Electronic pressure sensing paper
By using a grid design of flexible insulating substrate and conductive layer, the problem of bonding electronic pressure-sensitive paper to complex curved surfaces is solved, improving the accuracy and applicability of pressure measurement.
Patent Information
- Application Number
- CN202520525073.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-03-24
AI Technical Summary
Existing electronic pressure-sensitive paper has high requirements for the flatness of the pressure-sensitive surface and is difficult to adapt to complex curvature changes. It cannot achieve good pressure measurement results in situations where the contact surface is arc-shaped or has a large curvature, resulting in a decrease in pressure detection accuracy.
The structure adopts a flexible insulating substrate, a conductive layer, and a flexible insulating protective layer. The conductive layer has conductive lines and projection overlap points in the direction perpendicular to the flexible insulating substrate. An array of conductive voltage-sensitive particles is set on the conductive lines. The flexible insulating protective layer covers the conductive lines and conductive voltage-sensitive particles, forming a grid structure that can adapt to various shaped surfaces.
It achieves good adhesion of electronic pressure-sensitive paper to complex curved surfaces, broadens the scope of application, and improves the accuracy and applicability of pressure measurement.
Smart Images
Figure CN223925879U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to pressure measurement technical field especially relates to an electronic pressure sensing paper. BACKGROUND
[0002] The pressure sensing paper is a film material that can accurately measure pressure, pressure distribution and pressure balance. The traditional pressure sensing paper distinguishes pressure conditions according to whether the pressure mark has color and the color depth by pressure color display, and the pressure size cannot be presented in numerical value. In order to solve the shortcoming that the traditional pressure sensing paper cannot be pressure data, the electronic pressure sensing paper is developed. However, the existing electronic pressure sensing paper has high flatness requirement for the pressure sensing surface, is difficult to adapt to complex curvature change, and cannot realize good pressure measurement effect in the occasion where the contact surface is arc or has large curvature, resulting in the decline of pressure detection precision. SUMMARY
[0003] Therefore, the utility model discloses an electronic pressure sensing paper, which is beneficial to solve at least part of the above problems in the prior art.
[0004] The electronic pressure sensing paper provided by the utility model embodiment comprises a flexible insulating base material, a conductive layer, a piezoresistive layer and a flexible insulating protective layer. The conductive layer is arranged on one side of the flexible insulating base material, and the conductive layer has a conductive circuit, and the conductive circuit has at least one projection overlapping point in the direction perpendicular to the flexible insulating base material. The piezoresistive layer has a plurality of conductive pressure-sensitive particles arranged on the conductive circuit, and the plurality of conductive pressure-sensitive particles are arranged at intervals to form a conductive pressure-sensitive particle array, and at least one conductive pressure-sensitive particle is arranged at the projection overlapping point. The flexible insulating protective layer is arranged at least partially on the side of the piezoresistive layer opposite to the flexible insulating base material.
[0005] Further, the conductive layer comprises a lower conductive layer and an upper conductive layer. The lower conductive layer is arranged between the piezoresistive layer and the flexible insulating base material, the upper conductive layer is arranged on the side of the piezoresistive layer opposite to the lower conductive layer, the conductive circuit of the upper conductive layer and the conductive circuit of the lower conductive layer are at least partially staggered, and at least part of the conductive pressure-sensitive particles are arranged at the projection overlapping point between the conductive circuit of the upper conductive layer and the conductive circuit of the lower conductive layer.
[0006] Further, the flexible insulating base material comprises a first curved portion, and at least part of the conductive pressure-sensitive particles are arranged in the first curved portion. The flexible insulating protective layer has a second curved portion corresponding to the first curved portion.
[0007] Further, the first curved portion has a concave surface, the conductive circuit is arranged on the concave surface and comprises a plurality of annular circuits arranged concentrically, each annular circuit is provided with a plurality of conductive pressure-sensitive particles, and the center of the annular circuit is arranged at the bottom of the concave surface.
[0008] Further, the conductive circuit further comprises a radial circuit extending along a radial direction of the annular circuit, and the conductive pressure-sensitive particles are arranged at the projection overlapping points between the annular circuit and the radial circuit.
[0009] Further, the conductive pressure-sensitive particles have a height of 0.2 mm and a diameter of 0.2 mm.
[0010] Further, the conductive circuit has a line width of 20-100 microns.
