A graphene flexible electrode and its preparation method

Abstract

The present invention relates to the field of graphene electrodes, and more specifically to a graphene flexible electrode and a method for preparing the same. The graphene flexible electrode comprises a first flexible substrate and a second flexible substrate, wherein the first flexible substrate is positioned below the second flexible substrate; the upper surface of the first flexible substrate is covered with a first graphene mesh; the lower surface of the second flexible substrate is fixedly provided with metal pole pieces, which are positioned at both ends of the second flexible substrate; the lower surface of the second flexible substrate is covered with a second graphene mesh, the ends of which are connected to the lower surface of the metal pole pieces; and multiple grids are provided on each of the first and second graphene meshes. This application also discloses a corresponding preparation method. This application improves the detection accuracy of the flexible electrode while making the graphene sensing mesh and metal electrode less susceptible to cracking or falling off.

Description

Technical Field

[0001] The present invention relates to the field of graphene electrodes, and in particular to a graphene flexible electrode and a preparation method thereof. Background Art

[0002] In many fields, including wearable devices and biomedicine, it is necessary to accurately measure tiny deformations in the human body to understand normal physiological activities and monitor physical health. For example, measuring pulse can reveal whether a person is ill. Measuring these tiny changes requires highly sensitive, flexible, and reliable pressure sensors.

[0003] For this type of pressure sensor, the flexible electrode is the main structure of the pressure sensor, combined with Figure 1 As shown, Figure 1 This is a top-down view of a conventional graphene flexible electrode. The graphene flexible electrode comprises a flexible substrate 1, metal electrodes 2 at either end of the flexible electrode, and a graphene sensing mesh 3 on the flexible substrate 1. The graphene sensing mesh 3 is a mesh structure with numerous meshes, and its two ends are fixed to the metal electrodes 2.

[0004] The detection principle of the graphene flexible electrode is as follows: external pressure acts on the flexible substrate 1, which transmits the external force to the graphene sensing mesh 3 through the flexible substrate 1, causing the graphene sensing mesh 3 to deform, resulting in a change in its resistance. This change in resistance is output through the metal electrode 2, and the output resistance value is calibrated with the external pressure value to ultimately measure the external pressure value.

[0005] The reason why the graphene sensing mesh 3 is set to a mesh structure is that under the action of external force, the edges of the graphene sensing mesh 3 will produce boundary effects, which will cause changes in the electronic band structure and conductivity characteristics of graphene, and then cause changes in the resistance of the graphene sensing mesh 3. Therefore, the existing technology uses a grid-shaped graphene sensing mesh 3, each grid having an edge. This increases the overall edge length and edge area of the graphene sensing mesh 3. When an external force is applied, the edge electrical characteristics of the graphene sensing mesh 3 are further changed, which in turn causes a significant change in the graphene resistance, greatly improving the sensitivity of the sensor.

[0006] Therefore, the greater the number of grids in the graphene sensing mesh 3, the larger the length and area of the edges of the grids in the graphene sensing mesh 3 will be, the higher the sensitivity of the sensor will be, and the more accurate the detection will be. However, when the number of grids in the graphene sensing mesh 3 increases, while the outermost side length of the graphene sensing mesh 3 remains unchanged, the mesh wires of the graphene sensing mesh 3 will become thinner, and the contact area between each mesh wire of the graphene sensing mesh 3 and the metal electrode 2 will decrease. The connection strength between each mesh wire of the graphene sensing mesh 3 and the metal electrode 2 will be weakened. As a result, when the graphene sensing mesh 3 is deformed frequently, the connection between the metal electrode 2 and the graphene sensing mesh 3 is prone to cracking and falling off in whole or in part, resulting in an unreliable connection between the metal electrode 2 and the graphene sensing mesh 3, damaging the pressure sensor and affecting its normal operation. Summary of the Invention

[0007] The present invention aims to provide a graphene flexible electrode and a preparation method thereof to improve detection accuracy while preventing the graphene mesh and metal electrodes from cracking or falling off.

