Three-dimensional flexible neural microelectrode and array and preparation method thereof

Abstract

The invention provides a three-dimensional flexible neural microelectrode and an array and a preparation method thereof. The three-dimensional flexible neural microelectrode comprises a cortical electrode part which comprises a first electrode site, and the first electrode site is used for recording a cortical electroencephalogram signal of a to-be-detected body when the cortical electrode part is attached to the cerebral cortical surface of the to-be-detected body; the implanted electrode part comprises a second electrode site, and the second electrode site is used for recording a single neuron discharge signal of the to-be-detected body when the implanted electrode part is implanted into the cerebral cortex of the to-be-detected body; wherein the cortical electrode part is located in an area defined by the implanted electrode part, so that when the implanted electrode part is implanted into the cerebral cortex, the relative position of the cortical electrode part and the surface of the cerebral cortex is kept fixed.

Description

Technical Field

[0001] The present invention relates to the field of neuroscience technology, and in particular to a three-dimensional flexible neural microelectrode and an array and a preparation method thereof. Background Art

[0002] Neural electrodes can record electrical signals generated by the brain and are an important tool for understanding the brain. Depending on the location of implantation, neural electrodes can be divided into non-invasive, semi-invasive and invasive types. Non-invasive electrodes directly contact the scalp and can be used to record electroencephalography (EEG) signals. Semi-invasive electrodes are attached to the dura mater or the surface of the cerebral cortex and can be used to record electrocorticography (ECoG) signals. Invasive electrodes, also called implantable electrodes, are directly implanted into the brain and can be used to record action potential (Spike) signals of brain neurons.

[0003] However, with the rapid development of brain science research, two-dimensional neural electrodes that record single neural signals cannot more accurately analyze the working principles of the brain. Summary of the invention

[0004] In view of this, the present invention provides a three-dimensional flexible neural microelectrode and an array and a preparation method thereof, so as to at least partially solve the above problems.

[0005] On the one hand, an embodiment of the present invention provides a three-dimensional flexible neural microelectrode, including: a cortical electrode part, including a first electrode site, the first electrode site is used to record the cortical electroencephalogram signal of the subject to be tested when the cortical electrode part is attached to the surface of the cerebral cortex of the subject to be tested; an implanted electrode part, including a second electrode site, the second electrode site is used to record the discharge signal of a single neuron of the subject to be tested when the implanted electrode part is implanted inside the cerebral cortex of the subject to be tested; wherein the cortical electrode part is located in the area surrounded by the implanted electrode part, so that when the implanted electrode part is implanted inside the cerebral cortex, the relative position of the cortical electrode part and the surface of the cerebral cortex is kept fixed.

[0006] According to an embodiment of the present invention, it also includes: a through hole, which is arranged on the cortical electrode part, and the through hole is used to discharge the gas and / or liquid between the three-dimensional flexible neural microelectrode and the surface of the cerebral cortex when the cortical electrode part is attached to the surface of the cerebral cortex.

[0007] According to an embodiment of the present invention, the implantable electrode part also includes: a first end, connected to the cortical electrode part, and the first end is coplanar with the cortical electrode part; a second end, connected to the first end, the second end is used to be implanted inside the cerebral cortex, and the second electrode site is protrudingly formed on the side wall of the second end so that the second electrode site is close to the neurons inside the cerebral cortex when the second end is implanted inside the cerebral cortex.

[0008] According to an embodiment of the present invention, there is a preset angle between the first end and the second end; the three-dimensional flexible neural microelectrode has a first form, in which the preset angle is 90 degrees, and the second end is perpendicular to the plane where the cortical electrode part is located, and the second end is implanted inside the cerebral cortex in the first form.

[0009] According to an embodiment of the present invention, the second end is flexibly connected to the first end; the three-dimensional flexible neural microelectrode also has a second form, and in the second form, the preset angle is adjusted to 0 degrees.

[0010] According to an embodiment of the present invention, on the same side length of the three-dimensional flexible neural microelectrode, the length of each second end is different, and the second end is in a needle tip shape.

[0011] According to an embodiment of the present invention, the implanted electrode portion is evenly distributed on the side length of the three-dimensional flexible neural microelectrode, wherein on any side length, the length of the second end changes in a gradient.

