Flexible micro electrical stimulator capable of being wound and adhered to peripheral nerve tracts and preparation method and application of flexible micro electrical stimulator

Abstract

The invention discloses a flexible micro electrical stimulator capable of being wound and adhered to peripheral nerve tracts and a preparation method and application thereof, and relates to the technical field of crossing of neural engineering, bioelectronics and medical instruments. A first insulation layer, a first friction electrode layer, a middle isolation layer, a second friction electrode layer and a second insulation layer are assembled layer by layer; the first insulation layer and the second insulation layer are self-adhesion polyurethane layers, and the first friction electrode layer, the middle isolation layer and the second friction electrode layer are packaged in the first insulation layer and the second insulation layer; the first friction electrode layer is a gold foil, and the surface of the gold foil is electroplated with a PEDOT: PSS plating layer formed by a 3, 4-ethylenedioxythiophene monomer and polystyrene sulfonate; the second friction electrode layer is gold foil or aluminum foil. According to the invention, macro-scale contact-separation type friction power generation is realized through ultrasonic driving, and the device has good output performance, long-term stability and nerve stimulation effect.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of neural engineering, bioelectronics and medical devices, and discloses a flexible micro-electric stimulator that can be wrapped around and adhered to peripheral nerve bundles, as well as its preparation method and application. Background Technology

[0002] Neurostimulation technology, as an important tool in the field of neuromodulation, has become a key method for treating nervous system diseases and restoring nerve function. By applying controllable electrical stimulation to specific nerve targets, nerve signal transmission can be effectively regulated, demonstrating significant efficacy in the treatment of various diseases such as Parkinson's disease, epilepsy, chronic pain, heart failure, and depression.

[0003] In terms of device structure, traditional rigid neurostimulators exhibit significant mechanical mismatch (elastic modulus difference of several orders of magnitude) with soft nerve tissue, easily leading to tissue inflammation, fiber encapsulation, and electrode performance degradation. In recent years, advancements in flexible electronics technology have driven the development of thin-film neurostimulators. These devices can conform to the curves of nerves, effectively reducing mechanical damage. However, existing flexible stimulators still rely on external wired power or built-in batteries, limiting their long-term autonomous operation capability within the body.

[0004] Triboelectric nanogenerators (TENGs), as an emerging energy harvesting technology, can convert mechanical energy into electrical energy, providing a self-powered solution for implantable devices. Among them, TENGs based on the contact-separation working mode have advantages such as simple structure, high output voltage, and flexible material selection. However, existing TENG-type neurostimulators mostly adopt rigid or semi-rigid structural designs, which are difficult to adapt to the dynamic deformation of nerve tissue; at the same time, their charge injection capacity between the stimulation electrode and the nerve interface is limited, which restricts stimulation efficiency and biosafety. Summary of the Invention

[0005] To address the aforementioned deficiencies and improvement needs of existing technologies, the present invention aims to provide a flexible micro-electrostimulator that can be wrapped and adhered to peripheral nerve bundles, along with its fabrication method and applications. The stimulator is assembled layer by layer from a first insulating layer, a first triboelectric electrode layer, an intermediate insulating layer, a second triboelectric electrode layer, and a second insulating layer. Both the first and second insulating layers are self-adhesive polyurethane layers, encapsulating the first, intermediate, and second triboelectric electrode layers within them. The first triboelectric electrode layer is gold foil, with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate electroplated on its surface. The second triboelectric electrode layer is either gold foil or aluminum foil. Under ultrasonic drive, the two triboelectric electrode layers generate a contact-separation triboelectric effect, thereby achieving wireless energy conversion and nerve stimulation. This stimulator possesses significant advantages such as small size, low modulus, ultrasonic wireless drive power supply, high charge injection capability, and long-term stability.

[0006] According to a first aspect of the present invention, a flexible micro-electric stimulator that can be wrapped and adhered to a peripheral nerve bundle is provided, as well as its preparation method and application. The device is assembled layer by layer from a first insulating layer, a first triboelectric electrode layer, an intermediate isolation layer, a second triboelectric electrode layer, and a second insulating layer. Both the first and second insulating layers are self-adhesive polyurethane layers, and the first and second insulating layers encapsulate the first triboelectric electrode layer, the intermediate isolation layer, and the second triboelectric electrode layer within them. The first triboelectric electrode layer is a gold foil, and the surface of the gold foil is electroplated with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate. The second triboelectric electrode layer is a gold foil or an aluminum foil.

