Flexible electrode and manufacturing method therefor
The present disclosure relates to a flexible electrode and a manufacturing method therefor. Provided is a flexible electrode, comprising at least one implantable and flexible electrode wire and a continuous limiting layer. Each electrode wire comprises: a wire, the wire being located between a first insulating layer and a second insulating layer of the flexible electrode, and an electrode site, the electrode site being in contact with the biological tissue after implantation of the electrode wire, being located on the first insulating layer, and being electrically coupled to the wire by means of a through hole in the first insulating layer. The limiting layer is located on the at least one electrode wire and is configured to be detachably adhered to the at least one electrode wire, so that the at least one electrode wire is kept in a fixed arrangement during the implantation process.
1 . A flexible electrode, comprising:
at least one implantable and flexible electrode wire; and
a continuous limiting layer,
wherein each electrode wire comprises:
a wire located between a first insulating layer and a second insulating layer, and
an electrode site, in contact with a biological tissue after implantation of the electrode wire, located on the second insulating layer and electrically coupled to the wire located between the first insulating layer and the second insulating layer by means of a through hole in the second insulating layer,
wherein the continuous limiting layer is located on the at least one electrode wire and is configured to be detachably adhered to the at least one electrode wire, so that the at least one electrode wire is kept in a fixed arrangement during the implantation process, and
wherein the continuous limiting layer comprises at least one through hole that extends through a thickness of the continuous limiting layer, the at least one through hole being at a position corresponding to a respective electrode site on the at least one electrode wire, a contour of each of the at least one through hole being surrounded by a contour of the respective electrode site.
2 . The flexible electrode according to claim 1 , wherein:
the wire in each electrode wire comprises a plurality of wires located in a wire layer of the flexible electrode and separated from each other, and
the electrode site in each electrode wire comprises a plurality of electrode sites each electrically coupled to one of the plurality of wires through a corresponding through hole in the second insulating layer.
3 . The flexible electrode according to claim 2 , wherein:
the flexible electrode comprises a plurality of wire layers, the plurality of wire layers are separated by additional insulating layers, and each wire layer comprises a plurality of wires separated from each other.
4 . The flexible electrode according to claim 1 , further comprising a back end portion, each electrode wire extending from the back end portion, wherein the back end portion comprises back end sites, each of which is electrically coupled to a respective wire and a back end circuit by means of a through hole in the first insulating layer and/or the second insulating layer, thereby achieving bidirectional signal transmission between each electrode site and the back end circuit.
5 . The flexible electrode according to claim 4 , wherein each back end site is obtained by stacking a plurality of layers, and the plurality of layers include an adhesive layer, a flux layer, a conductive layer, and a protective layer.
6 . The flexible electrode according to claim 4 , wherein each back end site comprises a metal film having three layers, the three layers comprising a first layer, closest to the respective wire, comprising titanium, titanium nitride, chromium, tantalum or tantalum nitride, a second layer comprising nickel, platinum or palladium, and a third layer, furthest from the respective wire, comprising any one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, carbon nanotubes, PEDOT or a combination thereof.
7 . The flexible electrode according to claim 4 , wherein the flexible electrode is connected to the back end circuit via a printed circuit board or a flexible circuit board through the back end sites, or wherein the flexible electrode is configured to be integrated in a reserved space on a pre-tapeout wafer of a chip serving as the back end circuit, so that the flexible electrode and the chip can be processed jointly or separately.
8 . The flexible electrode according to claim 1 ,
wherein the material of the limiting layer is any one of parylene, polydimethylsiloxane, UV film, electronic grade tape, and plastic film with heat shrinkage properties, or a combination thereof.
9 . The flexible electrode according to claim 1 , wherein the material of the first insulating layer and the second insulating layer is any one of polyimide, polydimethylsiloxane, parylene, epoxy resin, polyamideimide, polylactic acid, poly(lactic-co-glycolic acid), SU8 photoresist, silica gel, silicone rubber or a combination thereof.
10 . The flexible electrode according to claim 1 , wherein the second insulating layer of each electrode wire has a contour corresponding to at least a portion of the shape of electrode sites at positions corresponding to the electrode sites, and the contour surrounds the through holes corresponding to the electrode sites.
11 . The flexible electrode according to claim 10 , wherein the first insulating layer of each electrode wire has a contour that is the same as or surrounds the contour of the second insulating layer.
12 . The flexible electrode according to claim 1 , wherein the material of the wire is any one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, carbon nanotubes, PEDOT or a combination thereof.
13 . The flexible electrode according to claim 1 , wherein the wire is obtained by stacking a plurality of layers, and the material of the layer in contact with the first insulating layer or the second insulating layer among the plurality of layers is a material capable of enhancing adhesion between the wire and the first insulating layer or the second insulating layer.
