Flexible multi-channel implantable biological electrode, implantation device and method

Abstract

The invention belongs to the technical field of biological electrodes, and particularly relates to a flexible multi-channel implantable biological electrode, an implanting device and a method, and the biological electrode is formed by fixing at least two single-channel electrodes into a bundle in a spiral winding or parallel fixing mode; adjacent single-channel electrodes abut against and are fixed and insulated from each other, the single-channel electrodes are respectively provided with exposure sites used for collecting electroneurographic signals and / or electromyographic signals or used for nerve electrical stimulation and / or electromyographic stimulation at the implantation sections, and the single-channel electrodes have determined relative positions and jointly form multiple channels; and the exposed sites are arranged at the end part and / or the side surface of the implantation section of the single-channel electrode. Compared with the prior art, the problem that each single-channel electrode in a'multi-channel 'biological electrode in the prior art does not have certain relevance is solved. According to the scheme, all the single-channel electrodes forming the flexible multi-channel biological electrode have a clear relative position relation, and electrode exposure point positions can be arranged at designated positions according to needs.

Description

Technical Field

[0001] The present invention belongs to the technical field of bioelectrodes, and particularly relates to a flexible multi-channel implantable bioelectrode, an implantation device and a method. Background Art

[0002] Implantable neural electrodes (also known as bioelectrodes) play a crucial role in the fields of medicine and biomedicine, and are widely used in the fields of neural electrical signal monitoring, brain-computer interfaces, treatment of degenerative neurological diseases, etc. As a bridge for the communication between biological nerve tissues and the external environment, neural electrodes have the functions of recording neural electrical signal activities and electrically stimulating nerve tissues to restore functions.

[0003] In the initial stage of the development of neural electrodes, doctors and researchers directly used metal materials such as platinum, gold, and platinum-iridium alloys to directly manufacture neural electrodes. However, these electrodes have great limitations in terms of electrochemical properties, biocompatibility, and long-term stability. With the progress and development of technology, flexible neural electrodes have shown greater advantages in many aspects such as biocompatibility and long-term stability.

[0004] Carbon nanotubes (CNT) are a new type of inorganic non-metallic material, including single-walled carbon nanotubes and multi-walled carbon nanotubes, and have excellent electrochemical properties and mechanical characteristics. Carbon nanotube fiber (CNTf) is an elongated fiber material prepared based on CNT raw materials. It not only inherits the high charge injection ability, low impedance characteristics, and biocompatibility of CNT itself, but also has a diameter size and an elongated high aspect ratio structure comparable to neurons, and has a lower magnetothermal effect. These characteristics make CNTf one of the best materials for flexible implantable neural electrodes.

[0005] One development direction of neural electrodes is to achieve multi-channel recording and stimulation. However, due to their ultra-fine size, ultra-high aspect ratio, and low elastic modulus, it is very difficult to implement multi-channels for flexible neural microelectrodes. First, flexible neural electrodes are usually only exposed at the ends of the electrodes. Directly bundling them into a bundle cannot control the positions of multiple electrode points, and thus cannot accurately record and stimulate nerve tissues. Second, the sizes of flexible neural electrodes are very fine, and simply bundling them cannot control the relative positions of the electrode fibers and the exposed electrode points. Third, the exposed point forms of flexible neural electrodes are single, and generally only the insulating layer at the end of the electrode is removed to expose a section of the internal conductor.

[0006] After a search of existing literature patents, it is found that there are some limitations and defects in the current published multi-channel designs of flexible neural electrodes. For example, a fiber neural electrode disclosed in Patent CN 115538163 B forms a fiber neural electrode with any number of channels through assembly and forms a multi-channel neural electrode by twisting or arranging in parallel. Relative slippage, extrusion, and separation will occur between the electrode fibers, and the relative positions of the neural electrode targets cannot be accurately controlled. In addition, this patent does not describe the exposure method of the electrode points. For example, an implantable neural electrode based on carbon nanotube lines disclosed in Patent CN 108904972 A, although it is required that the implantable neural electrode is a single-channel electrode or a multi-channel electrode array, the structural design of the multi-channel electrode array is not described. More specifically, in this patent, two independent single-channel carbon nanotube fiber electrodes are directly used to record or stimulate two-channel neural electrical signals, but the two electrodes are implanted separately, and the distance between them is affected by surgical implantation and cannot be quantitatively determined. Therefore, it is not a true two-channel electrode. Moreover, the exposure method of this electrode only exposes a small section of the conductor at the electrode end face, and exposure at any other position cannot be achieved. Therefore, the relative positions of the exposure points of different channel electrodes cannot be fixed. For example, an implantable neural electrode system disclosed in Patent CN 110721402 A fixes the ends of multiple neural electrodes through connectors, but the slender electrode bodies are still free, and the relative positions of different single-channel electrodes cannot be controlled, so it is not a true multi-channel electrode either, and its exposure method is also direct exposure at the end.

[0007] In addition, different from traditional metal electrodes that can be directly inserted, due to the easy bending characteristics of flexible microelectrodes, they are tensile but not compressive, and special implantation methods are required to successfully implant them into neural tissues to avoid electrode buckling and damage to the structural performance of the electrodes. An implantation method of an implantable neural electrode disclosed in Patent CN 108904972 A uses a carrier to carry the implantable neural electrode to penetrate the perineurium and pierce into the internal neural tissue, and then the carrier is withdrawn. However, since there is no fixation between the neural electrode and the carrier, this method will still cause buckling of the flexible electrode during implantation.

[0008] In summary, the existing flexible neural electrodes have problems in realizing multi-channel stimulation and recording in a local range, personalized electrode point exposure, and difficult implantation of flexible electrodes. Summary of the Invention

[0009] The object of the present invention is to provide a flexible multi-channel implantable bioelectrode, an implant device and a method to solve at least one of the above problems, so as to solve the problem in the prior art that the "multi-channel" bioelectrode only implants multiple single-channel electrodes simultaneously, and there is no definite correlation between the single-channel electrodes. This solution realizes the reliable implantation of a truly flexible multi-channel bioelectrode. There is a clear relative position relationship between the single-channel electrodes that make up the flexible multi-channel bioelectrode, and electrode exposure points can be opened at designated positions according to needs to meet the requirements of point design.

[0010] The object of the present invention is achieved through the following technical solutions:

[0011] In the first aspect of the present invention, a flexible multi-channel implantable bioelectrode is disclosed. The flexible multi-channel implantable bioelectrode is formed into a bundle by fixing at least two single-channel electrodes in a spiral winding or parallel fixing manner;

[0012] Adjacent single-channel electrodes are abutted and fixed and insulated from each other. Moreover, the single-channel electrodes are each provided with an exposed site on the implanted section for collecting nerve electrical signals and / or myoelectric signals, or for nerve electrical stimulation and / or myoelectric stimulation. Each single-channel electrode has a definite relative position and jointly constructs a multi-channel;

[0013] The exposed site is opened at the end and / or side of the implanted section of the single-channel electrode.