[0007] Preferably, the first insulating layer and the first friction electrode layer are led out, the second friction electrode layer and the second insulating layer are led out, and the portions of the first insulating layer and the first friction electrode layer led out are symmetrically arranged with the portions of the second friction electrode layer and the second insulating layer led out.

[0008] Preferably, the second triboelectric electrode layer is gold foil, and the surface of the led-out portion is electroplated with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate.

[0009] Preferably, the intermediate isolation layer is polytetrafluoroethylene or polyurethane.

[0010] According to another aspect of the present invention, a method for preparing the aforementioned flexible micro-electrical stimulator that can be wrapped around and adhered to a peripheral nerve bundle is provided, comprising the following steps: (1) Isophorone diisocyanate and dibutyltin dilaurate are dissolved in an organic solvent to obtain a mixed solution; under non-oxidizing protective gas conditions, the mixed solution is added to dried polytetrahydrofuran diol for reaction, and then dimethylglyoxime is added. After the reaction is completed, a diluent is added to obtain an elastomer solution; the elastomer solution is dropped into a mold and heated to make the diluent evaporate, thereby obtaining a self-adhesive polyurethane insulating film; (2) 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate were co-dissolved in deionized water to form a homogeneous mixed solution. Then, using gold foil as the working electrode, a PEDOT:PSS conductive layer was deposited on the surface of the gold foil by constant current electrochemical polymerization. (3) Attach gold foil or aluminum foil to the surface of the first self-adhesive polyurethane insulating layer, and then attach an isolation layer gasket to the surface of the gold foil or aluminum foil; at the same time, attach gold foil with PEDOT:PSS plating to the surface of the second self-adhesive polyurethane insulating layer; align and attach the two self-adhesive polyurethane insulating layers, and use the adhesive properties of self-adhesive polyurethane to achieve encapsulation.

[0011] Preferably, the first self-adhesive polyurethane insulating layer and the gold foil or aluminum foil on its surface are led out, and the second self-adhesive polyurethane insulating layer and the gold foil on its surface plated with PEDOT:PSS are led out, and the structures of these two led-out parts are symmetrically arranged.

[0012] Preferably, gold foil is attached to the surface of the first self-adhesive polyurethane insulating layer, and the portion of the gold foil extending from the surface of the first self-adhesive polyurethane insulating layer is electroplated with a PEDOT:PSS coating.

[0013] According to another aspect of the present invention, an application of the flexible micro-electro-stimulator that can be wrapped around and adhered to a peripheral nerve bundle is provided, wherein, under ultrasonic drive, the first and second triboelectric electrode layers generate a contact-separation triboelectric effect, thereby realizing wireless energy conversion and nerve stimulation.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages: (1) The flexible micro-electric stimulator of the present invention can be wrapped and adhered to the peripheral nerve bundle. It has a small volume structure, low rigidity, and good self-adhesion performance.

[0015] (2) The self-adhesive polyurethane material used in the electrostimulator of the present invention has a low elastic modulus (i.e., low stiffness) and excellent adhesion properties. The triboelectric electrode material used maintains stable performance during long-term stimulation and has good interfacial stability.

[0016] (3) The electrical stimulator in this invention has good output performance driven by ultrasound, and the output can activate nerves.

[0017] (4) The electrostimulator in this invention has good biocompatibility.

[0018] (5) By electroplating PEDOT:PSS onto the gold foil surface used as the triboelectric electrode, the stimulator's lead-out end possesses excellent charge injection capability, increasing the maximum charge injection amount (CIC) from 147.1 μC·cm⁻¹ for gold. - ² Significantly improved to 708.3 μC·cm² for PEDOT:PSS. - ², and verified that it has good long-term stability.

[0019] (6) The stimulator in this invention was used to stimulate the splenic nerve of mice and the cervical vagus nerve of rats to verify the feasibility of the stimulator in the treatment of inflammation. Attached Figure Description

[0020] Figure 1 This is a physical diagram showing the overall structure and composition of a flexible micro-electric stimulator that can be wrapped around and adhered to a peripheral nerve bundle, its preparation method, and application embodiments according to the present invention.

[0021] Figure 2 The thin-film configuration of the device and its adaptation to the coating of neural tissue were demonstrated.

[0022] Figure 3 Detailed dimensioning of the components of a flexible micro-electric stimulator that can be wrapped around and adhered to peripheral nerve bundles, using gold and PEDOT:PSS as the friction layer, is presented as a method for fabrication and integration.

