Microelectrode array device, preparation method and organoid detection device

Abstract

The embodiment of the invention provides a microelectrode array device, a preparation method and an organoid detection device, and relates to the technical field of electrophysiology. The microelectrode array device includes: a substrate layer; the conductor layer comprises a microneedle array and at least two wires; the microneedle array comprises at least two microneedles arranged in an array mode, each microneedle is electrically connected with one wire, and each microneedle is provided with a protrusion in the direction perpendicular to the substrate layer; the microneedle is used for detecting electric signals; and the packaging layer is used for wrapping the wires and at least exposing the bulges of the microneedles. According to the embodiment of the invention, the signal detection range can be enlarged, and comprehensive signal detection can be carried out.

Description

Technical Field

[0001] This application relates to the field of electrophysiology technology, and particularly to a microelectrode array device, a preparation method, and an organoid detection device. Background Art

[0002] Organoids refer to miniature organs obtained through in vitro culture, which can partially simulate real organs in terms of morphology and function. Currently, electrophysiological signals of organoids (such as neural organoids and cardiac organoids) can be detected by microelectrode arrays, so as to record or stimulate the electrophysiological activities of cells in the organoids for biomedical research. However, current microelectrode arrays are difficult to detect the electrophysiological signals of organoids over a large range. For example, current microelectrode arrays are difficult to comprehensively detect the electrophysiological signals of the neural network composed of neurons in neural organoids, which affects the research on the electrophysiological activities of the nervous system.

[0003] Therefore, how to increase the signal detection range of microelectrode arrays has become a technical problem to be solved urgently. Summary of the Invention

[0004] The main purpose of the embodiments of this application is to propose a microelectrode array device, a preparation method, and an organoid detection device, aiming to increase the signal detection range and enable comprehensive signal detection.

[0005] To achieve the above purpose, in the first aspect of the embodiments of this application, a microelectrode array device is proposed, and the microelectrode array device includes:

[0006] A substrate layer;

[0007] A conductor layer, the conductor layer includes a micro-needle array and at least two wires; the micro-needle array includes at least two micro-needles arranged in an array, each micro-needle is electrically connected to one wire, and each micro-needle has a protrusion in the direction perpendicular to the substrate layer; the micro-needles are used to detect electrical signals;

[0008] An encapsulation layer, the encapsulation layer is used to cover the wires and at least expose the protrusions of each micro-needle.

[0009] In some embodiments, the shape of each micro-needle is conical, and the material of each micro-needle is graphene polymer.

[0010] In some embodiments, the micro-needle array has a central region and a peripheral region, the peripheral region does not overlap with the central region, and the peripheral region embeds the central region;

[0011] The heights of the micro-needles in the central region are different from the heights of the micro-needles in the peripheral region.

[0012] In some embodiments, the material of the wire is liquid metal polymer; the materials of the base layer and the encapsulation layer are both elastic materials;

[0013] The height of the microneedles in the central region is greater than the height of the microneedles in the peripheral region.

[0014] In some embodiments, the height value range of the microneedles in the central region includes 80 to 200 microns, and the height value range of the microneedles in the peripheral region includes 20 to 60 microns.

[0015] In some embodiments, the central region of the microneedle array is a rectangular region, the length of the central region is 1500 microns, and the width of the central region is 1500 microns;

[0016] The peripheral region of the microneedle array is a frame-shaped region, the outer frame length of the peripheral region is 2500 microns, and the outer frame width of the peripheral region is 2500 microns;

[0017] Wherein, the inner frame length of the peripheral region is consistent with the length of the central region, and the inner frame width of the peripheral region is consistent with the width of the central region.

[0018] To achieve the above object, a second aspect of the embodiments of the present application proposes a preparation method of a microelectrode array device, the method is used to prepare the microelectrode array device described in the first aspect above, and the method includes:

[0019] Prepare a conductor layer including microneedles and wires;

[0020] Prepare a base layer;

[0021] Make a protective shell for each microneedle of the conductor layer so that each microneedle is in a closed space formed by the protective shell and the base layer;

[0022] Encapsulate the wires of the conductor layer with an encapsulation material mixture to obtain an encapsulation layer; wherein, the protective shell is insoluble in the encapsulation material mixture;

[0023] Perform a dissolution operation on each protective shell to expose each microneedle, and obtain the microelectrode array device.

[0024] In some embodiments, the base layer has a grid-like region and a non-grid-like region;

[0025] The encapsulating the wires of the conductor layer with an encapsulation material mixture to obtain an encapsulation layer includes:

[0026] Cover the wire on the non-mesh area with a thermoplastic elastomer film, and perform a fusing operation on the thermoplastic elastomer film and the wire on the non-mesh area to obtain the first encapsulation part of the encapsulation layer;

[0027] Immerse the wire on the mesh area in the encapsulation material mixture; wherein, the encapsulation material mixture is a mixture of a liquid polymer and a curing agent;

[0028] Heat the wire on the mesh area to cure the polymer and obtain the second encapsulation part of the encapsulation layer.

[0029] In some embodiments, the preparation of the conductor layer including micro needles and wires includes:

[0030] Prepare a conductor layer transfer mold; wherein, the conductor layer transfer mold includes at least two micro needle grooves and at least two wire microchannels, each of the micro needle grooves is arranged in an array, and each micro needle groove is connected to a wire microchannel;

[0031] Fill each micro needle groove with graphene ink;

[0032] Fill each wire microchannel with liquid metal ink;

[0033] Immerse the conductor layer transfer mold in a polymer solution to allow the polymer solution to fill the gaps inside the graphene ink and the gaps inside the liquid metal ink;

[0034] Dry the graphene ink, the liquid metal ink, and the polymer solution to obtain the conductor layer; wherein, the material of each micro needle is graphene polymer, and the material of each wire is liquid metal polymer.

[0035] To achieve the above object, a third aspect of the embodiments of the present application proposes an organoid detection device, and the organoid detection device includes:

[0036] A microelectrode array device prepared according to the method described in the first aspect above;

[0037] A culture chamber for culturing the organoids to be tested;

[0038] A cover body disposed inside the culture chamber, and the inside of the cover body and the inner bottom surface of the culture chamber form a closed culture space;

[0039] Wherein, the organoids to be tested are disposed in the closed culture space, and each micro needle of the microelectrode array device is disposed in the closed culture space.

[0040] To achieve the above object, a fourth aspect of the embodiments of the present application provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the method described in the first aspect above.

