Liquid metal microwire neural electrode and preparation method and application thereof

Abstract

The application provides a liquid metal micro-wire neural electrode and a preparation method and application thereof, and the method comprises the following steps: preparing a first mold with a micro-fluid channel, placing gallium-based liquid metal in the micro-fluid channel of the first mold, condensing at low temperature, solidifying the gallium-based liquid metal, and forming a liquid metal micro-wire; separating the liquid metal micro-wire from the first mold; immersing the liquid metal micro-wire separated from the mold into a first polymer material solution, and after the solvent in the first polymer material solution volatilizes, encapsulating a layer of polymer film on the surface of the liquid metal micro-wire to obtain the liquid metal micro-wire neural electrode. The preparation method of the liquid metal micro-wire neural electrode provided by the application can adjust the softness and hardness of the micro-wire neural electrode, and the micro-wire neural electrode has the advantages of rigid neural electrodes and flexible neural electrodes, thereby providing a new idea for the expansion application of neural electrodes and brain-computer interfaces.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of neural electrodes, in particular to a liquid metal micro-wire neural electrode and a preparation method and application thereof. BACKGROUND

[0002] As a core component of brain-computer interface, neural electrode is a key interface connecting external devices and neural tissue, and is a crucial research focus of brain-computer interface system and a research direction to be broken through in recent years. Detecting and analyzing human body electrophysiological signals through neural electrodes not only helps us understand the transmission mechanism of neural system electrophysiological information, but also has extremely important development significance for brain science and brain disease diagnosis. Micro-wire neural electrode is the most widely used invasive neural electrode in the field of electrophysiological signal recording, which is generally made of metal micro-wires with a diameter less than 100 μm such as gold, platinum and iridium, and a layer of encapsulation insulation layer is wrapped on the surface of the micro-wire, and the exposed electrode tip contacts with neural cells or tissues to record the action potential or local field potential of neurons.

[0003] However, the micro-wire neural electrode prepared by rigid materials such as gold or platinum is prone to mechanical damage during long-term implantation, and there is a large difference in Young's modulus between the rigid electrode and the flexible neural tissue, which seriously affects the examination quality and sensitivity of neural signals. In recent years, flexible electrodes have attracted widespread attention, but the operation of flexible electrodes during implantation is relatively complex, and they cannot be accurately, deeply and conveniently implanted into the target neural brain area like rigid electrodes, which may cause certain implantation damage. SUMMARY

[0004] The problem solved by the present application is to provide a liquid metal micro-wire neural electrode which is not prone to implantation damage and has good neural signal examination quality and sensitivity.

[0005] To solve at least one aspect of the above problems, the present application provides a preparation method of a liquid metal micro-wire neural electrode, comprising the following steps:

[0006] Step S1, a first mold with a micro-fluid channel is prepared, gallium-based liquid metal is placed in the micro-fluid channel of the first mold, and the first mold is placed at low temperature for condensation, so that the gallium-based liquid metal is solidified to form a liquid metal micro-wire, wherein the melting point of the gallium-based liquid metal is greater than 25℃ and less than 37℃;

[0007] Step S2, the liquid metal micro-wire is separated from the first mold;

[0008] Step S3, immersing the liquid metal microwire separated from the first mold into a first polymer material solution, after the solvent in the first polymer material solution volatilizes, encapsulating a layer of polymer film on the surface of the liquid metal microwire, to obtain a liquid metal microwire neural electrode.

[0009] Preferably, in the step S1, the preparation method of the first mold comprises:

[0010] Step S11, designing an electrode pattern, and preparing a silicon wafer with the electrode pattern on the surface by photolithography;

[0011] Step S12, pouring a second polymer material on the silicon wafer, and after the second polymer material is solidified, peeling off the silicon wafer to obtain a second mold with a groove;

[0012] Step S13, attaching the second mold to a substrate, and forming a microfluidic channel between the groove and the substrate to obtain the first mold with the microfluidic channel.

[0013] Preferably, the second polymer material comprises at least one of polydimethylsiloxane and polymethyl methacrylate.

[0014] Preferably, the substrate comprises one of a glass slide, glass and a cell culture dish.

[0015] Preferably, in the step S1, the gallium-based liquid metal comprises one of gallium, gallium-indium alloy and gallium-indium-tin alloy.

