Customizable microwire electrode array and preparation method thereof

Abstract

The invention discloses a customizable microwire electrode array and a preparation method thereof, the customizable microwire electrode array comprises a customizable substrate, and the interior of the customizable substrate is provided with perforation grooves which are distributed in a customized manner according to a brain region; the microwire electrode array penetrates through the through hole groove from top to bottom; and the packaging material is positioned at the bottom of the customizable substrate and is used for fixing the microfilament electrode array. The microwire electrode array has better flexibility and is simpler to process.

Description

Technical Field

[0001] The invention belongs to the technical field of electrode arrays, and in particular relates to a customizable microwire electrode array and a preparation method thereof. Background Art

[0002] As one of the important media of brain-computer interface (BCI), microwire electrode array is widely used in basic experimental research such as multi-channel electrophysiology due to its high-throughput recording, cheap consumables, simple production and stable performance. Microwire electrode array is an array composed of multiple tiny electrodes, which are usually made of metal wires with micron size, such as nickel-chromium alloy, platinum-iridium alloy, tungsten, platinum and stainless steel, and wrapped in a layer of insulating material. This array can record and stimulate the activity of neurons at the same time, and has the characteristics of high-throughput recording, cheap consumables, simple production and stable performance.

[0003] The invention patent application with publication number CN114767129A discloses a brain-computer interface based on nerve tentacles, including several nerve tentacles and an electronic interface; the first end of the nerve tentacles is used for two-way electrical signal interactive communication; the second end of the nerve tentacles is connected to the first end of the electronic interface, and the second end of the electronic interface is used to connect to an external device; the electronic interface includes several axon electrodes, and the axon electrodes are correspondingly arranged at the second end of the nerve tentacles; nerve axons are induced to grow in the branches of the nerve tentacles; the axon electrodes include insulating microtubes, microelectrodes and wires; the tail end of the nerve axon passes through the insulating microtube and bends and extends toward the head end of the nerve axon; the microelectrode is arranged in the insulating microtube; one end of the wire is connected to the microelectrode, and the other end is used to connect to an external device; the present invention avoids intracranial immune rejection reactions and improves the service life of the interface by growing nerve axons in the branches of the nerve tentacles, and the nerve axons serve as the electrical recording or electrical stimulation of the brain.

[0004] The invention patent application with publication number CN110115581A discloses a flexible brain-computer interface electrode with an enhanced wrinkled microstructure and a preparation method. The electrode includes: a substrate, an elastic polymer film is arranged on the substrate to form an elastic polymer substrate, silicone oil is mixed into the elastic polymer film, a first layer of polymer film is deposited on the elastic polymer substrate, and wrinkles are spontaneously generated by depositing the first layer of polymer film as an insulating layer. Compared with the elastic polymer substrate that has not been treated with silicone oil, the wrinkle amplitude of the present invention is significantly increased, and the specific surface area is significantly improved; the preparation method is highly compatible with the micro-electromechanical system process, and the enhanced wrinkles obtained remain unchanged in the subsequent graphic electrode layer and polymer encapsulation layer process; it can effectively improve the bonding force between the electroplated electrode modification material and the electrode interface, and ensure stable and reliable electrochemical performance. Therefore, the present invention has a wide range of application value in the field of micro-flexible electrophysiological sensors, especially brain-computer interface electrodes.

[0005] However, with the deepening of neuroscience research, the demand for understanding the brain's neural network and functional mechanisms is growing. It also puts higher requirements on neural electrodes. The traditional microwire electrodes disclosed in the above-mentioned comparative documents are generally 8-channel or 16-channel, distributed in a matrix, and cannot detect signals from specific brain regions. Different neuroscience studies may require electrodes with different configurations, including the number, arrangement, spacing and length of electrodes. Therefore, it is urgent to design a customizable microwire electrode. Summary of the invention

[0006] The invention provides a customizable microwire electrode array, which has good flexibility and is relatively simple to process.

[0007] The present invention provides a customizable microwire electrode array, comprising:

[0008] A customizable substrate, wherein the customizable substrate is provided with perforated grooves distributed according to customized brain regions;

[0009] A microwire electrode array, wherein the microwire electrode array passes through the perforated groove from top to bottom;

[0010] The packaging material is located at the bottom of the customizable substrate and is used to fix the microwire electrode array.

[0011] Preferably, the material of the substrate is a 3D printing material that is compatible with biological organisms.

[0012] Preferably, the 3D printing material is polylactic acid, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, thermoplastic polyurethane, nylon or polycarbonate.

[0013] Preferably, the substrate has a side length of 1 mm to 10 mm and a thickness of 0.5 mm to 3 mm.

[0014] Preferably, the microwire electrode array is composed of a plurality of arrays of microwire electrodes, and the material of the microwire electrodes is tungsten wire, nickel-chromium alloy wire or platinum-iridium alloy wire that is compatible with biological organisms.

[0015] Preferably, the surface of the microwire electrode is covered with an insulating material, and the insulating material is polyimide or polyparaxylene.

[0016] Preferably, the number of channels of the microwire electrode array is 4-128 channels, and the spacing between the microwire electrodes is 100um-1mm.

[0017] Preferably, the packaging material is polyparaxylene, polydimethylsiloxane, polylactic acid, polyglycolic acid, polyurethane, polyester, polyimide or silicone.

[0018] Preferably, the perforation groove is expanded from bottom to top.

[0019] The present invention also provides a customizable microwire electrode array, comprising:

[0020] S1: A customizable substrate with a perforated groove inside is manufactured by a 3D printing method. The morphology of the substrate and the position and size of the perforated groove thereon are customized according to experimental requirements. The perforated groove is flared from bottom to top;

[0021] S2: The microwire electrode array passes through the perforated slot from top to bottom.