[0041] The microelectrode array device, preparation method and organoid detection device proposed by the present application form a microelectrode array device with a three-dimensional structure by setting a micro-needle array, and each micro-needle in the micro-needle array has a protrusion in the direction perpendicular to the base layer; the wire is coated with a packaging layer, and at least the protrusions of each micro-needle are exposed, so as to ensure that the micro-needles can detect electrical signals and increase the signal detection range. For example, the micro-needles can be inserted into biological tissues (such as organoids) to detect signals inside the biological tissues, thereby expanding the signal detection range from the surface of the biological tissues to the inside of the biological tissues and increasing the signal detection range. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic structural diagram of a conductor layer provided by an embodiment of the present application;

[0043] Figure 2 is Figure 1 an enlarged schematic diagram of part A in

[0044] Figure 3 is a partial schematic diagram of a conductor layer and a base layer provided by an embodiment of the present application;

[0045] Figure 4 is an application schematic diagram of a microelectrode array device provided by an embodiment of the present application;

[0046] Figure 5 is a flowchart of a preparation method of a microelectrode array device provided by an embodiment of the present application;

[0047] Figure 6 is Figure 5 a flowchart of step 101 in

[0048] Figure 7 is Figure 5 a flowchart of step 104 in

[0049] Figure 8 is a schematic structural diagram of an original mold of a conductor layer provided by an embodiment of the present application;

[0050] Figure 9 is Figure 8 an enlarged schematic diagram of part B in

[0051] Figure 10 is an original mold of a base layer provided by an embodiment of the present application;

[0052] Figure 11 It is a schematic diagram of preparing a conductor layer through a conductor layer transfer mold provided by an embodiment of the present application;

[0053] Figure 12 It is a schematic diagram of preparing a conductor layer through a conductor layer transfer mold provided by another embodiment of the present application;

[0054] Figure 13 It is a schematic diagram of preparing a base layer through a base layer transfer mold provided by an embodiment of the present application;

[0055] Figure 14 It is a schematic diagram of the structure of a conductor layer and a base layer provided by an embodiment of the present application;

[0056] Figure 15 It is a partial schematic diagram of a conductor layer and a base layer provided by another embodiment of the present application;

[0057] Figure 16 It is a physical diagram of a microelectrode array device provided by an embodiment of the present application;

[0058] Figure 17 It is a specific implementation schematic diagram of preparing a packaging layer provided by an embodiment of the present application;

[0059] Figure 18 It is a physical diagram of a protective case provided by an embodiment of the present application;

[0060] Figure 19 It is a physical diagram of a protective case provided by another embodiment of the present application;

[0061] Figure 20 It is a physical diagram of a microelectrode array device provided by another embodiment of the present application;

[0062] Figure 21 It is a specific implementation schematic diagram of preparing a microelectrode array device provided by an embodiment of the present application;

[0063] Figure 22 It is a schematic diagram of the structure of an organoid detection device provided by an embodiment of the present application.

[0064] Reference numerals: 100, base layer; 200, conductor layer; 210, micro needle; 220, wire; 230, flexible cable connection part. Detailed implementation manners

[0065] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0066] It should be noted that although the functional modules are divided in the device schematic diagram and the logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the module division in the device or the sequence in the flowchart. The terms "first", "second", etc. in the description, claims, and the above-mentioned drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0068] First, some terms involved in this application are parsed as follows:

[0069] Microelectrode array: It is an electrode structure composed of tiny electrodes. The microelectrode array can be used to detect and transmit signals. The microelectrode array can be used to measure potential, current, and temperature, and can also be used to detect the bioelectrical activity of biological samples.

[0070] Polymer: Abbreviated as high polymer, it refers to a high molecular weight compound (or mixture) formed by a large number of atoms connected by covalent bonds. Polymers include plastics, rubbers, and fibers.

[0071] Eutectic gallium-indium alloy (EGaIn): It is a liquid metal with a melting point close to or below room temperature, having good fluidity, electrical conductivity, and stretchability.

[0072] Thermoplastic polyurethane elastomer (abbreviated as TPU): It is an elastomer with thermoplasticity. TPU can be processed by heating and plasticizing. Among them, thermoplasticity refers to the property that the material softens when heated and hardens when cooled. An elastomer refers to a high molecular material that can undergo significant deformation under the action of external force and can quickly return to a state close to the original state after the external force is removed.

[0073] The microelectrode array device, preparation method, and organoid detection device provided by the embodiments of this application are specifically described through the following embodiments. First, the microelectrode array device in the embodiments of this application is described.

[0074] Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 14 , the embodiments of this application provide a microelectrode array device. The microelectrode array device includes:

[0075] Base layer 100;

[0076] Conductor layer 200, the conductor layer 200 includes a microneedle array and at least two wires 220; the microneedle array includes at least two microneedles 210 arranged in an array, each microneedle 210 is electrically connected to a wire 220, and each microneedle 210 has a protrusion in the direction perpendicular to the base layer 100; the microneedles 210 are used to detect electrical signals;

[0077] Encapsulation layer, the encapsulation layer is used to cover the wires 220 and at least expose the protrusions of each microneedle 210.

[0078] The beneficial effects of the embodiments of the present application include but are not limited to: by setting a microneedle array, and each microneedle 210 in the microneedle array has a protrusion in the direction perpendicular to the base layer 100, a microelectrode array device with a three-dimensional structure is jointly formed; the wires 220 are covered with an encapsulation layer, and at least the protrusions of each microneedle 210 are exposed, so as to ensure that the microneedles 210 can detect electrical signals and increase the signal detection range. For example, the microneedles 210 can be inserted into biological tissues (such as organoids) to detect signals inside the biological tissues, thereby expanding the signal detection range from the surface of the biological tissues to the inside of the biological tissues and increasing the signal detection range.

[0079] It should be noted that the base layer 100 is a hierarchical structure for supporting the conductor layer 200. Specifically, the base layer 100 is attached to one side of the conductor layer 200 to support the conductor layer 200. The material of the base layer 100 can be an insulating material, such as plastic, rubber, etc.

[0080] It should be noted that the conductor layer 200 is a hierarchical structure for detecting and conducting electrical signals. Specifically, the wires 220 and microneedles 210 in the conductor layer 200 are both made of conductive materials, such as metals, metal compounds, etc.

[0081] It should be noted that the encapsulation layer is a hierarchical structure for encapsulating the wires 220. Specifically, the material of the encapsulation layer is an insulating material. The encapsulation layer covers each wire 220, thereby improving the insulation performance of the wires 220, effectively blocking the current leakage in the wires 220, and avoiding short circuits. And, the encapsulation layer at least exposes the protrusions of each microneedle 210 so that the microneedles 210 can detect signals. In one embodiment, the encapsulation layer completely exposes each microneedle 210. In another embodiment, the encapsulation layer exposes a part of each microneedle 210, such as only exposing the tip part of each microneedle 210 (i.e., the protrusion of the microneedle 210).

[0082] In some embodiments, it should be noted that the current planar electrodes can only contact the surface of biological tissues and cannot contact the interior of biological tissues, making it difficult to detect the signals inside them. In view of the above problems, the embodiments of the present application change the structure of the microelectrode array device and add micro-needles 210 thereto. Specifically, the micro-needles 210 have protrusions in the direction perpendicular to the base layer 100, making the microelectrode array device have a three-dimensional structure. This structure can improve the accessibility of the microelectrode array device to contact biological tissues. For example, the micro-needles 210 can contact the interior of biological tissues to fully detect signals and increase the signal detection range.

