Medical in-vivo implanted ECoG electrode
By introducing a flexible substrate, an adhesive layer, and an encapsulation layer into the medical implantable ECoG electrode, the problem of poor electrode durability was solved, and the stability and durability of the electrode were improved.
Patent Information
- Application Number
- CN202423130343.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-17
AI Technical Summary
Existing medical implantable ECoG electrodes have poor durability and are prone to deformation and failure after implantation.
The structure adopts a flexible substrate, an adhesive layer, and an encapsulation layer. The adhesive layer is placed between the flexible substrate and the encapsulation layer. The electrode layer includes electrode contacts, electrode solder joints, and conductive lines. By placing the adhesive layer between the flexible substrate and the encapsulation layer, the interfacial force is increased, cracking is avoided, and stability is improved.
This improves the stability and durability of the ECoG electrode, avoids cracking at the interface between the flexible substrate and the encapsulation layer, and extends the electrode's lifespan.
Smart Images
Figure CN223612106U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of brain-computer interface, and particularly relates to a medical in-vivo implanted ECoG electrode. BACKGROUND
[0002] Brain-computer interface is an important technology, which connects brain and computer or other external devices directly through a sensing terminal to realize extraction and decoding of brain signals and finally convert them into instruction signals that can be used to control external devices. One of the main functions of brain-computer interface is information extraction, that is, reading information in the biological brain.
[0003] Currently, there are generally two information extraction methods, namely non-implanted and implanted information extraction methods. The non-implanted method is to read EEG (electroencephalogram) data through a head cap worn on the scalp; and the implanted method includes obtaining electroencephalogram data through an implanted microelectrode array, or a deep brain electrode, or a semi-implanted ECoG (electrocorticography) electrode. Among these technologies, the implanted ECoG electrode has been widely used in the field of brain-computer interface due to its high signal resolution, relatively long stability and relatively low invasiveness.
[0004] The implanted ECoG electrode is usually implanted under the dura mater to collect information in the biological brain. In the related art, the implanted ECoG electrode has the problem of poor durability. UTILITY MODEL CONTENT
[0005] Therefore, the present application provides a medical in-vivo implanted ECoG electrode, which aims to improve the problem of poor durability of the existing medical in-vivo implanted ECoG electrode.
[0006] In a first aspect, an embodiment of the present application provides a medical in-vivo implanted ECoG electrode, which comprises a flexible substrate, an adhesion layer, an electrode layer and a packaging layer.
[0007] The electrode layer is arranged on one side of the flexible substrate, and the electrode layer comprises a plurality of electrode contacts, a plurality of electrode pads and a plurality of conductive wires. The plurality of electrode contacts and the plurality of electrode pads are arranged one by one in a one-to-one correspondence. Each conductive wire is electrically connected to the electrode contact and the corresponding electrode pad.
[0008] The adhesion layer is arranged between the flexible substrate and the packaging layer and / or the adhesion layer is arranged between the flexible substrate and the electrode layer.
[0009] The packaging layer is used to package the area on the flexible substrate and the electrode layer except the electrode contacts and the electrode pads.
[0010] In some embodiments of the application, the adhesion layer has a thickness of 5 nm to 1 micrometer.
[0011] In some embodiments of the application, the adhesion layer is at least one of a chromium layer, a silane coupling agent layer, a silicon carbide layer, an amorphous silicon carbide layer, a diamond-like carbon layer, an amorphous carbon layer, a silicon nitride layer, a silicon oxynitride layer, and a silicon oxycarbide layer.
[0012] In some embodiments of the application, the encapsulation layer is provided with a contact opening, the electrode contact is exposed in the contact opening, and a normal projection of the contact opening on the plane of the electrode contact is located within the outer contour of the electrode contact; the minimum distance between the contour line of the normal projection of the contact opening on the plane of the electrode contact and the contour line of the electrode contact therein is d, d satisfies greater than or equal to 3 micrometers.
[0013] In some embodiments of the application, the d is greater than or equal to 3 micrometers and less than or equal to 100 micrometers.
[0014] In some embodiments of the application, the electrode layer comprises a first metal layer and a second metal layer arranged in a stack.
[0015] In some embodiments of the application, the flexible substrate is a polyimide layer, the first metal layer comprises a first titanium layer and a first sub-metal layer; the second metal layer comprises a second titanium layer and a second sub-metal layer, and neither the first sub-metal layer nor the second sub-metal layer is a titanium metal layer.
[0016] The polyimide layer, the first titanium layer, the first sub-metal layer, the second titanium layer, and the second sub-metal layer are arranged in a stack on one side.
[0017] In some embodiments of the application, the first sub-metal layer comprises a first platinum layer, and the second sub-metal layer comprises a second platinum layer and a gold layer, and the polyimide layer, the first titanium layer, the first platinum layer, the second titanium layer, the second platinum layer, and the gold layer are arranged in a stack in order.
[0018] In some embodiments of the application, the first sub-metal layer comprises a first platinum layer, and the second sub-metal layer comprises a gold layer, and the polyimide layer, the first titanium layer, the first platinum layer, the second titanium layer, and the gold layer are arranged in a stack in order.
[0019] In some embodiments of the application, the first metal layer and the second metal layer are each independently selected from a cobalt alloy layer, a gold layer, a platinum layer, a titanium and its compound layer, a tungsten layer, an iridium and its compound layer, and a ruthenium and its compound layer.
