WO2024109854A1

WO2024109854A1 - Flexible optical electrode and preparation method therefor

Info

Publication number: WO2024109854A1
Application number: PCT/CN2023/133462
Authority: WO
Inventors: 蒋路遥; 钟成; 鲁艺; 曹燚; 孙重阳; 吴歌
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2022-11-23
Filing date: 2023-11-22
Publication date: 2024-05-30
Also published as: CN115721315A

Abstract

The present application discloses a flexible optical electrode and a preparation method therefor, belonging to the technical field of biomedical materials. Compared with the prior art wherein the shape of existing commercial optical electrodes does not adapt well to the peripheral nerve tissue after being implanted therein, the flexible optical electrode of the present application comprises a flexible optical fiber inner core and a flexible optical fiber coating layer coating the outer side of the flexible optical fiber inner core. The flexible optical electrode of the present application thus exhibits excellent optical transmission performance as well as excellent flexibility and a low modulus of elasticity. The flexible optical electrode further comprises PEDOT conductive fiber arranged on two sides of the flexible optical fiber inner core. The flexible optical electrode of the present application thus further exhibits excellent electrical performance, can exert optical stimulation on the peripheral nerve tissue, and can further record neural electrical signals. The flexible optical electrode further comprises a flexible packaging layer, giving the entirety of the flexible optical electrode excellent biocompatibility, and can effectively reduce damage during long-term implantation in the peripheral nerve tissue.

Description

A flexible photoelectrode and a method for preparing the same

Technical Field

The present application relates to the technical field of biomedical materials, and in particular to a flexible photoelectrode and a preparation method thereof.

Background technique

After the existing commercial photoelectrodes are implanted into the peripheral nerve tissue, due to the mismatch in elastic modulus between the tissue surrounding the peripheral nerve and the existing commercial photoelectrodes, the photoelectrodes will not deform along with the tissue. Therefore, during the bending and contraction of the tissue, a stress concentration effect will occur at the interface where the photoelectrode contacts the tissue, causing serious damage to the tissue at the interface, thereby inducing inflammation, necrosis, and effusion of the tissue.

technical problem

The existing technology has the problem that implanted photoelectrodes cause significant damage to peripheral nerve tissue.

Technical Solutions

The main purpose of the present application is to provide a method for preparing a flexible photoelectrode, aiming to solve the technical problem in the prior art that implanted photoelectrodes cause significant damage to peripheral nerve tissue.

To achieve the above objectives, the present application provides a flexible optical electrode, which includes a flexible optical fiber core, a flexible optical fiber coating layer coated on the outside of the flexible optical fiber core, PEDOT conductive fiber filaments arranged on both sides of the flexible optical fiber core, and a flexible packaging layer.

Optionally, the materials of the flexible optical fiber inner core and the flexible packaging layer are both PDMS, and the material of the flexible optical fiber coating layer is polymethylhydrogensiloxane.

Optionally, the refractive index of the inner core of the flexible optical fiber is 1.41-1.412.

The present application also provides a method for preparing a flexible photoelectrode, the preparation method comprising:

A layer of polymethylhydrogensiloxane is coated on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer;

Arrange multiple PEDOT conductive fibers on both sides of a flexible optical fiber core coated with polymethylhydrogensiloxane;

The arranged flexible optical fiber cores and PEDOT conductive fiber filaments are encapsulated using PDMS through a 3D printer to form a flexible encapsulation layer to obtain a prepared flexible photoelectrode.

Optionally, the method for preparing the flexible optical fiber inner core comprises:

The PDMS and the PDMS curing agent are mixed and stirred evenly to obtain a mixed solution of the PDMS and the PDMS curing agent, wherein the mass ratio of the PDMS and the PDMS curing agent is 5:1;

removing bubbles in the mixed solution, and injecting the mixed solution into a Teflon tube through an injection device;

After the mixed liquid is solidified and formed, the Teflon tube is peeled off to obtain a flexible optical fiber inner core.