[0083] In some embodiments, it should be noted that during the signal detection process, the current planar electrodes may be detached or displaced from the surface of biological tissues due to external interference factors (such as shaking), which will cause changes in the electrode contact state and thus reduce the accuracy of signals. To fix the planar electrodes on the surface of biological tissues, a large amount of time is often required. Especially for biological tissues such as organoids that are spherical (or quasi-spherical) in shape and suspended in a culture solution, it is difficult to quickly fix the planar electrodes on their surfaces. In the embodiments of the present application, the microelectrode array device adopts a three-dimensional structure, which can significantly shorten the coupling time between the microelectrode array device and biological tissues. For example, by inserting the micro-needles 210 into the organoids, the microelectrode array device can be quickly fixed on the organoids, thereby achieving faster and more efficient signal detection.

[0084] Please refer to Figure 1 , in some embodiments, the conductive layer further includes a flexible flat cable connection portion 230. The flexible flat cable connection portion 230 is connected to each micro-needle 210 through a wire 220. The flexible flat cable connection portion 230 is used to connect an external electrical signal acquisition instrument. Specifically, the flexible flat cable connection portion 230 can be connected to the flexible flat cable through a conductive adhesive. For example, an anisotropic conductive adhesive is used to align and paste the pin points of the flexible flat cable with the pin points of the electrical signal acquisition instrument.

[0085] Specifically, the conductive layer can have two flexible flat cable connection portions 230, and the two flexible flat cable connection portions 230 are symmetrically arranged on both sides of the micro-needle array.

[0086] When the flexible flat cable connection portion 230 of the microelectrode array device is connected to the electrical signal acquisition instrument, the electrical signal acquisition instrument can acquire the signals detected by the microelectrode array device and thus analyze the signals. For example, the electrical signal acquisition instrument can be a neural signal acquisition and analysis system, such as the Plexon system.

[0087] Please refer to Figure 2 and Figure 16 , in some embodiments, the shape of each micro-needle 210 is conical, and the material of each micro-needle 210 is graphene polymer.

[0088] The advantages of this embodiment are as follows. By setting the shape of the microneedle 210 to be conical, it is convenient for the microneedle 210 to be inserted into the biological tissue to detect electrical signals. Moreover, considering that the microneedle 210 is prone to wear during the process of being inserted into the biological tissue, the material of the microneedle 210 is set to graphene polymer with high hardness and good electrical conductivity, thereby improving the structural strength of the microneedle 210, reducing the wear generated during the contact between the microneedle 210 and the biological tissue, thus increasing the service life of the microneedle 210 and improving the stability of the microelectrode array device for detecting electrical signals.

[0089] It should be noted that in Figure 16 , the scale is 500 micrometers (μm). The graphene microneedle refers to the microneedle 210 made of graphene polymer. The graphene polymer refers to a mixture of graphene and polymer. Among them, the polymer can include thermoplastic polyurethane elastomer (TPU).

[0090] It should be noted that during the signal detection process, the electrode is prone to damage, which affects the stability of signal detection. For example, the electrode often needs to be in contact with the biological tissue for a long time, which easily leads to damage to the electrode.

[0091] In one embodiment, the microneedle 210 of the microelectrode array device is inserted into the biological tissue to detect signals, which causes the microneedle 210 to be easily affected by extrusion or other factors, increasing the probability of electrode damage. For example, the material of the microneedle 210 can also include liquid metal polymer. However, the liquid metal polymer is composed of micron-sized liquid metal particles embedded in TPU. The liquid metal particles are relatively soft, resulting in insufficient hardness of the material of the microneedle 210. When the microneedle 210 contacts the inside of the biological tissue, due to interference such as extrusion by the biological tissue, the liquid metal particles in the microneedle 210 are easily detached and dropped from the TPU, causing the microneedle 210 to be worn. To solve the above problems, the microneedle 210 (abbreviated as graphene microneedle) made of graphene polymer is adopted in the embodiments of the present application. The graphene polymer is formed by embedding solid graphene particles in TPU. When being extruded or interfered in other ways, the solid graphene particles are not easily detached from the TPU. Therefore, the graphene microneedle has higher hardness and structural strength, which can reduce the wear generated during the contact between the microneedle 210 and the biological tissue, extend the service life of the microneedle 210, and further improve the stability of signal detection.

[0092] Please refer to Figure 3 , in some embodiments, the microneedle array has a central region and a peripheral region. The peripheral region does not overlap with the central region, and the peripheral region embeds the central region;

[0093] The height of the microneedle 210 in the central region is different from the height of the microneedle 210 in the peripheral region.

[0094] The advantage of this embodiment is that the microneedles 210 in the central region of the microneedle array have different heights from the microneedles 210 in the peripheral region, enabling the microelectrode array device to fully contact biological tissue to detect electrical signals. The microneedles 210 in different regions have different heights, which can comprehensively detect signals from organoids with irregular shapes, thus detecting signals more fully.

[0095] It should be noted that in Figure 3 , D1 represents the central region of the microneedle array, specifically the region inside the green dashed box. D2 represents the peripheral region of the microneedle array, specifically the region between the red solid box and the green dashed box.

[0096] In some embodiments, the material of the wire 220 is liquid metal-polymer; the materials of the base layer 100 and the encapsulation layer are both elastic materials; the height of the microneedles 210 in the central region is greater than the height of the microneedles 210 in the peripheral region.

[0097] The advantage of this embodiment is that a liquid metal-polymer with good stretchability and conductivity is used as the material of the wire 220 in the conductor layer 200. The base layer 100 and the encapsulation layer with a grid-like structure and made of elastic materials are used to improve the stretchability and flexibility of the base layer 100 and the encapsulation layer. The microelectrode array device composed of the above three layers (conductor layer 200, base layer 100, and encapsulation layer) has high stretchability and flexibility, can be deformed and bent arbitrarily, increasing the signal detection range. In addition, considering the problem that it is difficult for the microelectrode array device to fully fit biological tissue (such as spherical organoids) due to different bending amplitudes at different parts, the height of the microneedles 210 in the central region is further set to be greater than the height of the microneedles 210 in the peripheral region, so as to improve the degree of contact between the microneedles 210 in each region (including the central region and the peripheral region) and biological tissue under different bending amplitudes, thereby detecting signals from all parts of biological tissue more fully and increasing the signal detection range.

[0098] It should be noted that liquid metal-polymer conductor (MPC) is a composite material, which can be prepared by mixing liquid metal and polymer. Liquid metal-polymer has good toughness. In the embodiments of the present application, the wire 220 made of liquid metal-polymer can increase the toughness of the wire 220, making the conductor layer 200 have good flexibility.

[0099] Specifically, the material of the base layer 100 is an elastic material, including thermoplastic polyurethane elastomer (TPU). The base layer 100 can also use other elastic materials, such as rubber, and the embodiments of the present application do not limit this.

[0100] Specifically, the material of the encapsulation layer is an elastic material, including one or more of TPU and polydimethylsiloxane (PDMS for short). Other elastic materials can also be used for the encapsulation layer, and are not limited thereto.