[0020] In some embodiments of the present application, the electrode contact includes at least one of a platinum contact, a cobalt alloy contact, a gold contact, a titanium contact, a titanium nitride contact, a tungsten contact, an iridium contact, an iridium oxide contact, a ruthenium and its compound contact, a carbon nanotube contact, a poly(3,4-ethylenedioxythiophene) contact; and / or
[0021] The electrode welding point includes at least one of a gold welding point, a platinum welding point, an aluminum welding point, a tungsten welding point, a titanium welding point, a nickel welding point, a tin welding point, and a copper welding point.
[0022] In some embodiments of the present application, the electrode contact includes at least one of a platinum contact, a cobalt alloy contact, a gold contact, a titanium contact, a titanium nitride contact, a tungsten contact, an iridium contact, an iridium oxide contact, a ruthenium and its compound contact, a carbon nanotube contact, a poly(3,4-ethylenedioxythiophene) contact; and / or
[0023] The electrode contact is circular, and the diameter of the electrode contact is 5um to 2500um; and / or
[0024] The electrode layer includes a plurality of electrode contacts, and the plurality of electrode contacts are arranged in an array; and / or
[0025] The electrode layer includes a plurality of electrode welding points, and the plurality of electrode welding points are arranged in an array.
[0026] In some embodiments of the present application, the large contact is circular, and the diameter of the large contact is 500um to 2500um; and / or
[0027] The small contact is circular, and the diameter of the small contact is 5um to 500um.
[0028] Advantages:
[0029] The present application discloses a medical in-vivo implanted ECoG electrode, and relates to the technical field of brain-computer interface. The medical in-vivo implanted ECoG electrode provided by the embodiments of the present application includes a flexible substrate, an adhesion-increasing layer, an electrode layer, and a packaging layer. The electrode layer is arranged on one side of the flexible substrate, and includes a plurality of electrode contacts, a plurality of electrode welding points, and a plurality of conductive wires. The plurality of electrode contacts and the plurality of electrode welding points are arranged one by one in a one-to-one correspondence. Each conductive wire is electrically connected to the electrode contact and the corresponding electrode welding point. The adhesion-increasing layer is arranged between the flexible substrate and the packaging layer, and is used for bonding the flexible substrate and the packaging layer. The packaging layer is used for packaging the flexible substrate and the electrode layer except the area of the electrode contact and the electrode welding point. In the present application, the ECoG electrode is arranged with the adhesion-increasing layer between the flexible substrate and the packaging layer, so as to increase the interfacial force between the flexible substrate and the packaging layer, which is beneficial to avoid cracking at the interface of the flexible substrate and the packaging layer, thereby improving the stability of the ECoG electrode product. BRIEF DESCRIPTION OF DRAWINGS
[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.
[0031] Figure 1 is a front view of one embodiment of the medical in-vivo implanted ECoG electrode provided by the present application;
[0032] Figure 2 is a front view of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 1 is a partial enlarged view of A in FIG. 1;
[0033] Figure 3 is a front view of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 1 is a partial enlarged view of B in FIG. 1;
[0034] Figure 4 is a front view of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application;
[0035] Figure 5 is a front view of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 4 is a partial enlarged view of C in FIG. 1;
[0036] Figure 6 is a sectional view of a certain part of the medical in-vivo implanted ECoG electrode provided by the present application;
[0037] Figure 7 is a partial enlarged view of D in FIG. 1; Figure 6
[0038] is a sectional view of a certain part of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 8
[0039] is a sectional view of a certain part of another embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 9
[0040] is a microscope view of the electrode contact of the medical in-vivo implanted ECoG electrode in Comparative Example 1 after the aging experiment; Figure 10
[0041] is a microscope view of the electrode contact of the medical in-vivo implanted ECoG electrode in Example 1 after the aging experiment; Figure 11
[0042] is a microscope view of the conductive wire of one embodiment of the medical in-vivo implanted ECoG electrode provided by the present application; Figure 12
[0043] Figure 13 Fig. 4 is a microscope image of a conductive wire of another embodiment of the medical in-vivo implanted ECoG electrode provided in the present application.
[0044] Reference signs:
[0045] 100, medical in-vivo implanted ECoG electrode; 1, contact area; 11, electrode contact; 111, small contact; 112, large contact; 12, hollow part; 2, soldering point area; 21, electrode soldering point; 3, conductive wire; 4, flexible substrate; 5, electrode layer; 51, first metal layer; 52, second metal layer; 6, encapsulation layer; 61, contact opening; 7, adhesion layer. DETAILED DESCRIPTION
[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. In addition, it should be understood that the specific embodiments described herein are only for the purpose of illustration and explanation of the present application, and are not intended to limit the present application.
[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.
[0048] In the present application, the orientation words such as "upper" and "lower" are generally used to refer to the upper and lower in the actual use or working state of the device, specifically the drawing surface direction in the drawings; and "inner" and "outer" are used in relation to the outline of the device. In addition, in the description of the present application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish an order.
[0049] In the present application, "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural.
[0050] In the present application, "at least one" means one or more, and "multiple" means two or more. "One or more", "at least one of the following (one)", or similar expressions, means any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can mean a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.
[0051] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has been specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated in this document, it refers to any cited number (fraction or integer) within the indicated range.
[0052] Brain-computer interface is an important technology, which connects brain and computer or other external devices directly through sensing terminal, to realize extraction and decoding of brain signals, and finally convert into instruction signals that can be used to control external devices. One of the main functions of brain-computer interface is information extraction, that is, reading information in the biological brain.