[0012] An embodiment of the present invention also provides a three-dimensional flexible neural microelectrode array, comprising: a plurality of three-dimensional flexible neural microelectrodes of any of the above embodiments, wherein the contour of the cortical electrode portion of the three-dimensional flexible neural microelectrode is composed of a plurality of straight line segments, so that the cortical electrode portions of the plurality of three-dimensional flexible neural microelectrodes are spliced ​​together on the same plane to form a three-dimensional flexible neural microelectrode array.

[0013] According to an embodiment of the present invention, the shape of the outline includes a rectangle.

[0014] An embodiment of the present invention also provides a method for preparing the three-dimensional flexible neural microelectrode of the above embodiment, comprising: forming a first insulating layer on a substrate; performing metal patterning on the first insulating layer to form a first recording channel of the cortical electrode part and a second recording channel of the implanted electrode part; forming a second insulating layer on the first recording channel and the second recording channel; performing photolithography and etching on the second insulating layer to expose the first electrode site of the cortical electrode part and the second electrode site of the implanted electrode part; performing photolithography and etching on the first insulating layer to obtain a three-dimensional flexible neural microelectrode.

[0015] Based on the above embodiments, the present invention integrates cortical electrodes and implant electrodes on the same three-dimensional flexible neural microelectrode at the same time, which can be used to record ECoG signals and Spike signals on the surface of the cerebral cortex and inside the brain respectively. The entire electrode is not only expanded in the plane, but also increases the number of recording channels in three dimensions, so that the signal transmission and brain operation can be more accurately understood from a three-dimensional perspective. The implant electrode part surrounds the cortical electrode part, and when the implant electrode is implanted inside the cortex of the subject to be tested, the relative position of the cortical electrode and the surface of the cerebral cortex can be kept fixed, thereby ensuring the stability of the recording of ECoG signals and Spike signals. The three-dimensional flexible neural microelectrode of the embodiment of the present invention can be expanded into a neural microelectrode array, and multiple neural microelectrodes that can simultaneously record ECoG signals and Spike signals can be spliced ​​and used to achieve high-resolution signal recording. The splicing method can also select the arrangement of the array according to the needs of different brain regions. The preparation method of the three-dimensional flexible neural microelectrode of the embodiment of the present invention has a simple preparation process and can obtain an integrally formed neural microelectrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0017] Figure 1 A three-dimensional state diagram of a three-dimensional flexible neural microelectrode according to an embodiment of the present invention is schematically shown;

[0018] Figure 2 Schematically shows Figure 1 A local magnified image of the three-dimensional flexible neural microelectrode shown;

[0019] Figure 3 A two-dimensional state diagram of a three-dimensional flexible neural microelectrode according to an embodiment of the present invention is schematically shown;

[0020] Figure 4 A schematic diagram showing the structure of a three-dimensional flexible neural microelectrode array according to an embodiment of the present invention;

[0021] Figure 5 A flowchart schematically shows a method for preparing a three-dimensional flexible neural microelectrode array according to an embodiment of the present invention;

[0022] Figure 6 The flowchart of the method for preparing a three-dimensional flexible neural microelectrode array according to another embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0023] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0025] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0026] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0027] Figure 1 The three-dimensional state diagram of a three-dimensional flexible neural microelectrode according to an embodiment of the present invention is schematically shown.

[0028] like Figure 1 As shown, a three-dimensional (3D) flexible neural microelectrode 100 is provided, and the three-dimensional flexible neural microelectrode 100 may include a cortical electrode portion 120 and an implanted electrode portion 130. The electrode routing in the three-dimensional flexible neural microelectrode 100 is not drawn to simplify the diagram.

[0029] The cortical electrode part 120 may include first electrode sites 121 and 122, which are used to fit the surface of the cerebral cortex of the subject to be tested to record the cortical electroencephalogram signal of the subject to be tested, that is, the ECoG signal. The implanted electrode part 130 includes second electrode sites 131, 132, and 133, which are used to be implanted inside the cerebral cortex of the subject to be tested to record the neuronal discharge signal of the subject to be tested, that is, the Spike signal.

[0030] As an example, the subject to be tested can be a human body, which is not shown in the figure for simplicity. It can be understood that when using the three-dimensional flexible neural microelectrode 100, the three-dimensional flexible neural microelectrode 100 can be placed on the human cerebral cortex, so that the first electrode sites 121 and 122 of the cortical electrode part 120 are attached to the upper surface of the cerebral cortex, and the second electrode sites 131, 132, and 133 of the implanted electrode part 130 are inserted into the interior of the cerebral cortex, and the ECoG signal and the Spike signal are recorded at the same time.