[0101] It should be noted that the current electrodes have insufficient flexibility and stretchability, which may lead to insufficient matching between the microelectrode array device and biological tissues. For example, the brain tissue is very soft. When detecting signals from the brain tissue, excessive rigidity of the electrodes will increase the risk of signal attenuation and distortion. In addition, the current electrodes have insufficient stretchability, which may cause the electrodes to fail to maintain good contact with biological tissues during application, thereby affecting the stability of signal transmission and recording. To address the above problems, the microelectrode array device of the embodiments of the present application has high stretchability and flexibility, and can be deformed and bent arbitrarily (reference can be made to Figure 14 and Figure 15 ), increasing the signal detection range, improving the stability of signal detection, and improving the signal quality.

[0102] In some embodiments, the microelectrode array device is used to detect signals from organoids. The shape of organoids, such as the shape of brain organoids or heart organoids, is usually close to spherical (i.e., spheroidal). Therefore, it is necessary to bend the part where the micro-needle array of the microelectrode array device is located into a shape that fits the spherical shape, such as an arc. However, it is difficult to accurately bend the microelectrode array device into a shape that fits the spherical shape. In practice, the bending amplitudes of different parts of the microelectrode array device are not the same. The bending shape of the part where the micro-needle array of the microelectrode array device is located is usually close to a V shape or a U shape. In this case, the micro-needles 210 in the peripheral area are closer to the surface of the spherical organoid, and the micro-needles 210 in the central area are farther from the surface of the spherical organoid.

[0103] In some embodiments, as Figure 4 shown, Figure 4 the circle in Figure 4), for contacting with the organoid, such as contacting the surface of the organoid, or inserting into the interior of the organoid. D1 represents the substrate area corresponding to the central area of ​​the microneedle array, and D2 represents the substrate area corresponding to the peripheral area of ​​the microneedle array. In this case, the distance between the microneedles 210 in the central area and the surface of the organoid is farther than the distance between the microneedles 210 in the peripheral area and the surface of the organoid. Therefore, the height of the microneedles 210 in the central area is set to be greater than the height of the microneedles 210 in the peripheral area to increase the possibility of the microneedles 210 in the central area contacting the organoid, thereby making each microneedle 210 more fully contact the organoid and improving the signal detection range.

[0104] In some embodiments, the material of the wire 220 is a liquid metal polymer, the material of the base layer 100 and the material of the encapsulation layer are both elastic materials, and the material of the microneedle 210 is a graphene polymer. This ensures that the microneedle 210 has sufficient structural strength and conductivity while taking into account the overall stretchability and flexibility of the device.

[0105] In some embodiments, Figure 14 and Figure 15 As shown, the base layer 100 has a grid structure, specifically, the base layer 100 has a grid-shaped hollow area (equivalent to the grid-shaped area in step 203). The use of the base layer 100 with a grid structure can further increase the stretchability of the base layer 100, thereby increasing the overall stretchability of the microelectrode array device.

[0106] In some embodiments, the base layer 100 has a grid-shaped hollow area, the encapsulation layer has a grid-shaped hollow area, and the hollow area of ​​the encapsulation layer corresponds to the hollow area of ​​the base layer 100. It should be noted that the correspondence means that the hollow area of ​​the encapsulation layer is the same as the hollow area of ​​the base layer 100 (such as shape and size), and the two areas overlap. In the embodiment of the present application, the base layer 100 and the encapsulation layer of the microelectrode array device are provided with a grid-shaped hollow area, so that the culture fluid can contact the biological tissue through the hollow area, thereby improving the stability of signal detection on the biological tissue. For example, biological tissues (such as organoids) are usually cultured in culture fluid. When performing signal detection on organoids, the current microelectrode array device may block the organoids from contacting the culture fluid, affecting the electrophysiological activity of the organoids, resulting in reduced signal quality. In the embodiment of the present application, both the base layer 100 and the encapsulation layer of the microelectrode array device have a grid-shaped hollow area, and the two areas overlap, that is, the microelectrode array device as a whole has a hollow area, so that the biological tissue can fully contact with external substances such as the culture medium through the hollow area, thereby increasing the possibility of contact between the culture medium and the organoid, reducing the impact of the signal detection process on the biological tissue, and improving the quality of the signal.

[0107] In some embodiments, the height of the microneedles 210 in the central region ranges from 80 to 200 microns, and the height of the microneedles 210 in the peripheral region ranges from 20 to 60 microns.

[0108] The advantage of this embodiment is that, considering the problem that it is difficult to fully conform to biological tissues (such as spherical organoids) due to different bending amplitudes at various parts of the microelectrode array device, the height of the microneedles 210 in the central region is set to be greater than the height of the microneedles 210 in the peripheral region. Specifically, the height of the microneedles 210 in the central region ranges from 80 to 200 microns, and the height of the microneedles 210 in the peripheral region ranges from 20 to 60 microns, thereby improving the degree of full contact between the microneedles 210 and biological tissues, more fully detecting signals from various parts of biological tissues, and increasing the signal detection range.

[0109] In some embodiments, specifically, the height of the microneedles 210 in the central region may include any one of 80, 85, 90, 95, 100, 125, 150, 175, and 200 microns (μm). The height of the microneedles 210 in the peripheral region may include any one of 20, 25, 30, 35, 40, 45, 50, 55, and 60 microns. The microneedles 210 in the central region and the microneedles 210 in the peripheral region may also be set to other heights, which are not limited.

[0110] In some embodiments, for example, when the height of the microneedles 210 in the peripheral region is 50 microns, the height of the microneedles 210 in the central region is 100 microns.

[0111] In some embodiments, for example, when the height of the microneedles 210 in the peripheral region is 20 microns, the height of the microneedles 210 in the central region is 80 microns. Also, for example, when the height of the microneedles 210 in the peripheral region is 60 microns, the height of the microneedles 210 in the central region is 200 microns. Other height combinations can also be adopted, which are not limited thereto.

[0112] In some embodiments, the central region of the microneedle array is a rectangular region, the length of the central region is 1500 microns, and the width of the central region is 1500 microns;

[0113] The peripheral region of the microneedle array is a frame-shaped region, the outer frame length of the peripheral region is 2500 microns, and the outer frame width of the peripheral region is 2500 microns;

[0114] Among them, the inner frame length of the peripheral region is the same as the length of the central region, and the inner frame width of the peripheral region is the same as the width of the central region.

[0115] The advantage of this embodiment is that by setting the central region of the microneedle array as a square with a side length of 1500 microns, setting the peripheral region of the microneedle array as a frame shape with an outer frame side length of 2500 microns, and embedding the central region in the peripheral region, the region division of the microneedle array is adapted to the size of the organoid, so that the microneedles 210 in the central region and the microneedles 210 in the peripheral region can more fully contact the organoid and more comprehensively detect signals from the organoid.

[0116] Figure 5 It is an optional flowchart of the preparation method of the microelectrode array device provided by the embodiment of the present application. Figure 5 The method in [it] may include but is not limited to steps 101 to 105.