[0008] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a graphene flexible electrode, comprising a first flexible substrate and a second flexible substrate, the first flexible substrate being located below the second flexible substrate; the upper surface of the first flexible substrate being covered with a first graphene mesh; the lower surface of the second flexible substrate being fixed with metal pole pieces, the metal pole pieces being located at both ends of the second flexible substrate, the lower surface of the second flexible substrate being covered with a second graphene mesh, the ends of the second graphene mesh being connected to the lower surface of the metal pole pieces; the first graphene mesh and the second graphene mesh being both provided with a plurality of grids, the grids on the first graphene mesh and the grids on the second graphene mesh being the same size, and the number of grids on the second graphene mesh being greater than the number of grids on the first graphene mesh.

[0009] The principle and advantage of this solution are: in this solution, the number of grids on the second graphene mesh is greater than the number of grids on the first graphene mesh. Therefore, when the overall sizes of the first graphene mesh and the second graphene mesh are the same, the overall edge length and edge area of the second graphene mesh are greater than the overall edge length and edge area of the first graphene mesh. Therefore, the sensitivity of the second graphene mesh is greater than the sensitivity of the first graphene mesh.

[0010] When external pressure is applied, it acts on the first flexible substrate. The external force is transmitted through the first flexible substrate to the first graphene mesh, causing the first graphene mesh to deform. The first graphene mesh then transmits the external force to the second graphene mesh, causing the second graphene mesh to deform, resulting in a change in the resistance of the second graphene mesh. The change in the resistance of the second graphene mesh is output through the metal electrode, and the output resistance value is calibrated with the external pressure value, ultimately achieving the purpose of measuring the external pressure value. In this solution, the external pressure does not act directly on the second graphene mesh, but first acts on the first graphene mesh, which then transmits the pressure to the second graphene mesh. During the pressure transmission process, the first graphene mesh absorbs and reduces the pressure fluctuations and vibrations. In other words, the pressure level received by the second graphene mesh is less than the initial pressure level acting on the first flexible substrate. As a result, the pressure vibrations, fluctuations, and pressure values received by the second graphene mesh are smaller, making it less likely for the second graphene mesh and the metal electrode to crack or fall off, either entirely or partially. Moreover, the second graphene mesh is more sensitive due to the large number of grids. Even if the pressure transmitted to the second graphene mesh is smaller than that in the prior art, the second graphene mesh can still detect the pressure, and the detection sensitivity of the sensor can be guaranteed.

[0011] For the first graphene mesh, although the first graphene mesh receives a greater degree of pressure than the second graphene mesh, the first graphene mesh has a smaller number of grids and the mesh wires of the first graphene mesh are thicker, thereby increasing the connection area of the end of the first graphene mesh. Even if the first graphene mesh receives a greater degree of pressure, the end of the first graphene mesh is not prone to cracking or falling off when connected to the corresponding position.

[0012] In summary, this solution employs two layers of graphene mesh. The first graphene mesh is used to reduce and absorb pressure, minimizing the pressure received by the second graphene mesh. The second graphene mesh is used to receive and detect pressure. With this solution, the first graphene mesh has fewer grids and thicker wires, making it less susceptible to deformation. This effectively absorbs and reduces pressure, minimizing pressure vibrations, fluctuations, and pressure values transmitted to the second graphene mesh. The second graphene mesh, however, has more grids and thinner wires, making it more susceptible to deformation and thus capable of detecting even smaller transmitted pressures.

[0013] Preferably, as an improvement, a support block is fixedly provided on the upper surface of the first flexible substrate, and the support blocks are located at both ends of the flexible substrate; the end of the first graphene mesh and the end of the second graphene mesh are both pressed between the metal electrode and the support block. Thus, the end of the first graphene mesh and the end of the second graphene mesh are pressed together by the support block and the metal pole piece, so that when the first graphene mesh and the second graphene mesh are vertically deformed under pressure, the end of the first graphene mesh and the end of the second graphene mesh are not easy to move in the vertical direction. In this way, the end of the first graphene mesh and the support block are not easy to move vertically, and the end of the second graphene mesh and the metal pole piece are not easy to move vertically, thereby limiting the end of the first graphene mesh and the end of the second graphene mesh in the vertical direction, increasing the firmness and stability of the connection between the end of the first graphene and the support block, and between the end of the second graphene mesh and the metal pole piece, further making it difficult for the end of the first graphene mesh to fall off and crack from the support block, and the end of the second graphene mesh to fall off and crack from the metal pole piece.