[0016] Preferably, in the step S1, the condensation at low temperature to solidify the gallium-based liquid metal comprises:

[0017] Setting the condensation temperature to be below 0℃ to solidify the gallium-based liquid metal.

[0018] Preferably, in the step S3, the first polymer material solution comprises a first polymer material and a solvent, wherein the first polymer material comprises at least one of polyvinyl butyral, polyurethane, polycaprolactone, polylactic acid copolymer, polyvinylpyrrolidone, polydimethylsiloxane, gelatin and silk fibroin; and the solvent comprises at least one of ethanol, tetrahydrofuran, N,N-dimethylformamide, acetone, hexafluoroisopropanol and water.

[0019] Preferably, in the step S3, after the encapsulation of the layer of polymer film on the surface of the liquid metal microwire, the step further comprises:

[0020] Winding the plurality of liquid metal microwires encapsulated with the polymer film together to form a liquid metal microwire bundle.

[0021] The liquid metal micro-wire nerve electrode can be prepared by the preparation method of the liquid metal micro-wire nerve electrode, and the liquid metal micro-wire nerve electrode can be adjusted in hardness and softness, and has the advantages of rigid nerve electrodes and flexible nerve electrodes, thereby providing a new idea for the expansion application of nerve electrodes and brain-computer interfaces.

[0022] The application further provides a liquid metal micro-wire nerve electrode prepared by the preparation method of the liquid metal micro-wire nerve electrode.

[0023] The liquid metal micro-wire nerve electrode provided by the application has the beneficial effects of the preparation method of the liquid metal micro-wire nerve electrode, which will not be repeated here.

[0024] In addition, the application provides an application of the liquid metal micro-wire nerve electrode in nerve signal detection.

[0025] The application of the liquid metal micro-wire nerve electrode provided by the application has the beneficial effects of the preparation method of the liquid metal micro-wire nerve electrode, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A flow chart of the preparation method of the liquid metal micro-wire nerve electrode in the embodiment of the application is shown in the figure.

[0027] Figure 2 A flow chart of the preparation method of the first mold in the embodiment of the application is shown in the figure.

[0028] Figure 3 A result figure of the liquid metal gallium filling the micro-fluidic channel in the embodiment 1 of the application is shown in the figure.

[0029] Figure 4 A display figure of the liquid metal micro-wire taken out from the first mold in the embodiment 1 of the application is shown in the figure.

[0030] Figure 5 A display figure of the liquid metal micro-wire bundle in the embodiment 1 of the application is shown in the figure.

[0031] Figure 6It is an enlarged view of the liquid metal micro-wire cluster tip part in Embodiment 1 of the present application. DETAILED DESCRIPTION

[0032] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below.

[0033] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict. The terms "comprise", "include", "contain", "have" are non-limiting, that is, other steps and other components that do not affect the results can be added. The above terms encompass the terms "consist of" and "consist essentially of". Unless otherwise specified, the materials, devices, reagents are commercially available.

[0034] The embodiment of the present application provides a preparation method of a liquid metal micro-wire neural electrode, as shown in the figure, comprising the following steps: Figure 1 The preparation method of the liquid metal micro-wire neural electrode comprises the following steps:

[0035] Step S1, a first mold with a micro-fluid channel is prepared, gallium-based liquid metal is placed in the micro-fluid channel of the first mold, and the first mold is placed at low temperature for condensation, so that the gallium-based liquid metal is solidified to form a liquid metal micro-wire, wherein the melting point of the gallium-based liquid metal is greater than 25℃ and less than 37℃;

[0036] Step S2, the liquid metal micro-wire is separated from the first mold;

[0037] Step S3, the liquid metal micro-wire is immersed in a first high polymer material solution, and after the solvent in the first high polymer material solution is volatilized, a layer of high polymer film is encapsulated on the surface of the liquid metal micro-wire to obtain a liquid metal micro-wire neural electrode.

