Flexible electrode and method of making the same

Abstract

This application discloses a flexible electrode and its fabrication method, relating to the field of brain-computer interface technology. The electrode includes: a flexible body; a first sensing electrode disposed on the outer surface of the flexible body, the first sensing electrode being used to acquire a first biosignal; a microchannel located within the flexible body; the microchannel having a first end and a second end opposite to each other; the first end being sealed; the second end having an opening; the opening being used to infuse pressurized liquid into the microchannel and to extract pressurized liquid from the microchannel; wherein the flexible electrode has a first form and a second form; when in the first form, pressurized liquid is present within the microchannel, and the flexible body has a first stiffness; when in the second form, the inner wall of the microchannel is seamlessly and separably fitted, and the flexible body has a second stiffness; the first stiffness is greater than the second stiffness. The flexible electrode provided by this application allows for flexible adjustment of the stiffness of the flexible body by controlling the pressure of the pressurized liquid within the microchannel, and electrode implantation does not require a rigid implanter or the assistance of degradable or soluble temporary reinforcing materials.

Description

Technical Field

[0001] This application relates to the field of brain-computer interface technology, and in particular to a flexible electrode and its preparation method. Background Technology

[0002] Flexible electrodes offer significant advantages in the field of neural signal acquisition due to their excellent biocompatibility and biomechanical compatibility with brain tissue. Current implantation techniques for flexible electrodes mainly include the following two methods:

[0003] One approach involves using a rigid implant to assist in the implantation of the flexible electrode. This method typically uses microneedles made of metal or polymer as an auxiliary puncture device, attaching the flexible electrode to the tip of the rigid implant for implantation. However, this method is prone to causing mechanical damage to brain tissue during the implantation process. Furthermore, since the rigid implant needs to be withdrawn after implantation, the retraction action may dislodge the implanted flexible electrode or cause it to shift.

[0004] To avoid the risk of retraction from rigid implants, another approach is to temporarily harden the flexible electrode using a biodegradable or soluble temporary reinforcing material. While this method avoids the retraction of the rigid implant, the stiffness of the temporary reinforcing material cannot be adjusted intraoperatively, resulting in a lack of flexibility during electrode implantation. Furthermore, this method requires the introduction of additional temporary reinforcing material to enhance the electrode's strength during implantation, increasing the complexity of the electrode manufacturing process. Moreover, the degradation or dissolution of the temporary reinforcing material requires a certain time interval, making immediate separation of the electrode from the temporary reinforcing material impossible. This results in a longer waiting period after electrode implantation to reach its final stable state, which is detrimental to obtaining reliable neural signals immediately.

[0005] Therefore, there is an urgent need for a flexible electrode design scheme that is adjustable in stiffness, safe to implant, and easy to manufacture. Summary of the Invention

[0006] In view of the above problems, this application provides a flexible electrode and its preparation method, the specific solution of which is as follows:

[0007] The first aspect of this application provides a flexible electrode, comprising:

[0008] Flexible body;

[0009] A first sensing electrode is disposed on the outer surface of the flexible body, and the first sensing electrode is used to collect a first biological signal;

[0010] The microchannel is located within the flexible body; the microchannel has a first end and a second end opposite to each other; the first end is sealed; the second end has an opening; the opening is used to inject pressurized liquid into the microchannel and to extract pressurized liquid from the microchannel.

[0011] The flexible electrode has a first form and a second form; when in the first form, there is pressurized liquid in the microchannel and the flexible body has a first stiffness; when in the second form, the inner wall of the microchannel is gapless and separable, and the flexible body has a second stiffness; the first stiffness is greater than the second stiffness.

[0012] Optionally, in the above-mentioned flexible electrode, the flexible body has a first flexible insulating layer and a second flexible insulating layer that are relatively adhered and fixed.

[0013] The region of the first flexible insulating layer corresponding to the microchannel is a hydrophobic surface, so that the first flexible insulating layer and the second flexible insulating layer can be separated and bonded together on the hydrophobic surface to form a microchannel.

[0014] Optionally, in the above-described flexible electrode, in the second configuration, the second flexible insulating layer is in direct contact with the hydrophobic surface.

[0015] Optionally, in the above-mentioned flexible electrode, the hydrophobic surface is covered with a soluble film, and in the second configuration, the second flexible insulating layer is in direct contact with the soluble film.

[0016] Optionally, in the above-mentioned flexible electrode, the flexible electrode further includes a second sensing electrode, which is used to collect a second biosignal;

[0017] The area of ​​the second sensing electrode is larger than that of the first sensing electrode.

[0018] Optionally, the flexible electrode described above also includes an electrode conduit, with the second sensing electrode located on the outer surface of the electrode conduit;

[0019] The flexible body is fixed to the electrode conduit, and the portion of the flexible body with the first sensing electrode extends beyond the electrode conduit.

[0020] Optionally, in the above-mentioned flexible electrode, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end.

[0021] The second section is attached and fixed to the outer surface of the electrode conduit, while the first section extends beyond the electrode conduit.

[0022] Optionally, in the above-mentioned flexible electrode, the electrode conduit has a groove extending in the length direction, and the second section is fixed in the groove.

[0023] Optionally, in the above-mentioned flexible electrode, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end.

[0024] It is installed inside the electrode conduit, with the first section extending outside the electrode conduit.

[0025] Optionally, in the above-mentioned flexible electrode, the electrode conduit includes a plurality of coaxially arranged annular electrodes, and an insulating isolation ring is provided between adjacent annular electrodes.

[0026] Optionally, in the above-mentioned flexible electrode, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end.

[0027] Both the first sensing electrode and the second sensing electrode are located on the side surface of the second flexible insulating layer that is away from the first flexible insulating layer; the first sensing electrode is located in the first section, and the second sensing electrode is located in the second section.

[0028] Optionally, in the above-mentioned flexible electrode, the area of ​​the second sensing electrode is 0.2 mm². 2 ~10mm 2 The center-to-center distance between adjacent second sensing electrodes is 2mm to 10mm;

[0029] The area of ​​the first sensing electrode is 2 μm. 2 ~100μm 2 The center-to-center distance between adjacent first sensing electrodes is 10μm to 1000μm.

[0030] Optionally, in the above-mentioned flexible electrode, the number of second sensing electrodes is 4 to 16, and the number of first sensing electrodes is 8 to 64;

[0031] The flexible electrode is also provided with multiple pads for connecting to external circuits, with the first sensing electrode and the second sensing electrode each connected to a pad.

[0032] Optionally, in the above-mentioned flexible electrode, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end.