[0014] Preferably, as an improvement, a limiting portion is provided between the metal electrode and the support block; the second flexible substrate and the second graphene mesh are both bent downward, the end of the second flexible substrate is higher than the middle of the second flexible substrate, and the end of the second graphene mesh is higher than the middle of the second graphene mesh;

[0015] The limiting portion is fixedly positioned on the support block, abutting against the outer sidewall of the metal pole piece; alternatively, the limiting portion is fixedly positioned on the metal pole piece, abutting against the inner sidewall of the support block. As a result, when the first graphene mesh is subjected to pressure, it changes from a flat surface to an upwardly curved state, with the ends of the first graphene mesh tending to pull the two support blocks toward each other. Simultaneously, when the second graphene mesh is subjected to pressure, it gradually changes from a downwardly curved state to a flat surface, with the ends of the second graphene mesh tending to push the two metal pole pieces away from each other. In this way, the two metal pole pieces and the two support blocks have opposite movement directions, and the two metal pole pieces and the two support blocks are offset against each other under the action of the limiting portion, so that the metal pole pieces and the support blocks are laterally squeezed against each other under the action of the limiting portion. There is a certain pressure between the limiting portion and the metal pole piece (or support block). The existence of pressure increases the friction between the limiting portion and the metal pole piece (or support block), and the metal pole piece and the support block are not easy to separate, which avoids the separation of the metal pole piece and the support block when subjected to pressure. The metal pole piece and the support block can maintain the state of squeezing the end of the first graphene mesh and the end of the second graphene mesh, further avoiding the cracking and falling off of the ends of the first graphene mesh and the second graphene mesh.

[0016] Preferably, as an improvement, the limiting portion is fixed on the metal pole piece, and when the limiting portion abuts against the inner side wall of the support block, a plurality of partitions are fixedly provided on the metal pole piece along the length direction of the metal pole piece, with gaps between adjacent partitions, and the limiting portion is fixed at the bottom of the partition; the end of the second graphene mesh passes through the gaps between adjacent partitions and covers the metal pole piece, and the opposite sides of the adjacent partitions are in contact with the second graphene mesh; the limiting portion passes through the grid at the end of the first graphene mesh and abuts against the inner wall of the support block.

[0017] Thus, with this structure, the end of the second graphene mesh passes through the gap between adjacent separators and covers the metal pole piece. The opposite sides of the adjacent separators are in contact with the second graphene mesh. The second graphene mesh can not only interact with the metal pole piece, but can also be attached to the side of the separator. In this way, the separator has the function of limiting and fixing the end of the second graphene mesh, making it less likely for the second graphene mesh to crack and detach from the metal pole piece. Similarly, the limiting portion passes through the mesh at the end of the first graphene mesh, and the first graphene mesh can be attached to the side of the separator or the side of the limiting portion. In this way, the separator or the limiting portion has the function of limiting and fixing the end of the first graphene mesh, making it less likely for the first graphene mesh to crack and detach from the support block.

[0018] Preferably, as an improvement, a pressing portion is provided on the lower surface of the metal pole piece, and the pressing portion and the support block abut against each other. The pressing portion can cause the bottom of the metal pole piece to protrude downward, thereby ensuring that the metal pole piece and the support block are pressed more fully, and the support block and the metal pole piece have a better fixing effect on the first graphene mesh end portion and the second graphene mesh end portion.

[0019] Preferably, as an improvement, the metal pole piece material is one of platinum, titanium, copper, aluminum, nickel, tin, zinc, gold, and silver.

[0020] Preferably, as an improvement, the first graphene mesh is replaced with an LCP mesh. The first graphene mesh can be replaced with an LCP mesh having a grid structure. LCP is a liquid crystal polymer, which has many unique advantages, including excellent molding and processing properties such as bendability and foldability, and can be used in various products with complex shapes such as curves and bends.