[0031] Please continue reading Figure 1 , the cortical electrode part 120 is located in the area surrounded by the implanted electrode part 130, so that when the implanted electrode part 130 is implanted inside the cerebral cortex, the relative position of the cortical electrode part 120 and the surface of the cerebral cortex is kept fixed. This is equivalent to a "claw" piercing into the cerebral cortex, and the three-dimensional flexible neural microelectrode 100 is fixed on the inner and outer surfaces of the cerebral cortex through the implanted electrode part 130. In this way, when the second electrode sites 131, 132, and 133 are implanted inside the cortex of the subject to be tested, the relative position of the first electrode sites 121, 122 and the surface of the cerebral cortex can be kept fixed, so that the three-dimensional flexible neural microelectrode 100 can not only record ECoG signals and Spike signals at the same time, but also can record signals stably.

[0032] It should be emphasized that Figure 1 The number of the second electrode sites 131, 132, 133 and the first electrode sites 121, 122 shown is only an example and is not used to limit their number and specific arrangement positions. In order to enable the "claw" to fix the three-dimensional flexible neural microelectrode 100 on the cerebral cortex, the number of the second electrode sites 131, 132, 133 can be set to multiple, for example, at least one second electrode site is set on each side of the three-dimensional flexible neural microelectrode 100. The number of the first electrode sites 121, 122 can be reasonably set according to the needs of signal recording, and the present invention does not make specific limitations.

[0033] Please continue reading Figure 1, the three-dimensional flexible neural microelectrode 100 can be made of flexible materials to facilitate fitting to the cerebral cortex. The electrode can also be made of flexible materials, which causes less damage to brain tissue and has good biocompatibility. In this embodiment, when the three-dimensional flexible neural microelectrode 100 is used alone, its contour shape is not limited, for example, it can be a variety of shapes such as rectangle, circle, triangle or polygon. It can be understood that when the three-dimensional flexible neural microelectrode 100 is combined into a three-dimensional flexible neural microelectrode array, in order to make each three-dimensional flexible neural microelectrode tightly spliced ​​together, the contours of the three-dimensional flexible neural microelectrodes need to cooperate with each other, for example, it can be a rectangular contour. The specific content of the three-dimensional flexible neural microelectrode will be further explained later.

[0034] Figure 2 Schematically shows Figure 1 A partial (region A) magnified view of the three-dimensional flexible neural microelectrode shown. In the accompanying drawings, the same parts are numbered the same.

[0035] like Figure 1 and Figure 2 As shown, in some embodiments, a through hole 230 is provided on the cortical electrode portion 120. The through hole 230 can be used to attach the cortical electrode portion 120 to the surface of the cerebral cortex ( Figure 2 When the three-dimensional flexible neural microelectrode 100 is below the cortical electrode part 120 (not shown in the figure), the gas and / or liquid between the three-dimensional flexible neural microelectrode 100 and the surface of the cerebral cortex are discharged. In this way, the cortical electrode part 120 can be more closely attached to the cerebral cortex.

[0036] like Figure 1 and Figure 2 As shown, the implant electrode part 130 may include a first end 131a and a second end 131b. The first end 131a is connected to the cortical electrode part 120, and the first end 131a is coplanar with the cortical electrode part 120. The first end 131a supports the implant electrode part 130 and transmits the signal recorded by the implant electrode part 130. The second end 131b is connected to the first end 131a and is used to be implanted inside the cerebral cortex. The second end can be called a shank, that is, the insertion part of the electrode.

[0037] like Figure 2 As shown, the second electrode sites 221, 222 are formed protrudingly on the side wall of the second end 131b, so that the second electrode sites 221, 222 are close to the neurons in the cerebral cortex when the second end 131b is implanted in the cerebral cortex. In other words, when the second end 131b penetrates into the cerebral cortex, the distance between the second electrode sites 221, 222 and the neurons can be made smaller, thereby improving the quality of the recorded signal.

[0038] like Figure 2As shown, a preset angle θ is formed between the second end and the first end. Since the second end 131b is flexibly connected to the first end 131a, the preset angle θ can be adjusted. By adjusting the preset angle θ, the three-dimensional flexible neural microelectrode 100 can be switched between the first form and the second form.