[0033] The first sensing electrode is located on the side surface of the second flexible insulating layer that is away from the first flexible insulating layer, and the first sensing electrode is located in the first section;

[0034] In the first section, the deformation capacity of the first flexible insulation layer is greater than that of the second flexible insulation layer.

[0035] Optionally, in the above-mentioned flexible electrode, in the second section, the deformation capacity of the second flexible insulating layer is greater than that of the first flexible insulating layer.

[0036] A second aspect of this application provides a method for preparing a flexible electrode, comprising:

[0037] Provide a base;

[0038] A first flexible insulating layer is formed on one side surface of the substrate;

[0039] The surface of a predetermined area of ​​the first flexible insulating layer is treated with a hydrophobic coating to form a hydrophobic surface;

[0040] A second flexible insulating layer is formed on the surface of the first flexible insulating layer;

[0041] A patterned conductive layer is formed on the surface of the second flexible insulating layer opposite to the first flexible insulating layer. The conductive layer includes a first sensing electrode. The first sensing electrode is used to acquire a first biosignal.

[0042] An insulating protective layer is covered on the surface of the conductive layer, with the insulating protective layer exposing the first sensing electrode;

[0043] Remove the substrate;

[0044] The first flexible insulating layer and the second flexible insulating layer are fixed together in areas other than the hydrophobic surface to form a flexible body. The first and second flexible insulating layers are separably and seamlessly bonded together on the hydrophobic surface to form a microchannel. The microchannel has a first end and a second end. The first end is sealed. The second end has an opening. The opening is used to inject pressurized liquid into the microchannel and to extract pressurized liquid from the microchannel. The flexible electrode has a first shape and a second shape. When in the first shape, pressurized liquid is present in the microchannel, and the flexible body has a first stiffness. When in the second shape, the inner wall of the microchannel is separably and seamlessly bonded together, and the flexible body has a second stiffness. The first stiffness is greater than the second stiffness.

[0045] Optionally, in the above preparation method, before forming the second flexible insulating layer, the following steps are further included:

[0046] A soluble film is formed on a hydrophobic surface.

[0047] Optionally, the above preparation method further includes: preparing a second sensing electrode, which is used to collect a second biosignal;

[0048] The area of ​​the second sensing electrode is larger than that of the first sensing electrode.

[0049] Optionally, in the above preparation method, the method for preparing the second sensing electrode includes:

[0050] An electrode conduit is fabricated, the outer surface of which includes a second sensing electrode;

[0051] The flexible body is fixed to the electrode conduit, and the portion of the flexible body with the first sensing electrode extends beyond the electrode conduit.

[0052] Optionally, in the above preparation method, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end;

[0053] Methods for fixing the flexible body to the electrode conduit include:

[0054] The second section is attached and fixed to the outer surface of the electrode conduit, and the first section extends beyond the electrode conduit.

[0055] Optionally, in the above preparation method, the flexible body has a first segment and a second segment, the end of the first segment that is opposite to the second segment is the first end, and the end of the second segment that is opposite to the first segment is the second end;

[0056] Methods for fixing the flexible body to the electrode conduit include:

[0057] The second section is placed inside the electrode conduit, and the first section extends outside the electrode conduit.

[0058] Optionally, in the above preparation method, the method for preparing the second sensing electrode includes:

[0059] When the first sensing electrode is fabricated through a patterned conductive layer, the second sensing electrode is simultaneously formed through the patterned conductive layer.

[0060] Using the above technical solution, the flexible electrode and its preparation method provided in this application include a microchannel within the flexible body. The microchannel allows for the injection and extraction of pressurized liquid through an opening at the second end of the flexible body, resulting in a first and a second form for the flexible electrode. When pressurized liquid is injected into the microchannel, the flexible electrode is in the first form. The liquid pressure causes the flexible body to expand, thereby enhancing its stiffness and giving the flexible electrode a higher first stiffness, facilitating implantation into the organism. When no pressurized liquid is injected into the microchannel, the flexible electrode is in the second form. The inner wall of the microchannel is seamlessly separable and adheres well to the body, giving the flexible body excellent flexibility and deformation properties, facilitating tissue adaptation and adhesion.

[0061] On the one hand, the flexible electrode provided by this application does not require a rigid implant. When the flexible electrode is implanted into brain tissue, pressurized liquid is introduced into the microchannel to temporarily enhance the rigidity of the flexible body, so that the flexible electrode is in a first state with greater rigidity, which facilitates the implantation of the flexible electrode and avoids the mechanical damage to brain tissue caused by rigid implantation. After implantation, the pressurized liquid is withdrawn through an opening located outside the organism, so that the flexible electrode is in a second flexible state. The implantation process of the flexible electrode only involves the injection and withdrawal of pressurized liquid inside the microchannel. Compared with the rigid implantation method, the injection and withdrawal of pressurized liquid will not cause mechanical damage to brain tissue, and the liquid withdrawal operation will not cause problems such as the flexible electrode being carried out or displaced.

[0062] On the other hand, compared with the implantation method that uses degradable or soluble temporary reinforcing materials to temporarily harden the flexible electrode, the flexible electrode provided by this application can flexibly adjust the stiffness of the flexible electrode in the first state by controlling the pressure of the perfusion pressurized liquid, so that the stiffness of the electrode implantation process can be flexibly adjusted according to the surgical requirements; the microchannel can be prepared using the current mature MEMS technology, the electrode structure and preparation process are simple and the cost is low; moreover, after the implantation is completed, there is no need for a long waiting time, and the pressurized liquid in the microchannel can be quickly extracted before subsequent signal acquisition operations can be carried out. Attached Figure Description

[0063] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0064] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0065] Figure 1 A top view of a flexible electrode provided in an embodiment of this application;

[0066] Figure 2 for Figure 1 A schematic diagram of the flexible electrode in its second configuration;

[0067] Figure 3for Figure 1 The diagram shows the structure of the flexible electrode in its first configuration.

[0068] Figure 4 A top view of a flexible electrode provided in an embodiment of this application;

[0069] Figure 5 for Figure 4 Side view of the flexible electrode shown;

[0070] Figure 6 for Figure 4 The image shows a cross-sectional view of the flexible electrode perpendicular to its length.

[0071] Figure 7 for Figure 6 The diagram shows the structure of the flexible electrode during pressurized liquid injection.

[0072] Figure 8 A three-dimensional view of a flexible electrode provided in an embodiment of this application;

[0073] Figure 9 for Figure 8 A cross-sectional view of the flexible electrode shown.

