A flexible electrode and a method for preparing the same

Abstract

The present invention provides a flexible electrode, comprising a columnar implantation section and a connection section; the connection section is formed by a wiring section of a planar flexible circuit board, and the portion of the planar flexible circuit board other than the wiring section is a stimulation section; the stimulation section comprises a strip-shaped substrate and a plurality of extensions formed on the same side or different sides of the length direction of the strip-shaped substrate; the extensions carry at least one electrode contact; the implantation section comprises an electrode ring formed by curling the extensions along a predetermined direction and a flexible insulating sleeve encapsulating and covering the strip-shaped substrate and filling the inner cavity of the electrode rings, and the electrode contacts of the extensions are exposed on the outer wall of the corresponding electrode ring; the present invention prepares a planar flexible circuit board based on mature technology, and after curling the extensions on the planar flexible circuit board to form electrode rings, the strip-shaped substrate and the electrode rings are reinforced and fixed by encapsulation to form a flexible insulating sleeve encapsulating the strip-shaped substrate, so as to avoid breakage and / or shedding of the coating layer during use.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a flexible electrode and a preparation method thereof. Background Art

[0002] A neurostimulation electrode is a medical device for treating neurological diseases. When treating neurological diseases, the neurostimulation electrode needs to be implanted in the body to apply electrical stimulation to the area to be stimulated on the nerve tissue.

[0003] With the continuous progress of microelectronics technology and materials science, implantable neural electrodes are developing towards flexibility, miniaturization, and high density (i.e., multi-electrode channels). In addition, in order to ensure the space utilization of the flexible electrode, its implanted part needs to be set in a columnar shape. The traditional manufacturing method of a columnar flexible electrode is: a guide wire is placed in each cavity of a multi-cavity flexible tube (each guide wire has a stimulation contact and a connection contact at both ends) to form a columnar flexible electrode; when using this method to form a high-density columnar flexible electrode, it takes a lot of time to insert a large number of guide wires into the multi-cavity flexible tube, which greatly affects the manufacturing efficiency of the flexible electrode, and because a large number of guide wires need to be accommodated, the diameter of the multi-cavity flexible tube is bound to increase, which is not conducive to the miniaturization of the electrode; in addition, because the guide wire is very thin, it is extremely dependent on the worker's operating experience when routing the guide wire, and it is very easy for the guide wire to break, which is not conducive to mass production.

[0004] In order to achieve precision mass production of columnar flexible electrodes, some researchers have proposed to first produce flexible electrode films based on mature MEMS and other technologies, and then curl the flexible electrode films to form columnar flexible electrodes; however, when they are implanted in vivo for use, they are very likely to break and / or the covering film may fall off due to the movement of biological tissues, resulting in poor reliability.

[0005] The invention patent with application number 202310479850.3 discloses a multifunctional flexible tube neural electrode and its preparation method, which first spirally winds the FPC neural electrode on the base microtube to form a tubular electrode body; then the tubular electrode body is placed in a chemical vapor deposition system to deposit a parylene film to form a protective layer on the outside of the tubular electrode body to obtain a multifunctional flexible tube neural electrode; the base microtubes set in this scheme greatly improve the anti-fracture ability of the multifunctional flexible tube neural electrode, but it is difficult to ensure the flatness and uniformity of the FPC neural electrode (i.e., the thin film electrode) when the FPC neural electrode is spirally wound, which greatly affects the performance of the FPC neural electrode. In addition, since the FPC neural electrode is only protected by the protective layer, there is still a problem that the covering film (i.e., the protective layer) is easy to fall off during actual use, affecting the reliability of use. Summary of the invention