Optionally, the method for preparing the PEDOT conductive fiber comprises:

PEDOT:PSS is injected into an isopropanol solution through a 3D printer and solidified to form PEDOT:PSS conductive fiber filaments;

Place the PEDOT:PSS conductive fiber in concentrated sulfuric acid for pickling for 8-15 minutes;

The acid-washed PEDOT:PSS conductive fiber filaments were washed multiple times with ethanol and dried to obtain PEDOT conductive fiber filaments.

Optionally, the needle size of the 3D printer used in the process of injecting PEDOT:PSS into the isopropanol solution through the 3D printer is 23G, the printing radius is 50-80 mm, and the injection speed is 300-400 μl/min.

Optionally, the diameter of the PEDOT conductive fiber is 10-100 microns.

Optionally, after the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further comprises:

The flexible optical fiber inner core coated with polymethylhydrogensiloxane is placed in an oven and heated at 120-130 degrees Celsius for 30-35 minutes under vacuum.

Optionally, before the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further comprises:

The prepared flexible optical fiber core was cleaned using ethanol and ultrapure water.

Beneficial Effects

The present application proposes a method for preparing a flexible photoelectrode. Compared with the prior art in which the existing commercial photoelectrode is implanted into peripheral nerve tissue, the photoelectrode will not deform along with the peripheral nerve tissue. The flexible photoelectrode of the present application includes a flexible optical fiber core and a flexible optical fiber coating layer coated on the outside of the flexible optical fiber core. Therefore, the flexible photoelectrode of the present application not only has good light transmission performance, but also has good flexibility and a low elastic modulus, which can match the nerve tissue; the flexible photoelectrode also includes PEDOT conductive fiber filaments arranged on both sides of the flexible optical fiber core. Therefore, the flexible photoelectrode of the present application also has good electrical properties, can apply light stimulation to the peripheral nerve tissue, and can also record neural electrical signals, maintaining the basic properties of the photoelectrode; the flexible photoelectrode also includes a flexible packaging layer, so that the flexible photoelectrode as a whole has good biocompatibility, which can effectively reduce damage during long-term implantation in peripheral nerve tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

FIG1 is a schematic diagram of the structure of a flexible photoelectrode of the present application;

FIG. 2 is a schematic flow chart of a second embodiment of a method for preparing a flexible photoelectrode according to the present application.

The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

Embodiments of the present invention

It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

An embodiment of the present application provides a flexible photoelectrode, referring to FIG. 1 , which is a schematic diagram of the structure of a flexible photoelectrode.

As an example, a photoelectrode is an electrophysiological device that combines light stimulation with the recording of electrical activity. In the field of brain nerves, photoelectrode devices, which are currently widely used in major neurological laboratories, are made by gluing multiple metal (chromium, nickel, copper, platinum, etc.) microwires to the same section of optical fiber. Since brain nerve tissue is a static tissue, the elastic modulus, that is, the flexibility requirements of the photoelectrode are not high.

The peripheral nervous system, also known as the peripheral nervous system, refers to the nerves other than the cranial nerves and part of the spinal nerves included in the central nervous system.

Compared with the mature photoelectrode technology in the brain, there is a mismatch in elastic modulus between the tissue of peripheral nerves and the existing photoelectrodes. Taking the diaphragm as an example, the elastic modulus of the human diaphragm is 8-10Kpa (resting) and 17-20Kpa (activated), while the elastic modulus of general commercial photoelectrodes is between 1.3-16Gpa. Therefore, after this photoelectrode is implanted in the peripheral nerve tissue (dynamic tissue), the photoelectrode will not deform with the tissue. Therefore, during the process of tissue bending and contraction, a stress concentration effect will occur at the interface where the photoelectrode contacts the tissue, causing serious damage to the tissue on the interface, thereby inducing inflammation, necrosis, and effusion of the tissue.

Therefore, there is still a lack of a reliable optoelectronic tool for the peripheral nervous system.

In this embodiment, a flexible optical electrode is provided. Referring to FIG. 1 , the flexible optical electrode includes a flexible optical fiber core 4, a flexible optical fiber coating layer 3 coated on the outside of the flexible optical fiber core, PEDOT conductive fiber filaments 2 arranged on both sides of the flexible optical fiber core, and a flexible packaging layer 1.