[0053] Currently, there are usually two information extraction methods, namely non-implanted and implanted information extraction methods. The non-implanted method is to read EEG (electroencephalogram) data through the EEG cap worn on the scalp; while the implanted method includes obtaining EEG data through implanted microelectrode array, or deep brain electrode, or semi-implanted ECoG (electrocorticography) electrode. Among these technologies, implanted ECoG electrode has been widely used in the field of brain-computer interface due to its higher signal resolution, relatively longer stability and relatively less invasiveness.
[0054] The implanted ECoG electrode is usually implanted in the subdural cortex to collect information in the biological brain. In related technologies, the implanted ECoG electrode has the problem of poor durability.
[0055] In view of this, the medical in-vivo implanted ECoG electrode is provided in the embodiments of the present application, which will be further described below in conjunction with the drawings.
[0056] Please see Figures 1 to 7 The medical implantable ECoG electrode 100 provided in this application embodiment includes a flexible substrate 4, an electrode layer 5, and an encapsulation layer 6 stacked together. The flexible substrate 4 supports the electrode layer 5 and the encapsulation layer 6.
[0057] For example, a flexible substrate 4 can be prepared by coating a flexible material onto a substrate (e.g., a silicon wafer substrate or a glass substrate, not shown in the figure). The coating method includes spin coating, spray coating, blade coating, etc., and is not limited thereto.
[0058] For example, the materials used to prepare the flexible substrate 4 include at least one of polyimide, SU8, liquid crystal polymer and Parylene C.
[0059] Furthermore, the flexible substrate 4 is a polyimide layer, that is, the material used to prepare the flexible substrate 4 is polyimide. It is understood that, due to the good biocompatibility of polyimide, and the simple molding process and good economy, it is beneficial to improve the biocompatibility of the medical implantable ECoG electrode 100 in this application, and also beneficial to reduce the preparation cost of the flexible substrate 4.
[0060] In some embodiments of this application, the thickness of the flexible substrate 4 can be from 0.1 μm to 1000 μm, that is, from 0.1 micrometers to 1000 micrometers. For example, the thickness of the flexible substrate 4 is 0.1 μm, 1 μm, 2 μm, 4 μm, 6 μm, 9 μm, 15 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, and any value between the above values.
[0061] In some embodiments of this application, the thickness of the flexible substrate 4 can be from 1µm to 1000µm.
[0062] In some embodiments of this application, the electrode layer 5 is disposed on the side of the flexible substrate 4 facing away from the substrate. The electrode layer 5 includes a plurality of electrode contacts 11, a plurality of electrode solder joints 21, and a plurality of conductive lines 3.
[0063] Specifically, the electrode layer 5 includes an electrode contact region 1 and an electrode solder joint region 2. The electrode contact region 1 is disposed at the first end of the flexible substrate 4 (e.g., Figure 1 The electrode contact region 1 includes a plurality of electrode contacts 11. The pad region is located on the flexible substrate 4 at a second end away from the first end (e.g., near the top end). Figure 1The electrode pad area includes a plurality of electrode pads. The plurality of electrode contacts 11 and the plurality of electrode pads 21 are arranged in one-to-one correspondence, each electrode contact 11 and the corresponding electrode pad 21 are connected by a conductive wire 3, and different conductive wires 3 are insulated from each other. In the embodiment of the present application, the area provided with the electrode contact 11 on the ECoG electrode 100 implanted in the body of a medical worker can be used to implant the subdural cortex, the electrode contact 11 is used for signal acquisition, the electrode pad 21 is used for connecting an external device (for example, the electrode pad 21 is welded with the FPC connector), and the subdural cortex signal collected by the electrode contact 11 is transmitted to the external device through the conductive wire 3 and the electrode pad 21 connected thereto.
[0064] In some embodiments of the present application, the shape of the electrode contact 11 is not limited. For example, the horizontal cross section of the electrode contact 11 can be one of a circle, a square, a rectangle, a triangle, a diamond, an oval, or a polygon. Hereinafter, unless otherwise specified, the horizontal cross section of the electrode contact 11 is taken as a circle (i.e., the orthogonal projection of the electrode contact 11 is a circle) as an example for description.
[0065] In some embodiments of the present application, the diameter of the electrode contact 11 can be between 5 um and 15000 um. For example, the electrode contact 11 is generally circular, and the diameter of the electrode contact 11 is 5 um, 10 um, 15 um, 20 um, 50 um, 100 um, 200 um, 300 um, 400 um, 500 um, 600 um, 700 um, 800 um, 900 um, 1000 um, 2000 um, 3000 um, 4000 um, 5000 um, 6000 um, 7000 um, 8000 um, 9000 um, 10000 um, 11000 um, 12000 um, 13000 um, 14000 um, 15000 um, and a value between any two of the above values. It should be noted that in another embodiment of the present application, the electrode contact 11 can also not be circular, for example, the electrode contact 11 is triangular, square, oval, etc., at this time, the diameter of the electrode contact 11 can be understood as the diameter of its equivalent circle.
[0066] Further, the diameter of the electrode contact is 5 um to 2500 um.
[0067] Further, the diameter of the electrode contact 11 can be between 100 um and 500 um. In the present application, the size of the electrode contact 11 is designed in the micron level, which can be closer to the neuron tissue, and the size is closer to the cortical functional column of our research object, and the size of the cortical functional column is between 100 microns and 500 microns, which is considered as the basic unit of information processing. The size of the electrode contact 11 in the present application can obtain higher spatial resolution and finer information, and has better biocompatibility.
