A method for preparing a fully printed stretchable triboelectric pressure sensor array

Abstract

The present invention discloses a method for preparing a fully printed stretchable triboelectric pressure sensor array, wherein the triboelectric pressure sensor array prepared by the method comprises a friction sensing layer, an array electrode layer and a packaging layer; the method comprises: selecting a printing device and a substrate layer; setting printing parameters, printing a friction sensing layer on the upper surface of the substrate layer, wherein the upper surface of the friction sensing layer is in a groove-wrinkle shape; after the friction sensing layer is solidified and formed, removing the substrate layer; performing an elastic deformation operation on the friction sensing layer, and printing an array electrode layer on the lower surface of the deformed friction sensing layer; performing a reduction operation on the friction sensing layer, wherein the lower surface of the friction sensing layer and the array electrode layer are deformed into a wrinkle shape; and printing a packaging layer on the lower surface of the friction sensing layer to complete the preparation process. The method provided by the present invention has a simple preparation process, saves preparation time and materials, and improves manufacturing efficiency; the prepared triboelectric pressure sensor array has sensitive touch and pressure sensing performance and excellent response performance.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of triboelectric pressure sensor arrays, and more specifically, to a method for preparing a fully printed stretchable triboelectric pressure sensor array. Background Art

[0002] As the only functional device for data collection, the sensor is the basic core component of information technology. The collected data is the "blood" flowing in the entire perception, transmission and processing information system. As a new type of nano energy technology, the triboelectric sensor is a small-scale energy collection and conversion device that converts mechanical signals into electrical signals based on the coupling of friction electrification and electrostatic induction. It has the advantages of self-driving, high energy conversion efficiency, simple structure, clean and efficient, etc. It has broad application prospects in the fields of self-driven sensing, implantable medical devices, electronic skin, etc.

[0003] The friction sensing layer of the friction electric pressure sensor array contacts and separates with external objects under the action of external force, generating a negative potential on the surface of the friction sensing layer, and using electrostatic induction to achieve electrical signal transmission through external electrodes; therefore, the friction sensing layer has a huge impact on the sensing performance of the sensor array. Currently, the commonly used friction electric pressure sensor arrays use the following methods to enhance performance: (1) adding graphene, carbon nanotubes and other materials inside the friction sensing layer; (2) preparing a porous friction sensing layer; (3) forming a film on the electrode surface by spin coating, magnetron sputtering and other methods, and then using etching methods to manufacture microstructures on the surface of the friction sensing layer film. The above methods have complex manufacturing processes, high costs, low manufacturing efficiency, and cannot accurately control the formation of the functional structure of the friction sensing layer. The manufactured sensor array has insensitive touch pressure sensing performance and poor response performance.

[0004] Chinese patent CN108515694A published on September 11, 2018 discloses a flexible pressure sensor chip based on 3D printing technology and its manufacturing method. First, the flexible upper and lower plates are 3D printed and cleaned; then the conductive glue is used to tightly adhere the wires to the flexible upper and lower plates and solidify; then the flexible upper and lower plates are treated with oxygen plasma, soaked with a layer of PEDOT:PSS solution, and baked to complete the production of flexible thin film electrodes; finally, polyimide insulating tape is used to stick the flexible upper and lower plates together, and the side gaps of the flexible upper and lower plates are closed at the same time; although the upper and lower plates of the flexible pressure sensor chip prepared by this method are flexible, they have a small specific surface area, are not sensitive to touch pressure under deformation conditions, and have poor response performance. Summary of the invention

[0005] In order to overcome the defects of the friction electric pressure sensor array prepared by the above-mentioned prior art, such as insensitive touch and pressure sensing performance and poor response performance, the present invention provides a method for preparing a fully printed stretchable friction electric pressure sensor array. The prepared friction electric pressure sensor array has sensitive touch and pressure sensing performance and excellent response performance.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] The present invention provides a method for preparing a fully printed stretchable triboelectric pressure sensor array. The triboelectric pressure sensor array prepared by the method comprises a friction sensing layer, an array electrode layer and a packaging layer. The method comprises the following steps:

[0008] S1: Select the printing equipment and the substrate layer for preparing the triboelectric pressure sensor array;