[0039] In the first form, which may also be called a folded form or a three-dimensional form, the preset angle is 90 degrees, and the second end 131b is perpendicular to the plane where the cortical electrode portion 120 is located, and the second end 131b is implanted inside the cerebral cortex in the first form. In this way, it is easy to implant the electrode portion 130 into the cerebral cortex.

[0040] In the second form, which can also be called an unfolded state or a two-dimensional state, the preset angle θ is 0 degrees. That is, the second end 131b and the first end 131a are in a straight line. The two-dimensional plane state facilitates the production and preparation of the three-dimensional flexible neural microelectrode 100, and the three-dimensional state facilitates the implantation of the three-dimensional flexible neural microelectrode 100.

[0041] Figure 3 The diagram schematically shows a two-dimensional state (second form) of a three-dimensional flexible neural microelectrode according to an embodiment of the present invention. Figure 1 and Figure 3 In the same parts, the same numbers are used. The main difference is Figure 3 The three-dimensional flexible neural microelectrode 300 shows an electrode routing portion 310 .

[0042] like Figure 3 As shown, the electrode wiring part 310 includes a plurality of cortical electrode wirings 312 and a plurality of implanted electrode wirings 311 to receive and transmit cortical EEG signals and neuron discharge signals, respectively. It should be noted that, due to the proportion of the diagram, the plurality of cortical electrode wirings 312 and the plurality of implanted electrode wirings 311 are connected together to form a black area in the middle. In fact, each cortical electrode wiring 312 and each implanted electrode wiring 311 are not connected to each other, and there is a gap to ensure that the signal transmission is not interfered.

[0043] The electrode routing portion 310 can also lead multiple cortical electrode routings 312 and multiple implanted electrode routings 311 from the three-dimensional flexible neural microelectrode 300 to electrode pads (not shown in the figure). The electrode pads can be connected to an external circuit (not shown) to transmit cortical EEG signals and neuron discharge signals to the external circuit for subsequent processing.

[0044] As an example, the electrode pads may be concentric metal pads that may be connected to an external circuit by gold ball rivet welding for signal transmission.

[0045] Please continue reading Figure 3, on one side of the figure, there are four second ends 131b of the implanted electrode parts, and the lengths of these second ends are d1, d2, d3, and d4 respectively. The length of the second end is the distance from the end to the edge of the electrode contour. In this embodiment, the lengths d1, d2, d3, and d4 of the second ends are different. In some embodiments, the lengths d1, d2, d3, and d4 can vary in a gradient, for example, d1+a=d2, d2+a=d3, d3+a=d4, where a is the gradient value of two adjacent second ends. In this way, the resistance when multiple second ends are implanted inside the cortex can be reduced. In addition, each second end can be in the shape of a needle tip to facilitate the implantation of the electrode.

[0046] It can be understood that when the three-dimensional flexible neural microelectrode 300 has multiple edges, each edge can be configured to have a second end with the above-mentioned gradient change, and the second end is in the shape of a needle tip to minimize the resistance of the entire three-dimensional flexible neural microelectrode 300 when implanted inside the cortex.

[0047] Based on the three-dimensional flexible neural microelectrodes 100 and 300 of the above embodiments, the present invention also provides a three-dimensional flexible neural microelectrode array and a method for preparing the three-dimensional flexible neural microelectrode.

[0048] Figure 4 The structure of a three-dimensional flexible neural microelectrode array according to an embodiment of the present invention is schematically shown.

[0049] like Figure 4 As shown, the three-dimensional flexible neural microelectrode array 400 can be formed by splicing a three-dimensional flexible neural microelectrode 410 and a three-dimensional flexible neural microelectrode 420. The three-dimensional flexible neural microelectrodes 410 and 420 have the characteristics and effective effects of the neural electrode 100 and / or the neural electrode 300 of the above-mentioned embodiment, which will not be repeated here. It should be emphasized that in order to enable multiple three-dimensional flexible neural microelectrodes 410 and 420 to be tightly spliced ​​together, the contours of the three-dimensional flexible neural microelectrodes 410 and 420 can be set to be composed of multiple straight line segments.

[0050] In some embodiments, the outline of the electrode can be set to a rectangle to facilitate quick and accurate splicing up and down and left and right. The spliced ​​three-dimensional flexible neural microelectrodes 410 and 420 can be used in coordination to jointly record the cortical EEG signals and neuronal discharge signals of the subject to be tested.