[0068] In some embodiments of the present application, referring to Figure 5 The electrode contact 11 includes a large contact 112 and a small contact 111, the area of the small contact 111 is smaller than the area of the large contact 112, wherein the small contact 111 is used for signal acquisition, and the large contact 112 is used for electrical stimulation. Exemplarily, the small contact 111 and the large contact 112 are both circular, the diameter of the small contact 111 is 5 um to 500 um, and further, the diameter of the small contact 111 is 10 um to 200 um. The diameter of the large contact 112 is 500 um to 8000 um. Further, the diameter of the large contact 112 is 500 um to 2500 um.
[0069] In some embodiments of the present application, the electrode contact 11 includes at least one of a platinum contact, a cobalt alloy contact, a gold contact, a titanium contact, a titanium nitride contact, a tungsten contact, an iridium contact, an iridium oxide contact, a ruthenium and its compound contact, a carbon nanotube contact, and a poly(3,4-ethylenedioxythiophene) contact.
[0070] Further, the electrode contact 11 includes a platinum contact, that is, the material forming the electrode contact 11 includes platinum. It can be understood that platinum has extremely high corrosion resistance, is not easy to react with chemicals, has good biocompatibility, and has excellent electrical conductivity. The embodiment adopts platinum material to prepare the electrode contact 11, which is conducive to making the contact electrode in the present application have excellent biocompatibility, electrical conductivity and stability.
[0071] In some embodiments of the present application, the shape, size and material of the electrode welding point 21 are not limited. Exemplarily, the horizontal cross section of the electrode welding point 21 is one of a circular shape, a square shape, a rectangular shape, a triangular shape, a rhombus shape, an oval shape or a polygonal shape.
[0072] In some embodiments of the present application, the electrode welding point 21 includes at least one of a gold welding point, a platinum welding point, an aluminum welding point, a tungsten welding point, a titanium welding point, a nickel welding point, a nickel welding point, and a copper welding point, that is, the material forming the electrode welding point 21 can include at least one of gold, platinum, aluminum, tungsten, titanium, nickel, nickel, and copper.
[0073] Further, the electrode welding point 21 includes a gold welding point, that is, the material for preparing the electrode welding point 21 is gold. It can be understood that gold has excellent welding firmness and stability, and in the embodiment, gold is used as the material for preparing the electrode welding point 21, which is conducive to improving the signal acquisition quality of the medical in-vivo implanted ECoG electrode 100 prepared and improving the stability of the electrical connection between the medical in-vivo implanted ECoG electrode 100 and the external device.
[0074] In some embodiments of the present application, the thickness of the electrode layer 5 can be between 1 nm and 2000 nm. For example, the thickness of the electrode layer 5 can be 1 nm, 10 nm, 15 nm, 20 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, 2000 nm, or any value between any two of the above values.
[0075] For example, the thickness of the electrode layer 5 can be between 10 nm and 1000 nm. In this way, the electrode layer 5 has good stability and reliability.
[0076] In some embodiments of the present application, the number of the electrode contacts 11 is multiple, and the multiple electrode contacts 11 are arranged in an array. For example, the number of the electrode contacts 11 can be between 16 and 1024. In this way, the recording and / or stimulation effect of the electrode is good. For example, the number of the electrode contacts 11 can be 32, 64, 128, or 256.
[0077] Further, the number of the electrode contacts 11 is multiple, and the multiple electrode pads 21 are arranged in an array. For example, the number of the electrode contacts 11 is the same as the number of the electrode pads 21. In this way, it is convenient to connect by using the conductive wire 3.
[0078] In some embodiments of the present application, the width of the middle region of the conductive wire 3 is smaller than the width of the electrode contact region 1 and the width of the pad region, and the width of the pad region is smaller than the width of the electrode contact region 1. In this way, the layout compactness of the ECoG electrode can be improved, and the miniaturization of the ECoG electrode is facilitated.
[0079] In some embodiments of the present application, the material for manufacturing the electrode contacts 11 and the electrode pads 21 is the same. Further, the material for manufacturing the electrode contacts 11, the electrode pads 21, and the conductive wire 3 is the same. In this way, the electrode layer 5 can be manufactured by one thin film deposition process. For example, the material for manufacturing the electrode contacts 11 and the electrode pads 21 is platinum, and for another example, the material for manufacturing the electrode contacts 11 and the electrode pads 21 is gold.
[0080] It should be noted that the thin film deposition process can include any one of electron beam evaporation, thermal evaporation, and magnetron sputtering. The thin film deposition process is not the main improvement point of the present application, and is not limited herein.
[0081] In some embodiments of the present application, the electrode layer 5 is formed by one thin film deposition process. Correspondingly, please refer to Figure 9The electrode layer 5 in the ECoG electrode 100 for medical in-vivo implantation is a single metal layer.
[0082] In some embodiments of the present application, in order to make different materials fully play their respective advantages and further optimize the performance of the ECoG electrode 100 for medical in-vivo implantation, the materials for manufacturing the electrode contact 11 and the electrode pad 21 are different, for example, the material for manufacturing the electrode contact 11 is platinum and the material for manufacturing the electrode pad 21 is gold, so that the materials of the exposed surfaces of the electrode contact 11 and the electrode pad 21 (i.e. the parts of the electrode contact 11 and the electrode pad 21 not covered by the encapsulation layer 6) are different.
[0083] For example, the materials of the exposed surfaces of the electrode contact 11 and the electrode pad 21 can be made different through multiple (two or more) thin film deposition processes.