[0023] Figure 4 The results show the mechanical properties and adhesion characteristics of the self-adhesive polyurethane film. Among them, (A) is the stress-strain curve, which shows that the polyurethane material has a low elastic modulus and can achieve mechanical matching with nerve tissue; (B) is the adhesion performance test result of the polyurethane film, which verifies its reliable self-adhesion ability.

[0024] Figure 5 for Figure 1 (A) shows the charge injection capability (CIC) test results of the electroplated PEDOT:PSS modified layer at the stimulator-nerve contact interface; (A) compares the charge injection capabilities of the gold electrode and the PEDOT:PSS modified electrode; (B) demonstrates the long-term stability of the charge injection capability of the PEDOT:PSS modified electrode.

[0025] Figure 6 for Figure 1The output performance test results of the stimulator in (A) under the conditions of 500 kHz sine wave drive, trigger frequency 1 Hz and pulse period 2 ms; where (A) is the short-circuit current output characteristic; and (B) is the long-term stability voltage test result after soaking in PBS solution for one month.

[0026] Figure 7 for Figure 1 The results of the efficacy verification of the stimulator in (A) of the study on the sciatic nerve in mice confirm the effectiveness of the device in activating nerves.

[0027] Figure 8 for Figure 1 The biocompatibility verification results of the stimulator in (A) are shown.

[0028] Figure 9 for Figure 1 Data on the use of (A) stimulator to stimulate the splenic nerve in mice to treat osteoarthritis.

[0029] Figure 10 for Figure 1 Data on the treatment of rat myocarditis by stimulating the vagus nerve in the neck of rats using the (B) stimulator. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] This invention discloses a flexible micro-electric stimulator that can be wrapped and adhered to a peripheral nerve bundle, its preparation method, and its application. It is assembled layer by layer from a first insulating layer, a first triboelectric electrode layer, an intermediate isolation layer, a second triboelectric electrode layer, and a second insulating layer. Both the first and second insulating layers are self-adhesive polyurethane layers, and they encapsulate the first triboelectric electrode layer, the intermediate isolation layer, and the second triboelectric electrode layer within them. The first triboelectric electrode layer is gold foil, and the surface of the gold foil is electroplated with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate. The second triboelectric electrode layer is gold foil or aluminum foil.

[0032] The stimulator can be designed in various configurations according to the size differences and neuroanatomical characteristics of the target animal, including: (1) Long lead type, nerve coverage is achieved through lead (see Example 1 for details). (2) Square structure, which achieves full nerve coverage (see Example 2 for details).

[0033] The following are specific examples.

[0034] Example 1 The present invention discloses a method for fabricating and integrating a flexible micro-electrical stimulator that can be wrapped and adhered to a peripheral nerve bundle, comprising the following steps: (1) The self-adhesive insulating polyurethane layer is prepared according to the following steps: S1: Weigh 14.5g of polytetrahydrofuran diol into a dry three-necked flask, mechanically stir it evenly in a 100℃ oil bath, vacuum dry it for one hour, and then cool it down to 70℃ for later use. S2: Weigh 6.77g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate and dissolve them in 5ml of dimethylacetamide; S3: Under nitrogen protection, add the solution from step S2 to S1 and stir continuously for two hours. Then cool to room temperature, add 1.683g of dimethylglyoxime, and stir further at 40°C for 12 hours. Take 2ml of polyurethane solution and add 10ml of diluent DMAc to dissolve it to obtain an elastomer solution for later use. S4: The elastomer solution is dropped into a polytetrafluoroethylene mold, heated to 150°C, and DMAc is continuously volatilized for 6 hours. Then it is allowed to cool naturally to room temperature to obtain a self-adhesive polyurethane insulating film with a thickness of 30 μm. S5: Design a mold of a specific size to cut the polyurethane film, which is slightly larger than the internal friction layer and nerve contact interface, in order to facilitate subsequent self-adhesive encapsulation.

[0035] (2) The double-layer triboelectric electrode layer is prepared according to the following steps: S1: The friction layer on one side is selected as commercial gold foil with a thickness of 0.4μm, and is adhered using commercial polyurethane with a thickness of 5μm, or aluminum foil with a thickness of 20μm can be used directly; S2: The other side friction layer is PEDOT:PSS, which is prepared by in-situ polymerization on the gold foil surface using electrochemical deposition: 3,4-ethylenedioxythiophene (EDOT) monomer and polystyrene sulfonate (PSS) are co-dissolved in deionized water and magnetically stirred for 12 h to form a homogeneous mixed solution. Then, using the gold foil as the working electrode, a PEDOT:PSS conductive layer is deposited on its surface by constant current electrochemical polymerization. S3: Using the same electrochemical deposition process, a PEDOT:PSS modified layer is electroplated at the electrode interface in contact with the nerve to enhance charge injection capability.