[0011] Further, the conductive pressure-sensitive particles comprise carbon nanotube elastomers.
[0012] Further, the protective layer comprises an aluminum oxide layer and a polydimethylsiloxane layer arranged on one side of the aluminum oxide layer.
[0013] Further, the conductive circuit comprises an interdigital electrode.
[0014] The electronic pressure-sensitive paper provided by the embodiment of the present application has good flexibility and can fully adapt to surfaces of various shapes, thereby widening the application range of the electronic pressure-sensitive paper. BRIEF DESCRIPTION OF DRAWINGS
[0015] The above and other objects, features and advantages of the present application will become more apparent from the following description of the embodiments of the present application taken with reference to the accompanying drawings, in which:
[0016] Figure 1 is a top view structural schematic diagram of the electronic pressure-sensitive paper of one embodiment of the present application;
[0017] Figure 2 is a sectional view structural schematic diagram of the electronic pressure-sensitive paper of one embodiment of the present application;
[0018] Figure 3 is a top view structural schematic diagram of the electronic pressure-sensitive paper of another embodiment of the present application;
[0019] Figure 4 is a sectional view structural schematic diagram of the electronic pressure-sensitive paper of another embodiment of the present application.
[0020] EXPLANATION OF REFERENCE NUMERALS:
[0021] 1 - flexible insulating substrate; 11 - first bending portion; 12 - concave surface; 2 - conductive layer; 21 - conductive line; 211 - annular line; 212 - radial line; 22 - upper conductive layer; 23 - lower conductive layer; 3 - piezoresistive layer; 31 - conductive piezoresistive particles; 4 - flexible insulating protective layer; 41 - second bending portion. DETAILED DESCRIPTION
[0022] The present application is described herein below based on examples, but the present application is not limited to only these examples. In the following detailed description of the present application, some specific details are described in detail. The present application can also be fully understood without the description of these details by those skilled in the art. In order to avoid confusion of the essence of the present application, well-known methods, processes, procedures, elements and circuits are not described in detail.
[0023] In addition, those of ordinary skill in the art will understand that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.
[0024] Unless otherwise clearly indicated and limited, the terms "mount", "connect", "connection", "fixed", and the like, should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0025] For ease of description, spatially relative terms such as "inner", "outer", "below", "lower", "bottom", "top", "upper", and the like, are used herein for describing the relationship of one element or feature to another element or feature as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.
[0026] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".
[0027] In the description of the present application, it should be understood that the terms "first", "second", and the like are used only for the purpose of description and should not be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.
[0028] Figures 1-4 is a structural schematic diagram of an electronic pressure-sensitive paper according to an embodiment of the present application, wherein Figure 1 is a top view of the electronic pressure-sensitive paper according to an embodiment of the present application, Figure 2 is Figure 1 is a sectional view of the electronic pressure-sensitive paper according to an embodiment of the present application. Figure 3 is a top view of the electronic pressure-sensitive paper according to another embodiment of the present application, Figure 4 is Figure 3 is a sectional view of the electronic pressure-sensitive paper according to another embodiment of the present application. Referring to Figures 1-4 , the present application provides an electronic pressure-sensitive paper, which comprises a flexible insulating substrate 1, a conductive layer 2, a piezoresistive layer 3 and a flexible insulating protective layer 4. The conductive layer 2 is arranged on one side of the flexible insulating substrate 1 and has a conductive circuit 21. The piezoresistive layer 3 has a plurality of conductive pressure-sensitive particles 31, which are arranged as an array of conductive pressure-sensitive particles 31 as pressure sensing points and are arranged at intervals. The conductive pressure-sensitive particles 31 are arranged on the conductive circuit 21. When the conductive pressure-sensitive particles 31 are pressed, the resistance between the conductive pressure-sensitive particles 31 and the conductive circuit 21 changes, and thus the pressure applied to the electronic pressure-sensitive paper at different positions can be determined according to the resistance characteristics of the electronic pressure-sensitive paper. The flexible insulating protective layer 4 is arranged at least partially on the side of the piezoresistive layer 3 opposite to the flexible insulating substrate 1.
[0029] The flexible insulating substrate 1 can be made of a flexible polymer material film, such as polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN) and the like, which has good flexibility so that the electronic pressure-sensitive paper can be attached to surfaces of various shapes.