[0021] To achieve the above object, the present invention also adopts the following technical solution: a method for preparing a graphene flexible electrode, comprising the following steps:

[0022] Step 1: Take a first flexible substrate, prepare a mesh-shaped graphene oxide layer on the first flexible substrate using a photolithography technique, and then reduce the graphene oxide layer to form a mesh-shaped first graphene network on the first flexible substrate;

[0023] Step 2: Take a second flexible substrate, spray a metal layer on the first flexible substrate, and use photolithography technology to transform the metal layer into a metal electrode; then use photolithography technology to prepare a mesh-shaped graphene oxide layer on the surface of the first flexible substrate and the metal electrode, and then reduce the graphene oxide layer on the second flexible substrate to form a mesh-shaped second graphene network on the second flexible substrate;

[0024] The second graphene mesh is the same size as the first graphene mesh, and the number of meshes in the second graphene mesh is greater than the number of meshes in the first graphene mesh;

[0025] Step 3, combining: the side of the first flexible substrate with the second graphene mesh and the side of the second flexible substrate with the first graphene mesh are opposite to each other and combined.

[0026] Preferably, as an improvement, the first graphene mesh is replaced with an LCP mesh;

[0027] In step 1, a first flexible substrate is taken, a layer of LCP film is bonded to the surface of the first flexible substrate by hot pressing, and a grid is processed on the LCP film by laser cutting technology to form an LCP mesh.

[0028] By adopting the above technical solution, a flexible electrode with the structure of the present application can be prepared, so the manufacturing method is patented.

[0029] Preferably, as an improvement, nitrogen is used as a shielding gas when reducing the graphene oxide layer. Using nitrogen as a shielding gas can prevent the metal electrode from being oxidized. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the top view structure of the graphene flexible electrode in the prior art.

[0031] Figure 2 Schematic diagram of the vertical cross-sectional structure of the graphene flexible electrode in Example 1.

[0032] Figure 3 This is a schematic diagram of the vertical cross-sectional structure of the graphene flexible electrode in Example 2.

[0033] Figure 4 This is a three-dimensional diagram of the metal pole piece in Example 2.

[0034] Figure 5 2 is a top view of the second graphene network.

[0035] Figure 6 2 is a top view of the first graphene network. DETAILED DESCRIPTION

[0036] The following is further described in detail through specific implementation methods:

[0037] The figure marks in the drawings of the specification include: flexible substrate 1, metal electrode 2, graphene sensing network 3, first flexible substrate 4, first graphene network 5, second graphene network 6, second flexible substrate 7, support block 8, metal pole piece 9, extrusion portion 10, support block limiting portion 11, separator 12, metal pole piece limiting portion 13, gap 14.

[0038] Example 1

[0039] Basically as attached Figure 2 、 Figure 5 and Figure 6 As shown: A graphene flexible electrode includes a first flexible substrate 4 and a second flexible substrate 7, wherein the first flexible substrate 4 is located below the second flexible substrate 7; the materials of the first flexible substrate 4 and the second flexible substrate 7 are both polymer film materials, and the polymer film materials include polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polyethylene naphthalate and polyimide.

[0040] The upper surface of the first flexible substrate 4 is provided with support blocks 8, which are located at both ends of the first flexible substrate. The upper surface of the first flexible substrate is covered with a first graphene mesh 5, and both ends of the first graphene mesh 5 are connected to the support blocks 8. The lower surface of the second flexible substrate 7 is fixed with a metal pole piece 9, which is located at both ends of the second flexible substrate 7. The lower surface of the second flexible substrate 7 is covered with a second graphene mesh 6, and the ends of the second graphene mesh 6 are connected to the lower surface of the metal pole piece 9. Figure 5 and Figure 6 As shown, the first and second graphene meshes 5 and 6 are each provided with multiple meshes. The meshes on the first and second graphene meshes 5 and 6 have the same size (their sides are the same length), and the second graphene mesh 6 has a greater number of meshes than the first graphene mesh 5. The ends of the first and second graphene meshes 5 and 6 are both pressed between the metal pole piece 9 and the support block 8. To ensure that the ends of the first and second graphene meshes 5 and 6 are fully compressed by the metal pole piece 9 and the support block 8, a compression portion 10 is integrally formed on the lower surface of the metal pole piece 9, which abuts against the support block 8.