[0074] Figure 10 This is a schematic diagram illustrating the fabrication principle of an electrode conduit provided in an embodiment of this application;

[0075] Figure 11 This is a three-dimensional structural schematic diagram of an electrode conduit provided in an embodiment of this application;

[0076] Figure 12 A top view of another flexible electrode provided in an embodiment of this application;

[0077] Figure 13 A schematic flowchart illustrating a flexible electrode fabrication method provided in this application embodiment;

[0078] Figures 14-20 Schematic diagrams of device structures at different process stages of a flexible electrode fabrication method provided in this application embodiment;

[0079] Figure 21 This is a schematic diagram illustrating the pressurization principle of the flexible electrode provided in the embodiments of this application;

[0080] Figure 22 This is a schematic diagram illustrating the implantation principle of the flexible electrode provided in the embodiments of this application;

[0081] Figure 23 This is a schematic diagram illustrating another implantation principle of the flexible electrode provided in the embodiments of this application.

[0082] The annotations in the attached figures are explained as follows:

[0083] 100 Flexible body; 101 First sensing electrode; 102 Microchannel; 103 First end; 104 Second end; 105 Opening; 106 First flexible insulating layer; 107 Second flexible insulating layer; 108 Hydrophobic surface; 109 Second sensing electrode; 110 Electrode conduit; 111 First section; 112 Second section; 113 Trench; 114 Signal line; 115 Insulating isolation ring; 116 Pad; 117 Pad section; 118 Substrate; 119 Conductive layer; 120 Insulating protective layer. Detailed Implementation

[0084] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0085] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments described in this application are merely some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The terminology used in the embodiments of this application is only used to explain the specific embodiments of this application and is not intended to limit this application.

[0086] refer to Figures 1-3 , Figure 1 This is a top view of a flexible electrode provided in an embodiment of this application. Figure 2 for Figure 1 The diagram shows the structure of the flexible electrode in its second configuration. Figure 3 for Figure 1 The diagram shows the structure of the flexible electrode in its first configuration. Figure 2 and Figure 3 This is a cross-sectional view of the flexible electrode parallel to its thickness direction.

[0087] It should be noted that, in the embodiments of this application, the relative directional positions are shown based on the same coordinate system in the structural schematic diagram of the flexible electrode. In the naturally flat state of the flexible electrode, its length direction is parallel to the first direction X, its width direction is parallel to the second direction Y, and its thickness direction is parallel to the third direction Z.

[0088] like Figure 1As shown, the flexible electrode includes: a flexible body 100; a first sensing electrode 101 disposed on the outer surface of the flexible body 100, the first sensing electrode 101 being used to acquire a first biosignal; a microchannel 102 located within the flexible body 100; the microchannel 102 having a first end 103 and a second end 104 opposite to each other; the first end 103 being sealed; the second end 104 having an opening 105; the opening 105 being used to fill the contents of the microchannel 102 with pressurized liquid and to extract the pressurized liquid from the microchannel 102; wherein the flexible electrode has a first shape and a second shape.

[0089] like Figure 3 As shown, in the first state, the microchannel 102 contains pressurized liquid, and the flexible body 100 has a first stiffness. Figure 3 Pressurized liquid is not shown in the image; for example... Figure 2 As shown, when in the second state, the inner wall of the microchannel 102 is seamlessly and separably bonded, and the flexible body 100 has a second stiffness; the first stiffness is greater than the second stiffness.

[0090] In the flexible electrode provided in this embodiment, a microchannel 102 is provided within the flexible body 100. The microchannel 102 can be filled with and extracted with pressurized liquid through the opening 105 of the second end 104, thereby giving the flexible electrode a first shape and a second shape. When pressurized liquid is filled into the microchannel 102, the flexible electrode is in the first shape. The liquid pressure can cause the flexible body 100 to expand, thereby strengthening the rigidity of the flexible body 100 and giving the flexible electrode a greater first rigidity. The flexibility facilitates the implantation of the flexible electrode in a biological body. When no pressurized liquid is filled into the microchannel 102, the flexible electrode is in the second shape. The inner wall of the microchannel 102 is gapless and separable, and the flexible body 100 has good flexible deformation properties, which facilitates the adaptation and adhesion of the flexible body 100 to the tissues of a biological body.

[0091] When the flexible electrode is implanted into brain tissue, the flexible electrode provided in this application does not require a rigid implanter. By introducing pressurized liquid into the microchannel 102, the rigidity of the flexible body 100 is temporarily enhanced, allowing the flexible electrode to be in its first state, facilitating implantation and avoiding the mechanical damage to brain tissue caused by rigid implanters. After implantation, the pressurized liquid is withdrawn through the opening 105 located outside the organism, returning the flexible electrode to its natural initial flexible state. The implantation process of the flexible electrode involves only the injection and withdrawal of pressurized liquid within the microchannel 102. Compared to rigid implanters, the injection and withdrawal of pressurized liquid do not cause mechanical damage to brain tissue, and the liquid withdrawal operation does not lead to problems such as the flexible electrode being pulled out or displaced.

[0092] Compared to the implantation method that uses biodegradable or soluble temporary reinforcing materials to temporarily harden the flexible electrode, the flexible electrode provided by this application can flexibly adjust its stiffness in the first state by controlling the pressure of the infused pressurized liquid, so that the stiffness of the electrode during implantation can be flexibly adjusted according to the surgical requirements; the microchannel 102 can be fabricated using current mature MEMS technology, the electrode structure and fabrication process are simple and the cost is low; moreover, after implantation, there is no need for a long waiting time, and the pressurized liquid in the microchannel 102 can be quickly extracted before subsequent signal acquisition operations can be carried out.

[0093] like Figure 2 As shown, the flexible body 100 has a first flexible insulating layer 106 and a second flexible insulating layer 107 that are relatively adhered and fixed. The area of ​​the first flexible insulating layer 106 corresponding to the microchannel 102 is a hydrophobic surface 108, so that the first flexible insulating layer 106 and the second flexible insulating layer 107 are adhered to the hydrophobic surface 108 without gaps, forming the microchannel 102. The hydrophobic surface 108 can effectively prevent the two flexible insulating layers from irreversibly sticking together in the area of ​​the microchannel 102, ensuring that the microchannel 102 can be smoothly opened when pressurized liquid is injected.

[0094] In this embodiment of the application, as described below, a first sensing electrode 101 may be formed on the surface of the second flexible insulating layer 107 opposite to the first flexible insulating layer 106; an insulating protective layer 120 may also be formed on the surface of the second flexible insulating layer 107, with the insulating protective layer 120 exposing the first sensing electrode 101.