[0006] In view of the above shortcomings of the prior art, an object of the present invention is to provide a flexible electrode and a preparation method thereof, so as to achieve low-cost production of high-reliability flexible columnar electrodes.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention provides a flexible electrode, including an implantation section and a connection section, wherein the implantation section is a columnar structure; the connection section is formed by a wiring section of a planar flexible circuit board; the portion of the planar flexible circuit board other than the wiring section is a stimulation section, wherein the stimulation section includes a strip-shaped substrate and a plurality of extensions arranged at intervals along the length direction of the strip-shaped substrate, and the plurality of extensions are formed on the same side or different sides of the length direction of the strip-shaped substrate; the extension carries at least one electrode contact; the implantation section includes an electrode ring formed by curling the extensions along a predetermined direction and a flexible insulating sleeve that encapsulates and covers the strip-shaped substrate and fills the inner cavity of the electrode rings, and the electrode contacts of the extensions are exposed on the outer wall of the corresponding electrode ring; the present invention prepares a planar flexible electrode with multiple electrode contacts based on mature MEMS and other technologies. The circuit board is prepared by curling the extension body carrying the electrode point area on the flat flexible circuit board to form a ring with exposed electrode contacts, and then the strip-shaped substrate and each electrode ring are strengthened and fixed by means of potting and injection of glue to form a flexible insulating sleeve that covers the strip-shaped substrate and exposes the contacts on each electrode ring. The processes involved in the entire preparation process are very mature, which effectively reduces the preparation cost. In addition, since the strip-shaped substrate of the flat flexible circuit board is wrapped by the flexible insulating sleeve, when the stimulation segment of the flat flexible circuit board is implanted in biological tissue, the flexible insulating sleeve can protect the flexible insulating coating layer at the stimulation segment of the flat flexible circuit board to prevent it from falling off during repeated bending and folding to cause short circuit or open circuit problems. At the same time, the flexible insulating sleeve can also enhance the anti-fracture ability of the flat flexible circuit board to meet the long-term use requirements of the flexible nerve stimulation electrode.

[0008] Preferably, when the extension body is curled to form the electrode ring, the free end of the extension body is connected to the root of the extension body by welding or gluing to maintain the shape of the electrode ring and prevent it from spreading and affecting subsequent operations.

[0009] Preferably, the extension body includes a main body and an anti-detachment plug formed at the free end of the main body, and a slot cooperating with the anti-detachment plug is provided at the root of the main body; when the extension body is curled to form an electrode ring, the anti-detachment plug is plugged into and cooperated with the slot to maintain the shape of the electrode ring, thereby preventing the electrode ring from spreading out and affecting subsequent operations.

[0010] Preferably, the anti-dropout plug includes an anti-dropout portion and a plug neck located between the anti-dropout portion and the main body; the length dimension of the plug neck is not greater than the length dimension of the slot, and the thickness dimension of the plug neck is not greater than the width dimension of the slot; when the extension body is curled to form an electrode ring, the anti-dropout portion passes over the slot and abuts against the main body to limit the anti-dropout plug from falling off.

[0011] Preferably, the extension body carries an electrode contact; when the extension body is curled to form an electrode ring, the electrode contact on the extension body forms an omnidirectional electrode contact to meet the omnidirectional stimulation requirement.

[0012] Preferably, the extension body carries a plurality of electrode contacts, and the plurality of electrode contacts are distributed in an array; thus, when the extension body where the electrode sites are located is curled to form an electrode ring, each electrode contact thereon can serve as a directional electrode contact for directional stimulation.

[0013] Preferably, the planar flexible circuit board includes a flexible insulating base layer, a patterned conductive layer and a flexible insulating coating layer which are stacked; the patterned conductive layer includes electrode contacts located on each extension body, conductive pins located at the far end of the wiring segment and conductive circuits for connecting the electrode contacts with the corresponding conductive pins.

[0014] Preferably, the planar flexible circuit board is a single-sided board, a double-sided board, or a multi-layer board, which can be determined by the user according to actual needs.

[0015] Preferably, the flexible insulating sleeve is formed by potting with polyurethane potting glue or silicone potting glue to ensure the biocompatibility of the implant segment with biological tissue, while improving the fracture resistance of the implant segment to avoid problems such as conductive line breakage during use.