Specifically, the flexible optical electrode includes a flexible optical fiber core 4 and a flexible optical fiber coating layer 3 coated on the outside of the flexible optical fiber core. Therefore, the flexible optical electrode of the present application not only has good light transmission performance, but also has good flexibility and a low elastic modulus, and can match peripheral nerve tissue.

Specifically, the flexible photoelectrode also includes PEDOT conductive fiber filaments 2 arranged on both sides of the flexible optical fiber core 4. Specifically, the PEDOT material has the property of being resistant to bending and has good conductivity. Therefore, the flexible photoelectrode of the present application also has good electrical properties, can apply light stimulation to neural tissue, and can also record neural electrical signals, maintaining the basic properties of the photoelectrode.

Specifically, the flexible photoelectrode also includes a flexible packaging layer 1, which makes the flexible photoelectrode as a whole have good biocompatibility and can effectively reduce damage during long-term implantation in the human body.

As an example, the materials of the flexible optical fiber inner core 4 and the flexible packaging layer 1 are both PDMS (Polydimethylsiloxane), and the material of the flexible optical fiber coating layer 3 is polymethylhydrogensiloxane.

Specifically, the material of the flexible optical fiber inner core 4 is Sylgard 184 PDMS (Dow Corning DC 184), which has the characteristics of high transparency, strong fluidity, high elastic coefficient, etc., increases the toughness and flexibility of the flexible optical fiber inner core 4, and improves the light transmission efficiency.

Specifically, the refractive index of the flexible optical fiber core 4 is 1.41-1.412. The refractive index of the polymethylhydrogensiloxane material of the flexible optical fiber coating 3 is 1.39. Since light is transmitted in the flexible optical fiber core 4 and is totally reflected in the flexible optical fiber coating 3, the refractive index of the polymethylhydrogensiloxane material used in the flexible optical fiber coating 3 is lower than that of the flexible optical fiber core 4, so as not to affect the transmission rate of light in the flexible optical fiber core 4.

Therefore, the flexible optical fiber composed of the flexible optical fiber core 4 and the flexible optical fiber coating layer 3 has good flexibility and toughness, and a high light transmission rate.

As an example, the material of the flexible encapsulation layer 1 is SE1700 PDMS, which has high transparency, high elastic modulus, and lower fluidity than Sylgard 184 PDMS. Therefore, it is suitable as the flexible encapsulation layer 1. It is not easy to deform after encapsulation and has good flexibility. It constitutes an integrated flexible optical electrode with the above-mentioned flexible optical fiber core 4, flexible optical fiber coating layer 3, and PEDOT conductive fiber filament 2.

As an example, the elastic modulus of the flexible photoelectrode composed of the above-mentioned flexible optical fiber core 4, the flexible optical fiber coating layer 3 coated on the outside of the flexible optical fiber core, the PEDOT conductive fiber filaments 2 arranged on both sides of the flexible optical fiber core, and the flexible packaging layer 1 is less than 1000kPa, while the elastic modulus of the general commercial photoelectrode is between 1.3-16GPa. Therefore, the flexible photoelectrode provided in this embodiment has better flexibility and toughness, better biocompatibility, and can effectively reduce the damage during the peripheral nerve implantation process.

In this embodiment, since the flexible photoelectrode provided in this embodiment has better flexibility and toughness, the flexible photoelectrode is suitable for the field of peripheral nerve regulation, and is also suitable for optogenetic regulation of cranial nerves and spinal nerves that do not require so much flexibility.

In this embodiment, a method for preparing the above-mentioned flexible photoelectrode is also provided, and the preparation method comprises:

Step S10: coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer;

As an example, a layer of polymethylhydrogensiloxane is coated on the surface of the flexible optical fiber inner core 4 to form the flexible optical fiber coating layer 3 .

In this embodiment, before the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further includes:

Step S40: using ethanol and ultrapure water to clean the prepared flexible optical fiber inner core.