[0095] In this embodiment, microchannels 102 can be formed by hydrophobic treatment of a designated area of ​​the first flexible insulating layer 106. The formation of microchannels 102 does not require an etching process. Compared to microchannels formed by etching trenches, the technical solution of this embodiment does not require the formation of microchannels with air gap structures. Instead, it achieves in-situ self-forming of microchannels 102 based on the separable contact surface between the two flexible insulating layers. This not only simplifies the process and increases product yield, but also reduces the thickness of the flexible electrode and improves its flexibility in the second morphology, facilitating better conformal adhesion to the surface of biological tissues. Furthermore, the thinner flexible electrode allows for more flexible adjustment of its stiffness by applying pressure to the liquid, enabling flexible adjustment of electrode stiffness according to implantation requirements during the implantation process.

[0096] In one embodiment, in the second configuration, the second flexible insulating layer 107 is in direct contact with the hydrophobic surface 108. This method directly forms microchannels 102 based on the hydrophobic surface 108 in the first flexible insulating layer 106 and the second flexible insulating layer 107, resulting in a simple fabrication process and low manufacturing cost.

[0097] In another approach, the hydrophobic surface 108 is covered with a soluble film, and in the second configuration, the second flexible insulating layer 107 is in direct contact with the soluble film. The soluble film is at least readily soluble in the pressurized liquid. Compared to the scheme where the two flexible insulating layers form the microchannel 102 solely based on the hydrophobic surface 108 of the first flexible insulating layer 106, this approach further ensures better surface release characteristics of the two flexible insulating layers in the microchannel 102 region by covering the hydrophobic surface 108 with the soluble film, preventing adhesion between the two layers on the inner wall of the microchannel 102, thus facilitating better infusion of pressurized liquid during implantation.

[0098] The thickness of the soluble film can be 0.5 μm to 100 μm. Preferably, the thickness can be set to 0.5 μm to 10 μm. The thickness of the soluble film does not exceed 100 μm, which prevents adhesion to the inner wall of the microchannel 102 while avoiding excessive thickness that would affect the electrode thickness.

[0099] refer to Figure 4 and Figure 5 , Figure 4 This is a top view of a flexible electrode provided in an embodiment of this application. Figure 5 for Figure 4 The side view of the flexible electrode shown illustrates that, in this configuration, the flexible electrode further includes a second sensing electrode 109 for acquiring a second biosignal; wherein the area of ​​the second sensing electrode 109 is larger than the area of ​​the first sensing electrode 101. The first sensing electrode 101 and the second sensing electrode 109 are two types of electrode contacts with different areas. The larger second sensing electrode 109 can be used to acquire local electric field signals to characterize the overall electrical activity of the surrounding neuronal cluster; the smaller first sensing electrode 101 is used to acquire electrical pulse signals to characterize the firing activity of a single neuron.

[0100] When the flexible electrode simultaneously incorporates the first sensing electrode 101 and the second sensing electrode 109, dual-modal signal acquisition can be achieved, resulting in more comprehensive information acquisition and significantly improved signal acquisition comprehensiveness and spatial resolution. Specifically, the small-sized first sensing electrode 101 can be used to capture high-precision signals from a single neuron, while the large-sized second sensing electrode 109 can be used to capture group signals from clusters of neurons in a region. The size difference between the different sensing electrodes enables natural partitioning of the signal acquisition area, which is beneficial for signal processing algorithms to distinguish and fuse different types of neural signals.

[0101] In one implementation, such as Figure 4 and Figure 5As shown, the flexible electrode also includes an electrode conduit 110, with a second sensing electrode 109 located on the outer surface of the electrode conduit 110. The flexible body 100 is fixed to the electrode conduit 110, and the portion of the flexible body 100 with the first sensing electrode 101 extends beyond the electrode conduit 110. When the flexible electrode is implanted in the brain, the electrode conduit 110 and the second sensing electrode 109 on its outer surface form a SEEG electrode (stereotactic electroencephalography electrode). In this method, the flexible body 100 is bonded and fixed to the outer surface of the electrode conduit 110, resulting in a simple fixation method and low manufacturing cost.

[0102] like Figure 4 and Figure 5 As shown, the flexible body has a first segment 111 and a second segment 112. The end of the first segment 111 facing away from the second segment 112 is the first end 103, and the end of the second segment 112 facing away from the first segment 111 is the second end 104. The second segment 112 is attached and fixed to the outer surface of the electrode conduit 110, and the first segment 111 extends beyond the electrode conduit 110. In this method, the mature SEEG electrode conduit 110 can be used as a carrier, and the flexible body 100 can be directly bonded and fixed to the outer surface of the electrode conduit 110. The large-sized second sensing electrode 109 is provided by the SEEG electrode conduit 110, which facilitates the acquisition of shallow, large-area biosignals through the second sensing electrode 109 on the electrode conduit 110. The small-sized first sensing electrode 101 is provided by the first segment 111 extending beyond the electrode conduit 110, which facilitates the first segment 111 penetrating into the tissue to be detected, so as to facilitate the acquisition of microelectrode signals through the first sensing electrode 101, thus achieving a good combination of the traditional electrode conduit 110 and the flexible electrode.

[0103] refer to Figure 6 , Figure 6 for Figure 4 The diagram shows a cross-sectional view of the flexible electrode perpendicular to its length. Based on the above embodiment, the electrode conduit 110 has a groove 113 extending along its length, and the second segment 112 is fixed within the groove 113. This method improves the stability and reliability of the second segment 112's fixation on the electrode conduit 110 through mechanical interlocking. The limiting and fixing effect of the groove 113 effectively prevents the second segment 112 from peeling off from the outer surface of the electrode conduit 110 due to deformation during the injection of pressurized liquid.

[0104] in, Figures 4-6 In the manner shown, the flexible body 100 and the electrode conduit 110 can be fixed by adhesive bonding. The adhesive material used for bonding can be epoxy, silicone, polyurethane, etc. Figure 4 and Figure 6The adhesive layer located between the flexible body 100 and the electrode conduit 110 is not shown. The width of the flexible electrode is smaller than the diameter of the electrode conduit 110 so that when it is attached to the outer partial surface of the electrode conduit 110, more than half of the area of ​​the second sensing electrode 109 is exposed, or it is built into the electrode conduit 110.