[0038] Further, as shown in the figure, in step S1, the preparation method of the first mold comprises: Figure 2

[0039] Step S11, an electrode pattern is designed, and a silicon wafer with the electrode pattern on the surface is prepared by photolithography;

[0040] Step S12, a second high polymer material is cast on the silicon wafer, and after the second high polymer material is solidified, it is peeled off from the silicon wafer to obtain a second mold with a groove; that is, the silicon wafer with the electrode pattern prepared by step S11 is a convex structure, and when the second high polymer material is solidified on the silicon wafer, a groove corresponding to the convex structure of the electrode pattern is formed to obtain a second mold with a groove;

[0041] ​Step S13, bonding the second mold to the substrate, the groove and the substrate form a microfluidic channel, and the first mold with the microfluidic channel is obtained.

[0042] The electrode pattern prepared by the photolithography method can control the line width of the electrode pattern to be below 30 μm, so that the mold with the microfluidic channel prepared by the electrode pattern can control the width of the microfluidic channel to be below 30 μm, and further control the width of the liquid metal micro-wire prepared to be below 30 μm. In the prior art, the liquid metal micro-wire obtained by printing using a mask template or a screen printing plate has a minimum width of 50 μm. Therefore, the liquid metal micro-wire prepared by the microfluidic channel has better conductivity and higher preparation accuracy than the printing method, and the conductivity between different liquid metal micro-wires is basically the same.

[0043] The second high polymer material includes at least one of polydimethylsiloxane (PDMS) and polymethyl methacrylate (PMMA); and the substrate includes one of a glass slide, glass and a cell culture dish.

[0044] The gallium-based liquid metal includes one of gallium, gallium-indium alloy and gallium-indium-tin alloy. The melting point of gallium is 29℃, and the melting points of the gallium-indium alloy and the gallium-indium-tin alloy are related to the proportions of different metals in the alloy. By controlling the proportions of metals in the gallium-indium alloy and the gallium-indium-tin alloy, the melting point of the alloy is greater than 25℃ and less than 37℃, so that the liquid metal is rigid at room temperature and flexible after being implanted into the human body, realizing soft and hard adjustment.

[0045] When the gallium-based liquid metal enters the microfluidic channel, it is condensed at low temperature to solidify the gallium-based liquid metal and form a liquid metal micro-wire. Preferably, the condensation temperature is set to be below 0℃, and the first mold is subjected to low-temperature condensation to solidify the gallium-based liquid metal. Further preferably, the first mold is placed in an environment of -80℃ for condensation for 15-20 min to solidify the gallium-based liquid metal, thereby forming a liquid metal micro-wire.

[0046] It should be understood that the first mold is subjected to low-temperature condensation to solidify the gallium-based liquid metal in the first mold into a solid state to form a liquid metal micro-wire. The lower the temperature, the faster the condensation speed and the better the condensation effect.

[0047] Liquid metal has unique properties such as low melting point, low toxicity, high conductivity and high stability, and shows great application potential in the fields of biomedical treatment, medical imaging, wearable electronic technology and the like.

[0048] In step S2, the liquid metal micro-wire is separated from the first mold; the liquid metal micro-wire in the microfluidic channel is separated from the first mold, thereby facilitating subsequent film sealing treatment of the liquid metal micro-wire.

[0049] Preferably, part of the liquid metal micro-wire can be separated from the first mold, and the other part of the liquid metal micro-wire remains in the first mold. The liquid metal micro-wire separated from the first mold can be used as one end of the implant in the body after encapsulation, reducing damage to the human body, and the liquid metal micro-wire remaining in the first mold can be used as a connection end with other devices.

[0050] In step S3, the first polymer material solution includes a first polymer material and a solvent, wherein the first polymer material includes at least one of polyvinyl butyral (PVB), polyurethane (TPU), polycaprolactone (PCL), polylactic acid copolymer (PLGA), polyvinylpyrrolidone (PVP), polydimethylsiloxane (PDMS), gelatin and silk fibroin; and the solvent includes at least one of ethanol, tetrahydrofuran, N,N-dimethylformamide, acetone, hexafluoroisopropanol and water.

[0051] Illustratively, when the first polymer material solution is a PVB solution, the mass fraction of the PVB solution is 7%, and the solvent is ethanol; when the first polymer material solution is a TPU solution, the mass fraction of the TPU solution is 5%, and the solvent is N,N-dimethylformamide (DMF).

[0052] The liquid metal micro-wire separated from the first mold is immersed in the first polymer material solution, and after the solvent in the first polymer material solution volatilizes, the first polymer material can solidify on the surface of the liquid metal micro-wire to form a polymer film, thereby encapsulating the liquid metal micro-wire separated from the first mold.