[0016] The present invention also provides a method for preparing a flexible electrode, comprising:

[0017] S1. Prepare a planar flexible circuit board; the planar flexible circuit board is divided into a stimulation section and a wiring section along its length direction; the stimulation section includes a strip-shaped substrate and a plurality of extensions arranged at intervals along the length direction of the strip-shaped substrate, and the plurality of extensions are formed on the same side or different sides of the length direction of the strip-shaped substrate; the planar flexible circuit board includes electrode contacts located on the extensions and conductive pins located at the far end of the wiring section; the electrode contacts are connected to the corresponding conductive pins through conductive lines;

[0018] S2, curling each extension body on the flat flexible circuit board along a preset direction to form an electrode ring with exposed electrode contacts, and fixing the free end of each extension body to the root of the corresponding extension body by gluing, welding or plugging to maintain the shape of the electrode ring; the center lines of the electrode rings formed by curling are collinear;

[0019] S3. The stimulation segment after curling the extension body is placed in a potting mold for overall potting, so as to cover the strip-shaped substrate of the stimulation segment with a flexible insulating sleeve that exposes the electrode contacts, thereby completing the preparation of the flexible electrode.

[0020] Since the planar flexible circuit board involved in the flexible electrode is manufactured based on existing mature processes (such as MEMS process, FPC board manufacturing process, etc.), the preparation cost is relatively low; in addition, the present application does not require additional welding of expensive conductive rings, and the corresponding electrode rings can be obtained by simply curling the extension body of the load electrode contact on the planar flexible circuit board, which not only simplifies the processing flow, but also reduces the cost of raw materials, thereby greatly reducing the processing and manufacturing cost of the flexible electrode.

[0021] As described above, a flexible electrode and a method for preparing the same according to the present invention have at least the following beneficial effects:

[0022] 1) The present invention adopts mature MEMS technology or FPC board manufacturing process to prepare a flat flexible circuit board with multiple electrode contacts, which can realize the integration and precision design of multiple electrode channels on a flexible insulating substrate with limited area, facilitate the high-precision and high-density mass production of flat flexible circuit boards, and provide a basis for the high-density and miniaturized design of flexible electrodes.

[0023] 2) When designing the planar flexible electrode plate, the present invention optimizes the shape of the planar flexible circuit board at the stimulation section, so that it has a strip-shaped substrate for routing, and a plurality of extension bodies for carrying electrode contacts are extended laterally on one or both sides of the length direction of the strip-shaped substrate; in this way, there is no need to additionally weld expensive electrode rings, and the electrode rings with exposed electrode contacts can be formed by simply curling the extension bodies, thereby effectively reducing the material cost and manufacturing cost of the flexible electrode.

[0024] 3) In order to achieve miniaturized design, the stimulation segment of a planar flexible circuit board usually has a thinner and narrower size, which will greatly affect the anti-fracture ability of the planar flexible circuit board; in order to ensure the anti-fracture ability of the planar flexible circuit board, the present invention places the stimulation segment after the extension body is curled in a potting mold for overall potting of flexible insulating material, so that the strip substrate at the stimulation segment is covered with flexible insulating material, which not only reduces the risk of the covering film layer on the strip substrate falling off, but also improves the anti-fracture ability of the implanted part of the flexible electrode, thereby ensuring the reliability of the flexible electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 4 is a three-dimensional diagram of a flexible electrode according to an embodiment of the present invention.

[0026] Figure 2 FIG. 4 is a front schematic diagram of a planar flexible circuit board according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the front layer structure of a flat flexible circuit board using a double-sided board.

[0028] Figure 4 This is a schematic diagram of the reverse layer when a flat flexible circuit board uses a double-sided board.

[0029] Figure 5 Schematic diagram of the manufacturing process of a flexible electrode in one embodiment of the present invention.

[0030] Figure 6 It is a schematic diagram of the planar structure of an extension body in one embodiment of the present invention.

[0031] Figure 7 for Figure 6 A cross-sectional view of the extended body after being curled into an electrode ring and a cross-sectional view of the extended body after being potted with a flexible insulating material.

[0032] Figure 8 It is a schematic diagram of the planar structure of an extension body in one embodiment of the present invention.

[0033] Fig. 9 for Figure 8 A cross-sectional view of the extended body after being curled into an electrode ring and a cross-sectional view of the extended body after being potted with a flexible insulating material.