[0105] refer to Figure 7 , Figure 7 for Figure 6 The diagram shows the structure of the flexible electrode during pressurized liquid injection. Figure 6 As shown, in the second state without pressurized liquid injection, the natural thickness of the second section 112 is less than the depth of the trench 113. (As...) Figure 7 As shown, in the first state of perfusion pressurized liquid, the outer surface of the second section 112 that expands meets the adaptation condition with the outer surface of the electrode conduit 110, so that the outer surface of the second section 112 that expands and the outer surface of the electrode conduit 110 are on the same arc surface or approximately on the same arc surface. When the flexible electrode is in the first state for electrode implantation, this method can make the second section 112 and the electrode conduit 110 form a smooth outer contour surface, reducing implantation resistance and damage to tissues.

[0106] refer to Figure 8 and Figure 9 , Figure 8 A three-dimensional view of a flexible electrode provided in an embodiment of this application. Figure 9 for Figure 8 The cross-sectional view of the flexible electrode is shown. Among them, Figure 9 This is a cross-sectional view of the flexible electrode along its length. (Compared to...) Figures 4-7 The method shown is the same. Figure 8 and Figure 9 In the illustrated configuration, the flexible body has a first segment 111 and a second segment 112. The end of the first segment 111 facing away from the second segment 112 is designated as the first end 103, and the end of the second segment 112 facing away from the first segment 111 is designated as the second end 104. Figures 4-7 The difference shown is that, Figure 8 and Figure 9 In the manner shown, the electrode is disposed within the electrode conduit 110, and the first section 111 extends beyond the electrode conduit 110.

[0107] exist Figure 8 and Figure 9 In the illustrated method, the second segment 112 of the flexible body 100 is directly embedded into the interior of the electrode conduit 110. This allows for direct embedding and fixing of the second segment 112 within the electrode conduit 110 using existing encapsulation processes, eliminating the need for separate process steps and adhesive layers to fix the second segment 112 and the electrode conduit 110. This improves the integration of the process and product structure compared to... Figures 4-7 The method shown reduces the risk that the second section 112 may easily peel off from the electrode conduit 110 when the outer side of the second section 112 is bonded and fixed.

[0108] refer to Figure 10 and Figure 11 , Figure 10 This is a schematic diagram illustrating the fabrication principle of an electrode conduit 110 provided in an embodiment of this application. Figure 11 This is a three-dimensional structural schematic diagram of an electrode conduit 110 provided in an embodiment of this application. The electrode conduit 110 includes multiple coaxially arranged annular electrodes, which serve as second sensing electrodes 109. An insulating isolation ring 115 is provided between adjacent annular electrodes. In this configuration, the annular electrodes can provide stable, large-sized electrode contacts, suitable for acquiring electric field potentials. The insulating isolation ring 115 effectively avoids signal interference between the annular electrodes, improving acquisition accuracy. The coaxial structure of the multiple annular electrodes facilitates the formation of a smooth columnar structure with the insulating isolation ring 115, thus facilitating electrode implantation.

[0109] The insulating isolation ring 115 can be made of polymers such as polyurethane, silicone, epoxy resin, etc. The annular electrode can be made of implantable stainless steel, platinum, platinum-iridium alloy, etc. The second segment 112 of the flexible body 100 can be fixed to the outer surface of the electrode conduit 110 or embedded inside the electrode conduit 110 by dispensing adhesive.

[0110] like Figure 10 and Figure 11 As shown, each annular electrode is connected to the outside via a corresponding signal line 114. In this method, each annular electrode needs to have a metal wire welded to its inner wall as a signal line 114 for connecting to the external circuit. The first sensing electrode 101 located on the flexible body 100 and its connected signal line 114 can be fabricated based on the same patterned conductive layer 119, formed on the surface of the flexible substrate 100.

[0111] refer to Figure 12 , Figure 12 This is a top view of another flexible electrode provided in an embodiment of this application. In this embodiment, the flexible body has a first segment 111 and a second segment 112. The end of the first segment 111 facing away from the second segment 112 is the first end 103, and the end of the second segment 112 facing away from the first segment 111 is the second end 104. The first sensing electrode 101 and the second sensing electrode 109 are both located on the side surface of the second flexible insulating layer 107 facing away from the first flexible insulating layer 106. The first sensing electrode 101 is located in the first segment 111, and the second sensing electrode 109 is located in the second segment 112.

[0112] exist Figure 12In the illustrated configuration, the first sensing electrode 101 and the second sensing electrode 109 can be fabricated simultaneously based on the same patterned conductive layer 119. They can be integrally formed using current mature MEMS technology. The large-sized second sensing electrode 109 does not need to rely on conventional electrode conduits 110, which facilitates the same process fabrication and unified packaging of sensing electrodes of different sizes. It also facilitates the bonding and packaging of flexible electrodes and the lead-out design of electrode connections, taking into account the process consistency and functional partitioning of two different-sized sensing electrodes.

[0113] like Figure 12 As shown, the flexible body 100 also includes a pad section 117, the surface of which is used to set pads. When the flexible electrode is designed in combination with the electrode conduit 110, the flexible electrode can also have pads set based on the pad section 117 in the flexible body 100. Each sensing electrode is connected to the pad based on a corresponding signal line 114. The pads, signal lines 114, and at least the first sensing electrode 101 can be fabricated simultaneously based on the same patterned conductive layer 119. For Figure 12 As shown, the second sensing electrode 109 can also be fabricated simultaneously from the patterned conductive layer 119.

[0114] Optionally, the area of ​​the second sensing electrode 109 is 0.2 mm². 2 ~10mm 2 The center-to-center distance between adjacent second sensing electrodes 109 is 2mm to 10mm; the area of ​​the first sensing electrode 101 is 2μm. 2 ~100μm 2 The center-to-center distance between adjacent first sensing electrodes 101 is 10μm to 1000μm. Two sensing electrodes of different sizes, based on their adapted electrode areas and center-to-center distances, can achieve decibel matching between local electric field signal acquisition and electrical pulse signal acquisition, reducing the signal-to-noise ratio and signal overlap interference. The shape of the sensing electrodes can be rectangular, circular, or other geometric structures; this embodiment does not limit the specific geometric structure of the sensing electrodes.

[0115] Based on sensing requirements, the number of second sensing electrodes 109 can be 4 to 16, and the number of first sensing electrodes 101 can be 8 to 64. The flexible electrode also has multiple pads for connecting to external circuits, with each of the first and second sensing electrodes 101 and 109 connected to a corresponding pad. The two different sized sensing electrodes, based on the appropriate number of electrodes, can balance acquisition density and minimally invasive implantation. Each sensing electrode can be connected to an external circuit one-to-one based on its corresponding pad, meeting the requirements for multi-channel and high-density neural signal acquisition. The number of pads is equal to the sum of the number of first and second sensing electrodes 101 and 109. Each of the first and second sensing electrodes 101 is connected to a pad based on its corresponding signal line 114. The number of the two types of sensing electrodes can be set according to requirements; this embodiment does not limit the number of either.