[0036] (3) Gold foil is attached to the surface of the first self-adhesive polyurethane insulating layer, and then a polytetrafluoroethylene gasket is attached to the surface of the gold foil or aluminum foil; at the same time, gold foil with a PEDOT:PSS plating layer is attached to the surface of the second self-adhesive polyurethane insulating layer; the two self-adhesive polyurethane insulating layers are aligned and bonded together, with the first insulating layer and the first friction electrode layer leading out, and the second friction electrode layer and the second insulating layer leading out, and the portions of the first insulating layer and the first friction electrode layer leading out are symmetrically arranged with the portions of the second friction electrode layer and the second insulating layer leading out. The adhesive properties of the self-adhesive polyurethane are used to achieve encapsulation, providing a macroscopic gap for the contact-separation movement of the friction layer.

[0037] The physical diagrams of each layer of the wireless stimulator in this embodiment, the complete device structure, and the assembled device are shown below. Figure 1 As shown in (A) in the diagram. Figure 1 From left to right, (A) in the image shows a self-adhesive polyurethane, a gold foil friction layer, polytetrafluoroethylene (PTFE), a PEDOT:PSS friction layer, and the self-adhesive polyurethane. The self-adhesive polyurethane substrate is 30 μm thick, the insulating layers on both sides are 60 μm thick, the commercial PTFE is 20 μm thick, the gold foil electrode is 0.4 μm thick, and the commercial polyurethane tape used to adhere the gold foil is 5 μm thick. After PEDOT:PSS electroplating modification, the thickness of the friction layer slightly increases. The total thickness of the device after overall encapsulation is approximately 100 μm.

[0038] Example 2 The present invention discloses a method for fabricating and integrating a flexible micro-electrical stimulator that can be wrapped and adhered to a peripheral nerve bundle, comprising the following steps: (1) The self-adhesive insulating polyurethane layer is prepared according to the following steps: S1: Weigh 14.5g of polytetrahydrofuran diol into a dry three-necked flask, mechanically stir it evenly in a 100℃ oil bath, vacuum dry it for one hour, and then cool it down to 70℃ for later use. S2: Weigh 6.77g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate and dissolve them in 5ml of dimethylacetamide; S3: Under nitrogen protection, the solution from step S2 is added to S1 and stirred continuously for two hours. Then, the temperature is lowered to room temperature, and 1.683g of dimethylglyoxime is added. The mixture is stirred at 40°C for 12 hours. After the reaction is complete, 2ml of polyurethane solution is dissolved in 10ml of diluent DMAc to obtain an elastomer solution for later use. S4: The elastomer solution is dropped into a polytetrafluoroethylene mold, heated to 150°C, and DMAc is continuously volatilized for 6 hours. Then it is allowed to cool naturally to room temperature to obtain a self-adhesive polyurethane insulating film with a thickness of 30 μm. S5: Design a mold of a specific size to cut the polyurethane film, which is slightly larger than the internal friction layer and nerve contact interface, in order to facilitate subsequent self-adhesive encapsulation.

[0039] (2) The double-layer triboelectric electrode layer is prepared according to the following steps: S1: The friction layer on one side is selected as commercial gold foil with a thickness of 0.4μm, and is adhered using commercial polyurethane with a thickness of 5μm, or aluminum foil with a thickness of 20μm can be used directly; S2: The other side friction layer is PEDOT:PSS, which is prepared by in-situ polymerization on the gold foil surface using electrochemical deposition: 3,4-ethylenedioxythiophene (EDOT) monomer and polystyrene sulfonate (PSS) are co-dissolved in deionized water and magnetically stirred for 12 h to form a homogeneous mixed solution. Then, using the gold foil as the working electrode, a PEDOT:PSS conductive layer is deposited on its surface by constant current electrochemical polymerization. (3) Attach the gold foil to the surface of the first self-adhesive polyurethane insulation layer, and then attach a polytetrafluoroethylene gasket to the surface of the gold foil or aluminum foil; at the same time, attach the gold foil with PEDOT:PSS plating to the surface of the second self-adhesive polyurethane insulation layer; align and attach the two self-adhesive polyurethane insulation layers, and use the adhesion properties of the self-adhesive polyurethane to achieve encapsulation, providing a macroscopic gap for the contact-separation movement of the friction layer.