[0030] In an embodiment, the conductive pressure-sensitive particles 31 are pressure-sensitive elastomers with conductive properties, such as elastomers mixed with carbon nanotubes. The conductive pressure-sensitive particles 31 can have a cylindrical shape, a prismatic shape, a circular truncated cone shape, a pyramid shape, a prismatic truncated cone shape, a strip shape or other shapes. In some embodiments, the conductive pressure-sensitive particles 31 can have a cylindrical shape, which is convenient for manufacturing and size control. Optionally, the height of the conductive pressure-sensitive particles 31 is 0.2 mm and the diameter is 0.2 mm.
[0031] The conductive circuit 21 can be made of conductive metal (such as copper, silver, etc.), carbon conductive circuit 21, graphene film, flexible transparent electrode, etc. The conductive circuit 21 is formed by printing, vacuum plating or other methods on the surface of the flexible insulating substrate 1 and patterning. In the present embodiment, the line width of the conductive circuit 21 is 20-100 microns. In an embodiment, the conductive circuit 21 can include interdigital electrodes.
[0032] The flexible insulating protective layer 4 at least partially covers the conductive circuit 21 and the conductive pressure-sensitive particles 31 to achieve encapsulation and protection of the circuit. The flexible insulating protective layer 4 can be made of flexible and stable insulating materials such as light-cured glue, polydimethylsiloxane (PDMS) film, etc. In one embodiment, the flexible insulating protective layer 4 includes an aluminum oxide layer and a polydimethylsiloxane layer disposed on one side of the aluminum oxide layer. The flexible insulating protective layer 4 can achieve encapsulation of the conductive layer 2 and the piezoresistive layer 3 through bonding with the flexible insulating substrate 1.
[0033] In some embodiments, referring to Figure 2 , the conductive layer 2 includes a lower conductive layer 23 and an upper conductive layer 22, the lower conductive layer 23 is disposed between the piezoresistive layer 3 and the flexible insulating substrate 1, and the upper conductive layer 22 is disposed on the side of the piezoresistive layer 3 opposite to the lower conductive layer 23. The upper conductive layer 22 and the lower conductive layer 23 are insulated from each other and staggered together to conduct the piezoelectric signal of each conductive pressure-sensitive particle 31. For example, the regions of the upper conductive layer 22 opposite to the lower conductive layer 23 have insulating layers. The conductive circuit 21 of the upper conductive layer 22 and the conductive circuit 21 of the lower conductive layer 23 are at least partially staggered, referring to Figure 1 , when viewed in the direction perpendicular to the electronic pressure-sensitive paper, the conductive circuit 21 is staggered to form a mesh, the transverse part of the conductive circuit 21 in the figure is used to illustrate the lower conductive layer 23, and the longitudinal part of the conductive circuit 21 in the figure is used to illustrate the upper conductive layer 22. As shown, at least part of the conductive pressure-sensitive particles 31 are disposed at the projection overlapping points between the conductive circuit 21 of the upper conductive layer 22 and the conductive circuit 21 of the lower conductive layer 23 in the direction perpendicular to the flexible insulating substrate 1 (i.e., the direction perpendicular to the plane of the figure of Figure 1 .
[0034] It should be understood that, Figure 2 and Figure 4 only schematically show the multi-layer structure and the schematic stacking position of each layer, and are not a limitation on the actual shape of the cross section of the electronic pressure-sensitive paper. For example, although there are gaps between the flexible insulating protective layer 4 and the lower conductive layer 2 in Figure 4 , in fact, the flexible insulating protective layer 4 can be filled in these gaps.
[0035] In some embodiments, the electronic pressure-sensitive paper is formed as a curved surface, which can be applied to occasions where the contact surface is a curved surface or has a large curvature to achieve pressure sensing. Referring to Figure 3 and Figure 4The flexible insulating substrate 1 includes a first curved portion 11, and at least a portion of the conductive voltage-sensitive particles 31 are disposed on the first curved portion 11. The curvature of the first curved portion 11 can be specifically selected according to the needs of the application scenario. For example, it can be designed according to the curvature of the contact surface of the predetermined detection scenario to fully fit the contact surface. The flexible insulating protective layer 4 has a second curved portion 41 corresponding to the first curved portion 11. The curvature of the second curved portion 41 corresponds to the curvature of the first curved portion 11, so that the first curved portion 11 and the second curved portion 41 sandwich the conductive layer 2 and the piezoresistive layer 3 between them, and the surface of the electronic pressure-sensitive paper is formed as a curved surface with a predetermined curved shape, for example, it can be formed as a partially spherical surface.