[0084] Specifically, a photoresist can be provided on the electrode flexible substrate 4, the photoresist covers part of the surface of the electrode flexible substrate 4, and the surface of the flexible substrate 4 not covered by the photoresist includes the position of the electrode contact 11, and / or the position of the conductive wire 3, and / or the position of the electrode pad 21. Then, a first metal layer 51 is deposited on the photoresist by a first thin film deposition process, the first metal layer 51 covers at least one of the electrode contact 11 and the electrode pad 21 (i.e. the first metal layer 51 includes at least one of the electrode contact 11 layer and the electrode pad 21 layer), and a second metal layer 52 is deposited on the photoresist by a second thin film deposition process, the second metal layer 52 covers the other of the electrode contact 11 and the electrode pad 21 (i.e. the second metal layer 52 includes the other of the electrode contact 11 layer and the electrode pad 21 layer). Wherein, the first metal material and the second metal material are different. It should be noted that the first metal layer 51 covering at least one of the electrode contact 11 and the electrode pad 21 can be that the first metal layer 51 only covers the electrode contact 11, or that the first metal layer 51 only covers the electrode pad 21, or that the first metal layer 51 covers both the electrode contact 11 and the electrode pad 21, which is not limited herein.
[0085] Exemplarily, a first photoresist layer is arranged on the flexible substrate 4, the surface of the flexible substrate 4 not covered by the first photoresist layer only includes the electrode contact 11, then a first thin film deposition process is performed to deposit a first metal layer 51 on the flexible substrate 4 and the first photoresist layer, then the first photoresist layer and the first metal layer 51 on the first photoresist layer are removed, to obtain the flexible substrate 4 with the electrode contact 11 (at this time, the first metal layer 51 only covers the area where the electrode contact 11 is located). Then a second photoresist layer is arranged on the flexible substrate 4, the surface of the flexible substrate 4 not covered by the second photoresist layer only includes the area where the electrode pad 21 is located, the area where the conductive wire 3 is located, and the area where the conductive wire 3 is connected with the electrode contact 11, then a second thin film deposition process is performed to deposit a second metal layer 52 on the flexible substrate 4 and the second photoresist layer, at this time, the second metal layer 52 covers the area where the electrode pad 21 is located, the area where the conductive wire 3 is located, and the area where the conductive wire 3 is connected with the electrode contact 11, and the first metal layer 51 and the second metal layer 52 jointly form the electrode layer 5.
[0086] Similarly, in other embodiments, the first metal layer 51 covers the area where the electrode contact 11 is located and the area where the conductive wire 3 is located, the second metal layer 52 covers the area where the electrode pad 21 is located and the area where the conductive wire 3 is located, and the first metal layer 51 and the second metal layer jointly form the electrode layer 5, that is, each conductive wire 3 includes two metal layers (the first metal layer 51 and the second metal layer 52) arranged in a stack. For another example, the first metal layer 51 covers the area where the electrode contact 11 is located, the area where the conductive wire 3 is located, and the area where the electrode pad is located, the second metal layer 52 covers the area where the electrode pad 21 is located or the area where the electrode pad is located and the area where the conductive wire 3 is located, and the like, which is not limited herein.
[0087] It can be understood that, during the entire manufacturing process of the medical in-vivo implanted ECoG electrode 100, for example, during the process of depositing the first metal material to obtain the first metal layer 51, dust particles or impurities will inevitably exist, thereby causing the conductive wire 3 at the position where the dust particles are located to be broken, and the electrode contact 11 and the corresponding electrode pad 21 not to be conductive, thereby causing the signal collected by the electrode contact 11 connected with the conductive wire 3 to be unable to be transmitted out.
[0088] In some embodiments of the present application, the electrode layer 5 includes the first metal layer 51 and the second metal layer 52 arranged in a stack, the first metal layer 51 includes a plurality of first conductive wires, the second metal layer 52 includes a plurality of second conductive wires, the first conductive wires and the second conductive wires are arranged in a one-to-one correspondence, and the first conductive wire at least partially overlaps with the corresponding second conductive wire, that is, each conductive wire 3 in the embodiments of the present application includes the first conductive wire and the second conductive wire arranged in a stack.
[0089] In this embodiment, the first metal layer 51 and the second metal layer 52 are arranged at the positions where the conductive wires 3 are located, the first metal layer 51 includes a plurality of first conductive wires, the second metal layer 52 includes a plurality of second conductive wires, the first conductive wires and the second conductive wires are arranged one by one in a one-to-one correspondence, and the first conductive wires at least partially overlap the corresponding second conductive wires. When the first conductive wires in the first metal layer 51 are broken at some positions, the broken positions on the first conductive wires can be covered by the corresponding second conductive wires, so that the broken first conductive wires can be conducted, the defects of the first conductive wires are effectively repaired, and thus the stability of the ECoG electrode 100 implanted in the human body for medical use is improved.
[0090] For example, the second metal layer 52 covers the first metal layer 51. For another example, the second metal layer 52 is orthographically projected in the first metal layer 51, in other words, each second conductive wire in the second metal layer 52 is located in the corresponding first conductive wire in the first metal layer 51, so that each conductive wire 3 in the embodiment of the application includes the first conductive wire and the second conductive wire arranged in a stack. When the first conductive wire in the first metal layer 51 is broken, the broken position on the first conductive wire can be repaired by the corresponding second conductive wire in the second metal layer, so that the broken first conductive wire can be conducted, the defects of the first metal layer are effectively repaired, and thus the stability of the ECoG electrode 100 implanted in the human body for medical use is improved.