As an example, the prepared flexible optical fiber inner core 4 is cleaned with ethanol and ultrapure water, which can remove impurities in the flexible optical fiber inner core 4, make the surface of the flexible optical fiber smoother, and reduce the impact on the light transmission rate.

In this embodiment, after the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further includes:

Step S50: placing the flexible optical fiber inner core coated with polymethylhydrogensiloxane into an oven and heating it at 120-130 degrees Celsius under vacuum for 30-35 minutes.

As an example, the flexible optical fiber core 4 coated with polymethyl hydrogen siloxane can be placed in an oven and heated at 130 degrees Celsius in a vacuum for 30 minutes. Alternatively, the flexible optical fiber core 4 coated with polymethyl hydrogen siloxane can be placed in an oven and heated at 120 degrees Celsius in a vacuum for 35 minutes, etc., without specific limitation.

Specifically, by heating, the flexible optical fiber coating 3 and the flexible optical fiber core 4 can be tightly combined, reducing the volume of the flexible optical fiber and avoiding the existence of a gap between the flexible optical fiber coating 3 and the flexible optical fiber core 4, without affecting the transmission rate of light.

Step S20: arranging a plurality of PEDOT conductive fiber filaments on both sides of the inner core of the flexible optical fiber coated with polymethylhydrogensiloxane;

As an example, the plurality of PEDOT conductive fiber filaments 2 may be one, two, three, etc., without specific limitation.

Specifically, the number of signal channels required for electrophysiological recording can be adjusted by increasing or decreasing the number of PEDOT conductive fibers 2 according to demand, and the operation is simple and convenient.

As an example, two PEDOT conductive fiber filaments 2 can be symmetrically arranged on both sides of the flexible optical fiber core 4 coated with polymethylhydrogensiloxane, or three PEDOT conductive fiber filaments 2 can be randomly arranged on both sides of the flexible optical fiber core 4 coated with polymethylhydrogensiloxane, etc., without specific limitation.

At this time, referring to FIG. 1 , since the PEDOT conductive fiber filaments 2 and the flexible optical fiber are very small, they can be regarded as being on the same plane after being arranged.

Step S30: using PDMS through a 3D printer to encapsulate the arranged flexible optical fiber cores and PEDOT conductive fiber filaments to form a flexible encapsulation layer to obtain a prepared flexible photoelectrode.

As an example, the PDMS used by the 3D printer is SE1700 PDMS.

As an example, referring to Figure 1, PDMS is used by a 3D printer to encapsulate the arranged flexible optical fiber core and PEDOT conductive fiber filaments. A layer of SE1700 PDMS can be coated on the upper layer of the plane where the arranged PEDOT conductive fiber filaments 2 and the flexible optical fiber are located by a 3D printer, and then a layer of SE1700 PDMS is coated on the lower layer of the plane where the arranged PEDOT conductive fiber filaments 2 and the flexible optical fiber are located by a 3D printer to complete the encapsulation, form a flexible encapsulation layer, and obtain a prepared flexible photoelectrode.

Compared with commercial photoelectrodes that require precise manual preparation, the flexible photoelectrode provided in this embodiment has fewer preparation steps and a simpler production process, and therefore has a lower preparation cost.

Wherein, the method for preparing the flexible optical fiber inner core comprises:

Step A1: PDMS and PDMS curing agent are mixed and stirred evenly to obtain a mixed solution of PDMS and PDMS curing agent, wherein the mass ratio of PDMS to PDMS curing agent is 5:1;

As an example, sylgard 184 PDMS and sylgard 184 PDMS curing agent in a mass ratio of 5:1 are mixed and stirred evenly to obtain a mixed solution of sylgard 184 PDMS and sylgard 184 PDMS curing agent.

Step A2: removing bubbles in the mixed solution, and injecting the mixed solution into a Teflon tube through an injection device;

As an example, the bubbles in the mixed liquid are removed, and the mixed liquid is injected into a Teflon tube through an injection device. Since the Teflon tube is anti-sticky and has a low friction coefficient, the raw materials are injected into the Teflon tube through the injection device, and the Teflon tube is used as a mold to shape the raw materials, so that a smooth and uniform flexible optical fiber core 4 can be prepared.