[0053] In the prior art, when a liquid metal wire is prepared by printing, the liquid metal needs to be ultrasonically mixed with a solvent. Although the solvent volatilizes, the gallium-based liquid metal is easily oxidized to form a thin film of gallium oxide due to the presence of gallium in the liquid metal. In addition, the liquid metal forms microspheres during ultrasonic mixing with the solvent, which seriously affects its conductivity, and the conductivity difference between different electrodes prepared is large. In the prior art, there is also a method of mixing liquid metal and polymer material, but the presence of the polymer material also destroys the conductivity of the liquid metal.

[0054] Compared with the prior art, the embodiment of the present application can prepare a conductive material formed by pure liquid metal through a microfluidic channel method, so that the conductivity is better, and the conductivity between the prepared electrodes is also basically the same due to the uniform size of the microfluidic channel.

[0055] By immersing the liquid metal micro-wire into the first polymer material solution, a polymer film is formed on the surface of the liquid metal micro-wire, and the thickness of the film can be controlled to be less than 10 μm, thereby better meeting the minimally invasive requirement when the electrode is implanted.

[0056] In addition, in some embodiments, after the surface of the liquid metal microwire is encapsulated with a polymer film in step S3, the liquid metal microwires encapsulated with the polymer film can be wound together to form a liquid metal microwire bundle.

[0057] By winding the liquid metal microwires encapsulated with the polymer film together to form a liquid metal microwire bundle, the rigidity of the liquid metal microwire electrode in a normal temperature state can be further improved, and the depth and accuracy of implantation can be ensured. In addition, more two-dimensional electrode arrays can be realized in one circuit by the liquid metal microwire bundle with a smaller contact area.

[0058] Another embodiment of the present application provides a liquid metal microwire neural electrode prepared by using the preparation method of the liquid metal microwire neural electrode as described above.

[0059] Still another embodiment of the present application provides the application of the liquid metal microwire neural electrode as described above in neural signal detection. By implanting the liquid metal microwire neural electrode into a brain region, neural signals can be detected, and new materials and new technologies are provided for long-term electroencephalogram information acquisition and brain-computer interface technology.

[0060] The liquid metal microwire neural electrode and the application thereof provided by the embodiments of the present application have the beneficial effects of the preparation method of the liquid metal microwire neural electrode relative to the prior art, and will not be described herein again.

[0061] The present application will be further illustrated by specific embodiments below, but these embodiments are only used to help understand the present application, and should not be used to limit the present application in any form.

[0062] Embodiment 1

[0063] 1.1, AutoCAD software is used to design a liquid metal wire pattern, and a silicon wafer with a 30-channel electrode pattern is prepared by orthogonal lithography, wherein the channel line width is 10 μm;

[0064] 1.2, 2 mL of liquid PDMS is poured on the silicon wafer, and the glue is uniformly coated at a speed of 600 r / min for 30 s;

[0065] 1.3, the silicon wafer with PDMS is placed in an oven at 80℃ for 15 min to solidify the PDMS, and the PDMS is removed from the silicon wafer to obtain a second mold with grooves;

[0066] 1.4, the second mold with grooves is pressed downward on a glass plate, and the second mold is cut to expose one end of the 30-channel grooves to the air, and holes are punched at the other end of the grooves, a total of 30 holes, to obtain a first mold with micro-channel pipelines;

[0067] 1.5, the gallium is placed in an oven at 80°C for 3 min, and is melted into liquid state. 1 mL of liquid gallium is weighed and dropped on one end of 30 grooves exposed to air. The liquid gallium is sucked into 30 microfluidic channels of the first mold through the 30 holes on the other end of the grooves by a syringe as shown in Figure 3 .

[0068] 1.6, the first mold with the liquid gallium is placed in a refrigerator at -80°C together with the glass plate, and is left for 20 min to completely solidify the liquid gallium into liquid metal microwires.

[0069] 1.7, the first mold with the liquid metal microwires is removed from the glass plate as shown in Figure 4 , and a part of the liquid metal microwires is removed from the end of the first mold without holes.

[0070] 1.8, the removed liquid metal microwires are immersed in a PDMS solution and left at room temperature until the PDMS is completely solidified, so that a layer of polymer film is encapsulated on the surface of the liquid metal microwires.