[0041] A stopper is provided between the metal electrode 9 and the support block 8. Both the second flexible substrate 7 and the second graphene mesh 6 are bent downward, with the ends of the second flexible substrate 7 higher than the middle of the second flexible substrate 7, and the ends of the second graphene mesh 6 higher than the middle of the second graphene mesh 6. The second flexible substrate 7 bends in this manner: either the second flexible substrate 7 is formed into a curved state during molding, or the weight of the middle portion of the second flexible substrate 7 is greater than the weight of the ends of the second flexible substrate 7, causing the middle portion of the second flexible substrate 7 to bend downward under the action of gravity. Furthermore, in this embodiment, the first flexible substrate 4 is planar, meaning that it is flat during molding, or its weight is evenly distributed, making it flatter than the second flexible substrate 7.

[0042] The limiting portion in this embodiment is specifically fixed on the support block 8, so it is called the support block limiting portion 11. Specifically, the support block limiting portion 11 and the support block 8 are integrally formed, and the support block limiting portion 11 is bent upward and abuts against the outer wall of the metal pole piece 9 (the outer wall of the metal pole piece 9 is the side of the two metal pole pieces 9 away from each other).

[0043] The material of the metal pole piece 9 in this embodiment is one of platinum, titanium, copper, aluminum, nickel, tin, zinc, gold, and silver.

[0044] The following specifically describes a method for preparing a graphene flexible electrode, which includes the following steps:

[0045] Step 1: Take a first flexible substrate 4 and process a support block 8 on the first flexible substrate 4. The support block 8 has an upwardly extending support block limiter 11 integrally formed on the support block 8. In this embodiment, the support block 8 is integrally formed on the first flexible substrate 4. The specific method is as follows: when the first flexible substrate 4 is formed, the support blocks 8 can be directly formed at both ends of the first flexible substrate 4 in the mold. Alternatively, the middle portion of the first flexible substrate 4 can be cut off by laser cutting, so that the middle portion of the first flexible substrate 4 is thin and the thickness of the two ends is large, thereby forming support blocks 8 at the ends of the first flexible substrate 4.

[0046] A first graphene mesh 5 is then prepared on the first flexible substrate 4: multiple photoresist layers are applied to the top surface of the first flexible substrate 4 and the top surface of the support block 8, and then patterned; each photoresist layer is square, and the multiple photoresist layers are arranged in an array on the top surface of the first flexible substrate 4, with gaps between adjacent photoresist layers. A layer of graphene oxide is then spin-coated on the entire upper surface of the support block 8 and the entire upper surface of the first flexible substrate 4, with the graphene oxide layer simultaneously covering the photoresist layer. The photoresist layer and the graphene oxide layer located on the photoresist layer are then removed, thereby forming a graphene oxide mesh on the first flexible substrate 4 and the support block 8. Finally, heating is performed to reduce the graphene oxide mesh to form a grid-like first graphene mesh 5. Nitrogen is used as a protective gas during the above reduction process.

[0047] Step 2: Take the second flexible substrate 7, spray-coat a metal layer on the first flexible substrate 4, and use photolithography to transform the metal layer into metal pole pieces 9. A photoresist layer is applied to each end of the metal layer and patterned. The metal layer not covered by the photoresist layer is etched. The photoresist layer is removed, and the metal layer directly below the photoresist layer forms metal pole pieces 9. Metal pole pieces 9 are located at both ends of the second flexible substrate 7.

[0048] A mesh-shaped graphene oxide layer is then formed on the surface of the first flexible substrate 4 and the metal electrode 9 using photolithography. The graphene oxide layer on the second flexible substrate 7 is then reduced to form a mesh-shaped second graphene mesh 6 on the second flexible substrate 7. The specific preparation process of the second graphene mesh 6 on the second flexible substrate 7 is the same as the preparation process of the first graphene mesh 5 on the first flexible substrate 4 and will not be repeated here.