[0022] S3: Fix the microwires and substrate using packaging materials.

[0023] S4: One end of the implanted microwire is corroded by electrochemical method to make the implanted end of the microwire pointed.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The microwire electrode array provided by the present invention can customize the electrode distribution position according to the specific needs of the experiment, provide higher flexibility and adaptability, and realize simultaneous recording of multiple brain regions. At the same time, the processing method of printing substrate through microwires also greatly reduces the process cost and complexity of manually pasting microwires. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0027] Figure 1 This is a longitudinal cross-sectional view of a customizable microelectrode array provided by the present invention; 1 is a custom substrate, 2 is a perforated groove; 3 is a microwire electrode; 4 is a packaging material;

[0028] Figure 2 This is a top view of the electrode in this embodiment;

[0029] Figure 3 This is a flow chart of electrode preparation in this embodiment. DETAILED DESCRIPTION

[0030] In order to solve the problem that the microelectrode disclosed in the prior art cannot detect signals in specific multiple brain regions, the present invention flexibly sets the arrangement position of the perforation grooves through 3D printing technology, thereby improving the flexibility of the microelectrode, which is specifically described as follows:

[0031] Specific embodiments of the present invention provide customizable microwire electrode arrays, such as Figure 1 and Figure 2 As shown, it includes a customizable substrate 1, a perforation groove 2 arranged inside the substrate and expanding from bottom to top, the purpose of which is to make it easier for the microelectrode to pass through and the packaging material to be packaged, a microwire electrode 3 passing through the perforation groove from top to bottom, and a packaging material 4 located at the bottom of the substrate for fixing the substrate and the microwire electrode together.

[0032] The material of the customizable substrate 1 provided in the specific embodiment of the present invention is one of the HTL photosensitive resins. The substrate 1 is circular with a diameter of 4 mm and a thickness of 1 mm.

[0033] The diameter of the perforated groove structure 2 inside the customizable substrate 1 provided in the specific embodiment of the present invention is 50 um.

[0034] A microwire electrode 3 is inserted into the perforated groove structure 2 provided in a specific embodiment of the present invention. The microwire electrode is made of a tungsten wire with a diameter of 30 um. The surface of the microwire is covered with one of the polyparaxylenes. The number of channels of the microwire is 16, and the electrode spacing is 0.4 mm.

[0035] The customizable microwire electrode array packaging material provided in a specific embodiment of the present invention is medical silica gel.

[0036] The specific embodiment of the present invention provides a process for preparing a customizable microwire electrode array, such as Figure 3 As shown, the following steps are included:

[0037] 1. The substrate is prepared by 3D printing method, the substrate morphology is a curved surface, and the position distribution of the perforated grooves is a circular ring distribution.

[0038] 2. The perforated groove (2) has two openings, one large and one small. The diameter of the large opening is 200um, and the diameter of the small opening is 50um.

[0039] 3. Insert the microwire with the larger end. Adjust the length of the microwire to adjust its implantation depth.

[0040] 4. Use medical silicone to fix the microwires and substrate.

[0041] 5. The electrochemical corrosion of tungsten wire is carried out in sodium hydroxide (NaOH) solution. The tungsten wire is used as the anode and stainless steel or other metals are used as the cathode. The tungsten wire is gradually thinned by electrolysis and finally breaks under the action of gravity to form a needle tip.

Claims

1. A customizable microwire electrode array, characterized in that: include: A customizable substrate, wherein the customizable substrate is provided with perforated grooves distributed according to customized brain regions; A microwire electrode array, wherein the microwire electrode array passes through the perforated groove from top to bottom; The packaging material is located at the bottom of the customizable substrate and is used to fix the microwire electrode array.

2. The customizable microwire electrode array according to claim 1, characterized in that: The material of the substrate is a biocompatible 3D printing material.

3. The customizable microwire electrode array according to claim 2, characterized in that: The 3D printing material is polylactic acid, acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, thermoplastic polyurethane, nylon or polycarbonate.

4. The customizable microwire electrode array according to claim 1, characterized in that: The side length of the substrate is 1 mm to 10 mm, and the thickness is 0.5 mm to 3 mm.

5. The customizable microwire electrode array according to claim 1, characterized in that: The microwire electrode array is composed of a plurality of arrays of microwire electrodes, and the material of the microwire electrodes is biocompatible tungsten wire, nickel-chromium alloy wire or platinum-iridium alloy wire.

6. The customizable microwire electrode array according to claim 5, characterized in that: The surface of the microwire electrode is covered with an insulating material, and the insulating material is polyimide or polyparaxylene.

7. The customizable microwire electrode array according to claim 1, characterized in that: The number of channels of the microwire electrode array is 4-128 channels, and the spacing between the microwire electrodes is 100um-1mm.

8. The customizable microwire electrode array according to claim 1, characterized in that: The packaging material is polyparaxylene, polydimethylsiloxane, polylactic acid, polyglycolic acid, polyurethane, polyester, polyimide or silica gel.

9. The customizable microwire electrode array according to claim 1, characterized in that: The perforated groove is expanded from bottom to top.

10. A customizable microwire electrode array according to any one of claims 1 to 9, characterized in that: include: S1: A customizable substrate with a perforated groove inside is manufactured by a 3D printing method. The morphology of the substrate and the position and size of the perforated groove thereon are customized according to experimental requirements. The perforated groove is flared from bottom to top; S2: The microwire electrode array passes through the perforated slot from top to bottom. S3: The microwires and substrate are fixed using packaging materials. S4: One end of the implanted microwire is corroded by electrochemical method to make the implanted end of the microwire pointed.

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