[0014] Preferably, the single-channel electrode includes a conductor at the center and an insulating layer concentrically wrapped outside the conductor; the conductor is selected from one or more of flexible carbon nanotube fibers, platinum-iridium alloy wires, tungsten wires and nickel-chromium alloy wires, and the material of the insulating layer is selected from one or more of type C parylene, polyimide, phenolic resin and medical silicone.

[0015] Preferably, the conductor is a flexible carbon nanotube fiber, and the flexible carbon nanotube fiber is formed by integrating several carbon nanotubes into a bundle; the carbon nanotubes are selected from one or two of single-walled carbon nanotubes and multi-walled carbon nanotubes; the length of the flexible carbon nanotube fiber is 1 - 200 mm, and the diameter is 1 μm - 10 mm.

[0016] Preferably, when the flexible multi-channel implantable bioelectrode is fixed into a bundle in a spiral winding manner, the single-channel electrodes are spirally wound around each other. The length of the single-channel electrode is 1 - 500 mm, the diameter is 1 μm - 10 mm, and the pitch is 1 μm - 10000 μm.

[0017] The spiral-wound flexible multi-channel implantable bioelectrode can be fabricated in the following manner: (1) Select single-channel electrodes with appropriate quantity, size, and material according to requirements; (2) Fix one end of each single-channel electrode on a substrate, then twist the free end in a spiral manner, and subsequently cut off the spirally wound portion to obtain the spiral-wound bundle of flexible multi-channel implantable bioelectrodes. The formation of the exposed site can be carried out before winding or after winding.

[0018] Preferably, when the flexible multi-channel implantable bioelectrodes are fixed into a bundle in a parallel fixing manner, the single-channel electrodes are arranged parallel to each other. The length of the single-channel electrode is 1 - 500 mm, and the diameter is 1 μm - 10 mm; each single-channel electrode is fixed and limited by an electrode fixing material coated on the outside, and the electrode fixing material is selected from one or more of C-type parylene, medical silicone rubber, polyimide, and PDMS.

[0019] The parallel-fixed flexible multi-channel implantable bioelectrode can be fabricated in the following manner: (1) Select single-channel electrodes with appropriate quantity, size, and material according to requirements; (2) Arrange each single-channel electrode parallel to each other (arranged on the same plane or on the same ring) and keep the adjacent single-channel electrodes in close contact with each other; (3) Fix and limit the arranged single-channel electrodes with an electrode fixing material to form a bundle, thereby obtaining the parallel-fixed bundle of flexible multi-channel implantable bioelectrodes. The formation of the exposed site can be carried out before fixing and limiting with the electrode fixing material or after fixing and limiting with the electrode fixing material.

[0020] Preferably, the size of the exposed site is between 1 μm - 5 mm, and a single exposed site is opened on each single-channel electrode; the exposed site is formed by means of laser etching, ion beam etching, chemical reaction, or mechanical peeling.

[0021] More preferably, the exposed site is formed by laser etching; through laser etching, the exposed site can be formed at a specified position with high precision (the maximum error is 10 nm - 1 mm) without completely exposing the end, and thus can be personalized designed according to the target requirements. At the same time, combined with the fact that each single-channel electrode (exposed site) has a definite relative position, signals at specific points can be stimulated and acquired after the flexible multi-channel implantable bioelectrode is implanted.

[0022] Preferably, the exposed site can generally be designed in shapes such as circular, circular ring-shaped, square, rectangular strip, etc., as long as it meets the design requirements and performance needs; the setting position of the exposed site is obtained according to the position of the target nerve area and the target recording and stimulation target.

[0023] In the second aspect of the present invention, an implant device is disclosed, including a carrier and the flexible multi-channel implantable bioelectrode as described in any one of the above.

[0024] The described flexible multi-channel implantable bioelectrode is connected to the carrier by bonding with biological glue, or the flexible multi-channel implantable bioelectrode is wound around the carrier in a spiral winding manner.

[0025] Preferably, the carrier is a groove, and the flexible multi-channel implantable bioelectrode is bonded in the groove with biological glue; the end of the groove is a tip, the inner diameter of the groove is 0.1 μm to 10 mm, the outer diameter is 0.2 μm to 15 mm, and the length is 10 μm to 200,000 μm.

[0026] Preferably, the carrier is a metal needle, and the flexible multi-channel implantable bioelectrode is bonded to the surface of the metal needle with biological glue, or the flexible multi-channel implantable bioelectrode is wound around the surface of the metal needle in a spiral winding manner; the length of the metal needle is 10 μm to 100 mm, the diameter is 10 μm to 1000 μm, and the material is selected from stainless steel, tungsten or chromium.

[0027] Preferably, the biological glue has biocompatibility and can be selected from one or more of sucrose syrup, polyethylene glycol, gelatin, chitosan glue, protein glue and polyethylene oxide; the biological glue is dissociated by being dissolved in physiological saline or in a form of natural degradation.

[0028] The third aspect of the present invention discloses an implantation method, which uses any one of the above-described implantation devices; after determining the implantation position through a stereotaxic instrument, the implantation device is towed and implanted into the target area, and then the flexible multi-channel implantable bioelectrode is separated from the carrier; the carrier is withdrawn, and the flexible multi-channel implantable bioelectrode is retained in the target area to complete the implantation.

[0029] When the implantable bioelectrode is used, first connect the multi-channel implantable bioelectrode to the carrier. After determining the implantation position through a stereotaxic instrument, tow the implantation device into the interior of the brain tissue. Then, disconnect the connection between the multi-channel implantable bioelectrode and the carrier and withdraw the carrier, leaving the multi-channel implantable bioelectrode in the interior of the brain tissue to complete the implantation process. Specifically, to disconnect the connection between the multi-channel implantable bioelectrode and the carrier, corresponding methods should be adopted according to the different connection methods used by the two: if they are connected by bonding with biological glue, the dissociation between the two can be achieved by dissolving in physiological saline, natural degradation, etc.; if they are in a spiral winding form, after being implanted in place, the multi-channel implantable bioelectrode at the forefront can be fixed first with forceps, and then the metal needle can be slowly rotated and withdrawn to leave the multi-channel implantable bioelectrode in the interior of the brain tissue.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. In the bioelectrode provided by the present invention, the conductor material is preferably a carbon nanotube fiber. The carbon nanotube fiber inherits the excellent properties of carbon nanotubes and has good mechanical properties (low elastic modulus), electrochemical properties (high charge injection ability and low impedance characteristics), and magnetic compatibility (low magnetothermal effect). The carbon nanotube fiber is prepared by a wet spinning method, and its diameter can reach within several micrometers, which is of the same order of magnitude as the size of neurons, enabling spatial resolution of single neurons.