[0116] As described in the previous embodiment, the flexible body has a first segment 111 and a second segment 112. The end of the first segment 111 facing away from the second segment 112 is the first end 103, and the end of the second segment 112 facing away from the first segment 111 is the second end 104. The first sensing electrode 101 is located on the side surface of the second flexible insulating layer 107 facing away from the first flexible insulating layer 106, and the first sensing electrode 101 is located in the first segment 111. In the first segment 111, the deformation capability of the first flexible insulating layer 106 is greater than that of the second flexible insulating layer 107.

[0117] Whether it is a flexible electrode composed of a conventional electrode head and a flexible body 100, or a flexible electrode integrally formed based on MEMS technology, the first segment 111 of the flexible body 100 serves as the implantation end, and its implantation depth is greater than that of the second segment 112. Based on this, in the first segment 111, the deformation capacity of the first flexible insulating layer 106 is set to be greater than that of the second flexible insulating layer 107. During electrode implantation, when pressurized liquid is introduced into the microchannel 102, the first flexible insulating layer 106 can deform and expand more easily than the second flexible insulating layer 107, reducing the degree of deformation and expansion of the second flexible insulating layer 107. This reduces the degree of deformation mismatch between the first sensing electrode 101 and the second flexible insulating layer 107, which are not easily deformable, and reduces the risk of peeling off the first sensing electrode 101 and the second flexible insulating layer 107.

[0118] In the first section 111, the first flexible insulating layer 106 and the second flexible insulating layer 107 can be made of the same material, and the thickness of the first flexible insulating layer 106 is less than the thickness of the second flexible insulating layer 107, so that the deformation capacity of the first flexible insulating layer 106 is greater than that of the second flexible insulating layer 107; or, the first flexible insulating layer 106 and the second flexible insulating layer 107 are made of different materials, and the material of the first flexible insulating layer 106 has a greater deformation capacity, so that the deformation capacity of the first flexible insulating layer 106 is greater than that of the second flexible insulating layer 107; or, while the first flexible insulating layer 106 has a smaller thickness, it is made of a material with a greater deformation capacity, so that the deformation capacity of the first flexible insulating layer 106 is greater than that of the second flexible insulating layer 107.

[0119] In this embodiment, in the second section 112, the deformation capacity of the second flexible insulating layer 107 is greater than that of the first flexible insulating layer 106. During the implantation process of injecting pressurized liquid, this method allows the second section 112 to deform and expand more easily towards the second flexible insulating layer 107, reducing the degree of deformation and expansion towards the first flexible insulating layer 106. This reduces stress mismatch between the first flexible insulating layer 106 and other structures bonded to it in the second section 112, preventing the first flexible insulating layer 106 from peeling off from other structures. For example, in the bonding and fixing structure between the first flexible insulating layer 106 and the electrode conduit 110 in the second section 112, this method can prevent the first flexible insulating layer 106 from peeling off from the electrode conduit 110.

[0120] Based on the flexible electrode provided in the above embodiments, another embodiment of this application also provides a method for preparing a flexible electrode, which can be as follows: Figure 13 As shown.

[0121] refer to Figures 13-20 , Figure 13 This is a schematic flowchart of a flexible electrode fabrication method provided in an embodiment of this application. Figures 14-20 This application provides a schematic diagram of a flexible electrode fabrication method at different process stages, illustrating the device structure at each stage. The fabrication method includes:

[0122] Step S11: As Figure 14 As shown, a substrate 118 is provided.

[0123] Step S12: As Figure 15 As shown, a first flexible insulating layer 106 is formed on one side surface of the substrate 118.

[0124] Step S13: As Figure 16As shown, the surface of a predetermined area of ​​the first flexible insulating layer 106 is treated with hydrophobicity to form a hydrophobic surface 108.

[0125] Step S14: As Figure 17 As shown, a second flexible insulating layer 107 is formed on the surface of the first flexible insulating layer 106.

[0126] In areas other than the hydrophobic surface 108, the first flexible insulating layer 106 and the second flexible insulating layer 107 can be seamlessly bonded together. The two flexible insulating layers can be made of the same or different materials. The materials of the flexible insulating layers include, but are not limited to, polyimide (PI), silicone (PDMS), epoxy resin (SU-8), and parylene.

[0127] Step S15: As Figure 18 As shown, a patterned conductive layer 119 is formed on the surface of the second flexible insulating layer 107 opposite to the first flexible insulating layer 106. The conductive layer 119 includes a first sensing electrode 101. The first sensing electrode 101 is used to collect a first biosignal.

[0128] The conductive layer 119 can be made of biocompatible metals such as gold, platinum, and titanium. The conductive layer 119 is patterned and glassed to obtain the required pads, electrode patterns, and signal lines 114 connected to the electrodes.

[0129] Step S16: As Figure 19 As shown, an insulating protective layer 120 covers the surface of the conductive layer 119, exposing the first sensing electrode 101. The insulating protective layer 120 also exposes the individual pads of the pad section 117 to facilitate connection between the pads and external circuitry.

[0130] The material of the insulating protective layer 120 may be the same as or different from the material of the flexible insulating layer.

[0131] Step S17: As Figure 20 As shown, the substrate 118 is removed.

[0132] The second flexible insulating layer 107 and the first flexible insulating layer 106 are fixed in areas other than the hydrophobic surface 108 to form a flexible body 100. The first flexible insulating layer 106 and the second flexible insulating layer 107 are separably and gaplessly bonded to the hydrophobic surface 108 to form a microchannel 102. The microchannel 102 has a first end 103 and a second end 104. The first end 103 is sealed. The second end 104 has an opening 105. The opening 105 is used to fill the contents of the microchannel 102 with pressurized liquid and to extract the pressurized liquid from the microchannel 102. The flexible electrode has a first shape and a second shape. When in the first shape, the microchannel 102 contains pressurized liquid and the flexible body 100 has a first stiffness. When in the second shape, the inner wall of the microchannel 102 is separably and gaplessly bonded and the flexible body 100 has a second stiffness. The first stiffness is greater than the second stiffness.

[0133] The preparation methods disclosed in the above embodiments have the same or corresponding beneficial effects as the flexible electrode embodiments, and will not be repeated here to avoid repetition.