[0009] S2: setting printing parameters of a printing device, and using the printing device to print a friction sensing layer on the upper surface of the substrate layer, wherein the upper surface of the friction sensing layer is in a groove-wrinkle shape;

[0010] S3: performing a curing operation on the friction sensing layer, and removing the substrate layer after the friction sensing layer is cured and formed;

[0011] S4: performing an elastic deformation operation on the friction sensing layer, and printing an array electrode layer on the lower surface of the deformed friction sensing layer using a printing device;

[0012] S5: performing a reduction operation on the friction sensing layer, so that the lower surface of the friction sensing layer and the array electrode layer are deformed into a wrinkled shape;

[0013] S6: Printing a packaging layer on the lower surface of the friction sensing layer using a printing device to complete the preparation of the friction electric pressure sensor array.

[0014] Preferably, the substrate layer is a metal film or an organic film. A metal film such as an aluminum film, a copper film or an organic film is selected as the substrate layer. The surface of the substrate layer has an ultra-high flatness, which is conducive to the preparation of the friction sensing layer.

[0015] Preferably, the friction sensing layer is printed using friction sensing layer printing ink; the friction sensing layer printing ink is made of an electronegative flexible material and filled with nanomaterials.

[0016] The electronegative flexible material is PDMS or silicone, and the filled nanomaterial is one or more of carbon nanotubes, two-dimensional materials, and nanometals; the friction sensing layer prepared by selecting the electronegative flexible material has the advantages of being light, thin, flexible, stretchable, chemically stable, thermally stable, and having a strong ability to attract electrons, thereby improving the environmental adaptability, sensitivity, and response performance of the friction electric pressure sensor array;

[0017] The filled nanomaterials enhance the sensing performance of the triboelectric pressure sensor array.

[0018] Preferably, the friction sensing layer is printed by ink direct writing 3D printing method;

[0019] The printing parameters of the printing device are specifically set as follows: selecting a nozzle diameter of 100-600 microns, setting the height between the nozzle and the substrate layer to 80-600 microns, controlling the printing speed to 20-200 mm / min, and setting the printing path. By setting the printing parameters of the printing device, a groove structure is formed on the surface of the prepared friction sensing layer, a wrinkle structure is formed at the bottom of the groove, and a groove-wrinkle-shaped micro-groove array is formed as a whole, with a regular distribution, which expands the specific surface area of ​​the friction sensing layer surface, strengthens the generation of friction charges, has high sensitivity, and improves the response performance of the friction electric pressure sensor array. The use of ink direct writing 3D printing method simplifies the preparation process, saves preparation time, and improves preparation efficiency.

[0020] Preferably, when a metal film is selected as the substrate layer, an acidic solution is used to remove the substrate layer; when an organic film is selected as the substrate layer, a release agent is sprayed on the surface of the organic film to separate and remove the substrate layer.

[0021] Preferably, an external force is applied to the friction sensing layer in two or four directions to make the friction sensing layer produce tensile elastic deformation, and the deformation amount is 10%-200%. After the friction sensing layer produces tensile elastic deformation, an array electrode is prepared on the back of the friction sensing layer. After the preparation is completed, the applied external force is removed, the friction sensing layer is restored, and the lower surface of the friction sensing layer and the electrodes on the array electrode layer are both wrinkled, so that the friction electric pressure sensor array still has good sensing ability under tensile deformation conditions and adapts to a richer use environment.

[0022] Preferably, the array electrode layer is printed using electrode printing ink; the electrode printing ink is configured from a conductive liquid metal material or a conductive liquid polymer.

[0023] Conductive liquid metal materials such as nanosilver, conductive liquid polymers such as PEDOT:PSS, polypyrrole, one or more of them are selected as electrode printing ink.

[0024] Preferably, the array electrode layer is printed by inkjet printing or ink direct writing 3D printing, and the array electrode layer has a thickness of 200-700 microns and a sheet resistance of 0.3-1.52 ohms / square meter.

[0025] Preferably, the encapsulation layer is printed with an encapsulation layer printing ink; the material of the encapsulation layer printing ink is a flexible curing sealant. The flexible curing sealant cures quickly, has softness after curing, and has a good encapsulation effect.