[0117] Step 101, prepare a conductor layer 200 including microneedles 210 and wires 220;

[0118] Step 102, prepare a base layer 100;

[0119] Step 103, make a protective shell for each microneedle 210 of the conductor layer 200 so that each microneedle 210 is in a closed space formed by a protective shell and the base layer 100;

[0120] Step 104, encapsulate the wires 220 of the conductor layer 200 with an encapsulating material mixture to obtain an encapsulation layer; wherein, the protective shell is insoluble in the encapsulating material mixture;

[0121] Step 105, perform a dissolving operation on each protective shell to expose each microneedle 210, thereby obtaining a microelectrode array device.

[0122] The beneficial effects of the embodiment of the present application include but are not limited to: by preparing a conductor layer 200 including microneedles 210 and wires 220, and a base layer 100 perpendicular to the microneedles 210 protruding from the conductor layer 200, so as to encapsulate the wires 220 of the conductor layer 200 to prepare a microelectrode array device. Make a protective shell for each microneedle 210 of the conductor layer 200 so that each microneedle 210 is in a closed space formed by a protective shell and the base layer 100, avoiding the subsequent encapsulation process from affecting the microneedles 210. Encapsulate the wires 220 of the conductor layer 200 with an encapsulating material mixture to obtain an encapsulation layer. Since the protective shell is insoluble in the encapsulating material mixture, the protective shell separates the microneedles 210 from the encapsulating material mixture, and the encapsulation layer formed by the encapsulating material mixture only covers the surface of the wires 220 and does not cover the microneedles 210, thereby enabling precise encapsulation of the wires 220. Perform a dissolving operation on each protective shell to expose the microneedles 210, realizing the preparation of the microelectrode array device for signal detection.

[0123] In step 101 of some embodiments, the conductor layer 200 is a hierarchical structure for detecting and conducting electrical signals. The conductor layer 200 includes microneedles 210 and wires 220. For their connection relationship, reference can be made to the specific description of the microelectrode array device above, which will not be elaborated here.

[0124] It should be noted that the microneedles 210 are used to detect signals. The microneedles 210 are made of a conductive material. For example, the material of the microneedles 210 can be graphene polymer.

[0125] It should be noted that the wire 220 is used to transmit the signal of the microneedle 210 electrically connected to the wire 220 to an external device. The wire 220 in the conductor layer 200 is made of a conductive material. For example, the material of the wire 220 can be liquid metal polymer.

[0126] In step 102 of some embodiments, the prepared base layer 100 is connected to the conductor layer 200. It should be noted that the base layer 100 is a hierarchical structure for supporting the conductor layer 200. Specifically, the material of the base layer 100 can be an elastic material, such as thermoplastic polyurethane elastomer (TPU).

[0127] In step 103 of some embodiments, the material of the protective shell is a material insoluble in the encapsulation material mixture, so as to ensure that the protective shell will not be dissolved when the wire 220 is encapsulated subsequently. For example, when the encapsulation material mixture is a mixture of PDMS and a curing agent, the material of the protective shell can include sodium alginate. Among them, sodium alginate is insoluble in PDMS. Also for example, the material of the protective shell can also include water-soluble polyurethane (PU). The material of the protective shell can also include other materials insoluble in the encapsulation material mixture, and is not limited thereto.

[0128] In some embodiments, a protective shell is made for each microneedle 210 of the conductor layer 200. Specifically, it can include: for each microneedle 210, dropping a water-soluble sodium alginate solution; placing the conductor layer 200 and the base layer 100 in an oven at 80 degrees Celsius and baking for 5 minutes to form a sodium alginate protective shell on the surface of each microneedle 210 (reference can be made to Figures 17 to 19 ).

[0129] It should be noted that in Figure 17 , the spherical shell represents the sodium alginate protective shell, and the PDMS encapsulation layer refers to the encapsulation layer made of PDMS. Figure 18 And Figure 19 The transparent material pointed by the red arrow in is the sodium alginate protective layer. In Figure 18 , the scale bar is 200 microns. In Figure 19 , the scale bar is 100 microns.

[0130] In step 104 of some embodiments, the encapsulation layer is a hierarchical structure for encapsulating the wire 220.

[0131] In step 105 of some embodiments, the grid-like region of the microelectrode array device can be placed in water, that is, the microneedles 210 with sodium alginate protective shells are placed in water and soaked until the sodium alginate protective shells are largely dissolved, so as to completely release the microneedles 210 (for reference, see Figure 17 and Figure 20 ).

[0132] It should be noted that, as Figure 20 shown, the images in the first row represent the scanning electron microscope (SEM) images of the microelectrode array device before encapsulation with the PDMS mixture. Among them, the part pointed by the white dashed arrow represents the EGaIn particles embedded in the wire 220 and at the connection between the wire 220 and the microneedle 210.

[0133] The images in the second row represent the scanning electron microscope images of the microelectrode array device after encapsulation with the PDMS mixture. Among them, the part pointed by the white dashed arrow represents the PDMS encapsulation layer.

[0134] It should be noted that in Figure 20 , the scale of the images in the first column is 1 millimeter (mm), that is, 1000 micrometers. The scale of the images in the second column is 100 micrometers, and the scale of the images in the third column is 100 micrometers.

[0135] Please refer to Figure 6 , in some embodiments, step 101 may include but is not limited to steps 201 to 205:

[0136] Step 201, preparing a conductor layer transfer mold; wherein, the conductor layer transfer mold includes at least two microneedle grooves and at least two wire microchannels, each microneedle groove is arranged in an array, and each microneedle groove is connected to a wire microchannel;

[0137] Step 202, filling graphene ink in each microneedle groove;

[0138] Step 203, filling liquid metal ink in each wire microchannel;

[0139] Step 204, soaking the conductor layer transfer mold in a polymer solution to fill the gaps inside the graphene ink and the gaps inside the liquid metal ink with the polymer solution;

[0140] Step 205, drying the graphene ink, the liquid metal ink, and the polymer solution to obtain the conductor layer 200; wherein, the material of each microneedle 210 is graphene polymer, and the material of each wire 220 is liquid metal polymer.

[0141] The advantage of this embodiment is that by filling graphene ink into each microneedle groove and then filling the gaps inside the graphene ink with a polymer solution, and drying it, each microneedle 210 composed of graphene polymer is obtained, so as to obtain graphene microneedles with greater hardness and good electrical conductivity, thereby improving the structural strength of the microneedles 210 and reducing the wear generated during the process of the microneedles 210 contacting biological tissues. Filling liquid metal ink into the wire microchannel, and then filling the gaps inside the liquid metal ink with a polymer solution, and drying it, a wire 220 composed of liquid metal polymer is obtained, improving the stretchability and flexibility of the wire 220, and preparing a conductor layer 200 composed of the microneedles 210 and the wire 220. In the embodiment of the present application, while ensuring that the microneedles 210 of the conductor layer 200 have sufficient strength and conductivity, the stretchability and flexibility of the wire 220 of the conductor layer 200 are taken into account.