[0040] The physical diagrams of each layer of the wireless stimulator in this embodiment, the complete device structure, and the assembled device are shown below. Figure 1 (B) From left to right, the layers are: self-adhesive polyurethane, aluminum foil friction layer, commercial polyurethane, PEDOT:PSS friction layer, and self-adhesive polyurethane. The polyurethane substrate is 30 μm thick, the insulating layers on both sides are 60 μm thick, the commercial polyurethane is 5 μm thick, the aluminum foil electrode is 20 μm thick, and the commercial polyurethane tape used for adhering the gold foil is 5 μm thick. After PEDOT:PSS electroplating modification, the thickness of the friction layer increases slightly. The total thickness of the device after overall encapsulation is approximately 100 μm.

[0041] Results and Analysis: Experimental demonstrations of the stimulators prepared in Examples 1 and 2 covering the splenic nerve and cervical vagus nerve, respectively, are shown below. Figure 2 As shown in (A) and (B) in the figure.

[0042] Figure 1 The planar dimensions of each layer of the stimulator in (A) are as follows: Figure 3 As shown.

[0043] The mechanical and adhesive properties of the self-adhesive polyurethane films prepared in step (1) of Examples 1 and 2 were characterized using a tensile testing machine. Figure 4As shown in (A) and (B), this polyurethane material has a low modulus of elasticity (i.e., low stiffness) and excellent adhesion properties.

[0044] Subsequently, the charge injection capability (CIC) of the PEDOT:PSS modified interface prepared in step (2) of Examples 1 and 2 was tested using an electrochemical workstation, and its long-term stability was assessed by immersing it in PBS solution, with performance changes measured weekly. Figure 5 As shown in (A) and (B), the modified interface maintains stable performance during long-term stimulation, verifying its good interface stability.

[0045] The stimulator packaged in step (3) of Example 1 was further tested for output performance under the following conditions: 500 kHz sinusoidal ultrasonic drive, trigger frequency 1 Hz, and pulse period 2 ms. Simultaneously, the long-term stability of the stimulator after immersion in PBS solution for one month was tested for voltage output. Figure 6 As shown in (A) and (B), the stimulator can generate a peak-to-peak current of 520 μA and a peak-to-peak voltage of 24 V under the above driving conditions; after being soaked in PBS solution for one month, its peak-to-peak voltage decreased slightly to 22 V, indicating that the stimulator has good output stability.

[0046] Subsequently, the neural activation efficacy of the wireless stimulator in Example 1 was verified using a mouse sciatic nerve model. Specifically, the stimulator was implanted into mice, with its exposed electrode interface tightly covering the surface of the sciatic nerve; an ultrasound probe was used externally to apply ultrasound waves of a specific frequency to drive the stimulator. Figure 7 As shown, by monitoring changes in muscle tone in mice in real time, it was confirmed that the stimulator can effectively induce nerve excitation and achieve nerve activation function.

[0047] The biocompatibility of the stimulator in Example 1 was assessed using PC12 cells. Figure 8 As shown, by setting up a control group and an experimental group, cell staining analysis was performed and compared after 1 day, 3 days and 5 days of culture, respectively. The results confirmed that the device has good biocompatibility.

[0048] Figures 5-8 Only use Figure 1 The stimulator shown in (A) was used to verify its output performance, effectiveness, and safety. Both stimulators are made of the same substrate, with the only difference being the use of gold and aluminum for the friction layer. The main difference lies in their shape design, which is adapted to the body shape and neuroanatomical structure of different experimental animals.

[0049] Ultimately, adopted Figure 1 (A) and Figure 1The stimulator shown in (B) stimulates the splenic nerve in mice and the vagus nerve in the neck of rats, respectively. Figure 1 The portions of the first insulating layer and the first triboelectric electrode layer of the stimulator shown in (A) are respectively wrapped around the mouse splenic nerve which is adhered to the tissue. Figure 1 The stimulator shown in (B) utilizes the self-adhesive properties of the first and second insulating layers to wrap the electrical stimulator around the detached rat cervical vagus nerve.