[0032] 2. The structural design of the multi-channel bioelectrode provided by the present invention realizes multi-channel electrical signal recording and stimulation of flexible ultra-fine bioelectrodes. Among them, the parallel fixed method can achieve electrical stimulation and recording at the same depth within a small range of nerve tissue, and can also achieve electrical stimulation and recording at different depths; the spiral winding fixed method can achieve electrical stimulation and recording at different orientations and depths. The relative positions of the exposed sites of each channel in the multi-channel carbon nanotube fiber electrode with parallel fixation and spiral fixation are clear, so it is convenient to judge its relative position in biological tissue after implantation. For example, when the multi-channel electrode is implanted into the cerebral cortex, the specific depth of each channel in the cerebral cortex can be determined according to the relative position of the exposed sites, thereby helping to clarify the connection between different cerebral cortex nerve electrical signals.

[0033] 3. The preferred method for exposing the multi-channel electrode points provided by the present invention is laser etching technology, which has ultra-high-precision resolution and controllable shape control. By controlling the intensity, position, and path of the laser, exposed sites with different diameters, positions, and shapes can be obtained, thereby realizing personalized electrode design to meet the usage requirements.

[0034] 4. The flexible electrode implantation device provided by the present invention effectively solves the buckling phenomenon and positioning problem during the implantation process of flexible electrodes, and avoids the structural damage and difficult accurate positioning problems during the implantation process of bioelectrodes. Brief Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the preparation process of a flexible multi-channel implantable bioelectrode;

[0036] Figure 2 It is a schematic diagram of the structure of a parallel fixed four-channel implantable bioelectrode. (a), (b), and (c) are respectively schematic diagrams of the structures of parallel fixed four-channel implantable bioelectrodes with three different forms of exposed sites, and (d) is a schematic cross-sectional structure diagram of a parallel fixed four-channel implantable bioelectrode;

[0037] Figure 3 It is a schematic diagram of the structure (a) and a schematic cross-sectional structure diagram (b) of a spiral fixed four-channel implantable bioelectrode;

[0038] Figure 4Schematic diagram of the theoretical structure of a groove-type implant device;

[0039] Figure 5 Schematic diagram of the theoretical structure of a metal needle-type implant device (spirally wound);

[0040] Figure 6 Schematic diagram of the theoretical structure of a metal needle-type implant device (adhesive connection);

[0041] Figure 7 Scanning electron microscope images during the preparation of a spiral-fixed four-channel implantable bioelectrode. (a) Scanning electron microscope image of the conductor CNTf, (b) Scanning electron microscope image of a single-channel electrode formed by coating the insulating layer, (c) Scanning electron microscope image of the exposed sites formed by laser etching, (d) Scanning electron microscope image of the flexible multi-channel implantable bioelectrode formed by spiral winding;

[0042] Figure 8 Physical photos of two groove-type implant devices. (a) A needle-shaped implant device with grooves prepared by 3D printing, (b) A needle-shaped implant device with grooves formed by grinding the needle tip;

[0043] Figure 9 Physical photo of a groove-type implant device;

[0044] Figure 10 Photo when implanting a multi-channel bioelectrode using a groove-type implant device;

[0045] Figure 11 Photo after implanting a multi-channel bioelectrode using a groove-type implant device;

[0046] Figure 12 Schematic diagram when implanting a multi-channel bioelectrode using a metal needle-type implant device;

[0047] In the figure: 1 - single-channel electrode; 101 - conductor; 102 - insulating layer; 2 - electrode fixing material; 3 - exposed site; 4 - flexible multi-channel implantable bioelectrode; 5 - bio-glue; 6 - groove; 7 - metal needle. Detailed implementation manners

[0048] The flexible multi-channel implantable bioelectrode and implant device provided by the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. Before describing the present invention in detail, it should be understood that the terms and words used in this specification and claims should not be construed as having their ordinary and dictionary meanings, but should be considered as having meanings and concepts corresponding to the spirit of the present invention, which the inventor can appropriately define the terms and words, so as to describe their inventions in the best way.

[0049] In the following description, unless otherwise specified, the reagents used are conventional commercially available products, and the methods used are common general knowledge in the art.

[0050] Before elaborating on the specific embodiments, the preparation method of CNTf in the embodiments of this patent is described herein first: 1) First, use few-walled, highly crystalline CNT powder, and purify the CNT powder to remove amorphous carbon and catalyst impurities; 2) Disperse the purified CNT powder in chlorosulfonic acid liquid, and adopt a dispersion process to make it uniformly dispersed. At the same time, the rheological properties of the dispersion can be adjusted by adding a small amount of polymer as needed, and it also plays a role in increasing the toughness of the fiber; 3) Adopt the wet spinning method, inject the dispersion from the spinneret into the coagulation bath, and CNT precipitates to form CNT fibers; 4) Through stretching for further orientation to improve performance, and dry the CNT fibers to obtain continuous CNT fibers.

[0051] It should be noted that the multi-channel implantable bioelectrode based on CNTf prepared in this embodiment can not only use the CNTf raw material proposed above, but also use CNTf prepared by other existing published patents or literatures. For example: Patent CN 105263570A discloses another preparation method of CNTf. This method immerses low-density CNT yarn in a volatile solvent, volatilizes the solvent to perform fluid-based densification, and finally obtains the texture densification of CNT yarn, which has excellent electrical, mechanical and thermal properties; Patent CN 105263570A also discloses a CNTf prepared based on the dry spinning method. And other materials with high aspect ratio and flexibility, such as carbon fiber, metal wire, etc. Select and adjust according to actual needs.

[0052] A flexible multi-channel implantable bioelectrode 4, the flexible multi-channel implantable bioelectrode 4 is formed into a bundle by fixing at least two single-channel electrodes 1 in a spiral winding or parallel fixing manner;

[0053] Adjacent single-channel electrodes 1 are abutted and fixed and insulated from each other. Moreover, the single-channel electrodes 1 are each provided with exposed sites 3 for collecting nerve electrical signals and / or myoelectric signals, or for nerve electrical stimulation and / or myoelectric stimulation in the implantation section. Each single-channel electrode 1 has a determined relative position and jointly constructs a multi-channel;

[0054] The exposed site 3 is opened at the end and / or side of the implantation section of the single-channel electrode 1.

[0055] Further, the single-channel electrode 1 is composed of a conductor 101 and an insulating layer 102, and has a length of 1 mm to 500 mm and an ultra-fine structure (diameter of 1 μm to 10 mm). Among them, the conductor 101 is selected from one or more of flexible carbon nanotube fibers, platinum-iridium alloy wires, tungsten wires, and nickel-chromium alloy wires; among them, the insulating layer 102 material of the single-channel electrode 1 is selected from one or more of type C parylene, polyimide, phenolic resin, and medical silicone rubber.