[0034] Fig.10 It is a schematic diagram of the planar structure of an extension body in one embodiment of the present invention.

[0035] Fig.11 for Fig.10 A cross-sectional view of the extended body after being curled into an electrode ring and a cross-sectional view of the extended body after being potted with a flexible insulating material.

[0036] Description of Reference Numerals

[0037] Implantation segment 1, electrode ring 11, flexible insulating sleeve 12, connecting segment 2, flat flexible circuit board 3, stimulation segment 31, strip-shaped base 311, extension body 312, main body 3121, slot 3121a, plug neck 31221, anti-detachment portion 31222, wiring segment 32, flexible insulating base layer 33, electrode contact 341, conductive pin 342, conductive circuit 343, flexible insulating coating layer 35. DETAILED DESCRIPTION

[0038] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0039] See also Figures 1 to 11. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0040] The flexible electrode involved in the present invention is a columnar three-dimensional electrode, which needs to be implanted in a living body to apply electrical stimulation to the nerve tissue to achieve the purpose of treating neurological diseases. When in use, the flexible electrode needs to be implanted in the living body with the help of a puncture needle. The specific method is: insert the flexible electrode into the hollow channel of the puncture needle to form a puncture assembly, puncture the puncture assembly to the vicinity of the target stimulation site, and then withdraw the puncture needle so that a part of the flexible electrode remains in the living body. At this time, the flexible electrode includes an internal part and an external part, and the external part can be connected to a stimulation generator; the pulse generator generates an electrical stimulation signal and transmits the electrical stimulation signal to the target stimulation site through the flexible electrode to play a role in treating neurological diseases.

[0041] Since flexible electrodes need to be implanted in the body, the smaller the outer diameter of the flexible electrode, the more advantages it has. However, the reduction in outer diameter will inevitably affect the integration of multi-electrode channels. In addition, the modulus of the flexible electrode needs to be as close as possible to that of the biological tissue to ensure that it can deform together with the biological tissue, thereby reducing tissue damage and sustained immune response. However, when the modulus of the flexible electrode is low and easy to deform, its resistance to fracture will be greatly reduced. Therefore, it is particularly important to obtain a flexible electrode with high reliability, high density, miniaturization and low production cost.

[0042] See also Figure 1 , Figure 2 and Figure 5The flexible electrode provided in the present application comprises an implantation section 1 with a columnar structure and a connection section 2 capable of docking with an external pulse stimulator; wherein the connection section 2 is formed by a wiring section 32 of a planar flexible circuit board 3; and the portion of the planar flexible circuit board 3 other than the wiring section 32 is defined as a stimulation section 31, wherein the stimulation section 31 comprises a strip-shaped substrate 311, and a plurality of extension bodies 312 are extended laterally on the same side or different sides of the length direction of the strip-shaped substrate 311; the plurality of extension bodies 312 are arranged at intervals along the length direction of the strip-shaped substrate 311, and each extension body 312 carries at least one electrode contact 341; the implantation section 1 comprises an electrode ring 11 formed by curling the extension bodies 312 in a predetermined direction and a flexible insulating sleeve 12 encapsulating and covering the strip-shaped substrate 311 and filling and connecting the electrode rings 11; after the implantation section 1 is formed, the electrode contact 341 of each extension body 312 is exposed on the outer wall of the corresponding electrode ring 11, so that after being implanted in a biological body, the electrode contact 341 can contact the corresponding part to be stimulated.

[0043] When making a flexible electrode, the present application does not need to curl the entire planar flexible circuit board 3, but only needs to curl the extension body 312 carrying the electrode contact 341 on the planar flexible circuit board 3 to form the electrode ring 11; the present application only curls the extension body 312 with a limited length, which effectively overcomes the shortcomings of the planar flexible circuit board 3 that is prone to accumulate errors during the curling process and is difficult to control the curling accuracy; in addition, the present application does not require additional welding of a conductive ring with biocompatible properties, and only needs to curl the extension body 312 carrying the electrode contact 341 to form the required electrode ring 11; since the expensive conductive ring is eliminated, the material cost of the flexible electrode is greatly reduced, effectively reducing the production cost of the flexible electrode.