[0026] Preferably, the encapsulation layer is printed by an ink direct writing 3D printing method, and the thickness of the encapsulation layer is 300-800 microns.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] (1) The upper surface of the friction sensing layer prepared by the method for preparing the fully printed stretchable triboelectric pressure sensor array proposed in the present invention is grooved and wrinkled, and the function of the upper surface of the friction sensing layer is to receive external friction and touch pressure. The grooved and wrinkled upper surface expands the specific surface area of ​​the friction sensing layer, strengthens the generation of triboelectric charge, has high sensitivity, and improves the response performance to touch pressure sensing;

[0029] (2) The array sensing layer prepared by the fully printed stretchable triboelectric pressure sensor array preparation method proposed in the present invention is wrinkled and still has sensing ability under deformation conditions, adapting to a richer use environment and improving the response performance;

[0030] (3) The fully printed stretchable triboelectric pressure sensor array preparation method proposed in the present invention adopts a fully printed method to prepare all structures of the triboelectric pressure sensor array. The process is simple, saves preparation time and materials, and improves manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a structural diagram of the friction electric pressure sensor array described in the embodiment;

[0032] Figure 2 It is a flow chart of the method for preparing the fully printed stretchable triboelectric pressure sensor array described in the embodiment;

[0033] Figure 3 A schematic diagram of printing a friction sensing layer on a substrate layer according to an embodiment;

[0034] Figure 4 This is a schematic diagram of printing an array electrode layer on the back of the friction sensing layer after elastic deformation according to an embodiment;

[0035] Figure 5 This is a schematic diagram of the friction sensing layer that is restored after the array electrode layer is prepared as described in the embodiment;

[0036] Figure 6 This is a schematic diagram of printing a packaging layer on the back of a friction sensing layer according to an embodiment;

[0037] Figure 7 A schematic diagram of the groove-wrinkle composite structure on the surface of the friction sensing layer described in the embodiment;

[0038] Figure 8 is a schematic diagram of electrodes on the array electrode layer described in the embodiment;

[0039] Fig. 9 A schematic diagram of the electrode wrinkle structure on the array electrode layer after the external force is removed according to the embodiment;

[0040] Among them, 1 is a friction sensing layer, 2 is an array electrode layer, 3 is a packaging layer, and 4 is a substrate layer. DETAILED DESCRIPTION

[0041] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0042] In order to better illustrate the present embodiment, some parts in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product;

[0043] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0044] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] Example

[0046] This embodiment provides a method for preparing a fully printed stretchable triboelectric pressure sensor array. Figure 1 As shown, the triboelectric pressure sensor array prepared by the method comprises a triboelectric sensing layer 1, an array electrode layer 2 and a packaging layer 3; Figure 2 As shown, the method comprises the following steps:

[0047] S1: Selecting a printing device and a substrate layer 4 for preparing a triboelectric pressure sensor array;

[0048] A metal film such as an aluminum film, a copper film or an organic film is selected as the substrate layer 4. A metal film such as an aluminum film, a copper film or an organic film is selected as the substrate layer 4. The surface of the substrate layer 4 has ultra-high flatness, which is conducive to the subsequent preparation of the friction electric pressure sensor array.

[0049] S2: setting printing parameters of a printing device, and using the printing device to print a friction sensing layer 1 on the upper surface of the substrate layer 4, wherein the upper surface of the friction sensing layer 1 is in a groove-wrinkle shape;

[0050] like Figure 3As shown, the friction sensing layer 1 is printed on the upper surface of the substrate layer 4 using friction sensing layer printing ink, and the friction sensing layer printing ink is selected from electronegative flexible materials and filled with nanomaterials. In this embodiment, the electronegative flexible material is PDMS or silica gel, and the filled nanomaterial is one or more of carbon nanotubes, two-dimensional materials, and nanometals; the friction sensing layer 1 prepared by selecting electronegative flexible materials has the advantages of being light, thin, flexible, stretchable, chemically stable, thermally stable, and having strong ability to attract electrons, thereby improving the environmental adaptability, sensitivity, and response performance of the friction electric pressure sensor array;

[0051] The friction sensing layer 1 is printed by ink direct writing 3D printing method, and the printing parameters of the printing equipment are set: the nozzle diameter is selected to be 100-600 microns, the height between the nozzle and the substrate layer is set to be 80-600 microns, the printing speed is controlled to be 20-200 mm / min, and the printing path is set to print the friction sensing layer 1. The surface of the prepared friction sensing layer 1 forms a groove shape, and the bottom of the groove forms a fold shape, forming a composite groove-fold-shaped micro-groove array as a whole. The groove-fold composite structure on the surface of the friction sensing layer 1 is as follows Figure 7 shown.