[0056] More preferably, the conductor 101 uses flexible carbon nanotube fibers, which are formed by integrating multiple carbon nanotubes into a bundle. Among them, the carbon nanotubes can be single-walled carbon nanotubes, multi-walled carbon nanotubes, and mixtures of both. The flexible carbon nanotube fibers have a diameter of 1 μm to 10 mm and a length of 1 mm to 200 mm.

[0057] Further, the spiral winding method is to fix two or more single-channel electrodes 1 into a bundle by spiral winding: there is a fixed relative position between different single-channel electrodes 1; different single-channel electrodes 1 are in close contact with each other and insulated from each other; it has a pitch of 1 μm to 10,000 μm and a length of 1 mm to 500 mm.

[0058] See Appendix Figure 1 , the detailed preparation process of the spiral-fixed multi-channel implantable bioelectrode is as follows: (1) According to the actual application requirements, determine the number, diameter, length, conductor 101, and insulating material of the required single-channel electrodes 1, and prepare multiple single-channel electrodes 1; (2) Fix the ends of multiple single-channel electrodes 1 on the substrate, then spiral-twist and wind the free ends, and then cut off the spiral-wound part to obtain a spiral-bundled fiber electrode bundle; (3) Use a specific exposure method to remove the insulating layer 102 material at the target position of each channel of the fixed-bundled fiber electrode to expose the internal conductor 101 and obtain a personalized exposure site 3. Among them, step (3) can be adjusted to be carried out after step (1). At this time, it should be noted that when winding in step (2), the exposure site 3 should be wound towards the outside.

[0059] Further, the parallel fixing method is to place multiple single-channel electrodes 1 parallel and closely, and then use a fixing material to fix the single-channel electrodes 1 into a bundle: there is a fixed relative distance and position between different single-channel electrodes 1; the insulating parts of different single-channel electrodes 1 are in close contact with each other; the fixation of different single-channel electrodes 1 is achieved through the electrode fixing material 2, and the electrode fixing material 2 is selected from one or more of type C parylene, medical silicone rubber, polyimide, and PDMS.

[0060] See Appendix Figure 1, The detailed preparation process of the parallel fixed multi-channel implantable bioelectrode is as follows: (1) According to the actual application requirements, determine the number, diameter, length, conductor 101 and insulating material of the single-channel electrode 1 required, and prepare multiple single-channel electrodes 1; (2) Horizontally arrange multiple single-channel electrodes 1 on a plane, or arrange them rotationally, and keep the different fiber electrodes in close contact; (3) Use the electrode fixing material 2 to fix the arranged single-channel electrodes 1 into a bundle; (4) Use a specific exposure method to remove the insulating layer 102 material at the target position of each channel of the fixed fiber electrode bundle, expose the internal conductor 101, and obtain the personalized exposure site 3. Among them, step (4) can be adjusted to be carried out after step (1). At this time, it should be noted that when applying the electrode fixing material 2 in step (3), the exposure site 3 should be avoided from being coated.

[0061] Furthermore, the exposure site 3 on the single-channel electrode 1: has a size ranging from 1 μm to 5 mm, and has various shapes such as circular, circular ring-shaped, square, strip-shaped and others; each single-channel electrode 1 has and only has one exposure site 3, and the position of the exposure site 3 is calculated according to the target nerve area position and the target recording and stimulation target.

[0062] Furthermore, the exposure method of the exposure site 3 is laser etching, ion beam etching, chemical drug reaction or physical mechanical peeling.

[0063] Preferably, the laser etching method can achieve high-precision control of size and position (the maximum error is from 10 nm to 1 mm).

[0064] An implantation method, connect the flexible multi-channel implantable bioelectrode 4 as described above to a carrier to form an implantation device; after determining the implantation position through a stereotaxic apparatus, tow and implant the implantation device into the target area, and then separate the flexible multi-channel implantable bioelectrode 4 from the carrier; withdraw the carrier and retain the flexible multi-channel implantable bioelectrode 4 in the target area to complete the implantation;

[0065] The flexible multi-channel implantable bioelectrode 4 is adhesively connected to the carrier through the biological glue 5, or the flexible multi-channel implantable bioelectrode 4 is wound around the carrier in a spiral winding manner.

[0066] Furthermore, the carrier includes but is not limited to the groove 6 and the metal needle 7. Among them, the groove 6 is a hard hollow device with a sharp front end, having an inner diameter ranging from 0.1 μm to 10 mm, an outer diameter ranging from 0.2 μm to 15 mm, and a length ranging from 10 μm to 200000 μm. The metal needle 7 has a length ranging from 100 μm to 100 mm, a diameter ranging from 10 μm to 1000 μm, and the material is stainless steel, tungsten or chromium.

[0067] Furthermore, the connection method is to use a biological glue 5 for adhesion and fixation, or to wind and fix the flexible multi-channel implantable bioelectrode 4 on the carrier. The biological glue 5 is selected from one or more of sucrose syrup, polyethylene glycol, gelatin, chitosan glue, protein glue, and polyethylene oxide; it can be transformed between a solid state and a liquid state under certain conditions, and then the dissociation of the flexible multi-channel implantable bioelectrode 4 from the carrier can be achieved by means such as saline dissolution and natural degradation; it has biocompatibility.

[0068] Example 1

[0069] Parallel multi-channel implantable bioelectrode and preparation process:

[0070] Appendix Figure 2 Illustrated are several feasible structures and cross-sections of a parallel four-channel implantable bioelectrode. The shown electrode includes four single-channel electrodes 1 and electrode fixing material 2. Among them, the single-channel electrode 1 includes a conductor 101 at the center and an insulating layer 102 concentrically wrapped outside the conductor 101; the four single-channel electrodes 1 are arranged in a ring, and the cross-sectional connection lines of the four centers can form a rectangle. Moreover, complete fixation and limitation are achieved by wrapping with the electrode fixing material 2 outside the four single-channel electrodes 1.

[0071] The following details the manufacturing process of the parallel multi-channel implantable bioelectrode, as Figure 1 shown.

[0072] 1) Preparation of the single-channel electrode 1: Determine the diameter and length of the required single-channel electrode 1 according to the application requirements (nerve tissue target area and surgical equipment); determine the material, diameter, and length of the required conductor 101; determine the material and thickness of the required insulating layer 102; prepare multiple single-channel electrodes 1.

[0073] 2) Place and fix the single-channel electrode 1: Select a suitable spacing and place the multiple single-channel electrodes 1 prepared in step 1) in parallel bundles. They can be arranged in parallel on a plane or arranged in a circle by rotation (see Figure 2 ).

[0074] 3) Fix and bundle the single-channel electrode 1: On the basis of step 2), use the electrode fixing material 2 to coat and wrap the multiple arranged single-channel electrodes 1.