[0071] 1.9, the liquid metal microwires are wound together to form a bundle of liquid metal microwires as shown in Figure 5 , and the tips of the polymer film are cut off to expose the electrode sites, thereby obtaining a liquid metal microwire neural electrode.

[0072] wherein, Figure 3 is a picture of the liquid metal gallium filling the microfluidic channels, Figure 4 is a picture of the gallium microwires removed from the mold; Figure 5 is a picture of the bundle of liquid metal microwires; Figure 6 is an enlarged view of the tip part of the bundle of liquid metal microwires.

[0073] As shown in Figure 3 , the size of the microfluidic channels is uniform, and when the liquid metal gallium fills each microfluidic channel, a liquid metal wire with uniform size is formed.

[0074] As shown in Figure 4 , Figure 4 the right middle picture is an enlarged view of the dashed line part in the left picture. After removing one end of the liquid metal microwires, the liquid metal microwires are exposed, which is convenient for further encapsulation treatment. The liquid metal microwires remaining in the mold remain in the microfluidic channels, which is convenient for connecting to other devices as the end.

[0075] As shown in Figure 5 , the liquid metal microwires encapsulated with the polymer film are wound together to form a bundle of liquid metal microwires, which can further improve the rigidity of the neural electrode, Figure 5As a reference object, the coin, it can be seen that the size of the liquid metal micro-wire neural electrode is small, which can reduce the damage during implantation.

[0076] Figure 6 For Figure 5 The magnified image of the liquid metal micro-wire bundle tip portion, from Figure 6 It can be seen that winding the liquid metal micro-wires together to form a liquid metal micro-wire bundle can further reduce the size of the tip.

[0077] Example 2

[0078] 2.1, using AutoCAD software to design a liquid metal wire pattern, preparing a silicon wafer with a 16-channel electrode pattern by orthogonal lithography, wherein the channel line width is 10 μm;

[0079] 2.2, pour 2 mL of liquid PDMS on the silicon wafer, and evenly glue for 30 s at a speed of 600 r / min;

[0080] 2.3, place the silicon wafer with PDMS into an oven and place it at 80°C for 15 min to solidify the PDMS, then remove the PDMS from the silicon wafer to obtain a second mold with grooves;

[0081] 2.4, press the side with grooves of the second mold downward on a glass plate, cut the second mold to expose one end of the 16-channel grooves to the air, and punch holes at the other end of the grooves, a total of 16 holes, to obtain a first mold with microfluidic channels;

[0082] 2.5, place gallium in an oven at 80°C and heat for 3 min to melt it into a liquid, weigh 1 mL of liquid gallium, and use a syringe to inject the liquid gallium from the 16 punched holes to make the liquid gallium enter the 16 microfluidic channels of the first mold;

[0083] 2.6, place the first mold with liquid gallium injected into it together with the glass plate in a -80°C refrigerator for 20 min to completely solidify the liquid gallium and form liquid metal micro-wires;

[0084] 2.7, remove the first mold together with the liquid metal micro-wires from the glass plate, and then remove part of the liquid metal micro-wires from the end of the first mold that is not punched;

[0085] 2.8, immerse the removed liquid metal micro-wires in a PVB solution with a mass fraction of 7%, and the solvent of the PVB solution is ethanol, and place it at room temperature for 10 min to evaporate the ethanol, so that a layer of polymer film is encapsulated on the surface of the liquid metal micro-wires;

[0086] 2.9, winding the liquid metal microwires together to form a bundle of liquid metal microwires, cutting the tips of the polymer film to expose the electrode sites, and obtaining the liquid metal microwire neural electrode.

[0087] Example 3

[0088] 3.1, using AutoCAD software to design a liquid metal wire pattern, and preparing a silicon wafer with an 8-channel electrode pattern by orthogonal lithography, wherein the channel line width is 10 μm;

[0089] 3.2, pouring 2 mL of liquid PDMS onto the silicon wafer and uniformly coating for 30 s at a speed of 600 r / min;

[0090] 3.3, placing the silicon wafer with PDMS into an oven and placing it at 80°C for 15 min to solidify the PDMS, and then removing the PDMS from the silicon wafer to obtain a second mold with grooves;