[0052] S3: performing a curing operation on the friction sensing layer 1, and removing the substrate layer 4 after the friction sensing layer 1 is cured and formed;

[0053] The friction sensing layer 1 is solidified and formed by standing in the air for more than 24 hours; when a metal film is used as the substrate layer 4, the substrate layer 4 is removed by using an acid solution; when an organic film is used as the substrate layer 4, a release agent is sprayed on the surface of the organic film to separate and remove the substrate layer 4.

[0054] S4: performing an elastic deformation operation on the friction sensing layer 1, and printing the array electrode layer 2 on the lower surface of the deformed friction sensing layer 1 by using a printing device;

[0055] In this embodiment, external force is applied to the friction sensing layer 1 in two directions or four directions, so that the friction sensing layer 1 undergoes tensile elastic deformation, and the deformation amount is 10%-200%;

[0056] The array electrode layer 2 is printed using electrode printing ink, wherein the electrode printing ink is configured from a conductive liquid metal material or a conductive liquid polymer. In this embodiment, one or more conductive liquid metal materials such as nanosilver and conductive liquid polymers such as PEDOT:PSS and polypyrrole are selected as the electrode printing ink.

[0057] like Figure 4As shown, after the friction sensing layer 1 is stretched and elastically deformed, an array electrode layer 2 is printed on the back of the friction sensing layer 1 by inkjet printing or ink direct writing 3D printing. The thickness of the array electrode layer 2 is 200-700 microns, and the square resistance is 0.3-1.52 ohms / square meter. The electrodes on the array electrode layer 2 are as shown in FIG. Figure 8 As shown;

[0058] S5: performing a reduction operation on the friction sensing layer 1 , so that the lower surface of the friction sensing layer 1 and the array electrode layer 2 are deformed into a wrinkled shape.

[0059] like Figure 5 As shown, after the array electrode layer 2 is prepared, the applied external force is removed, the friction sensing layer 1 is restored, and the lower surface of the friction sensing layer 1 and the electrodes on the array electrode layer 2 are deformed into wrinkles; when the electrodes are deformed into wrinkles, Fig. 9 shown.

[0060] The electrodes on the array electrode layer 2 are deformed into a wrinkled shape, so that they still have sensing capabilities under tensile deformation conditions and can adapt to a richer usage environment; nanosilver, PEDOT:PSS, and polypyrrole all have good conductivity and can conduct all the charges generated by the friction sensing layer 1, thereby enhancing the response performance.

[0061] S6: using a printing device to print the encapsulation layer 3 on the lower surface of the friction sensing layer 1 to complete the preparation of the friction electric pressure sensor array.

[0062] The encapsulation layer 3 is printed using an encapsulation layer printing ink; the material of the encapsulation layer printing ink is a flexible curing sealant. Figure 6 As shown, in this embodiment, after the friction sensing layer 1 is pre-stretched, the packaging layer 3 is printed on the friction sensing layer 1 by using an ink direct writing 3D printing method, and the thickness of the packaging layer 3 is 300-800 microns.

[0063] The method for preparing a fully printed stretchable triboelectric pressure sensor array proposed in this embodiment is based on the principle of additive manufacturing. It manufactures parts by adding materials layer by layer, which can save a lot of time and raw material costs and can manufacture complex structures. The structure of each layer of the triboelectric pressure sensor array is prepared by a full printing method and ink direct writing 3D printing technology, and is solidified on the work surface of the printing equipment to form a complete triboelectric pressure sensor array, directly realizing the surface enhanced sensing structure, improving the sensing performance of the triboelectric pressure sensor array, and the preparation process is simple, saving preparation time and preparation materials, and improving manufacturing efficiency.