[0075] 4) Obtain exposure site 3: Determine the position, diameter, and shape of exposure site 3 according to parameters such as the relative position of the target to be stimulated or recorded and the diameter of the single-channel electrode 1. Select an appropriate exposure method. Preferably, use the laser etching method. On the basis of step 3), etch the electrode bundle that is fixed in a bundle and wrapped with a fixing material to obtain exposure site 3. It should be noted that only one exposure site 3 is obtained on each single-channel electrode 1, and exposure site 3 should not be too large to cause the conductors 101 of different single-channel electrodes 1 to contact each other, resulting in a short circuit.

[0076] Through the above steps, the parallel multi-channel implantable bioelectrode of this embodiment is obtained.

[0077] In addition, the process of forming exposure site 3 in step 4) can also be adjusted after step 1), that is, the exposure site 3 is formed after the single-channel electrode 1 is prepared. At this time, it should be noted that when using the electrode fixing material 2 to smear and wrap in the subsequent step 3), the position of exposure site 3 should be avoided.

[0078] The following illustrates the preparation process of this embodiment through a preparation example

[0079]

Preparation Example 1

[0080] The electrode structure is shown in Appendix Figure 2 (b) and Appendix Figure 2 (d). The detailed preparation process is as follows:

[0081] ① Obtain CNTf: Refer to the aforementioned preparation method of CNTf, and obtain four CNTfs with the same length and a diameter of 20 μm through the wet spinning method;

[0082] ② Prepare a single-channel CNTf electrode fiber: Use chemical vapor deposition to generate a parylene coating on the surface of a single CNTf;

[0083] ③ Insulate and fix the electrode array again: Place the four insulated CNTf electrode fibers side by side at intervals, and use parylene for vacuum coating again to insulate and fix the electrode array again;

[0084] ④ Expose CNTf: Expose the end face at the depth of the target of the entire electrode through the laser etching method.

[0085] In this example, the single depth of the entire multi-channel electrode is exposed, and each channel is independent of each other. During the stimulation process using two of the channels, the neuroelectrophysiological signals at the target can be collected simultaneously through the other two channels.

[0086]

Preparation Example 2

[0087] The electrode structure is shown in the appendix Figure 2 (a), appendix Figure 2 (c) and appendix Figure 2 (d). The detailed preparation process is as follows:

[0088] ① Obtain CNTf: Refer to the preparation method of CNTf, and four CNTfs with the same length and a diameter of 20 μm are obtained by the wet spinning method;

[0089] ② Prepare a single-channel CNTf electrode fiber: Use chemical vapor deposition to form a parylene coating on the surface of a single CNTf;

[0090] ③ Insulate and fix the electrode array again: Place the four insulated CNTf electrode fibers side by side at intervals, and use parylene for vacuum coating again to insulate and fix the electrode array again;

[0091] ④ Expose CNTf at different depths: Cut according to the different depths of the required targets by laser etching to expose the internal CNTf conductor 101. The end faces at different depths are the electrode targets at different depths. The structure is shown in appendix Figure 2 (a). In addition, refer to appendix Figure 2 (c), and the laser intensity can also be controlled to only melt part of the insulating layer 102 material without cutting off the insulating layer 102 from the conductor 101, so as to realize exposed sites 3 with different shapes and positions.

[0092] In this example, different depths of the entire multi-channel bioelectrode are exposed. Each channel is independent of each other, and it is possible to stimulate and record targets in nerve tissues at different depths within a local cylindrical area, and even to stimulate and record electrical signals at different positions of the same neuron.

[0093] Example 2

[0094] Spiral Four-Channel Implantable Bioelectrode and Preparation Process

[0095] Appendix Figure 3 Illustrates the structure and cross-section of a spiral four-channel implantable bioelectrode. The shown electrode includes four single-channel electrodes 1. Among them, the single-channel electrode 1 includes a conductor 101 and an insulating layer 102 material. The single-channel electrode 1 includes a conductor 101 at the center and an insulating layer 102 concentrically wrapped outside the conductor 101; the four single-channel electrodes 1 are arranged in a spiral winding, and the cross-sectional connection lines of the four centers can form a rectangle.

[0096] The following will detail the manufacturing process of the spiral multi-channel implantable bioelectrode, asFigure 1 as shown

[0097] 1) Preparation of single-channel electrode 1: Refer to step 1) of Example 1.

[0098] 2) Fix the ends of multiple prepared single-channel electrodes 1 together on a substrate, then helically twist and wind the free ends, and then cut off the helically wound part to obtain a bundled electrode formed by helically winding multiple single-channel electrodes 1.

[0099] 3) Obtain exposure site 3: Determine the position, diameter, and shape of exposure site 3 according to the relative position of the target to be stimulated or recorded and parameters such as the diameter of single-channel electrode 1. Select a suitable exposure method. Preferably, use a laser etching method to etch the helically wound bundled electrode fibers to expose the internal conductor 101 and obtain exposure site 3. It should be noted that only one exposure site 3 is obtained on each single-channel electrode 1, and exposure site 3 should not be too large to cause the conductors 101 of different single-channel electrodes 1 to contact each other, resulting in a short circuit.

[0100] Through the above steps, a spiral multi-channel implantable bioelectrode is obtained.

[0101] In addition, step 3) can be adjusted after step 1), that is, the manufacturing of exposure site 3 is carried out after the single-channel electrode 1 is prepared. At this time, it should be noted that when helically winding in subsequent step 2), the exposure site 3 should be oriented outward instead of inward.

[0102] The following illustrates the preparation process of this example through a preparation example.

[0103]

Preparation Example 3

[0104] The following preparation process will be described in conjunction with the attached Figure 7 for illustration.

[0105] ① Refer to the preparation method of CNTf, and obtain four CNTfs with the same length and a diameter of 20 μm through a wet spinning method. The scanning electron microscope photo of the prepared CNTf is shown in Figure 7 (a).

[0106] ② Insulate the CNTf using the Low Pressure Chemical Vapor Deposition (LPCVD) method, and reliably insulate the carbon nanotube wires with parylene with good biocompatibility to form an insulating layer 102 with a thickness of 10 μm. The scanning electron microscope photo of the insulated carbon nanotube fibers is shown in Figure 7(b), it can be observed that the surface of the parylene-insulated carbon nanotube fiber exhibits a smooth surface, and at the same time, the parylene molecules form a partial hemispherical structure on the surface of the carbon nanofiber.

[0107] ③ By using the laser etching technique, the insulating layer 102 of the carbon nanotube fiber is melted, thereby exposing the carbon nanofiber wire sites and achieving the removal of the insulating layer 102 at the specified position. The effect after removal can be seen in Figure 7 (c). A clear demarcation line appears between the insulating layer 102 and the carbon nanotube conductor 101. At the same time, in the laser-treated part, the carbon nanofiber wires expose their original structures, while the untreated part is fully wrapped by the insulating layer 102.