[0044] Specifically, Figure 3 and Figure 4 As shown, the planar flexible circuit board 3 is a thin film electrode made based on mature processes such as MEMS technology or FPC technology, which includes a stacked flexible insulating base layer 33, a patterned conductive layer and a flexible insulating coating layer 35; wherein the patterned conductive layer includes electrode contacts 341 located on each extension body 312, conductive pins 342 located at the far end of the wiring segment 32 and conductive circuits 343 for connecting the electrode contacts 341 with the corresponding conductive pins 342; the flexible insulating coating layer 35 is used to cover the conductive circuits 343 in the patterned conductive layer to protect the conductive circuits 343; the routing of the conductive circuits 343 should be evenly distributed, and various existing routing forms such as S-shaped routing, straight routing, serpentine routing, etc. can be adopted based on actual conditions.

[0045] Since the flexible insulating sleeve 12 is wrapped around the outside of the strip-shaped base 311 of the stimulation segment 31 and is filled and connected with the electrode ring 11 formed by curling each extension body 312, it not only saves the cost of setting up additional electrode rings, but also prevents the flexible insulating coating layer 35 and the pattern conductive layer on the strip-shaped base 311 from falling off; at the same time, it can also maintain the shape of the electrode ring 11 and avoid the situation where the electrode ring 11 is scattered; in addition, the flexible insulating sleeve 12 can also improve the anti-fracture ability of the strip-shaped base 311, avoid repeated deformation and bending under the movement of biological tissue after implantation in the body and breakage, and improve the reliability of the flexible electrode.

[0046] It is understandable that the smaller the wire diameter and wire spacing of the conductive circuit 343 are, the more electrode channels can be arranged. In this embodiment, the wire diameter and wire spacing of the conductive circuit 343 are preferably set to 0.05 mm; in addition, the impedance of the conductive circuit 343 is not greater than 10Ω.

[0047] It is understandable that the material of the pattern conductive layer is made of various conductive materials such as copper, gold, molybdenum, etc., which is not limited; the thickness of the pattern conductive layer is 120nm~180nm.

[0048] It is understandable that the flexible insulating base layer 33 and the flexible insulating film layer 35 can be made of flexible materials such as polyimide (PI) or polyethylene terephthalate (PET) or polyurethane (TPU), and there is no limitation on this. The thickness of the flexible insulating base layer 33 and the flexible insulating film layer 35 is 100nm~300μm.

[0049] It can be understood that the width dimension of the planar flexible circuit board 3 at the strip-shaped substrate 311 and the width dimension at the extension body 312 need to be determined according to the outer diameter dimension required by the flexible electrode; for example, when the outer diameter dimension of the flexible electrode is D, the width dimension C1 at the strip-shaped substrate 311 needs to be smaller than D, and the width dimension C2 of the extension body 312 satisfies: π×D<C2≤4D; since the outer diameter dimension D of the flexible electrode is usually several hundred nanometers to several hundred microns, the width dimension and thickness dimension at the stimulation segment 31 of the planar flexible circuit board 3 are very small, which is conducive to ensuring the flexibility at the stimulation segment 31, but its anti-fracture ability is greatly reduced. Therefore, the setting of the flexible insulating sleeve 12 can improve the anti-fracture ability of the stimulation segment 31 without significantly losing the flexibility at the stimulation segment 31, so as to ensure that the flexible electrode can be implanted in the body for a long time; the flexible insulating sleeve 12 can be formed by encapsulation of various medical flexible insulating materials such as polyurethane potting glue or silicone potting glue, which is not limited to this. The flexible insulating sleeve 12 of this embodiment is preferably made of polyurethane potting glue.

[0050] It is understandable that the planar flexible circuit board 3 can be a single-sided board (that is, only one pattern conductive layer), a double-sided board (for details, see Figure 3 and Figure 4 , a patterned conductive layer is respectively arranged on the front and back sides of the flexible insulating base layer 33, so as to complete the routing of more conductive circuits 343 within a smaller width range) or a multilayer board (that is, there are multiple patterned conductive layers, formed by stacking multiple single-sided boards), and there is no limitation on this. The specific board form can be determined according to the number of electrode channels that need to be integrated; in this embodiment, the planar flexible circuit board 3 preferably adopts a double-sided board form to carry as many electrode channels as possible within a plane with limited width.