[0091] Specifically, the first metal layer 51 includes a platinum layer, the platinum layer covers the area where the electrode contact 11 is located, the area where the electrode pad 21 is located, and the area where the conductive wire 3 is located. The second metal layer includes a gold layer, the gold layer covers the area where the electrode pad 21 is located and the area where the conductive wire 3 is located, so that the material of the exposed side of the electrode contact 11 (i.e., the side of the electrode contact 11 away from the flexible substrate 4) is platinum, and the material of the exposed side of the electrode pad 21 (i.e., the side of the electrode pad 21 away from the flexible substrate 4) is gold.
[0092] Further, the inventors found that although each conductive wire 3 includes a platinum layer (i.e., the first metal layer 51) and a gold layer (i.e., the second metal layer 52) arranged in a stack, which is beneficial to avoid the problem of unstable product quality caused by the breakage of the conductive wire 3, it is also easy to cause burrs at the edges of the conductive wire 3, such as Figure 12 as shown, which affects the appearance of the product and even causes the problem of communication between adjacent two conductive wires 3 in severe cases.
[0093] To this end, the inventors found through research that during the process of depositing the gold layer (i.e., the second metal layer 52) on the platinum layer (i.e., the first metal layer 51), a Ti (titanium) layer can be first grown on the platinum layer, and then the gold layer is deposited on the Ti layer, so that the problem of burrs at the edges caused by the deposition of a platinum layer and then a gold layer at the positions where the conductive wires 3 are located can be avoided.
[0094] The applicant also finds that, in the process of depositing the second metal layer (e.g., the gold layer) 52 on the first metal layer (e.g., the platinum layer) 51, if the second metal layer (e.g., the gold layer) 52 is directly deposited on the first metal layer (e.g., the platinum layer) 51, when the pattern of the second metal layer (e.g., the gold layer) 52 is completely within the range of the pattern of the first metal layer (e.g., the platinum layer) 51, it is also beneficial to improve the problem of burrs at the edges of the conductive lines 3. Specifically, taking an example in which the first metal layer 51 includes first conductive lines, the second metal layer 52 includes second conductive lines, and the second conductive lines correspond one-to-one to the first conductive lines and are stacked with the corresponding first conductive lines, if the second conductive lines are located within the first conductive lines, the product obtained as shown in Figure 13 is also beneficial to improve the problem of burrs at the edges of the conductive lines 3.
[0095] Further, the distance between the edge of the second conductive line and the edge of the adjacent first conductive line is 1 μm or more, thereby being beneficial to further solve the problem of burrs at the edges of the conductive lines 3. Specifically, the material for preparing the first metal layer 51 includes a platinum material, and the platinum material covers the area where the electrode contact 11 and the conductive line 3 are located. Then, the photoresist and the platinum material located on the photoresist are removed, to obtain the first metal layer (i.e., the platinum layer) on the flexible substrate 4, wherein the first metal layer 51 includes the patterned electrode contact 11 and the conductive line 3. It should be noted that the first metal layer can include a single sub-metal layer (e.g., a platinum layer) or multiple sub-metal layers (i.e., multiple sub-metal layers formed in one thin film deposition process), which is not limited herein. Then, the photoresist is arranged on the first metal layer, and the photoresist covers part of the surface of the first metal layer. For example, the photoresist covers the area where the conductive line 3 and the electrode pad 21 are located, and then the Ti layer and the gold layer are sequentially deposited on the photoresist by one thin film deposition process. Then, the photoresist is removed, to form the electrode layer 5 on the flexible substrate 4.
[0096] In the embodiments of the present application, the packaging layer 6 is arranged on the side of the electrode layer 5 away from the flexible substrate 4, and the packaging layer 6 covers the flexible substrate 4 and the electrode layer 5 except the positions where the electrode contact 11 and the electrode pad 21 are located, i.e., the packaging layer 6 does not cover the side of the electrode contact 11 away from the flexible substrate 4, so that the electrode contact 11 exposed outside the packaging layer 6 can collect signals. The packaging layer 6 also does not cover the side of the electrode pad 21 away from the flexible substrate 4, so that the electrode pad 21 can be electrically connected with external equipment. In some embodiments of the present application, please refer to Figure 6 and Figure 7, a plurality of contact openings 61 are provided on the encapsulation layer 6, and the electrode contacts 11 are exposed in the corresponding contact openings 61. The orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located is located within the contour line of the corresponding electrode contact 11. The minimum distance between the contour line of the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 is d, and d satisfies not less than 3 micrometers (that is, the minimum distance d between the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 is greater than or equal to 3 micrometers). The inventor found through experiments that the ECoG electrode 100 implanted in the human body in the related art has the problem of poor durability. For example, after the ECoG electrode 100 implanted in the human body is implanted into the body, its electrode contact 11 is prone to deformation and failure, such as Figure 10 as shown. In this embodiment, by making the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located be located within the contour line of the corresponding electrode contact 11, and the minimum distance d between the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 is not less than 3 micrometers, the durability of the ECoG electrode 100 implanted in the human body can be effectively improved.
[0097] In some embodiments of the present application, the minimum distance d between the contour line of the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 is 3 micrometers to 100 micrometers. Exemplarily, d is 3 micrometers, 5 micrometers, 10 micrometers, 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, and values between any two of the above. Thus, it is beneficial to improve the durability of the ECoG electrode 100 implanted in the human body, and the ECoG electrode 100 implanted in the human body in the present application has a relatively small volume.