[0051] The number and shape of the three-dimensional flexible neural microelectrode array 400 can be increased or decreased as needed, so that the three-dimensional flexible neural microelectrode array 400 can realize signal recording in any brain region. For example, it can be a 1×2 arrangement, that is, Figure 4The illustrated one row and two columns splicing mode can be 2×1 (two rows and one column) or 2×2 (two rows and two columns), or can be a splicing combination of more rows and more columns. It is understandable that the number of rows and columns of splicing can be reasonably set according to the use requirements, and the present invention does not make specific limitations.

[0052] The implantable electrode part of the neural electrode needs to be implanted in the brain, and the cortical electrode part needs to fit the surface of the brain, so the electrode needs to be implanted and bonded at the same time. As an example, a module design can be used to assist in the implantation of electrodes, and multiple three-dimensional flexible neural microelectrodes can be implanted in parallel. The implantation position of the electrode can be adjusted according to the recording requirements. After multiple three-dimensional flexible neural microelectrodes are implanted, there are cortical electrodes around the top of each implanted electrode, which can better record and analyze signals. As an example, the implantation process can be as follows:

[0053] First, the second end of the implanted electrode part (i.e., shank) can be immersed in a polyethylene glycol (PEG) solution so that PEG wraps the shank part. After the PEG solidifies, the implanted electrode obtains temporary rigidity and can be implanted into the brain tissue. Next, the shank part is bent downward at 90 degrees to the plane where the cortical electrode part is located. The part with the cortical electrode is coated with PEG and bonded to the implant module, and the implant module is placed above the brain area to be recorded, and the electrode is implanted downward. After the three-dimensional flexible neural microelectrode is implanted, the PEG can be melted with saline to remove the implant module, completing the implantation of the three-dimensional flexible neural microelectrode.

[0054] In some embodiments, sucrose, glucose, PLGA, etc. may also be used as the immersion solution used during the implantation process.

[0055] The implantation process of the three-dimensional flexible neural microelectrode array is similar to that of a single three-dimensional flexible neural microelectrode. The position of each implantation module can be selectively adjusted according to the needs, and multiple three-dimensional flexible neural microelectrodes can be implanted into the target brain area in sequence and spliced ​​together. The implantation of implant modules will not affect each other. In this way, the implantation of the three-dimensional flexible neural microelectrode array can be achieved.

[0056] Figure 5 The flowchart of the method for preparing a three-dimensional flexible neural microelectrode array according to an embodiment of the present invention is schematically shown.

[0057] like Figure 5 As shown, the method for preparing a three-dimensional flexible neural microelectrode array may include steps S510 to S550.

[0058] In step S510 , a first insulating layer is formed on a substrate.

[0059] The material of the first insulating layer may be, for example, polyimide (PI), Parylene-C, SU-8, etc.

[0060] In step S520, metal patterning is performed on the first insulating layer to form a first recording channel of the cortical electrode part and a second recording channel of the implanted electrode part.

[0061] The recording channel may include electrode sites and electrode wiring. The electrode conductive material may be, for example, gold, platinum, chromium, Ti, graphene, PEDOT, or the like.

[0062] In step S530, a second insulating layer is formed on the first recording channel and the second recording channel.

[0063] The second insulating layer and the first insulating layer may be made of the same material, for example, polyimide (PI), Parylene-C, SU-8, etc.

[0064] In step S540, the second insulating layer is subjected to photolithography and etching processes to expose the first electrode site of the cortical electrode part and the second electrode site of the implanted electrode part.

[0065] In step S550, the first insulating layer is subjected to photolithography and etching to obtain a three-dimensional flexible neural microelectrode.

[0066] Through the above steps S510 to S550, a three-dimensional flexible neural microelectrode having a cortical electrode and an implant electrode formed in one piece can be obtained. The preparation method has a simple preparation process and good scalability, and multiple three-dimensional flexible neural microelectrodes can be prepared at the same time.

[0067] Figure 6 The flowchart of the method for preparing a three-dimensional flexible neural microelectrode array according to another embodiment of the present invention is schematically shown.

[0068] like Figure 6 As shown, first, polyimide (PI) material can be dropped on a clean silicon (Si) wafer, and then PI can be spin-coated using a coating machine, and then PI can be cured using a hot plate to obtain a PI lower insulating layer as the first insulating layer.

[0069] Then, a negative photoresist may be first spin-coated on the PI lower insulating layer, and then photolithography may be performed to facilitate the production of a patterned metal layer. Electrode metals, such as Cr / Au, may be deposited by thermal evaporation. After evaporating the metal, the silicon wafer is immersed in acetone for stripping to form a metal layer pattern of the cortical electrode and the implanted electrode, i.e., the first recording channel and the second recording channel.