[0108] ④ Twist and wind the single-channel carbon nanotube fiber exposed by the previous laser etching to obtain a spiral four-channel implantable bioelectrode. The scanning electron microscope photo of the final electrode can be seen in Figure 7 (d).

[0109] Example 3

[0110] Groove 6-Type Bioelectrode Implantation Device

[0111] Adopt the Figure 4 shown groove 6-type device to achieve the implantation of the flexible electrode.

[0112] Figure 4 The shown groove 6-type electrode implantation device includes three components: a flexible multi-channel implantable bioelectrode 4, a biological glue 5, and a groove 6. Place the flexible multi-channel implantable bioelectrode 4 to be implanted in the center of the groove 6 and connect and fix the two with the biological glue 5. Implant the fixed whole into the target biological tissue area, and then remove the biological glue 5 by means such as dissolving with physiological saline to achieve the dissociation between the flexible multi-channel implantable bioelectrode 4 and the groove 6. After that, remove the groove 6 and leave the flexible multi-channel implantable bioelectrode 4 in the tissue, thereby realizing the implantation of the bioelectrode without damaging the structure of the electrode.

[0113]

Preparation Example 4

[0114] In this example, two types of grooves 6 were prepared. As Figure 8 shown, the core of this design is to provide a strengthening structure during the bioelectrode implantation process, using a rigid structure with a groove 6 to fix the flexible multi-channel implantable bioelectrode 4, so as to determine the implantation depth while facilitating the implantation of the flexible multi-channel implantable bioelectrode 4 and the detachment of the implantation device.

[0115] Figure 8(a) shows an implant device fabricated integrally by 3D printing. Its advantage is that the manufacturing process is standardized, and both the thickness and length can be customized. However, due to its small size, the printing materials are limited, and currently, only resin materials can be selected. Therefore, both the hardness and precision are insufficient.

[0116] Another method is to fabricate the implant device by sanding the needle tip. As shown in Figure 8 (b), by sequentially sanding the needle tip with five sizes of sandpaper from D80 to D0.2 in order, half of the needle tip is sanded off along the axial direction to form a structure with a groove 6. In this example, the implant device fabricated from the needle tip may have problems such as insufficiently smooth edges and large manufacturing tolerances due to manual sanding (which can be overcome by considering mechanical sanding, precision grinding, etc.). However, it also has the following advantages: 1) The needle tip structure is relatively hard and is not prone to bending, breaking, etc.; 2) The grooves on the needle tip are clearer than those of the 3D printing structure, making it easier to fix the position of the electrode wire; 3) Since the needle tip has a hollow structure, injecting physiological saline into the needle tip with a smaller-sized needle can cause the physiological saline to flow down along the needle tip, thus better separating the bioelectrode adhesively connected to the needle tip.

[0117]

Preparation Example 5

[0118] In addition to sucrose syrup, common biofixation glues also include polyethylene glycol (PEG). PEGs with different molecular weights have different melting points, and the time required for melting in physiological saline and tissues is also different. The implant experiment requires a moderate melting rate. Therefore, PEG - 2000 (PEG molecules with an average molecular weight of 2000) is selected as the bio - glue 5 in this example. First, heat PEG - 2000 in a water bath at 60 °C to melt it into a transparent liquid state. Place the bioelectrode in the groove of the device, put the assembled device into the liquid PEG - 2000, and evenly coat a layer of PEG - 2000 at the tip. At room temperature, PEG - 2000 quickly solidifies into a white solid as the bio - glue 5, stably fixing the electrode wire and the implant device.

[0119] Compared with sucrose syrup used as the bio - glue 5, PEG - 2000 has the following characteristics: 1) PEG - 2000 has a fast solidification rate and more stable properties, and there is no need to wait for the syrup to solidify during operation; 2) PEG - 2000 has a long heating and melting time, providing a longer operation time and margin; 3) PEG has good biocompatibility and can be used as a brain drug - delivery carrier without damaging brain tissue cells.

[0120] The use of PEG - 2000 as the bio - glue 5 and the implant device with the sanded needle tip as the groove 6 is shown in Figure 9 .

[0121]

Experimental Example 6

[0122] As shown Figure 10 in the figure is a surgical schematic diagram of fixing the needle implant device with a stereotaxic apparatus for the brain and implanting the flexible multi-channel implantable bioelectrode 4 into the deep brain of a rat. After positioning and inserting the bioelectrode into the deep brain of the rat, physiological saline is slowly flowed down along the needle, which can dissolve PEG-2000 and successfully separate the bioelectrode from the needle. As shown Figure 11 is a schematic diagram of the flexible multi-channel implantable bioelectrode 4 after separation.

[0123] Example 4

[0124] Helical winding type bioelectrode implant device

[0125] The flexible electrode is implanted by using the helical winding type device shown Figure 5 in the figure.

[0126] The helical implant device uses the metal needle 7 as the main body, helically winds and fixes the flexible multi-channel implantable bioelectrode 4 on the surface of the metal needle 7, then directly inserts the metal needle 7 into the target biological tissue, and then slowly withdraws it, leaving the flexible multi-channel implantable bioelectrode 4 in the target area.

[0127]

Experimental Example 7

[0128] Refer to Figure 12 , implant the metal needle 7 (tungsten needle in this example) helically fixed with the bioelectrode into the target area through a stereotaxic apparatus for the brain, then use forceps to fix the front end of the bioelectrode, slowly rotate and withdraw the tungsten needle, leaving the bioelectrode in the target brain tissue area to complete the implantation.

[0129] Example 5

[0130] Parallel fixed type bioelectrode implant device

[0131] The flexible electrode is implanted by using the parallel fixed type device shown Figure 6 in the figure.

[0132] The parallel implant device uses the metal needle 7 as the main body, fixes and connects the flexible multi-channel implantable bioelectrode 4 to the metal needle 7 through the bioadhesive 5, then inserts the metal needle 7 into the target biological tissue, and then dissolves the bioadhesive 5 by injecting physiological saline or other appropriate solvents to release the fixation between the electrode and the metal needle 7, and then slowly withdraws the metal needle 7, leaving the bioelectrode in the target area to complete the implantation.

[0133]

Experimental Example 8

[0134] Similarly refer toFigure 12 After insulation and etching exposure treatment, the flexible multi-channel implantable bioelectrode 4 and the metal needle 7 (tungsten needle) with a diameter of 100 - 200 μm are bonded through a 4wt% polyethylene oxide solution, and then the bioelectrode / tungsten needle complex is implanted into the required target area through a stereotaxic apparatus. During this period, it should be noted that the time to reach the target area needs to be less than 3 minutes to avoid the separation of the bioelectrode and the tungsten needle before reaching the target position due to the premature dissolution of polyethylene oxide. After implantation to the target position, wait for 5 minutes until the bioelectrode and the tungsten needle are separated, withdraw the tungsten needle, and only the bioelectrode remains in the target area in the brain to complete the implantation.