[0050] The effect is as follows Figure 9 and Figure 10 As shown. Figure 9 The results in (A) and (B) indicate that splenic nerve stimulation can significantly reduce the degree of paw edema (manifested as reduced paw thickness) and the severity of the disease (manifested as a decrease in osteoarthritis score) in a mouse model of osteoarthritis. Figure 10 The results in (A) and (B) indicate that cervical vagal nerve stimulation can significantly improve cardiac function in myocarditis rats, specifically by significantly increasing left ventricular ejection fraction (EF) and fractional shortening (FS) (EF and FS are both echocardiographic indicators used to assess ventricular systolic function).

[0051] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flexible micro-electrical stimulator that can be wrapped around and adhered to a peripheral nerve bundle, its preparation method and application, characterized in that, It is assembled layer by layer from a first insulating layer, a first friction electrode layer, an intermediate isolation layer, a second friction electrode layer, and a second insulating layer; both the first and second insulating layers are self-adhesive polyurethane layers, and the first and second insulating layers encapsulate the first friction electrode layer, the intermediate isolation layer, and the second friction electrode layer; the first friction electrode layer is a gold foil, and the surface of the gold foil is electroplated with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate; the second friction electrode layer is a gold foil or an aluminum foil.

2. The flexible micro-electric stimulator that can be wrapped around and adhered to a peripheral nerve bundle as described in claim 1, characterized in that, The first insulating layer and the first friction electrode layer are led out, the second friction electrode layer and the second insulating layer are led out, and the portions of the first insulating layer and the first friction electrode layer led out are symmetrically arranged with the portions of the second friction electrode layer and the second insulating layer led out.

3. The flexible micro-electric stimulator that can be wrapped around and adhered to a peripheral nerve bundle as described in claim 2, characterized in that, The second triboelectric electrode layer is gold foil, and the surface of the led-out portion is electroplated with a PEDOT:PSS coating formed by 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate.

4. The flexible micro-electric stimulator that can be wrapped around and adhered to a peripheral nerve bundle as described in claim 1 or 2, characterized in that, The intermediate isolation layer is made of polytetrafluoroethylene or polyurethane.

5. The method for preparing a flexible micro-electrical stimulator that can be wrapped around and adhered to a peripheral nerve bundle as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Isophorone diisocyanate and dibutyltin dilaurate are dissolved in an organic solvent to obtain a mixed solution; under non-oxidizing protective gas conditions, the mixed solution is added to dried polytetrahydrofuran diol for reaction, and then dimethylglyoxime is added. After the reaction is completed, a diluent is added to obtain an elastomer solution; the elastomer solution is dropped into a mold and heated to make the diluent evaporate, thereby obtaining a self-adhesive polyurethane insulating film; (2) 3,4-ethylenedioxythiophene monomer and polystyrene sulfonate were co-dissolved in deionized water to form a homogeneous mixed solution. Then, using gold foil as the working electrode, a PEDOT:PSS conductive layer was deposited on the surface of the gold foil by constant current electrochemical polymerization. (3) Attach gold foil or aluminum foil to the surface of the first self-adhesive polyurethane insulating layer, and then attach an isolation layer gasket to the surface of the gold foil or aluminum foil; at the same time, attach gold foil with PEDOT:PSS plating to the surface of the second self-adhesive polyurethane insulating layer; align and attach the two self-adhesive polyurethane insulating layers, and use the adhesive properties of self-adhesive polyurethane to achieve encapsulation.

6. The method for preparing the flexible micro-electric stimulator that can be wrapped and adhered to the peripheral nerve bundle as described in claim 5, characterized in that, The first self-adhesive polyurethane insulating layer and the gold or aluminum foil on its surface are led out, and the second self-adhesive polyurethane insulating layer and the gold foil on its surface plated with PEDOT:PSS are led out, and the structures of these two led-out parts are symmetrically arranged.

7. The method for preparing the flexible micro-electric stimulator that can be wrapped and adhered to the peripheral nerve bundle as described in claim 6, characterized in that, Gold foil is attached to the surface of the first self-adhesive polyurethane insulation layer, and the portion of the gold foil extending from the surface of the first self-adhesive polyurethane insulation layer is electroplated with a PEDOT:PSS coating.

8. The application of the flexible micro-electrical stimulator that can be wrapped and adhered to a peripheral nerve bundle as described in any one of claims 1-4, characterized in that, Under ultrasonic drive, the first and second triboelectric electrode layers generate a contact-separation triboelectric effect, thereby realizing wireless energy conversion and nerve stimulation.

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