[0134] In this embodiment, the flexible body 100, the microfluidic channel 102 inside the flexible body 100, and the first sensing electrode 101 on its surface can all be fabricated using MEMS technology. The flexible body 100 includes three main sections, which are, sequentially along a first direction, a pad section 117, a second section 112, and a first section 111. The pad section 117 is used to set pads. The second section 112 can be used to set the second sensing electrode 109, or the second section 112 can be used to fix it to the electrode conduit 110, with the second sensing electrode 109 set on the outer surface of the electrode conduit 110. The first section 111 is used to set the first sensing electrode.

[0135] As described above, the microchannels 102 within the flexible body 100 can be infused with pressurized liquid to temporarily enhance the stiffness of the flexible body 100, enabling it to penetrate the target tissue.

[0136] In one embodiment, when the flexible body 100 is integrated with the electrode conduit 110, the electrode structure of the flexible electrode consists of two parts. A small-sized first sensing electrode 101 is fabricated on the flexible body 100 using MEMS technology. In this embodiment, the first sensing electrode 101 is formed only in the first segment 111 of the flexible body 100 as a small-sized microelectrode contact. A second sensing electrode 109 is formed on the outer surface of the electrode conduit 110. The fabrication process of the electrode conduit 110 can be as follows: Figure 10 and Figure 11 As shown. The second segment 112 of the flexible body can be as follows: Figures 4-7 As shown, it is bonded to the outer surface of the electrode conduit 110, or as... Figure 8 and Figure 9As shown, it is built into the electrode conduit 110. In these embodiments, the flexible body 100 is provided with a first section 111 of the first sensing electrode 101 extending outside the electrode conduit 110, and the stiffness of the first section 111 can be flexibly adjusted based on the filling of pressurized liquid.

[0137] In another approach, the first sensing electrode 101 and the second sensing electrode 109 can be formed simultaneously on the surface of the flexible body 100. This approach can fabricate two sensing electrodes of different sizes on the flexible body 100 simultaneously based on MEMS technology.

[0138] The preparation method provided in this application embodiment eliminates the need for a constant process to form the microchannel 102 with gas gaps, resulting in a simple preparation process and high product yield. The two flexible insulating layers can be separably bonded to the inner wall of the microchannel 102 without gaps, reducing the thickness of the flexible body 100 and improving its deformability.

[0139] refer to Figure 21 , Figure 21 This is a schematic diagram illustrating the pressurization principle of the flexible electrode provided in this application embodiment. The flexible electrode can be connected to a liquid injection device via an infusion pipeline to inject pressurized liquid into the flexible electrode, thereby enhancing the stiffness of the flexible body 100 of the flexible electrode. The liquid injection device is connected to a pressure gauge, which can detect the pressure of the injected pressurized liquid. Based on controlling the pressure of the pressurized liquid, the stiffness of the flexible body 100 in the flexible electrode can be flexibly adjusted. The pressure of the injected pressurized liquid can be 1MPa to 10MPa. After the electrode implantation is completed, the pressurized liquid in the microchannel can be withdrawn, and the stiffness of the flexible body 100 returns to its initial flexible state, demonstrating the flexible electrode's characteristic of being flexible enough to shape edges.

[0140] Optionally, before forming the second flexible insulating layer 107, the method further includes forming a soluble thin film on the hydrophobic surface 108. Based on the soluble thin film, the adhesion of the two flexible insulating layers to the inner wall of the microchannel 102 can be better prevented, facilitating the injection of pressurized liquid into the microchannel 102 during electrode injection.

[0141] The preparation method provided in this application embodiment further includes: preparing a second sensing electrode 109, the second sensing electrode 109 being used to collect a second biological signal; wherein the area of ​​the second sensing electrode 109 is larger than the area of ​​the first sensing electrode 101.

[0142] In one embodiment, the method for fabricating the second sensing electrode 109 includes: fabricating an electrode conduit 110, the outer surface of which includes the second sensing electrode 109; wherein a flexible body 100 is fixed to the electrode conduit 110, and a portion of the flexible body 100 in which the first sensing electrode 101 is disposed extends beyond the electrode conduit 110.

[0143] As described above, the flexible body has a first segment 111 and a second segment 112. The end of the first segment 111 that is away from the second segment 112 is the first end 103, and the end of the second segment 112 that is away from the first segment 111 is the second end 104.

[0144] The method of fixing the flexible body 100 to the electrode conduit 110 includes: attaching and fixing the second section 112 to the outer surface of the electrode conduit 110, and extending the first section 111 outside the electrode conduit 110; or, the method of fixing the flexible body 100 to the electrode conduit 110 includes: placing the second section 112 inside the electrode conduit 110, and extending the first section 111 outside the electrode conduit 110.

[0145] In another approach, the method for fabricating the second sensing electrode 109 includes: simultaneously forming the second sensing electrode 109 through the patterned conductive layer 119 while fabricating the first sensing electrode 101 through the patterned conductive layer 119.

[0146] As can be seen from the above description, the embodiments of this application can use MEMS technology to fabricate a flexible body 100 with a first sensing electrode 101. The flexible body 100 can be integrated with the existing electrode conduit 110 structure so that the flexible electrode can be two sensing electrodes with different sizes. Alternatively, two sensing electrodes of different sizes can be fabricated directly on the same flexible body 100 based on MEMS technology.

[0147] refer to Figure 22 , Figure 22 This is a schematic diagram of the implantation principle of a flexible electrode provided in the embodiments of this application. In this method, a flexible body 100 with a first sensing electrode 101 is prepared using MEMS technology. The flexible body 100 can be integrated with the existing electrode conduit 110 structure. When the electrode is implanted, the first section 111 extending to the electrode conduit 110 can be strengthened with pressurized liquid to facilitate a better implantation operation.

[0148] refer to Figure 23 , Figure 23 This is a schematic diagram of another implantation principle of the flexible electrode provided in the embodiments of this application. In this method, two sensing electrodes of different sizes are directly fabricated on the same flexible body 100 based on MEMS technology. When implanting the electrodes, the overall stiffness of the electrodes is enhanced by pressurized liquid to facilitate better implantation.

[0149] The various embodiments in this application are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. The embodiments provided in this application can be combined with each other without contradiction.

[0150] It should be noted that, in the description of this application, the accompanying drawings and embodiments are illustrative rather than restrictive. The same reference numerals throughout the embodiments identify the same structures. Additionally, for understanding and ease of description, the thicknesses of some layers, films, panels, regions, etc., may be exaggerated in the drawings. It is also understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element or there may be intermediate elements. Furthermore, "on" means positioning an element on or below another element, but does not inherently mean positioning it above another element according to the direction of gravity.

[0151] The terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the middle.