Step A3: After the mixed liquid is solidified and formed, the Teflon tube is peeled off to obtain a flexible optical fiber core.

As an example, after the raw materials are solidified and formed, the Teflon tube is peeled off to obtain the flexible optical fiber core 4. The tools used in the entire preparation process are relatively simple, and the preparation process is also very simple. The prepared flexible optical fiber core 4 not only has a smooth surface and uniform thickness, but also has a relatively simple preparation process.

Wherein, the preparation method of the PEDOT conductive fiber comprises:

Step B1: injecting PEDOT:PSS into an isopropanol solution through a 3D printer to solidify and form PEDOT:PSS conductive fiber filaments;

As an example, PEDOT conductive fiber is prepared using PEDOT:PSS material.

Specifically, PEDOT:PSS is a conductive polymer, which is a conductive polymer composed of components PEDOT and PSS. PEDOT is a solution, and PSS is used to assist the plasticity of the PEDOT solution.

Therefore, it is necessary to use a 3D printer to inject PEDOT:PSS into an isopropyl alcohol solution to solidify it into PEDOT:PSS conductive fiber filaments; wherein, the isopropyl alcohol solution can play a role in solidifying PEDOT:PSS.

In this embodiment, the needle size of the 3D printer used in the process of injecting PEDOT:PSS into the isopropanol solution through the 3D printer is 23G, the printing radius is 50-80 mm, and the injection speed is 300-400 μl/min.

As an example, before injecting PEDOT:PSS into an isopropyl alcohol solution through a 3D printer, first replace the needle of the 3D printer, and set the printing radius and injection speed (the speed at which the 3D printer extrude PEDOT:PSS). If the injection speed is too slow, the PEDOT:PSS conductive fiber filaments will be intermittent and unable to form. If the injection speed is too fast, the PEDOT:PSS material will accumulate, resulting in uneven prepared PEDOT:PSS conductive fiber filaments.

Specifically, a 23G needle of a 3D printer (where G is the inner diameter of the needle, 23G is 340 microns), a 50 mm printing radius (needle movement radius) of the 3D printer, and an injection speed of 300 microliters/minute can be used to prepare PEDOT:PSS conductive fiber filaments. A 23G needle of a 3D printer can also be used to print a 75 mm radius circle and an injection speed of 400 microliters/minute to prepare PEDOT:PSS conductive fiber filaments.

As an example, PEDOT:PSS is an aqueous solution with a weight percentage of 1.1%. During the process of injecting PEDOT:PSS into an isopropanol solution, PEDOT:PSS can be dehydrated. Depending on the coagulation time of PEDOT:PSS in the isopropanol solution, the diameter of the prepared PEDOT:PSS conductive fiber changes (from the original needle size of 340 microns to 10-100 microns after shrinkage).

Step B2: Place the PEDOT:PSS conductive fiber in concentrated sulfuric acid for pickling for 8-15 minutes;

As an example, PSS has a negative effect on the conductive properties of PEDOT. Therefore, the PEDOT:PSS conductive fiber needs to be washed in concentrated sulfuric acid for 8-15 minutes to wash away the PSS component in the PEDOT:PSS conductive fiber.

Specifically, the pickling may be performed for 10 minutes, 12 minutes or 15 minutes, etc., without limitation.

As an example, after the PEDOT:PSS conductive fiber is subjected to acid washing, acidic PEDOT conductive fiber is obtained.

Step B3: The acid-washed PEDOT:PSS conductive fiber filaments are washed multiple times with ethanol, and then dried to obtain PEDOT conductive fiber filaments.

As an example, the acid-washed PEDOT:PSS conductive fiber (acidic PEDOT conductive fiber) was washed several times with ethanol to neutralize the excess sulfuric acid.

As an example, the PEDOT conductive fiber filaments are dried to obtain usable PEDOT conductive fiber filaments.

As an example, the diameter of the PEDOT conductive fiber filament finally prepared is 10-100 microns.

Specifically, the diameters of the prepared PEDOT conductive fibers are 20 microns, 85 microns, 100 microns, etc.