[0142] In some embodiments, as Figure 21 shown, step 201 may include: preparing an original mold of the conductor layer (i.e., Figure 21 the photo-curing resin mold in Figure 21 ); pouring the first mold material solution into the original mold of the conductor layer and curing it, and peeling the cured mold from the original mold of the conductor layer to obtain a transfer mold of the conductor layer (i.e.,

[0143] the PDMS mold in Figure 8 ). Among them, the protruding part of the original mold of the conductor layer corresponds to the groove part of the transfer mold of the conductor layer (including each microneedle groove and each wire microchannel). Figure 9 )

[0144] Specifically, the first mold material solution may be a mixture of liquid PDMS and a cross-linking agent (for curing PDMS), that is, Figure 21 the liquid PDMS in

[0145] Figure 21 Figure 21Among them, the part referred to as doped graphene represents the microneedles 210 made of graphene, and the part referred to as liquid metal represents the wire 220 made of liquid metal. The part referred to as TPU represents the base layer 100 made of TPU.

[0146] In some embodiments, step 102 may include: preparing a raw mold of the base layer; pouring a second mold material solution into the raw mold of the base layer and curing it, peeling the cured mold from the raw mold of the base layer to obtain a transfer mold of the base layer; wherein, the transfer mold of the base layer includes microchannels of the base layer; aligning the transfer mold of the base layer with a transfer mold of the conductor layer with the conductor layer 200, injecting a base material solution into the microchannels of the base layer, and drying to obtain the base layer 100; performing a peeling operation on the transfer mold of the conductor layer and the transfer mold of the base layer to obtain the mutually attached conductor layer 200 and base layer 100.

[0147] In some embodiments, a virtual structure model of the base layer 100 of the microelectrode array device can be designed using 3D modeling software (refer to Figure 10 ). Based on the virtual structure model of the base layer 100, a raw mold of the base layer can be prepared by 3D printing technology. Among them, the material of the raw mold of the base layer can be photosensitive resin.

[0148] It should be noted that the second mold material solution can be a mixture of PDMS liquid and a cross-linking agent (for curing PDMS). The specific method for curing the second mold material solution can refer to the specific description of the first mold material solution above, and will not be elaborated here. After the PDMS on the surface of the raw mold of the base layer is cured, the cured PDMS is peeled from the raw mold of the base layer to obtain a transfer mold of the base layer for preparing the base layer 100.

[0149] In some embodiments, after preparing the raw mold of the base layer, the raw mold of the base layer can be subjected to plasma cleaning treatment, such as plasma cleaning for 1 minute at a power of 120 watts (W).

[0150] In some embodiments, under a vertical microscope, the transfer mold of the base layer can be aligned with the transfer mold of the conductor layer with the conductor layer 200, so as to accurately align the wire microchannels with the microchannels of the base layer to form grid pattern microchannels arranged along the microchannels of the base layer. After baking for 1 hour and waiting for cooling, the glass dish is tilted, and a TPU solution is dropped from one side of the transfer mold of the base layer to infiltrate and fill the entire grid microchannels.

[0151] In some embodiments, the base layer transfer mold can be immersed in a TPU solution, for example, immersed for 1-2 days, so that the TPU solution fills the microchannels of the base layer transfer mold. The base layer transfer mold is placed in an oven at 60 degrees Celsius and baked for 12 hours to completely volatilize the DMF solvent of the TPU, thereby obtaining the base layer 100 (refer to Figure 13 ). Then, the TPU film (i.e., the base layer 100) embedded with the conductor layer 200 is peeled off from the conductor layer transfer mold (refer to Figure 14 and Figure 15 ). In some embodiments, the edges of the peeled base layer 100 can be trimmed so that the edge shapes of the base layer 100 and the conductor layer 200 fit.

[0152] In step 202 of some embodiments, graphene ink is dropped into each microneedle groove to fill the entire microneedle groove (refer to Figure 11 ). In some embodiments, the conductor layer transfer mold can be placed in a low-pressure environment of a vacuum pump to prompt the graphene ink to fill each microneedle groove. Excess graphene ink can also be scraped off with a coverslip, and the graphene ink outside the microneedle groove can be cleaned by sticking with tape.

[0153] In some embodiments, the conductor layer transfer mold with the microneedle grooves filled with graphene ink is placed in an oven at 80 degrees Celsius and dried to obtain graphene particles.

[0154] In step 203 of some embodiments, the remaining space in the groove, such as the wire microchannel, is filled with liquid metal ink by scraping with a coverslip (refer to Figure 12 ). In some embodiments, tape can be used to clean the liquid metal ink outside the groove.

[0155] In some embodiments, the liquid metal ink is dried to obtain liquid metal particles.

[0156] In some embodiments, the liquid metal can be eutectic gallium indium alloy (EGaIn). The preparation method of the liquid metal ink includes using n-decanol as a solvent and mixing EGaIn and n-decanol in an ultrasonic crusher to obtain the liquid metal ink. Among them, the mass-volume fraction of EGaIn:n-decanol in the liquid metal ink is 6 g / ml (grams per milliliter).

[0157] In step 204 of some embodiments, the conductor layer transfer mold with graphene ink and liquid metal ink can be placed in a glass dish. Pour the TPU solution dissolved in N,N-dimethylformamide (DMF for short) into the glass dish until the conductor layer transfer mold is submerged below the TPU liquid level. Among them, the mass-volume fraction of TPU:DMF in the TPU solution is 0.25 g / ml. Place the glass dish horizontally and let it soak for 8 - 12 hours to allow the TPU solution to fully penetrate into the gaps between graphene particles and EGaIn particles.

[0158] In some embodiments, after step 204, the TPU solution can be poured out of the glass dish, and the area near the micro-needle grooves of the conductor layer transfer mold can be slowly rinsed with the TPU solution until no TPU solution remains on the surface of the conductor layer transfer mold.

[0159] In step 205 of some embodiments, place the glass dish containing the conductor layer transfer mold in an oven at 60 °C and bake for 30 minutes to completely volatilize the DMF in the TPU solution, so that the gaps between graphene particles and EGaIn particles are filled with TPU, obtaining the conductor layer 200. Among them, the material of each micro-needle 210 is a graphene polymer formed by the embedding of graphene particles and TPU, and the material of each wire 220 is a liquid metal polymer formed by the embedding of EGaIn particles (i.e., liquid metal particles) and TPU.

[0160] Please refer to Figure 7 , in some embodiments, the base layer 100 has a grid-like area and a non-grid-like area; step 104 may include but is not limited to steps 301 to 303:

[0161] Step 301, cover the wire 220 on the non-grid-like area with a thermoplastic elastomer film, and perform a fusing operation on the thermoplastic elastomer film and the wire 220 on the non-grid-like area to obtain the first encapsulation part of the encapsulation layer;

[0162] Step 302, soak the wire 220 on the grid-like area in the encapsulation material mixture; among them, the encapsulation material mixture is a mixture of a liquid polymer and a curing agent;

[0163] Step 303, heat the wire 220 on the grid-like area to cure the polymer and obtain the second encapsulation part of the encapsulation layer.