[0051] In an optional embodiment, the extension body 312 carries an electrode contact 341; when the extension body 312 is curled to form the electrode ring 11, the electrode contact 341 on the extension body 312 is curled together to form an omnidirectional electrode contact; in this embodiment, the layout area of ​​the electrode contact 341 is consistent with the plane area of ​​the corresponding extension body 312; thus, when the extension body 312 is curled to form the electrode ring 11, the electrode contact 341 thereon can be curled together to form an omnidirectional electrode contact.

[0052] In an alternative embodiment, if Figures 6 to 11 As shown, the extension body 312 carries a plurality of electrode contacts 341, and the plurality of electrode contacts 341 are arranged in an array (i.e., at least one row of electrode contacts 341 arranged at intervals is arranged along the extension direction of the extension body 312); in this way, when the extension body 312 is curled to form the electrode ring 11, the electrode contacts 341 thereon can be spaced along the circumferential direction of the outer wall of the electrode ring 11, and the electrode contacts at this time are directional electrode contacts, which can accurately stimulate and treat the lesions with a smaller area; in this embodiment, the corresponding electrode contact arrays are arranged on each extension body 312 of the flat flexible circuit board 3 according to the arrangement requirements of the directional electrode contacts (such as the angular orientation of the directional electrode contacts, etc.); then, the extension body 312 is curled to form the electrode ring 11, so that each electrode contact on the extension body 312 can be spaced along the circumferential direction of the outer wall of the electrode ring 11, thereby facilitating the application of directional stimulation; compared with the traditional method of using welding electrode arc sheets as directional stimulation points, the method of forming directional stimulation points in this embodiment is simpler to operate and is less likely to cause the directional stimulation points to be misplaced.

[0053] It is understandable that after the extension body 312 is curled to form the electrode ring 11, in order to prevent the electrode ring 11 from spreading out, the free end of the extension body 312 needs to be fixed to the root of the extension body 312 by gluing, welding, or clamping, so as to maintain the shape of the electrode ring 11; in the present embodiment, the root of the extension body 312 is the area close to the strip-shaped base 311.

[0054] In an alternative embodiment, if Figures 6 to 9As shown, the extension body 312 is rectangular as a whole. When the extension body 312 is curled to form the electrode ring 11, the free end of the extension body 312 is fixed to the root of the extension body 312 by gluing, lap welding or butt welding; then, the excess part of the free end of the extension body 312 is polished off to ensure that the electrode ring 11 can smoothly transition at the joint of the extension body 312.

[0055] In another embodiment, if Fig.10 and Fig.11 As shown, the extension body 312 includes a rectangular main body 3121 and an anti-dropping plug formed at the free end of the main body 3121, and a slot 3121a is provided at the root of the main body 3121 to engage with the anti-dropping plug; when the extension body 312 is curled to form the electrode ring 11, the anti-dropping plug is inserted into the slot 3121a and then engaged to maintain the shape of the electrode ring 11; this slot-engaging scheme is simple in design and easy to implement, and the relative position of the slot 3121a and the anti-dropping plug can be determined in advance to limit the circumference of the curling, thereby ensuring the consistency of the outer diameter of the electrode ring 11 obtained by curling each extension body 312.

[0056] Specifically, Fig.10 As shown, the anti-slip plug includes an anti-slip portion 31222 and a plug neck 31221 located between the anti-slip portion 31222 and the main body 3121; the length dimension of the plug neck 31221 is not greater than the length dimension of the slot 3121a, and the thickness dimension of the plug neck 31221 is not greater than the width dimension of the slot 3121a, so as to ensure that the plug neck 31221 can be inserted into the slot 3121a without deformation; the anti-slip portion 31222 has an end protruding from the plug neck 31221 in its length direction; when the extension body 312 is curled to form the electrode ring 11, the two ends of the anti-slip portion 31222 are squeezed and deformed under the action of the slot 3121a and then pass over the slot 3121a, so that the plug neck 31221 is located in the slot 3121a; at this time, the anti-slip portion 31222 returns to its original shape, and can cooperate with the main body 3121 to limit the slipping of the plug neck 31221; in this embodiment, the plug neck 31221 and the slot 3121a are clearance-fitted.