[0064] By selecting electronegative flexible material as the friction sensing layer printing ink, the printed friction sensing layer 1 is flexible and can be stretched; the array electrode layer 2 is printed on the lower surface of the friction sensing layer 1 after elastic deformation, and the array electrode layer 2 is also stretchable after the deformation is recovered; after the friction sensing layer 1 recovers the deformation, the packaging layer 3 is printed using a flexible curing sealant, and the packaging layer 3 is also stretchable; after curing, a complete friction electric pressure sensor array is formed, which is also stretchable; the upper surface of the friction sensing layer 1 is a groove-wrinkle structure, which increases the specific surface area of ​​the friction sensing layer 1, and cooperates with the wrinkled array electrode layer 2, so that it can also respond to touch pressure sensing in a stretched state, and completely conduct the charge generated by the friction sensing layer 1, and the friction electric pressure sensor array has sensitive sensing performance and excellent response performance.

[0065] The same or similar reference numerals correspond to the same or similar components;

[0066] The terms used in the drawings to describe positional relationships are only used for illustrative purposes and should not be construed as limiting this patent;

[0067] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a fully printed stretchable triboelectric pressure sensor array, characterized in that: The triboelectric pressure sensor array prepared by the method comprises a triboelectric sensing layer (1), an array electrode layer (2) and a packaging layer (3); the method comprises the following steps: S1: Selecting a printing device and a substrate layer (4) for preparing a triboelectric pressure sensor array; S2: setting printing parameters of a printing device, and using the printing device to print a friction sensing layer (1) on the upper surface of the substrate layer (4), wherein the upper surface of the friction sensing layer (1) is in a groove-wrinkle shape; a groove structure is formed on the upper surface of the friction sensing layer (1), and a wrinkle structure is formed at the bottom of the groove, thereby forming a groove-wrinkle micro-groove array as a whole; S3: performing a curing operation on the friction sensing layer (1), and after the friction sensing layer (1) is cured and formed, removing the substrate layer (4); S4: performing an elastic deformation operation on the friction sensing layer (1), and using a printing device to print an array electrode layer (2) on the lower surface of the deformed friction sensing layer (1); Performing an elastic deformation operation on the friction sensing layer (1) includes: applying external force to the friction sensing layer (1) in two directions or four directions, so that the friction sensing layer (1) generates a tensile elastic deformation; S5: performing a reduction operation on the friction sensing layer (1), so that the lower surface of the friction sensing layer (1) and the array electrode layer (2) are deformed into a wrinkled shape; S6: using a printing device to print the packaging layer (3) on the lower surface of the friction sensing layer (1), thereby completing the preparation of the friction electric pressure sensor array.

2. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 1, characterized in that: The substrate layer (4) is a metal film or an organic film.

3. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 1, characterized in that: A friction sensing layer (1) is printed using friction sensing layer printing ink; the friction sensing layer printing ink is prepared by selecting an electronegative flexible material and filling it with nanomaterials.

4. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 3, characterized in that: Printing the friction sensing layer (1) by using an ink direct writing 3D printing method; The printing parameters of the printing device are specifically set as follows: selecting a nozzle diameter of 100-600 microns, setting the height between the nozzle and the substrate layer to 80-600 microns, controlling the printing speed to 20-200 mm / min, and setting the printing path.

5. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 2, characterized in that: When a metal film is selected as the substrate layer (4), an acidic solution is used to remove the substrate layer (4); when an organic film is selected as the substrate layer (4), a release agent is sprayed on the surface of the organic film to separate and remove the substrate layer (4).

6. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 1, characterized in that: External force is applied to the friction sensing layer (1) in two directions or four directions, so that the friction sensing layer (1) undergoes tensile elastic deformation, with the deformation amount being 10%-200%.

7. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 1, characterized in that: The array electrode layer (2) is printed using electrode printing ink; the electrode printing ink is configured from a conductive liquid metal material or a conductive liquid polymer.

8. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 7, characterized in that: The array electrode layer (2) is printed by inkjet printing or ink direct writing 3D printing, wherein the thickness of the array electrode layer (2) is 200-700 microns and the sheet resistance is 0.3-1.52 ohms / square meter.

9. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 1, characterized in that: The encapsulation layer (3) is printed using encapsulation layer printing ink; the material of the encapsulation layer printing ink is a flexible curing sealant.

10. The method for preparing a fully printed stretchable triboelectric pressure sensor array according to claim 9, characterized in that: The encapsulation layer (3) is printed by an ink direct writing 3D printing method, and the thickness of the encapsulation layer (3) is 300-800 microns.

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