[0049] Combine Figure 5 and Figure 6 As shown, in this embodiment, the second graphene mesh 6 and the first graphene mesh 5 have the same overall size. That is, the outermost side length of the first graphene mesh 5 is equal to the outermost side length of the second graphene mesh 6. The grids on the first graphene mesh 5 and the second graphene mesh 6 are the same size, that is, the grid lengths are equal. However, the number of grids in the second graphene mesh 6 is greater than that in the first graphene mesh 5.

[0050] Step 3: Combining: The side of the first flexible substrate with the second graphene mesh 6 and the side of the second flexible substrate with the first graphene mesh 5 are aligned and combined. The specific combining method is: combining by hot glue.

[0051] Combine Figure 5 and Figure 6 As shown, in this embodiment, the number of grids on the second graphene mesh 6 is greater than the number of grids on the first graphene mesh 5. Therefore, when the overall size of the first graphene mesh 5 and the second graphene mesh 6 is the same, the overall edge length and edge area of the second graphene mesh 6 are greater than the overall edge length and edge area of the first graphene mesh 5. Therefore, the sensitivity of the second graphene mesh 6 is greater than the sensitivity of the first graphene mesh 5.

[0052] When external pressure is applied, it acts on the first flexible substrate 4. This force is transmitted through the first flexible substrate 4 to the first graphene mesh 5, causing deformation. This force is then transmitted to the second graphene mesh 6, causing deformation as well, resulting in a change in the resistance of the second graphene mesh 6. This change in resistance is output via the metal electrode 9. The output resistance is then calibrated with the external pressure, ultimately measuring the external pressure. In this embodiment, the external pressure does not act directly on the second graphene mesh 6, but first acts on the first graphene mesh 5. The first graphene mesh 5 then transmits the pressure to the second graphene mesh 6. In the process of transmitting pressure, the first graphene mesh 5 absorbs and reduces the pressure fluctuations and vibrations. In other words, the pressure level received by the second graphene mesh 6 is less than the pressure level initially applied to the first flexible substrate 4. As a result, the pressure vibrations, fluctuations, and pressure values received by the second graphene mesh 6 are smaller, making it less likely for the second graphene mesh 6 and the metal electrode 9 to crack or fall off, either entirely or partially. In addition, the second graphene mesh 6 is more sensitive due to the large number of meshes. Even if the pressure level transmitted to the second graphene mesh 6 is smaller than that of the existing technology, the second graphene mesh 6 can still detect the pressure, and the detection sensitivity of the sensor can be guaranteed.

[0053] For the first graphene mesh 5, although the first graphene mesh 5 receives a greater degree of pressure than the second graphene mesh 6, the number of grids of the first graphene mesh 5 is small and the mesh wires of the first graphene mesh 5 are thicker, thereby increasing the connection area of the end of the first graphene mesh 5. Even if the first graphene mesh 5 receives a greater degree of pressure, the end of the first graphene mesh 5 connected at the corresponding position is not prone to cracking or falling off.

[0054] In addition, in this embodiment, the end of the first graphene mesh 5 and the end of the second graphene mesh 6 are pressed by the support block 8 and the metal pole piece 9, thereby limiting the end of the first graphene mesh 5 and the end of the second graphene mesh 6 in the vertical direction, and the first graphene mesh 5 and the second graphene mesh 6 are not easy to detach and crack from the support block 8 and the metal pole piece 9, respectively.

[0055] At the same time, after being subjected to upward pressure, the first graphene mesh 5 changes from a flat surface to an upwardly arched state. The two ends of the first graphene mesh 5 tend to pull the two support blocks 8 toward each other. At the same time, after being subjected to upward pressure, the second graphene mesh 6 gradually changes from a downwardly curved state to a flat surface. The two ends of the second graphene mesh 6 tend to push the two metal pole pieces 9 away from each other. In this way, the two metal pole pieces 9 and the two support blocks 8 move in opposite directions. Under the action of the support block limiter 11, the two metal pole pieces 9 and the two support blocks 8 are pressed against each other, thereby increasing the pressure between the metal pole pieces 9 and the support blocks 8. The vertical friction between the metal pole pieces 9 and the support blocks 8 is relatively large, making it difficult for the two to slide vertically relative to each other. This ensures that when subjected to external pressure, the metal pole pieces 9 and the support blocks 8 will not separate and can still maintain a state of pressing the ends of the first graphene mesh 5 and the second graphene mesh 6. The ends of the first graphene mesh 5 and the second graphene mesh 6 are unlikely to fall off or crack from the support block 8 and the metal pole piece 9, respectively.