[0057] In addition, in order to facilitate the deformation of the anti-slip part 31222 through the slot 3121a, a guiding slope can be formed on the anti-slip part 31222. When the long side of the slot 3121a squeezes the corresponding guiding slope, the two ends of the anti-slip part 31222 will bend and deform in the direction close to the main body 3121 so that it can smoothly pass through the slot 3121a.

[0058] The present invention also provides a method for preparing a flexible electrode, which is used to prepare the above-mentioned flexible electrode. Figure 5 As shown, it includes:

[0059] S1. A planar flexible circuit board 3 is prepared based on mature processes such as MEMS technology or FPC board manufacturing technology; the planar flexible circuit board 3 is divided into a stimulation section 31 and a wiring section 32 along its length direction; the stimulation section 31 includes a strip-shaped substrate 311 and a plurality of extensions 312 arranged at intervals along the length direction of the strip-shaped substrate 311, and the plurality of extensions 312 are formed on the same side or different sides of the length direction of the strip-shaped substrate; the planar flexible circuit board 3 includes an electrode contact 341 located on the extension 312 and a conductive pin 342 located at the far end of the wiring section 32; the electrode contact 341 is connected to the corresponding conductive pin 342 through a conductive line 343;

[0060] S2, curling each extension body 312 on the flat flexible circuit board 3 along a preset direction to form an electrode ring 11 with the electrode contact 341 exposed, and fixing the free end of each extension body 312 to the root of the corresponding extension body 312 by gluing, welding or plugging to maintain the shape of the electrode ring 11; the center lines of the electrode rings 11 formed by curling are collinear;

[0061] S3, placing the stimulation segment 31 after the extension body 312 is curled in a potting mold for overall potting, so as to cover the flexible insulating sleeve 12 on the strip-shaped base 311 of the stimulation segment 31 so that the electrode contact 341 is exposed, thereby completing the preparation of the flexible electrode.

[0062] In summary, since the technology for preparing the planar flexible circuit board 3 is already very mature, it is conducive to the high-precision, high-density mass production of the planar flexible circuit board 3, and provides a basis for the high-density, miniaturized design of the flexible electrode; and the extension body 312 carrying the electrode contact 341 on the planar flexible circuit board 3 can be curled to form an electrode ring 11, so there is no need to additionally weld a conductive ring as the electrode ring 11, which effectively reduces the material cost of the flexible electrode; in addition, in order to achieve a miniaturized design, the implanted segment of the planar flexible circuit board usually has a thinner and narrower size, which greatly affects the anti-fracture ability of the planar flexible circuit board; in order to ensure the anti-fracture ability of the planar flexible circuit board, the present invention performs an overall potting of the stimulation segment carrying the electrode ring on the planar flexible circuit board with a flexible potting glue, so that the strip-shaped substrate 311 at the stimulation segment is coated with the flexible potting glue, which not only reduces the risk of the coating layer falling off, but also improves the anti-fracture ability of the implanted part of the flexible electrode, thereby ensuring the reliability of the flexible electrode.

[0063] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A flexible electrode, comprising an implantation segment (1) and a connection segment (2), wherein the implantation segment (1) is a columnar structure; characterized in that: The connecting section (2) is formed by a wiring section (32) of a planar flexible circuit board (3); the portion of the planar flexible circuit board (3) other than the wiring section (32) is a stimulation section (31); the stimulation section (31) comprises a strip-shaped substrate (311) and a plurality of extensions (312) arranged at intervals along the length direction of the strip-shaped substrate (311), and the plurality of extensions (312) are formed on the same side or different sides of the length direction of the strip-shaped substrate; the extensions (312) carry at least one electrode contact (341); the implant section (1) comprises an electrode ring (11) formed by curling the extensions (312) along a predetermined direction and a flexible insulating sleeve (12) encapsulating and covering the strip-shaped substrate (311) and filling the inner cavity of each electrode ring (11); the electrode contact (341) of the extension (312) is exposed on the outer wall of the corresponding electrode ring (11).