14 . The flexible electrode according to claim 13 , wherein the wire is a metal film obtained by stacking three layers, wherein the materials of the first layer and the second layer in contact with the first insulating layer and the second insulating layer respectively are titanium, titanium nitride, chromium, tantalum or tantalum nitride, and the material of the third layer located between the first layer and the second layer is any one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, carbon nanotubes, PEDOT or a combination thereof.
15 . The flexible electrode according to claim 1 , wherein the wire, at a position corresponding to a corresponding electrode site to which the wire is electrically coupled, has a contour corresponding to at least a portion of the shape of the corresponding electrode site.
16 . The flexible electrode according to claim 1 , wherein the electrode site is obtained by stacking a plurality of layers, wherein the material of the first layer close to the wire among the plurality of layers is a material capable of enhancing adhesion between the electrode site and the wire.
17 . The flexible electrode according to claim 16 , wherein the electrode site is a metal film obtained by stacking two layers, wherein the material of the first layer close to the wire is titanium, titanium nitride, chromium, tantalum or tantalum nitride, and the material of the second layer exposed to the outside is any one of gold, platinum, iridium, tungsten, magnesium, molybdenum, platinum-iridium alloy, titanium alloy, graphite, carbon nanotubes, PEDOT or a combination thereof.
18 . The flexible electrode according to claim 1 , wherein the shape, size and spacing of the electrode sites are selected according to the conditions of the biological tissue area to be recorded.
19 . The flexible electrode according to claim 1 , wherein the surface of the electrode site in contact with the biological tissue has a surface modification layer to improve the electrochemical properties of the electrode site.
20 . The flexible electrode according to claim 19 , wherein the surface is modified by any one or more of a conductive polymer and conductive metal particles, the conductive polymer includes poly(ethylenedioxythiophene), poly(p-styrene sulfonic acid), and polypyrrole, and the material of the conductive metal particles includes iridium, iridium oxide, platinum, and platinum-iridium alloy.
21 . The flexible electrode according to claim 1 , wherein the electrode wire further comprises an additional electrode site that is in contact with a biological tissue after implantation of the at least one electrode wire, the additional electrode site being located under the first insulating layer and electrically coupled to the wire by means of a through hole in the first insulating layer.
22 . The flexible electrode according to claim 21 , wherein the additional electrode site and the electrode site are at opposite positions on two sides of the flexible electrode, respectively, and the additional electrode site and the electrode site are electrically coupled to the same wire.
23 . The flexible electrode according to claim 1 , wherein each electrode wire has a mounting hole, and an electrode implantation device is attached to the electrode wire through the mounting hole for implantation.
24 . The flexible electrode according to claim 1 , further comprising a flexible separation layer, wherein the flexible separation layer is capable of being removed by a specific substance to separate portions of the flexible electrode while avoiding damage to the flexible electrode.
25 . The flexible electrode according to claim 24 , wherein the electrode site of the flexible electrode is a metal film obtained by stacking three layers, and the outermost layer of the three layers in contact with the flexible separation layer is made of the same material as the flexible separation layer, and is used to separate the electrode site from the limiting layer of the flexible electrode by removing the flexible separation layer.
26 . The flexible electrode according to claim 1 , wherein the flexible electrode has magnetic resonance imaging compatibility, or
wherein the flexible electrode is a degradable acupuncture electrode, used for acute stimulation or long-term stimulation in combination with meridian acupoints, and the shape, size and spacing of the electrode sites of the degradable acupuncture electrode are selected according to needs.
27 . The flexible electrode according to claim 26 , wherein the electrode site of the degradable acupuncture electrode is located proximate the at least one electrode wire and is exposed by means of a through hole in the first insulating layer and/or the second insulating layer.
28 . The flexible electrode according to claim 1 , wherein the flexible electrode is a stimulating electrode, the shape of the electrode site of the stimulating electrode has no tip, the surface of the electrode site of the stimulating electrode is modified, the material for modification includes at least one of a conductive polymer and conductive metal particles, the modification method includes at least one of electrodeposition and self-assembly, the conductive polymer includes one or more of poly(dioxyethylthiophene), poly(p-styrene sulfonic acid) or polypyrrole, the material of the conductive metal particles includes one or more of iridium, iridium oxide, platinum or platinum-iridium alloy, and the thickness of the wire layer of the stimulating electrode is 5 nm to 3000 nm.
29 . The flexible electrode according to claim 28 , wherein the electrode site of the stimulating electrode is located proximate the at least one electrode wire and is exposed by means of a through hole in the first insulating layer and/or the second insulating layer.
30 . The flexible electrode according to claim 1 , wherein the at least one electrode wire comprises two or more electrode wires.