[0152] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0153] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible electrode, characterized in that, include: Flexible body; A first sensing electrode is disposed on the outer surface of the flexible body, and the first sensing electrode is used to collect a first biosignal. A microchannel is located within the flexible body; the microchannel has a first end and a second end opposite to each other; the first end is sealed; the second end has an opening; the opening is used to inject pressurized liquid into the microchannel and to extract pressurized liquid from the microchannel. The flexible electrode has a first shape and a second shape; when in the first shape, the microchannel contains pressurized liquid and the flexible body has a first stiffness; when in the second shape, the inner wall of the microchannel is gaplessly separable and adhered, and the flexible body has a second stiffness; the first stiffness is greater than the second stiffness.

2. The flexible electrode according to claim 1, characterized in that, The flexible body has a first flexible insulating layer and a second flexible insulating layer that are relatively fitted and fixed together. The region of the first flexible insulating layer corresponding to the microchannel is a hydrophobic surface, so that the first flexible insulating layer and the second flexible insulating layer can be separably bonded to the hydrophobic surface to form the microchannel.

3. The flexible electrode according to claim 2, characterized in that, In the second configuration, the second flexible insulating layer is in direct contact with the hydrophobic surface.

4. The flexible electrode according to claim 2, characterized in that, The hydrophobic surface is covered with a soluble film, and in the second configuration, the second flexible insulating layer is in direct contact with the soluble film.

5. The flexible electrode according to claim 2, characterized in that, The flexible electrode also includes a second sensing electrode, which is used to collect a second biological signal; The area of ​​the second sensing electrode is larger than the area of ​​the first sensing electrode.

6. The flexible electrode according to claim 5, characterized in that, It also includes an electrode conduit, wherein the second sensing electrode is located on the outer surface of the electrode conduit; The flexible body is fixed to the electrode conduit, and the portion of the flexible body with the first sensing electrode extends beyond the electrode conduit.

7. The flexible electrode according to claim 6, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; The second section is attached to and fixed to the outer surface of the electrode conduit, and the first section extends beyond the electrode conduit.

8. The flexible electrode according to claim 7, characterized in that, The electrode conduit has a groove extending in the length direction, and the second section is fixed within the groove.

9. The flexible electrode according to claim 6, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; The second section is disposed within the electrode conduit, and the first section extends beyond the electrode conduit.

10. The flexible electrode according to claim 6, characterized in that, The electrode conduit includes a plurality of coaxially arranged annular electrodes, the annular electrodes being the second sensing electrodes, and an insulating isolation ring between adjacent annular electrodes.

11. The flexible electrode according to claim 5, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; Both the first sensing electrode and the second sensing electrode are located on the side surface of the second flexible insulating layer that is away from the first flexible insulating layer; the first sensing electrode is located in the first section, and the second sensing electrode is located in the second section.

12. The flexible electrode according to claim 5, characterized in that, The area of ​​the second sensing electrode is 0.2 mm. 2 ~10mm 2 The center-to-center distance between adjacent second sensing electrodes is 2mm to 10mm; The area of ​​the first sensing electrode is 2 μm. 2 ~100μm 2 The center-to-center distance between adjacent first sensing electrodes is 10μm to 1000μm.

13. The flexible electrode according to claim 5, characterized in that, The number of the second sensing electrodes is 4 to 16, and the number of the first sensing electrodes is 8 to 64; The flexible electrode is also provided with a plurality of pads for connection to external circuits, and the first sensing electrode and the second sensing electrode are respectively connected to one of the pads.

14. The flexible electrode according to claim 2, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; The first sensing electrode is located on the side surface of the second flexible insulating layer opposite to the first flexible insulating layer, and the first sensing electrode is located in the first section; In the first section, the deformation capacity of the first flexible insulating layer is greater than that of the second flexible insulating layer.

15. The flexible electrode according to claim 14, characterized in that, In the second section, the deformation capacity of the second flexible insulating layer is greater than that of the first flexible insulating layer.

16. A method for preparing a flexible electrode, characterized in that, include: Provide a base; A first flexible insulating layer is formed on one side surface of the substrate; The surface of a predetermined area of ​​the first flexible insulating layer is treated with a hydrophobic coating to form a hydrophobic surface; A second flexible insulating layer is formed on the surface of the first flexible insulating layer; A patterned conductive layer is formed on the surface of the second flexible insulating layer opposite to the first flexible insulating layer, the conductive layer including a first sensing electrode; the first sensing electrode is used to acquire a first biosignal. An insulating protective layer is covered on the surface of the conductive layer, with the insulating protective layer exposing the first sensing electrode; Remove the substrate; The second flexible insulating layer and the first flexible insulating layer are fixed to form a flexible body in areas other than the hydrophobic surface; the first flexible insulating layer and the second flexible insulating layer are separably and seamlessly bonded to the hydrophobic surface to form a microchannel; the microchannel has a first end and a second end; the first end is sealed; the second end has an opening; the opening is used to inject pressurized liquid into the microchannel and to extract pressurized liquid from the microchannel; the flexible electrode has a first shape and a second shape; when in the first shape, pressurized liquid is present in the microchannel, and the flexible body has a first stiffness; when in the second shape, the inner wall of the microchannel is separably and seamlessly bonded, and the flexible body has a second stiffness; the first stiffness is greater than the second stiffness.

17. The preparation method according to claim 16, characterized in that, Before forming the second flexible insulating layer, the method further includes: A soluble film is formed on the hydrophobic surface.

18. The preparation method according to claim 16, characterized in that, Also includes: A second sensing electrode is prepared, which is used to acquire a second biological signal; The area of ​​the second sensing electrode is larger than the area of ​​the first sensing electrode.

19. The preparation method according to claim 18, characterized in that, The method for preparing the second sensing electrode includes: An electrode conduit is prepared, wherein the outer surface of the electrode conduit includes the second sensing electrode; The flexible body is fixed to the electrode conduit, and the portion of the flexible body with the first sensing electrode extends beyond the electrode conduit.

20. The preparation method according to claim 19, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; The method for fixing the flexible body to the electrode conduit includes: The second section is attached and fixed to the outer surface of the electrode conduit, and the first section extends beyond the electrode conduit.

21. The preparation method according to claim 19, characterized in that, The flexible body has a first segment and a second segment, the end of the first segment opposite to the second segment is the first end, and the end of the second segment opposite to the first segment is the second end; The method for fixing the flexible body to the electrode conduit includes: The second section is disposed within the electrode conduit, and the first section extends beyond the electrode conduit.

22. The preparation method according to claim 18, characterized in that, The method for preparing the second sensing electrode includes: When the first sensing electrode is fabricated through the patterned conductive layer, the second sensing electrode is simultaneously formed through the patterned conductive layer.

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