2. A flexible electrode according to claim 1, characterized in that: When the extension body (312) is curled to form an electrode ring (11), the free end of the extension body (312) is connected to the root of the extension body (312) by welding or gluing to maintain the shape of the electrode ring (11).

3. A flexible electrode according to claim 1, characterized in that: The extension body (312) comprises a main body (3121) and an anti-dropping plug formed at the free end of the main body (3121); a slot (3121a) cooperating with the anti-dropping plug is provided at the root of the main body (3121); when the extension body (312) is curled to form an electrode ring (11), the anti-dropping plug is plugged into and matched with the slot (3121a) to maintain the shape of the electrode ring (11).

4. A flexible electrode according to claim 3, characterized in that: The anti-detachment plug comprises an anti-detachment portion (31222) and a plug neck (31221) located between the anti-detachment portion (31222) and the main body (3121); the length dimension of the plug neck (31221) is not greater than the length dimension of the slot (3121a), and the thickness dimension of the plug neck (31221) is not greater than the width dimension of the slot (3121a); ​​when the extension body (312) is curled to form an electrode ring (11), the anti-detachment portion (31222) passes over the slot (3121a) and then abuts against the main body (3121).

5. A flexible electrode according to any one of claims 1 to 4, characterized in that: The extension body (312) carries an electrode contact (341); when the extension body (312) is curled to form an electrode ring (11), the electrode contact (341) on the extension body (312) forms an omnidirectional electrode contact.

6. A flexible electrode according to any one of claims 1 to 4, characterized in that: The extension body (312) carries a plurality of electrode contacts (341), and the plurality of electrode contacts (341) are distributed in an array.

7. The flexible electrode according to claim 1, characterized in that: The planar flexible circuit board (3) comprises a stacked flexible insulating base layer (33), a patterned conductive layer and a flexible insulating coating layer (35); the patterned conductive layer comprises electrode contacts (341) located on each extension body (312), conductive pins (342) located at the far end of the wiring segment (32), and conductive lines (343) for connecting the electrode contacts (341) and the corresponding conductive pins (342).

8. A flexible electrode according to claim 7, characterized in that: The planar flexible circuit board (3) is a single-sided board, a double-sided board, or a multi-layer board.

9. The flexible electrode according to claim 1, characterized in that: The flexible insulating sleeve (12) is formed by potting with polyurethane potting glue or silicone potting glue.

10. A method for preparing a flexible electrode, characterized in that: include: S1. A planar flexible circuit board (3) is prepared; the planar flexible circuit board (3) is divided into a stimulation section (31) and a wiring section (32) along its length direction; the stimulation section (31) comprises a strip-shaped substrate (311) and a plurality of extension bodies (312) arranged at intervals along the length direction of the strip-shaped substrate (311), and the plurality of extension bodies (312) are formed on the same side or different sides of the length direction of the strip-shaped substrate; the planar flexible circuit board (3) comprises an electrode contact (341) located on the extension body (312) and a conductive pin (342) located at the far end of the wiring section (32); the electrode contact (341) is connected to the corresponding conductive pin (342) via a conductive line (343); S2, curling each extension body (312) on the flat flexible circuit board (3) along a preset direction to form an electrode ring (11) with an exposed electrode contact (341), and fixing the free end of each extension body (312) to the root of the corresponding extension body (312) by gluing, welding or plugging to maintain the shape of the electrode ring (11); the center lines of the electrode rings (11) formed by curling are collinear; S3, placing the stimulation segment (31) after the extension body (312) is curled in a potting mold for overall potting, so as to cover the strip-shaped base (311) of the stimulation segment (31) with a flexible insulating sleeve (12) that exposes the electrode contact (341), thereby completing the preparation of the flexible electrode.

Images