMF) to ethanol is 3:2; the stirring method is to place the mixture on a magnetic stirrer, and the magnetic stirring parameters are: temperature 55-65℃, stirring time 8-10 hours.

6. The manufacturing method according to claim 2, characterized in that: In step two (3), the ultrasonic dispersion time is 30 minutes; the mass ratio of 3-aminopropyltriethoxysilane to nano BaTiO3 particles is 1:10; the stirring reaction temperature is 45-55℃; the stirring time is 5-6 hours; the centrifugation speed of the mixture is 10000-15000r / min; the centrifugation time is 8-12 minutes; the precipitate is washed with ethanol 4-5 times; the vacuum drying temperature is 55-65℃; and the drying time is 10-12 hours. In step two (4), the ultrasonic dispersion time is 35-40 minutes, the mass ratio of polyvinylpyrrolidone (PVP) to PVDF particles added to the solution is 1:200, and the stirring time is continued for 3-4 hours. In step two (5), the PVDF / BaTiO3 electrospinning solution is loaded into a syringe with a metal needle. The syringe is installed on the electrospinning equipment. The first mesh electrode layer is used as the receiving substrate. The electrospinning equipment is started to obtain a PVDF / BaTiO3 nanofiber sensing membrane on the first mesh electrode layer. The metal needle is a 20G or 21G type. The electrospinning parameters are set as follows: voltage is 30-35kV, distance between the needle and the collector is 10-15cm, feed speed is 0.5-1mL / h, ambient temperature is 20-25℃, humidity is 40%-50%, and roller speed is 1800-2200r / min.

7. The manufacturing method according to claim 2, characterized in that: In step 3 (1), the diameter of the silver fiber wire is 0.05 mm; the collector rotation speed is 30 r / min during winding, the axial feed speed of the wire is 5 mm / min, and the wire is wound once in the forward direction and once in the reverse direction. In step 3 (2), the stirring method is to place the mixture on a magnetic stirrer, the magnetic stirring temperature is 60-70℃, and the stirring time is 2-3 hours; the defoaming treatment is carried out in a vacuum oven, and the process parameters are: vacuum degree 200-250 Pa, vacuuming time 6-10 minutes.

8. The manufacturing method according to claim 2, characterized in that: In step three (3), the defoamed PAA spinning precursor solution is loaded into a syringe with a metal needle. The syringe is installed on the electrospinning equipment. The second mesh electrode layer is used as the receiving substrate. The electrospinning equipment is started, and a PAA nanofiber protective film is obtained on the second mesh electrode layer. The metal needle is of model 20G or 21G. The electrospinning parameters are set as follows: voltage is 20-25kV, distance between needle and collector is 15-20cm, feed speed is 0.3-0.5mL / h, ambient temperature is 20-25℃, humidity is 40-50%, and roller speed is 1200-1500r / min. In step three (4), the oven drying temperature is 120-130℃ and the drying time is 3-5 minutes.

9. The manufacturing method according to claim 2, characterized in that: In step four (1), the binder is preferably ethyl cellulose, the solvent is preferably terpineol, the plasticizer is preferably dibutyl phthalate, the sintering aid is preferably glass powder, and the weight ratio of spherical silver powder, ethyl cellulose, terpineol, dibutyl phthalate and glass powder is 85:5:3:2:5, the particle size of the spherical silver powder is 1-3μm; the stirring method is to place it in a high-speed mixer, the high-speed mixing speed is 1500-2000r / min, and the stirring time is 3-4 hours; In step four (2), the oxygen plasma treatment process parameters are: power 50-60 watts, vacuum degree 200-250 Pa, and treatment time 3-4 minutes.

10. The manufacturing method according to claim 2, characterized in that: In step four (3), the design pattern of the stimulation electrode is a grid or strip shape, which is suitable for the rehabilitation target area of ​​facial paralysis and limb paralysis; the stainless steel wire mesh selected is 300-400 mesh, and the electrode pattern resolution should be ≥50μm; In step four (4), during the printing process using a screen printing plate, the squeegee angle is 45-60° and the squeegee speed is 5-10cm / s; In step four (5), the pre-drying temperature is 100-120℃ and the pre-drying time is 3-5 minutes; the vacuum drying process parameters are: temperature 80-100℃, vacuum degree 200-250 Pa, and drying time 15-20 minutes.

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