[0164] The advantage of this embodiment is that by covering the wires 220 on the non-mesh area with a thermoplastic elastomer film to ensure that they avoid the mesh area, and then fusing the thermoplastic elastomer film and the wires 220 on the non-mesh area, the wires 220 on the non-mesh area can be quickly encapsulated to obtain the first encapsulated part of the encapsulation layer. For the wires 220 on the mesh area, since the micro-needle array is located in the mesh area, the wires 220 are not directly encapsulated. Instead, after protecting each micro-needle 210 with a protective shell, the wires 220 on the mesh area are immersed in the encapsulation material mixture, and the wires 220 on the mesh area are heated to cure the polymer, obtaining the second encapsulated part of the encapsulation layer, so as to accurately encapsulate the wires 220 on the mesh area and expose the micro-needles 210.

[0165] In step 301 of some embodiments, the thermoplastic elastomer film can be a TPU film. The thermoplastic elastomer film can be fused with the base layer 100 through a hot press table to encapsulate the wires 220 on the non-mesh area. This fusing process can be carried out at 110 degrees Celsius.

[0166] In step 302 of some embodiments, a mixture of PDMS and a curing agent (i.e., the encapsulation material mixture) is dropped on both sides of the mesh area, and it is allowed to slowly penetrate the entire area.

[0167] In step 303 of some embodiments, the wires 220 on the mesh area (together with modules such as the base layer 100) are placed in an oven at 80 degrees Celsius and baked for 1 hour to completely crosslink and cure the PDMS.

[0168] In some embodiments, after step 303, the residual PDMS on the surface of the microelectrode array device can be cleaned with tweezers.

[0169] In some embodiments, the preparation method of the microelectrode array device mainly includes the following steps:

[0170] 1) 3D printing for mold making: Using three-dimensional modeling software, design the structural model of the microelectrode array device (including the conductor layer 200, the base layer 100, and the encapsulation layer). Through the stereolithography 3D printing technology, based on the structural model of the conductor layer 200, prepare the original mold of the conductor layer to prepare the conductor layer transfer mold for coating graphene and liquid metal ink. And, use the stereolithography 3D printing technology to prepare the original mold of the base layer, so as to prepare the mesh-shaped base layer 100. Among them, the printing material of the stereolithography 3D printing technology is photosensitive resin.

[0171] 2) Soft lithography reverse mold: Prepare a mixture of PDMS liquid and a crosslinking agent (for curing PDMS), also known as the PDMS mixture, at a mass ratio of 10:1. Bubbles in the PDMS mixture can be removed by using a vacuum machine or by allowing it to stand. Then, pour it into two 3D printed molds (including the original mold of the conductor layer and the original mold of the base layer), and heat it on a horizontal heating table at 70 degrees Celsius. Wait for the PDMS to crosslink and cure to obtain the PDMS transfer molds corresponding to each 3D printed template (including the conductor layer transfer mold and the base layer transfer mold). The raised part of the former corresponds to the grooved part of the latter.

[0172] 3) Coating graphene to prepare the microneedle array: Drop conductive graphene ink onto the conductor layer transfer mold until it covers the entire microneedle 210 structure area, and promote the graphene ink to fill the microneedle grooves under the low-pressure environment of a vacuum pump. Use a cover glass to scrape off the excess graphene ink, and use tape to clean the graphene ink outside the microneedle grooves. Place the conductor layer transfer mold with the microneedle 210 structure filled with graphene ink in an oven at 80 degrees Celsius for drying. Then, use liquid metal ink (EGaIn, solvent n-decanol, mass-volume fraction of EGaIn:n-decanol is 6 g / ml), and use a cover glass to scrape it to fill the remaining space in the grooves of the conductor layer transfer mold, such as the wire microchannel. Among them, the liquid metal ink can be prepared in an ultrasonic crusher. Use tape to clean the graphene ink outside the grooves. Dry the liquid metal ink.

[0173] 4) Embedding: Place the conductor layer transfer mold in a glass dish, and pour into the glass dish a TPU solution dissolved in N,N-dimethylformamide (abbreviated as DMF) (mass-volume fraction of TPU:DMF is 0.25 g / ml) until the conductor layer transfer mold is submerged below the TPU liquid level. Let the glass dish stand horizontally. Immerse the conductor layer transfer mold for 8 - 12 hours to allow the TPU solution to fully penetrate into the gaps between the graphene particles and the EGaIn particles to complete the embedding. Pour out the TPU solution, and slowly rinse the conductor layer transfer mold with the TPU solution until there is no TPU solution remaining on the surface of the conductor layer transfer mold. Place the glass dish in an oven at 60 degrees Celsius for baking for 30 minutes until the DMF in the TPU solution completely volatilizes, so that the gaps between the graphene particles and the EGaIn particles are filled with TPU material. If there are TPU fragments near the microneedle array of the dried conductive layer transfer mold, clean the conductive layer transfer mold.

[0174] 5) Preparation of the hollow grid-shaped base layer 100: The base layer transfer mold is subjected to plasma cleaning treatment (power: 120 W, time: 1 minute). Under a vertical microscope, the base layer transfer mold and the conductor layer transfer mold are aligned and assembled. And the two aligned molds are baked in an oven at 80 °C for 1 hour to form grid-patterned microchannels arranged along the groove structure of the base layer transfer mold. After cooling, the glass dish is tilted, and the TPU solution is dropped from one side of the base layer transfer mold to infiltrate and fill the entire grid microchannel. The TPU solution is poured into the glass dish, with the base layer transfer mold immersed below the liquid level, and left standing horizontally for 1 - 2 days to ensure that the TPU solution fully fills the microchannel without bubbles. Then, the glass dish is placed horizontally in an oven at 60 °C and baked for 12 hours until the DMF completely volatilizes, obtaining the base layer 100 connected to the conductor layer 200. Then, the base layer 100 embedded with the conductor layer 200 is peeled off from the conductor layer transfer mold. The edge of the base layer 100 can be trimmed.

[0175] 6) Precision encapsulation of the wire 220 using PDMS: The wire 220 on the non-grid-shaped area is covered with a TPU film, ensuring that it avoids the hollow grid-shaped area. The TPU film is fused with the base layer 100 using a hot press, and the fusion temperature can be 110 °C. For each graphene micro-needle, an aqueous sodium alginate solution is dropped and placed in an oven at 80 °C and baked for 5 minutes to form a sodium alginate protective shell. A mixture of PDMS and a curing agent is dropped on both sides of the grid-shaped area, allowing it to slowly penetrate the wire 220 in the entire grid-shaped area, and placed in an oven at 80 °C and baked for 1 hour until the PDMS is completely crosslinked and cured. Then, the grid-shaped area is placed in water and soaked until the sodium alginate protective shell is largely dissolved and the graphene micro-needles are completely released.

[0176] 7) Connect the flexible cable and assemble it into a device for culturing organoids: To facilitate the interface connection between the microelectrode array device and an electrical signal acquisition instrument (such as the Plexon system), anisotropic conductive adhesive is pasted at the flexible cable connection part 230, and then the pinpoints of the flexible cable are aligned and pasted together with the pinpoints of the flexible cable connection part 230. To facilitate the culturing of suspended organoids, the microelectrode array device and the culture dish are assembled to form an organoid detection device, as Figure 22 shown. The organoid detection device can be used after sterilization for detecting the electrical signals of organoids.