[0056] In addition, the mesh structure on the first flexible substrate 4 does not have to be made of graphene. The first graphene mesh 5 can also be replaced by an LCP mesh.

[0057] When the first graphene mesh 5 is replaced by an LCP mesh, the difference in the preparation method is that in step 1, a first flexible substrate 4 is taken, a layer of LCP film is bonded to the surface of the first flexible substrate 4 by hot pressing, and a grid is processed on the LCP film using laser cutting technology to form an LCP mesh.

[0058] Example 2

[0059] Combine Figure 3 and Figure 4 As shown, the limiting portion in this embodiment is integrally formed on the metal pole piece 9, which is called the metal pole piece limiting portion 13. The metal pole piece limiting portion 13 abuts against the inner side wall of the support block 8 (the side where the two support blocks 8 are close to each other). Figure 4 As shown, a plurality of partitions 12 are integrally formed on the metal pole piece 9 along the length direction of the metal pole piece 9, with gaps 14 between adjacent partitions 12, and a metal pole piece stopper 13 is integrally formed at the bottom of the partition 12. In this embodiment, the partitions 12 and the metal pole piece stopper 13 are both processed by laser cutting.

[0060] After the first flexible substrate 4 and the second flexible substrate 7 are combined, the end of the second graphene mesh 6 passes through the gap 14 between adjacent separators 12 and covers the metal electrode 9 (for a clear understanding, the separator 12 vertically passes through the gap 14 between adjacent separators 12). Figure 1The mesh holes on the end of the graphene sensing mesh 3 are shown in the figure. The separators 12 and the mesh lines at the end of the second graphene mesh 6 are arranged in an interlaced manner. The opposite sides of adjacent separators 12 are in contact with the second graphene mesh 6. At the same time, the separators 12 and the metal pole piece limiters 13 pass through the mesh at the end of the first graphene mesh 5. The separators 12 (or the metal pole piece limiters 13) and the mesh lines at the end of the first graphene mesh 5 are arranged in an interlaced manner. The metal pole piece limiters 13 abut against the inner wall of the support block 8.

[0061] In this embodiment, the metal pole piece limiting portion 13 and the support block 8 are opposed to each other, so that the pressure between the metal pole piece 9 and the support block 8 can be increased. The vertical friction between the metal pole piece 9 and the support block 8 is relatively large, and the two are not prone to vertical relative sliding. It can be ensured that when subjected to external pressure, the metal pole piece 9 and the support block 8 will not separate and can still maintain the state of pressing the end of the first graphene mesh 5 and the end of the second graphene mesh 6. The end of the first graphene mesh 5 and the end of the second graphene mesh 6 are not prone to fall off and crack from the support block 8 and the metal pole piece 9 respectively.

[0062] At the same time, the end mesh wires of the second graphene mesh 6 pass through the gaps 14 between adjacent separators 12 and cover the metal pole piece 9. The opposite sides of the adjacent separators 12 are in contact with the end mesh wires of the second graphene mesh 6, thereby increasing the contact area between the mesh wires of the second graphene mesh 6 and the metal pole piece 9 (the separator 12 is part of the metal pole piece 9). The second graphene mesh 6 can be attached to the side of the separator 12, so that the separator 12 has the function of limiting and fixing the end of the second graphene mesh 6, thereby making the second graphene mesh 6 less likely to crack and detach from the metal pole piece 9. Similarly, the metal pole piece limiting portion 13 passes through the grid at the end of the first graphene mesh 5, and the mesh wire at the end of the first graphene mesh 5 can be attached to the side of the separator 12 or the side of the metal pole piece limiting portion 13, thereby increasing the contact between the mesh wire at the end of the first graphene 5 and the side of the separator 12 (or the metal pole piece limiting portion 13). In this way, the separator 12 or the metal pole piece limiting portion 13 has the function of limiting and fixing the end of the first graphene mesh 5, thereby making the first graphene mesh 5 less likely to crack and detach from the support block 8.