[0135] Application Example 1

[0136] Long-term vagus nerve electrical signal recording and stimulation of rats based on a parallel four-channel CNT fiber electrode

[0137] Before the experiment, the rats were starved and water-deprived for 8 hours to reduce the vagus nerve electrical interference related to gastrointestinal digestion function in subsequent signal analysis. Before the surgery, the rats were placed in a closed anesthesia box, and isoflurane gas with a concentration of 3% was introduced at a gas flow rate of 1 L / min for 10 minutes of anesthesia. When it was observed that the rats were limp in the box, if the rats twitched or their breathing became deeper and faster when pinched or pressed on the toes with forceps, the anesthesia time was continued to be extended. After the rats showed no obvious response to the stimulation, they were transferred to the stereotaxic apparatus, the heating pad was turned on and the temperature was adjusted to 42°C, and the anesthesia gas flow was adjusted to the stereotaxic apparatus with the anesthesia concentration adjusted to 2.5%. The rats were fixed in the supine position, and the head and neck were padded with a hemostatic gauze to ensure the patency of the rat's airway, and anesthesia was continued for 5 - 10 minutes. If the rats showed no obvious signs of waking up, the anesthesia concentration was adjusted to 2.0%, and they were left to stand for 1 - 2 minutes. If there were no signs of waking up, the subsequent surgical procedures were continued.

[0138] During the bioelectrode implantation stage, a parallel four-channel CNT fiber electrode was selected. Under the real-time guidance of the nerve electrophysiological monitoring system, the exposed area of the electrode tip was accurately implanted into the perineurium of the vagus nerve through the above-developed electrode (the implantable bioelectrode in Example 1) and the corresponding implanting device (the implanting device in Example 3). Immediately after electrode positioning, α-cyanoacrylate bioadhesive was dripped for in-situ fixation, and the reference electrode and the ground electrode were respectively buried in the subcutaneous fascia layer of the neck and the muscle space of the hind limb. Then the tail end of the electrode was matched and connected with a micro wireless nerve stimulation device, and the quality of nerve signal acquisition was verified through a wireless telemetry system. When stable nerve electrical signals were continuously obtained for more than 10 minutes, it was confirmed that the electrode implantation was successful.

[0139] During the postoperative device fixation and verification phase, the experimental animals were turned into the prone position, and a medical-grade silicone adhesive was used to firmly fix the micro wireless nerve stimulation device to the subcutaneous tissue of the thoracolumbar region. After the incision was closed, the stability of nerve signal transmission was continuously monitored, and the antibiotic ceftriaxone sodium was intravenously injected immediately after the operation and during the awakening period for anti-infection treatment. After the animals woke up, they were transferred to a standard breeding cage, and the device displacement and signal stability were tracked in real time through a wireless monitoring system. If the vagus nerve signals were continuously and stably recorded during the 30-minute free activity observation period after the operation, the surgery was determined to be successful. For individuals with signal interruption or abnormal fluctuations, a second surgical exploration was immediately required, with a focus on evaluating the contact stability of the electrode-nerve interface and the integrity of device fixation.

[0140] Application Example 2

[0141] Electroencephalogram signal recording and stimulation of rats based on a spiral dual-channel CNT fiber electrode

[0142] The experimental rats were fasted and watered for 8 hours to reduce the cranial nerve interference related to gastrointestinal digestion function. Before the surgery, the rats were placed in a sealed anesthesia box, and isoflurane gas with a concentration of 3.0% was introduced for anesthesia. After complete anesthesia, the rats were transferred to a stereotaxic apparatus for the brain, the heating pad was turned on and the temperature was adjusted to 42 °C. The anesthesia gas flow was adjusted to the stereotaxic apparatus, and the anesthesia concentration was adjusted to 2.5%. A craniotomy was performed on the rats, the dura mater and pia mater were lifted, and the rat brain tissue was exposed.

[0143] The spiral multi-channel CNT fiber electrode (Example 2) was implanted into the deep prefrontal lobe of the rat brain tissue using the developed grooved electrode implantation device (Example 3). The biological glue used to fix the electrode and the groove was PEG-2000. After PEG-2000 dissolved at the rat body temperature, the groove was withdrawn, leaving the electrode in the target tissue area. Subsequently, α-cyanoacrylate bioadhesive was used to fix the electrode-tissue interface, and the reference electrode and the ground electrode were respectively implanted in the subcutaneous tissue. The other end of the electrode was connected to the TDT system. For 8 hours continuously after the operation, the electrophysiological activities of the rat cranial nerves were synchronously collected in dual channels. Pulse stimulation was performed through one channel of the electrode every 10 minutes, and the electrophysiological signal activities and physiological responses of the rats were observed and recorded.

[0144] Application Example 3

[0145] Vagus nerve electrophysiological signal recording based on a parallel four-channel implantable CNT fiber electrode

[0146] Before the experiment, the rats were deprived of food and water for 8 hours to reduce the vagus nerve electrical interference related to gastrointestinal digestive function in subsequent signal analysis. Before the operation, the rats were placed in a closed anesthesia box, and 3% isoflurane gas was introduced with a gas flow rate of 1L / min for 10 minutes of anesthesia. When the rats were observed to be limp in the box, the toes were squeezed or pressed with tweezers. If the rats twitched or their breathing deepened and accelerated, the anesthesia time was continued. After the rats had no obvious response to the stimulation, they were transferred to the brain stereotaxic instrument, the heating pad was turned on and the temperature was adjusted to 42°C, the anesthetic gas was adjusted to flow to the brain stereotaxic instrument, and the anesthetic concentration was adjusted to 2.5%. The rats were fixed in the supine position, and the head and neck were raised with hemostatic gauze to ensure that the rats' airways were unobstructed, and anesthesia was performed for 5-10 minutes. If the rats showed no obvious signs of awakening, the anesthetic concentration was adjusted to 2.0%, and they continued to stand for 1-2 minutes. If there were no signs of awakening, the subsequent surgical operation was continued.