[0098] Furthermore, the contour line of the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 are in a concentric ring structure, and the distance from each point on the contour line of the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located to the electrode contact 11 is equal. Exemplarily, the electrode contact 11 is circular, the contact opening 61 and the electrode contact 11 are concentric circles, and the minimum distance d between the two circles is not less than 3 micrometers. Another example is that the electrode contact 11 is square, the contact opening 61 is also square, the two squares are generally in a "hui" shape, and the minimum distance d between the contour line of the orthographic projection of the contact opening 61 on the plane where the electrode contact 11 is located and the contour line of the electrode contact 11 is not less than 3 micrometers.
[0099] In some embodiments of the present application, the material of the encapsulation layer 6 can include at least one of polyimide, SU 8, silicon carbide, liquid crystal polymer, Parylene C, ceramic and silicon dioxide. Exemplarily, the material of the encapsulation layer 6 is polyimide.
[0100] In some embodiments of the present application, the medical in-vivo implanted ECoG electrode 100 includes a polyimide layer (i.e. the flexible substrate 4), an electrode layer 5 and a polyimide encapsulation layer 6 which are stacked together; the electrode layer 5 includes the electrode contact 11, the electrode pad 21 and the conductive wire 3 which includes the first metal layer 51 and the second metal layer 52 stacked together, the polyimide encapsulation layer 6 covers the flexible substrate 4 and covers the electrode layer 5 except the area where the electrode contact 11 and the electrode pad 21 are located. The medical in-vivo implanted ECoG electrode 100 in this embodiment has good flexibility and biocompatibility.
[0101] In some embodiments of the present application, referring to Figure 6 , a hollow part 12 is arranged between two adjacent electrode contacts 11 on the electrode contact area 1 and at the position where the conductive wire 3 is not located, the hollow part 12 penetrates the top surface and the bottom surface of the electrode contact area 1, i.e. the hollow part 12 penetrates the electrode layer 5 on the electrode contact area 1.
[0102] In some embodiments of the present application, the medical in-vivo implanted ECoG electrode further includes an adhesion layer, the adhesion layer is arranged between the flexible substrate and the encapsulation layer and / or the adhesion layer is arranged between the flexible substrate and the electrode layer.
[0103] Exemplarily, referring to Figure 8 , an adhesion layer 7 is arranged between the encapsulation layer 6 and the flexible substrate 4. The inventors find that in the related art, after the medical in-vivo implanted ECoG electrode 100 is implanted in the body, the encapsulation layer 6 and the flexible substrate 4 are prone to separate and deform to fail. This embodiment arranges the adhesion layer 7 between the encapsulation layer 6 and the flexible substrate 4, which is conducive to avoiding the separation between the encapsulation layer 6 and the flexible substrate 4, thereby improving the durability of the medical in-vivo implanted ECoG electrode 100. Exemplarily, a very thin adhesion layer 7 can be spin-coated on the surface of the flexible substrate 4 to achieve the effect of improving the close adhesion between the support layer and the encapsulation layer 6.
[0104] Exemplarily, the adhesion layer 7 can be formed by chemical treatment method, chemical vapor deposition, atomic layer deposition or physical vapor deposition, oxygen plasma treatment and the like. It should be noted that the preparation process of the adhesion layer 7 can adopt the existing forming mode, which is not limited here.
[0105] In some embodiments of the present application, an adhesion layer can also be provided between the flexible substrate and the electrode layer to increase the adhesion between the flexible substrate and the electrode layer. Of course, an adhesion layer can also be provided between the flexible substrate and the encapsulation layer, between the flexible substrate and the electrode layer, without limitation.
[0106] Exemplarily, the adhesion layer 7 comprises at least one of a chromium layer, a silane coupling agent layer, a silicon carbide layer, an amorphous silicon carbide (a-SiC:H) layer, a diamond-like carbon (DLC) layer, an amorphous carbon (a-C:H) layer, a silicon nitride layer, a silicon oxynitride layer, and a silicon oxycarbide layer.
[0107] It should be noted that these materials as adhesion layers can help to improve the performance and stability of the ECoG electrode, while ensuring long-term biocompatibility. For example, the silane coupling agent can form a strong chemical bond between the interface of the electrode layer and the flexible substrate, improve the adhesion strength, and significantly improve the performance of the composite material. The silicon carbide layer and the amorphous silicon carbide layer have chemical stability and no biological toxicity, and can improve the adhesion between the metal and the flexible substrate interface through appropriate treatment. The amorphous carbon layer also has good chemical stability and mechanical properties, and exhibits good biocompatibility in a biological environment, does not cause excessive inflammation or tissue reaction, and can form strong adhesion with polyimide. In addition, it can also exhibit different conductive properties according to the structure and composition, and design more flexible. The silicon nitride layer and the silicon oxycarbide layer have good wear resistance and chemical stability; the silicon oxynitride layer has good dielectric properties and mechanical strength, good adhesion and environmental stability.
[0108] In some embodiments of the present application, the thickness of the adhesion layer 7 is 5 nanometers to 1 micrometer. Exemplarily, the thickness of the adhesion layer 7 is 5 nanometers, 10 nanometers, 20 nanometers, 30 nanometers, 50 nanometers, 100 nanometers, 200 nanometers, 500 nanometers, 800 nanometers, or 1 micrometer. If the thickness of the adhesion layer is too low, for example, less than 5 nanometers, the adhesion effect is not ideal, and if the thickness of the adhesion layer is too large, for example, greater than 1 micrometer, it can easily lead to poor flexibility of the product.