[0063] The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A graphene flexible electrode, characterized in that: The invention comprises a first flexible substrate and a second flexible substrate, wherein the first flexible substrate is located below the second flexible substrate; the upper surface of the first flexible substrate is covered with a first graphene mesh; the lower surface of the second flexible substrate is fixed with metal pole pieces, the metal pole pieces are located at both ends of the second flexible substrate, and the lower surface of the second flexible substrate is covered with a second graphene mesh, the ends of the second graphene mesh are connected to the lower surface of the metal pole pieces; the first graphene mesh and the second graphene mesh are each provided with a plurality of grids, the grids on the first graphene mesh and the grids on the second graphene mesh are the same size, and the number of grids on the second graphene mesh is greater than the number of grids on the first graphene mesh; A support block is fixedly provided on the upper surface of the first flexible substrate, and the support block is located at both ends of the flexible substrate; the end of the first graphene mesh and the end of the second graphene mesh are both pressed between the metal electrode and the support block; A limiting portion is provided between the metal electrode and the support block; the second flexible substrate and the second graphene mesh are both bent downward, the end of the second flexible substrate is higher than the middle of the second flexible substrate, and the end of the second graphene mesh is higher than the middle of the second graphene mesh; The limiting portion is fixed on the support block and abuts against the outer side wall of the metal pole piece; or the limiting portion is fixed on the metal pole piece and abuts against the inner side wall of the support block.

2. The graphene flexible electrode according to claim 1, characterized in that: The limiting portion is fixed on the metal pole piece. When the limiting portion abuts against the inner side wall of the support block, a plurality of partitions are fixedly provided on the metal pole piece along the length direction of the metal pole piece, and there is a gap between adjacent partitions. The limiting portion is fixed at the bottom of the partition; the end of the second graphene mesh passes through the gap between adjacent partitions and covers the metal pole piece, and the opposite sides of the adjacent partitions are in contact with the second graphene mesh; the limiting portion passes through the grid at the end of the first graphene mesh and abuts against the inner wall of the support block.

3. The graphene flexible electrode according to claim 1, characterized in that: The lower surface of the metal pole piece is provided with an extrusion portion protruding therefrom, and the extrusion portion abuts against the support block.

4. The graphene flexible electrode according to claim 3, characterized in that: The metal pole piece material is one of platinum, titanium, copper, aluminum, nickel, tin, zinc, gold and silver.

5. A graphene flexible electrode according to any one of claims 1 to 4, characterized in that: The first graphene mesh is replaced by an LCP mesh.

6. A method for preparing a graphene flexible electrode according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Take a first flexible substrate, prepare a mesh-shaped graphene oxide layer on the first flexible substrate using a photolithography technique, and then reduce the graphene oxide layer to form a mesh-shaped first graphene network on the first flexible substrate; Step 2: Take the second flexible substrate, spray a metal layer on the first flexible substrate, and use photolithography technology to transform the metal layer into a metal electrode; Then, a mesh-shaped graphene oxide layer is prepared on the surface of the first flexible substrate and the metal electrode using a photolithography technique, and then the graphene oxide layer on the second flexible substrate is reduced to form a mesh-shaped second graphene mesh on the second flexible substrate; The second graphene mesh is the same size as the first graphene mesh, and the number of meshes in the second graphene mesh is greater than the number of meshes in the first graphene mesh; Step 3, combining: the side of the first flexible substrate with the second graphene mesh and the side of the second flexible substrate with the first graphene mesh are opposite to each other and combined.

7. The preparation method according to claim 6, characterized in that: replacing the first graphene mesh with an LCP mesh; In step 1, a first flexible substrate is taken, a layer of LCP film is bonded to the surface of the first flexible substrate by hot pressing, and a grid is processed on the LCP film by laser cutting technology to form an LCP mesh.

8. The preparation method according to claim 6 or 7, characterized in that: When reducing the graphene oxide layer, nitrogen was used as the protective gas.

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