[0147] The left cervical vagus bioelectrode implantation surgery is performed. First, the hair near the neck is removed and disinfected with iodine cotton swabs. The skin of the rat neck is cut along the midline to the vicinity of the sternum with surgical scissors, and the skin and muscle are separated to find the left thyroid gland. The thyroid gland is pushed aside, and the muscle and fat are separated to the lower left, the carotid sheath is found and the pulsating carotid artery is observed, accompanied by the cervical sympathetic trunk, the aortic decompression nerve and the vagus nerve. Among them, the vagus nerve is the thickest, the sympathetic trunk is second, and the decompression nerve is the thinnest. The carotid sheath is cut open with tweezers, the vagus nerve is carefully peeled off from the carotid artery and other nerves, and the vagus nerve is picked up with a hook and fixed, and the electrode (Example 1) is implanted into the perineurium along the vagus nerve using a groove-type flexible electrode implantation device (Example 3), so that the electrode exposure site is completely inside the nerve, and the different channels of the electrode are separated so that the exposure sites of multiple channels are near multiple nerve fibers in the vagus nerve bundle. After successful implantation, gently clamp with tweezers, add α-cyanoacrylate bioglue to fix the electrode, place the reference electrode subcutaneously near the neck incision, and the ground electrode subcutaneously near the leg. Observe the signal through the TDT system to ensure that the electrode is placed inside the nerve.

[0148] After the operation, the anesthetic concentration was adjusted to 1.5%, and the real-time vagus nerve electrical signals were continuously collected for 8 hours. During the collection process, the physiological condition of the rat and the signs of awakening should be continuously paid attention to. If the rat has convulsions or the breathing speeds up and deepens, the anesthetic concentration should be increased to prevent the rat from awakening and breaking free from the arterial cannula and biological electrode. After the collection is completed, the anesthetic concentration was increased to 5.0%, the rat was euthanized, and the experimental platform was tidied up.

[0149] In summary, the flexible multi-channel implantable bioelectrode 4 of the present invention solves the problem that it is difficult to integrate flexible microelectrodes with an elongated structure into a bundle to achieve multi-channel stimulation and recording; and further realizes the personalized exposure of multiple exposed sites 3 at specified positions of the multi-channel electrode through laser etching technology. At the same time, due to the soft and bendable characteristics of the flexible multi-channel implantable bioelectrode 4 itself, it is impossible or difficult to directly implant it into nerve tissue. The present invention also discloses a method for implanting the flexible multi-channel implantable bioelectrode 4, which solves the problem of how to successfully implant the flexible multi-channel implantable bioelectrode 4 into the brain tissue and locate it at the target position through the assistance of a connecting carrier. The flexible multi-channel implantable bioelectrode 4 and the corresponding bioelectrode implantation method disclosed in the present invention can be used in medical and scientific fields such as deep brain stimulation, neural prosthesis, and cardiac pacing.

[0150] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A flexible multi-channel implantable bioelectrode, characterized in that, The described flexible multi-channel implantable bioelectrode (4) is formed by bundling at least two single-channel electrodes (1) in a helical winding or parallel fixing manner; Adjacent single-channel electrodes (1) are abutted and fixed and insulated from each other. Moreover, each of the single-channel electrodes (1) has an exposed site (3) opened on its implant section for collecting nerve electrical signals and / or electromyographic signals, or for nerve electrical stimulation and / or electromyographic stimulation. Each single-channel electrode (1) has a determined relative position and jointly constructs a multi-channel; The exposed site (3) is opened at the end and / or side of the implant section of the single-channel electrode (1).

2. The flexible multi-channel implantable bioelectrode according to claim 1, characterized in that, The single-channel electrode (1) includes a conductor (101) at the center and an insulating layer (102) concentrically wrapped outside the conductor (101); the conductor (101) is selected from one or more of flexible carbon nanotube fibers, platinum-iridium alloy wires, tungsten wires, and nickel-chromium alloy wires, and the material of the insulating layer (102) is selected from one or more of C-type parylene, polyimide, phenolic resin, and medical silicone.

3. The flexible multi-channel implantable bioelectrode according to claim 2, wherein, The conductor (101) is a flexible carbon nanotube fiber, and the flexible carbon nanotube fiber is formed by integrating several carbon nanotubes into a bundle; the carbon nanotubes are selected from one or two of single-walled carbon nanotubes and multi-walled carbon nanotubes; the length of the flexible carbon nanotube fiber is 1 - 200 mm, and the diameter is 1 μm - 10 mm.

4. A flexible multi-channel implantable bioelectrode according to claim 1, characterized in that When the flexible multi-channel implantable bioelectrode (4) is bundled in a helical winding manner, the single-channel electrodes (1) are helically wound around each other. The length of the single-channel electrode (1) is 1 - 500 mm, the diameter is 1 μm - 10 mm, and the pitch is 1 μm - 10000 μm.

5. A flexible multi-channel implantable bioelectrode according to claim 1, wherein When the flexible multi-channel implantable bioelectrode (4) is bundled in a parallel fixing manner, the single-channel electrodes (1) are arranged parallel to each other. The length of the single-channel electrode (1) is 1 - 500 mm, and the diameter is 1 μm - 10 mm; each single-channel electrode (1) is fixed and limited by an electrode fixing material (2) coated on the outside, and the electrode fixing material (2) is selected from one or more of C-type parylene, medical silicone rubber, polyimide, and PDMS.

6. The flexible multi-channel implantable bioelectrode according to claim 1, characterized in that, The size of the exposed site (3) is between 1 μm and 5 mm, and a single exposed site (3) is opened on a single single-channel electrode (1); the exposed site (3) is formed by laser etching, ion beam etching, chemical reaction, or mechanical peeling.

7. An implant device, characterized in that, It includes a carrier and the flexible multi-channel implantable bioelectrode (4) according to any one of claims 1 - 6; The flexible multi-channel implantable bioelectrode (4) is adhesively connected to the carrier by a bioadhesive (5), or the flexible multi-channel implantable bioelectrode (4) is wound around the carrier in a helical winding manner.

8. An implant device according to claim 7, wherein, The carrier is a groove (6), and the flexible multi-channel implantable bioelectrode (4) is adhered to the groove (6) by a bioadhesive (5); the end of the groove (6) is a tip, the inner diameter of the groove is 0.1 μm to 10 mm, the outer diameter is 0.2 μm to 15 mm, and the length is 10 μm to 200,000 μm.

9. An implant device according to claim 7, characterized in that, The carrier is a metal needle (7), and the flexible multi-channel implantable bioelectrode (4) is adhered to the surface of the metal needle (7) by a bioadhesive (5), or the flexible multi-channel implantable bioelectrode (4) is wound around the surface of the metal needle (7) by a helical winding method; the length of the metal needle (7) is 10 μm to 100 mm, the diameter is 10 μm to 1000 μm, and the material is selected from stainless steel, tungsten or chromium.

10. An implantation method, characterized in that, An implant device as claimed in any one of claims 7 to 9 is used; after determining the implantation position by a stereotaxic instrument, the implant device is towed and implanted into the target area, and then the flexible multi-channel implantable bioelectrode (4) is separated from the carrier; the carrier is withdrawn, and the flexible multi-channel implantable bioelectrode (4) is retained in the target area to complete the implantation.

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