[0036] In one embodiment, the conductive line 21 is disposed on a curved surface and includes a plurality of concentrically arranged loop lines 211. For example, see reference to Figure 3 and Figure 4 The first curved portion 11 has a concave surface 12. The center of the annular circuit 211 can be located at the bottom of the concave surface 12, so that multiple annular circuits 211 of different diameters are nested outward around the bottom center of the concave surface 12, similar to annular ripples. Multiple conductive voltage-sensitive particles 31 are arranged on each annular circuit 211. Optionally, the conductive circuit 21 further includes a radial circuit 212, which extends radially along the annular circuit 211, as shown in the figure. Figure 3 When viewed in a direction perpendicular to the electronic pressure-sensitive paper, the radial lines 212 and the annular lines 211 intersect to form a mesh, and the conductive voltage-sensitive particles 31 are located at the projection overlap point between the annular lines 211 and the radial lines 212.
[0037] When using the electronic pressure-sensitive paper of this embodiment, it can be cut into suitable sizes and shapes as needed. Due to its good flexibility, the flatness requirement of the pressure-sensitive surface is not high; it can fit well with both flat and rough surfaces. When used for pressure measurement on curved contact surfaces (e.g., hemispheres), electronic pressure-sensitive paper formed into a curved surface can be used to better fit the curved contact surface and achieve pressure measurement of various areas of the curved contact surface. Since the electronic pressure-sensitive paper is based on the characteristic that the resistance values of the conductive voltage-sensitive particles 31 differ under different pressures, the resistance values of each area of the electronic pressure-sensitive paper can be converted into pressure values of the force-bearing surface using appropriate instruments. The measurement results of the electronic pressure-sensitive paper can then be obtained and displayed visually. Furthermore, by adjusting the characteristics of the conductive voltage-sensitive particles, the electronic pressure-sensitive paper of this embodiment can be suitable for scenarios involving real-time measurement under power, as well as scenarios where testing is performed first and then the pressure distribution is obtained through instrument detection.
[0038] In one aspect of this utility model embodiment, a feasible method for manufacturing electronic pressure-sensitive paper is also provided. The method for manufacturing electronic pressure-sensitive paper described in the above embodiment may include the following steps S100-S400:
[0039] Step S100: Pretreatment of flexible insulating substrate.
[0040] The flexible insulating substrate 1 was ultrasonically cleaned using isopropanol (IPA) and deionized water for 10 minutes to remove surface contaminants. The cleaned flexible insulating substrate 1 was then subjected to plasma treatment at 50W for 2 minutes to enhance the hydrophilicity of the substrate surface.
[0041] Step S200: Preparation of conductive layer.
[0042] A conductive film, with a thickness of 0.1 mm, is formed by printing or vacuum deposition. It is then patterned using laser engraving or mask etching to form a conductive line 21 of a predetermined shape. In one embodiment, the conductive film is formed by screen printing silver nanowire ink or conductive carbon paste, followed by drying with hot air circulation at 120°C to form interdigitated electrodes. In another embodiment, the conductive film is formed by vacuum deposition using magnetron sputtering of metal (e.g., copper, silver) to form a thin metal film. When the conductive layer 2 comprises multiple layers, such as an upper conductive layer 22 and a lower conductive layer 23, each conductive layer 2 can be fabricated separately. The conductive line 21 has lead-out sections for transmitting electrical signals, facilitating signal acquisition using instruments.
[0043] Step S300: Preparation of piezoresistive layer.
[0044] Step S400: The flexible insulating substrate, conductive layer, piezoresistive layer and flexible insulating protective layer are stacked in a predetermined order and bonded together with an adhesive to form a multi-layer structure.
[0045] During the stacking process, a precision alignment platform can be used to align the multiple layers, ensuring the alignment accuracy of the conductive lines 21 in the upper conductive layer 22 and the lower conductive layer 23. The adhesive can be polyurethane (PU), polydimethylsiloxane (PDMS), or other adhesives. Optionally, the flexible insulating protective layer 4 can be formed by spin-coating or blade-coating polydimethylsiloxane onto the surface of the flexible insulating substrate 1, conductive layer 2, and piezoresistive layer 3 after stacking, followed by heat curing or photocuring. The thickness of the flexible insulating protective layer 4 can be 0.1 mm.