[0091] 3.4, pressing the side with grooves of the second mold downward onto a glass plate, cutting the second mold to expose one end of the 8-channel grooves to the air, and punching holes at the other end of the grooves, a total of 8 holes, to obtain a first mold with microfluidic channels;

[0092] 3.5, heating gallium in an oven at 80°C for 3 min to melt it into a liquid, weighing 1 mL of liquid gallium, and using a syringe to inject the liquid gallium from the 8 punched holes to make the liquid gallium enter the 8 microfluidic channels of the first mold;

[0093] 3.6, placing the first mold with injected liquid gallium together with the glass plate in a -80°C refrigerator for 20 min to completely solidify the liquid gallium to form liquid metal microwires;

[0094] 3.7, removing the first mold together with the liquid metal microwires from the glass plate, and then removing part of the liquid metal microwires from the end of the first mold without holes;

[0095] 3.8, immersing the removed liquid metal microwires in a TPU solution with a mass fraction of 5%, and the solvent of the TPU solution is N,N-dimethylformamide (DMF), and placing it at room temperature for 30 min to volatilize the DMF, so that the liquid metal microwires are encapsulated with a layer of polymer film on the surface;

[0096] 3.9, winding the liquid metal microwires together to form a bundle of liquid metal microwires, cutting the tips of the polymer film to expose the electrode sites, and obtaining the liquid metal microwire neural electrode.

[0097] Although the present disclosure discloses as above, the protection scope of the present disclosure is not limited to this. The person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present disclosure.

Claims

1. A method for preparing a liquid metal microwire neural electrode, characterized in that, The method comprises the following steps: S1, preparing a first mold with a microfluidic channel, placing a gallium-based liquid metal in the microfluidic channel of the first mold, and condensing the first mold at low temperature to solidify the gallium-based liquid metal and form a liquid metal micro-wire, wherein the melting point of the gallium-based liquid metal is greater than 25℃ and less than 37℃; S2, separating the liquid metal micro-wire from the first mold; S3, immersing the liquid metal micro-wire separated from the first mold in a first polymer material solution, after the solvent in the first polymer material solution volatilizes, encapsulating a layer of polymer film on the surface of the liquid metal micro-wire, winding the liquid metal micro-wire encapsulated with the polymer film together to form a liquid metal micro-wire bundle, and obtaining a liquid metal micro-wire neural electrode; the first polymer material solution comprises a first polymer material and a solvent, wherein the first polymer material comprises at least one of polyvinyl butyral, polyurethane, polycaprolactone, polylactic acid copolymer, polyvinylpyrrolidone, polydimethylsiloxane, gelatin and silk fibroin; the solvent comprises at least one of ethanol, tetrahydrofuran, N,N-dimethylformamide, acetone, hexafluoroisopropanol and water.

2. The method of claim 1, wherein the liquid metal microwire neural electrode is prepared by the steps of: In the step S1, the preparation method of the first mold comprises: S11, designing an electrode pattern, and preparing a silicon wafer with the electrode pattern on the surface by photolithography; S12, pouring a second polymer material on the silicon wafer, and after the second polymer material is solidified, peeling it off from the silicon wafer to obtain a second mold with a groove; S13, attaching the second mold to a substrate, and forming a microfluidic channel between the groove and the substrate to obtain the first mold with the microfluidic channel.

3. The method of claim 2, wherein the liquid metal microwire neural electrode is prepared by the steps of: The second polymer material comprises at least one of polydimethylsiloxane and polymethyl methacrylate.

4. The method of claim 2, wherein the liquid metal microwire neural electrode is prepared by the steps of: The substrate comprises one of a glass slide, glass and a cell culture dish.

5. The method of claim 1, wherein the liquid metal microwire neural electrode is prepared by the steps of: In the step S1, the gallium-based liquid metal comprises one of gallium, gallium-indium alloy and gallium-indium-tin alloy.

6. The method of claim 1, wherein the liquid metal microwire neural electrode is prepared by the steps of: In the step S1, the condensation at low temperature to solidify the gallium-based liquid metal comprises setting the condensation temperature to be below 0℃ to solidify the gallium-based liquid metal.

7. A liquid metal microwire neural electrode, comprising: The liquid metal micro-wire neural electrode is prepared by the method of any one of claims 1-6.

8. The application of the liquid metal micro-wire neural electrode in claim 7 in neural signal detection.

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