[0070] Next, the PI material is continuously spin-coated on the metal layer pattern to form an upper insulating layer on the PI as a second insulating layer.

[0071] Next, a positive photoresist may be spin-coated on the PI upper insulating layer, and photolithography may be performed, and a reactive ion etching (RIE) process may be used to etch the PI upper insulating layer to expose the first electrode site and the second electrode site.

[0072] Finally, the photoresist positive photoresist can be spin-coated again and photolithography can be performed. The outline of the three-dimensional flexible neural microelectrode can be etched out using the RIE process to obtain the three-dimensional flexible neural microelectrode.

[0073] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional flexible neural microelectrode, characterized in that: include: The cortical electrode part comprises a first electrode site, wherein the first electrode site is used to record the cortical electroencephalogram signal of the subject when the cortical electrode part is attached to the surface of the cerebral cortex of the subject; The implantable electrode part comprises a second electrode site, wherein the second electrode site is used to record the discharge signal of a single neuron of the subject when the implantable electrode part is implanted inside the cerebral cortex of the subject; The cortical electrode portion is located within the area surrounded by the implanted electrode portion, so that when the implanted electrode portion is implanted inside the cerebral cortex, the relative position of the cortical electrode portion and the surface of the cerebral cortex is kept fixed.

2. The three-dimensional flexible neural microelectrode according to claim 1, characterized in that: Also includes: A through hole is arranged on the cortical electrode part, and the through hole is used to discharge the gas and / or liquid between the three-dimensional flexible neural microelectrode and the surface of the cerebral cortex when the cortical electrode part is attached to the surface of the cerebral cortex.

3. The three-dimensional flexible neural microelectrode according to claim 1, characterized in that: The implanted electrode portion further comprises: A first end connected to the cortical electrode portion, and the first end and the cortical electrode portion are coplanar; The second end is connected to the first end, and the second end is used to be implanted inside the cerebral cortex. The second electrode site is protrudingly formed on the side wall of the second end so that the second electrode site is close to the neurons inside the cerebral cortex when the second end is implanted inside the cerebral cortex.

4. The three-dimensional flexible neural microelectrode according to claim 3, characterized in that: There is a preset angle between the first end and the second end; The three-dimensional flexible neural microelectrode has a first form. In the first form, the preset angle is 90 degrees, and the second end is perpendicular to the plane where the cortical electrode part is located. The second end is implanted inside the cerebral cortex in the first form.

5. The three-dimensional flexible neural microelectrode according to claim 4, characterized in that: The second end is flexibly connected to the first end; The three-dimensional flexible neural microelectrode also has a second form, in which the preset angle is adjusted to 0 degrees.

6. The three-dimensional flexible neural microelectrode according to claim 4, characterized in that: On the same side of the three-dimensional flexible neural microelectrode, the length of each second end is different, and the second end is in a needle tip shape.

7. The three-dimensional flexible neural microelectrode according to claim 6, characterized in that: The implanted electrode portions are evenly distributed on the side lengths of the three-dimensional flexible neural microelectrode, wherein on any side length, the length of the second end changes in a gradient.

8. A three-dimensional flexible neural microelectrode array, characterized in that: include: A plurality of three-dimensional flexible neural microelectrodes as described in any one of claims 1 to 7, wherein the contour of the cortical electrode portion of the three-dimensional flexible neural microelectrode is composed of a plurality of straight line segments, so that the cortical electrode portions of the plurality of three-dimensional flexible neural microelectrodes are spliced ​​together on the same plane to form the three-dimensional flexible neural microelectrode array.

9. The three-dimensional flexible neural microelectrode array according to claim 8, characterized in that: The shape of the outline includes a rectangle.

10. A method for preparing a three-dimensional flexible neural microelectrode according to any one of claims 1 to 7, characterized in that: include: forming a first insulating layer on the substrate; Performing metal patterning on the first insulating layer to form a first recording channel of the cortical electrode part and a second recording channel of the implanted electrode part; forming a second insulating layer on the first recording channel and the second recording channel; Performing photolithography and etching on the second insulating layer to expose the first electrode site of the cortical electrode part and the second electrode site of the implanted electrode part; The first insulating layer is subjected to photolithography and etching to obtain the three-dimensional flexible neural microelectrode.

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