[0109] Embodiment 1
[0110] A polyimide layer was prepared on a silicon wafer substrate, and the thickness of the polyimide layer was 10 micrometers. Then, a conductive layer was prepared on the polyimide layer, and the thickness of the conductive layer was 20 nanometers. The conductive layer included a plurality of electrode contacts, a plurality of electrode pads, and a plurality of conductive lines. An encapsulation layer was prepared on the conductive layer. The plurality of electrode contacts were the same size, each electrode contact was circular, the diameter of the electrode contact was 200 um, and the diameter of the contact opening was 196 um.
[0111] Comparative Example 1
[0112] The difference between it and embodiment 1 is that the diameter of the contact opening is 199 um.
[0113] Aging experiment: the sample is immersed in a PBS solution for aging test, the experimental temperature is 90 degrees Celsius, and pH = 7.4.
[0114] Table 1
[0115] Example 1 Etching at the edge of the electrode contact Comparative Example 1 No etching at the edge of the electrode contact
[0116] The medical in-vivo implanted ECoG electrode in embodiment 1 and comparative example 1 is subjected to an aging experiment, and the test results are shown in Figure 10 , Figure 11 and Table 1. It can be seen that when d does not satisfy greater than or equal to 3 microns, there is obvious corrosion at the electrode contact edge of the medical in-vivo implanted ECoG electrode after the aging experiment, and the durability is poor. When d satisfies greater than or equal to 3 microns, there is no corrosion at the electrode contact edge of the medical in-vivo implanted ECoG electrode after the aging experiment, and the durability is good.
[0117] The above describes the technical solutions provided by the embodiments of the present application in detail, and the principles and implementation manners of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and the above description of the present application should not be understood as a limitation.
Claims
1. An ECoG electrode for medical in-vivo implantation, characterized in that, The medical in-vivo implanted ECoG electrode comprises a flexible substrate, an adhesion layer, an electrode layer and an encapsulation layer; The electrode layer is arranged on one side of the flexible substrate, and the electrode layer comprises a plurality of electrode contacts, a plurality of electrode pads and a plurality of conductive wires, the plurality of electrode contacts and the plurality of electrode pads are arranged one by one in correspondence, and each of the conductive wires is electrically connected to the electrode contact and the corresponding electrode pad; The adhesion layer is arranged between the flexible substrate and the encapsulation layer and / or between the flexible substrate and the electrode layer; The encapsulation layer is used to encapsulate the area on the flexible substrate and the electrode layer other than the electrode contact and the electrode pad.
2. The medical, in vivo implanted ECoG electrode of claim 1, wherein, The thickness of the adhesion layer is 5 nanometers to 1 micrometer.
3. The medical in vivo implanted ECoG electrode of claim 1, wherein, The adhesion layer is at least one of a chromium layer, a silane coupling agent layer, a silicon carbide layer, an amorphous silicon carbide layer, a diamond-like carbon layer, an amorphous carbon layer, a silicon nitride layer, a silicon oxynitride layer and a silicon oxycarbide layer.
4. The medical in-vivo implanted ECoG electrode according to any one of claims 1 to 3, wherein, The encapsulation layer is provided with a contact opening, the electrode contact is exposed in the contact opening, and the normal projection of the contact opening on the plane of the electrode contact is located within the outer contour of the electrode contact; the minimum distance between the contour line of the normal projection of the contact opening on the plane of the electrode contact and the contour line of the electrode contact therein is d, and d satisfies greater than or equal to 3 micrometers.
5. The medical in vivo implanted ECoG electrode of claim 4, wherein, The d is greater than or equal to 3 micrometers and less than or equal to 100 micrometers.
6. The medical in-vivo implanted ECoG electrode according to any one of claims 1 to 3, wherein, The electrode layer comprises a first metal layer and a second metal layer arranged in a stack.
7. The medical in vivo implanted ECoG electrode of claim 6, wherein, The first metal layer and the second metal layer are independently selected from a cobalt alloy layer, a gold layer, a platinum layer, a titanium and its compound layer, a tungsten layer, an iridium and its compound layer, a ruthenium and its compound layer.
8. The medical in vivo implanted ECoG electrode of claim 6, wherein, The electrode contact comprises at least one of a platinum contact, a cobalt alloy contact, a gold contact, a titanium contact, a titanium nitride contact, a tungsten contact, an iridium contact, an iridium oxide contact, a ruthenium and its compound contact, a carbon nanotube contact and a poly(3,4-ethylenedioxythiophene) contact; and / or The electrode pad comprises at least one of a gold pad, a platinum pad, an aluminum pad, a tungsten pad, a titanium pad, a nickel pad and a tin pad.
9. The medical in vivo implanted ECoG electrode according to any one of claims 1 to 3, wherein, The plurality of electrode contacts comprises large contacts and small contacts; and / or The electrode contact is circular, and the diameter of the electrode contact is 5 um to 2500 um; and / or The electrode layer comprises a plurality of electrode contacts arranged in an array; and / or The electrode layer comprises a plurality of electrode pads arranged in an array.
10. The medical, in vivo implanted ECoG electrode of claim 9, wherein, The large contact is circular, and the diameter of the large contact is 500 um to 2500 um; and / or The small contact is circular, and the diameter of the small contact is 5 um to 500 um.