[0177] Please refer to Figure 22 , this application embodiment also provides an organoid detection device, which includes:

[0178] The microelectrode array device prepared according to the above method;

[0179] A culture chamber for culturing an organoid to be tested.

[0180] A cover body disposed inside the culture chamber, and a closed culture space is formed between the inside of the cover body and the inner bottom surface of the culture chamber.

[0181] Wherein, the organoid to be tested is disposed in the closed culture space, and each micro-needle 210 of the microelectrode array device is disposed in the closed culture space.

[0182] In the embodiment of the present application, signal detection is performed on the organoid to be tested through an organoid detection device. Specifically, a closed culture space is formed between the inside of the cover body and the inner bottom surface of the culture chamber, thereby avoiding interference from external factors such as dust to the normal culture of the organoid to be tested; the organoid to be tested is in the closed culture space, and each micro-needle 210 of the microelectrode array device is disposed in the closed culture space, and the organoid to be tested is in contact with the micro-needle 210. The micro-needle 210 can detect the signal of the organoid to be tested, thereby realizing stable signal detection of the organoid to be tested and increasing the signal detection range.

[0183] It should be noted that Figure 22 The white sphere in the middle is the organoid to be tested, such as a neural organoid. The organoid to be tested can be suspended in the culture solution contained in the culture chamber.

[0184] The specific implementation manner of this organoid detection device is basically the same as that of the above-mentioned microelectrode array device, and will not be elaborated here.

[0185] It should be noted that the non-company software tools or components appearing in the embodiments of the present application are only for illustrative introduction and do not represent actual use.

[0186] The embodiments described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those skilled in the art know that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0187] Those skilled in the art can understand that the technical solutions shown in the figures do not constitute a limitation to the embodiments of the present application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0188] Those of ordinary skill in the art can understand that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices can be implemented as software, firmware, hardware and their appropriate combinations.

[0189] The terms "first", "second", "third", "fourth", etc. (if any) in the description of this application and the above-mentioned drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order different from those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0190] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "At least one of the following (items)" or similar expressions refer to any combination of these items, including any combination of single items (items) or plural items (items).

[0191] In several embodiments provided by this application, it should be understood that the disclosed devices and methods can be implemented in other ways.

[0192] In addition, each functional unit in the various embodiments of this application can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0193] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this application.

[0194] The preferred embodiments of the embodiments of this application have been described above with reference to the drawings, and thus do not limit the scope of rights of the embodiments of this application. Any modifications, equivalent replacements, and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of this application shall be within the scope of rights of the embodiments of this application.

Claims

1. A microelectrode array device, characterized in that, The microelectrode array device includes: A base layer; A conductor layer, the conductor layer including a micro-needle array and at least two wires; the micro-needle array includes at least two micro-needles arranged in an array, each micro-needle being electrically connected to one of the wires, and each micro-needle having a protrusion in a direction perpendicular to the base layer; the micro-needles are used for detecting electrical signals; A packaging layer, the packaging layer being used for covering the wires and at least exposing the protrusions of the respective micro-needles.

2. The microelectrode array device according to claim 1, wherein The shape of each micro-needle is conical, and the material of each micro-needle is graphene polymer.

3. The microelectrode array device according to claim 1, wherein The micro-needle array has a central region and a peripheral region, the peripheral region and the central region do not overlap with each other, and the peripheral region encloses the central region; The heights of the micro-needles in the central region are different from the heights of the micro-needles in the peripheral region.

4. The microelectrode array device according to claim 3, characterized in that, The material of the wires is liquid metal polymer; the materials of the base layer and the packaging layer are both elastic materials; The heights of the micro-needles in the central region are greater than the heights of the micro-needles in the peripheral region.

5. The microelectrode array device according to claim 4, wherein The height value range of the micro-needles in the central region includes 80 to 200 microns, and the height value range of the micro-needles in the peripheral region includes 20 to 60 microns.

6. The microelectrode array device according to claim 4, characterized in that, The central region of the micro-needle array is a rectangular region, the length of the central region is 1500 microns, and the width of the central region is 1500 microns; The peripheral region of the micro-needle array is a frame-shaped region, the outer frame length of the peripheral region is 2500 microns, and the outer frame width of the peripheral region is 2500 microns; Wherein, the inner frame length of the peripheral region is the same as the length of the central region, and the inner frame width of the peripheral region is the same as the width of the central region.

7. A method for preparing a microelectrode array device, characterized in that, The method is used for preparing the microelectrode array device according to any one of claims 1 to 6, and the method includes: Preparing a conductor layer including micro-needles and wires; Preparing a base layer; Making a protective shell for each micro-needle of the conductor layer so that each micro-needle is in a closed space formed by one of the protective shells and the base layer; Encapsulating the wires of the conductor layer with a packaging material mixture to obtain a packaging layer; wherein, the protective shell is insoluble in the packaging material mixture; Performing a dissolving operation on each of the protective shells to expose each micro-needle, thereby obtaining the microelectrode array device.

8. The preparation method according to claim 7, wherein The base layer has a grid-shaped region and a non-grid-shaped region; The encapsulating the wires of the conductor layer with a packaging material mixture to obtain a packaging layer includes: Covering the wires on the non-grid-shaped region with a thermoplastic elastomer film and performing a fusing operation on the thermoplastic elastomer film and the wires on the non-grid-shaped region to obtain a first encapsulation part of the packaging layer; Immersing the wires on the grid-shaped region in the packaging material mixture; wherein, the packaging material mixture is a mixture of a liquid polymer and a curing agent; Heating the wires on the grid-shaped region to cure the polymer to obtain a second encapsulation part of the packaging layer.

9. The preparation method according to any one of claims 7 to 8, characterized in that, The preparing a conductor layer including micro-needles and wires includes: Prepare a transfer mold for a conductor layer; wherein, the transfer mold for the conductor layer includes at least two micro-needle grooves and at least two wire micro-channels, each of the micro-needle grooves is arranged in an array, and each micro-needle groove is connected to one wire micro-channel; Fill each of the micro-needle grooves with graphene ink; Fill each of the wire micro-channels with liquid metal ink; Immerse the transfer mold for the conductor layer in a polymer solution so that the polymer solution fills the gaps inside the graphene ink and the gaps inside the liquid metal ink; Dry the graphene ink, the liquid metal ink, and the polymer solution to obtain the conductor layer; wherein, the material of each micro-needle is graphene polymer, and the material of each wire is liquid metal polymer.

10. An organoid detection device, characterized in that, The organoid detection device includes: A microelectrode array device prepared by the method according to any one of claims 7 to 9; A culture chamber for culturing the organoids to be tested; A cover body disposed inside the culture chamber, and the inside of the cover body and the inner bottom surface of the culture chamber form a closed culture space; Wherein, the organoids to be tested are disposed in the closed culture space, and each micro-needle of the microelectrode array device is disposed in the closed culture space.

Images