As an example, the flexible optical fiber core 4, the flexible optical fiber coating layer 3, the PEDOT conductive fiber filament 2, and the flexible packaging layer 1 prepared according to the above method are made into a flexible photoelectrode according to the above method. The elastic modulus of the flexible photoelectrode is less than 1000 kPa, while the elastic modulus of general commercial photoelectrodes is between 1.3-16 GPa.

Therefore, the flexible photoelectrode provided in this embodiment has better flexibility and toughness, better biocompatibility, and can effectively reduce damage to peripheral nerves during implantation.

The flexible photoelectrode provided in this embodiment can be connected to an existing laser generator and an electrophysiological recording device through an adapter, and fixed to a specific area of the peripheral nervous system by surgical implantation to realize the application of the flexible photoelectrode.

It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

The serial numbers of the embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present application.

The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

A flexible optical electrode, characterized in that the flexible optical electrode comprises a flexible optical fiber core, a flexible optical fiber coating layer coated on the outside of the flexible optical fiber core, PEDOT conductive fiber filaments arranged on both sides of the flexible optical fiber core, and a flexible packaging layer.
The flexible optical electrode according to claim 1 is characterized in that the materials of the flexible optical fiber inner core and the flexible packaging layer are both PDMS, and the material of the flexible optical fiber coating layer is polymethylhydrogensiloxane.
The flexible optical electrode as described in claim 2 is characterized in that the refractive index of the inner core of the flexible optical fiber is 1.41-1.412.
A method for preparing a flexible photoelectrode according to any one of claims 1 to 3, characterized in that the preparation method comprises:

A layer of polymethylhydrogensiloxane is coated on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer;

Arrange multiple PEDOT conductive fibers on both sides of a flexible optical fiber core coated with polymethylhydrogensiloxane;

The arranged flexible optical fiber cores and PEDOT conductive fiber filaments are encapsulated using PDMS through a 3D printer to form a flexible encapsulation layer to obtain a prepared flexible photoelectrode.
Type claim 5 here The method for preparing a flexible optical electrode according to claim 4, characterized in that the method for preparing the flexible optical fiber inner core comprises:

The PDMS and the PDMS curing agent are mixed and stirred evenly to obtain a mixed solution of the PDMS and the PDMS curing agent, wherein the mass ratio of the PDMS and the PDMS curing agent is 5:1;

removing bubbles in the mixed solution, and injecting the mixed solution into a Teflon tube through an injection device;

After the mixed liquid is solidified and formed, the Teflon tube is peeled off to obtain a flexible optical fiber inner core.
The method for preparing a flexible photoelectrode according to claim 4, characterized in that the method for preparing the PEDOT conductive fiber comprises:

PEDOT:PSS is injected into an isopropanol solution through a 3D printer and solidified to form PEDOT:PSS conductive fiber filaments;

Place the PEDOT:PSS conductive fiber in concentrated sulfuric acid for pickling for 8-15 minutes;

The acid-washed PEDOT:PSS conductive fiber filaments were washed multiple times with ethanol and dried to obtain PEDOT conductive fiber filaments.
The method for preparing a flexible photoelectrode as described in claim 6 is characterized in that the needle size of the 3D printer used in the process of injecting PEDOT:PSS into the isopropanol solution through a 3D printer is 23G, the printing radius is 50-80 mm, and the injection speed is 300-400 μl/min.
The method for preparing a flexible photoelectrode according to claim 7, characterized in that the diameter of the PEDOT conductive fiber filament is 10-100 microns.
The method for preparing a flexible optical electrode according to claim 4, characterized in that after the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further comprises:

The flexible optical fiber inner core coated with polymethylhydrogensiloxane is placed in an oven and heated at 120-130 degrees Celsius for 30-35 minutes under vacuum.
The method for preparing a flexible optical electrode according to claim 4, characterized in that before the step of coating a layer of polymethylhydrogensiloxane on the surface of the inner core of the flexible optical fiber to form a flexible optical fiber coating layer, the method further comprises:

The prepared flexible optical fiber core was cleaned using ethanol and ultrapure water.