[0046] In one implementation, step S300 may include the following steps S310-S330:
[0047] Step S310, Preparation of Piezoresistive Slurry: Add 1-5 wt% of carbon nanotubes to the PDMS prepolymer and add a curing agent. Add a diluent to adjust the viscosity of the slurry to 500-1000 centipoise (cP). Treat the piezoresistive slurry by ball milling or ultrasonic treatment to ensure uniform dispersion of carbon nanotubes.
[0048] Step S320: Apply the piezoresistive slurry to the surface of the conductive layer 2 according to the predetermined shape of the conductive voltage-sensitive particles 31, and cure it by heating at 80°C for 1 hour to form the piezoresistive layer 3.
[0049] Step S330: Apply pressure annealing to the cured piezoresistive layer 3 at a pressure of 0.5 MPa to improve the conductivity of the conductive network.
[0050] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An electronic pressure-sensitive paper, characterized in that, include: Flexible insulating substrate (1); A conductive layer (2) is disposed on one side of the flexible insulating substrate (1). The conductive layer (2) has a conductive line (21), and the conductive line (21) has at least one projected overlap point in a direction perpendicular to the flexible insulating substrate (1). A piezoresistive layer (3) has a plurality of voltage-sensitive particles (31) disposed on the conductive line (21), the plurality of voltage-sensitive particles (31) being spaced apart to form an array of voltage-sensitive particles (31), and at least one voltage-sensitive particle (31) being disposed at the projection overlap point; and A flexible insulating protective layer (4) is at least partially disposed on the side opposite to the piezoresistive layer (3) and the flexible insulating substrate (1).
2. The electronic pressure-sensitive paper according to claim 1, characterized in that, The conductive layer (2) includes a lower conductive layer (23) and an upper conductive layer (22). The lower conductive layer (23) is disposed between the piezoresistive layer (3) and the flexible insulating substrate (1). The upper conductive layer (22) is disposed on the side opposite to the piezoresistive layer (3) and the lower conductive layer (23). The conductive lines (21) of the upper conductive layer (22) and the conductive lines (21) of the lower conductive layer (23) are at least partially intersected. At least a portion of the voltage-sensitive particles (31) are disposed at the projection overlap point between the conductive lines (21) of the upper conductive layer (22) and the conductive lines (21) of the lower conductive layer (23).
3. The electronic pressure-sensitive paper according to claim 1, characterized in that, The flexible insulating substrate (1) includes a first curved portion (11), at least a portion of the voltage-sensitive conductive particles (31) are disposed in the first curved portion (11), and the flexible insulating protective layer (4) has a second curved portion (41) corresponding to the first curved portion (11).
4. The electronic pressure-sensitive paper according to claim 3, characterized in that, The first curved portion (11) has a concave surface (12), the conductive line (21) is disposed on the concave surface (12) and includes a plurality of concentrically arranged annular lines (211), each of the annular lines (211) is provided with a plurality of conductive voltage-sensitive particles (31), and the center of the annular line (211) is disposed at the bottom of the concave surface (12).
5. The electronic pressure-sensitive paper according to claim 4, characterized in that, The conductive line (21) further includes a radial line (212) that extends radially along the annular line (211), and the conductive voltage-sensitive particle (31) is disposed at the projection overlap point between the annular line (211) and the radial line (212).
6. The electronic pressure-sensitive paper according to claim 1, characterized in that, The height of the conductive voltage-sensitive particle (31) is 0.2 mm and the diameter is 0.2 mm.
7. The electronic pressure-sensitive paper according to claim 1, characterized in that, The line width of the conductive line (21) is 20-100 micrometers.
8. The electronic pressure-sensitive paper according to claim 1, characterized in that, The voltage-sensitive particles (31) include carbon nanotube elastomers.
9. The electronic pressure-sensitive paper according to claim 1, characterized in that, The protective layer includes an alumina layer and a polydimethylsiloxane layer disposed on one side of the alumina layer.
10. The electronic pressure-sensitive paper according to claim 1, characterized in that, The conductive line (21) includes interdigitated electrodes.