Stretchable substrates and electronic skin

Abstract

The embodiments of the present disclosure provide a stretchable substrate and an electronic skin. The stretchable substrate includes a plurality of island regions and a bridge region connecting adjacent island regions, the stretchable substrate includes a substrate, a sensor element and a conductive structure located on the substrate; the sensor element is located in the island region; the conductive structure is located in the bridge region, the conductive structure connects the sensor elements on the adjacent island regions, the conductive structure includes a buffer pattern and a connection pattern, the buffer pattern is connected between the connection pattern and the sensor element; the buffer pattern includes a grid pattern, and the connection pattern includes at least one connection line.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a stretchable substrate and electronic skin. Background Art

[0002] Stretchable sensors have good stretching and deformation capabilities, so they are increasingly used in electronic skin. However, due to the continuous movement of the human body, muscle changes will pull the skin to deform to varying degrees. Although stretchable sensors can actively adapt to the flexible skin surface and maintain conformal contact with it, as well as stretch in different directions, it is still hoped that the deformation amplitude of the stretchable sensor can be as small as possible to meet the needs of long-term high reliability. Summary of the invention

[0003] The embodiments of the present disclosure provide a stretchable substrate and electronic skin.

[0004] In a first aspect, an embodiment of the present disclosure provides a stretchable substrate, the stretchable substrate comprising a plurality of island regions and a bridge region connecting adjacent island regions, the stretchable substrate comprising a substrate and a sensor element and a conductive structure located on the substrate;

[0005] The sensor element is located in the island area;

[0006] The conductive structure is located in the bridge area, the conductive structure connects the sensor elements on the adjacent island areas, the conductive structure includes a buffer pattern and a connection pattern, and the buffer pattern is connected between the connection pattern and the sensor element;

[0007] The buffer pattern includes a grid pattern, and the connection pattern includes at least one connection line.

[0008] In some embodiments, the buffer pattern includes a plurality of grid groups pointing from the bridge area to the island area, each grid group includes a plurality of grids, and each grid has a plurality of edges;

[0009] For any two grid groups in the same buffer pattern, the number of edges of the grids in the grid group close to the island area is greater than the number of edges of the grids in the grid group far from the island area.

[0010] In some embodiments, the plurality of mesh groups include a first mesh group and a second mesh group, the second mesh group being located between the first mesh group and the connection pattern;

[0011] The grids in the first grid group are hexagonal patterns;

[0012] The grids in the second grid group are quadrilateral patterns.

[0013] In some embodiments, at least one of the bridge regions is provided with a plurality of stacked conductive structures, each conductive structure is connected to one of the sensor elements in an adjacent island region, and two adjacent conductive structures are separated by an insulating layer.

[0014] In some embodiments, the stretchable substrate further comprises a protective layer,

[0015] The sensor element and the conductive structure are located between the protection layer and the substrate.

[0016] In some embodiments, the substrate includes a first portion located in the island region and a second portion located in the bridge region,

[0017] The hardness of the first portion is greater than the hardness of the second portion.

[0018] In some embodiments, the connection line is a wavy line or a broken line in a natural state.

[0019] In some embodiments, the connection pattern includes a plurality of connection lines, and the plurality of connection lines are spaced apart from each other.

[0020] In some embodiments, the buffer pattern includes a plurality of grids, each grid has a plurality of edges, and the connection lines are connected to vertex positions of the grids.

[0021] In a second aspect, an embodiment of the present disclosure provides an electronic skin, comprising the stretchable substrate described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0023] Figure 1 A schematic plan view of a stretchable substrate provided for the disclosed technology.

[0024] Figure 2 A schematic plan view of a stretchable substrate provided in an embodiment of the present disclosure.

[0025] Figure 3 A schematic structural diagram of a stretchable substrate provided in an embodiment of the present disclosure.

[0026] Figure 4 A schematic plan view of a stretchable substrate in a natural state provided in an embodiment of the present disclosure.

[0027] Figure 5 A schematic plan view of a stretchable substrate in a stretched state provided in an embodiment of the present disclosure.

[0028] Figure 6 A planar structural diagram of another stretchable substrate provided for an embodiment of the present disclosure.

[0029] Figure 7 Schematic diagram of the structure of another stretchable substrate according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0032] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not represent any order, quantity or importance, but are only used to distinguish different components. Similarly, "including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] Stretchable sensors have good stretching and deformation capabilities, so they are increasingly used in electronic skin. However, due to the continuous movement of the human body, muscle changes will pull the skin to deform to varying degrees. Although stretchable sensors can actively adapt to the flexible skin surface and maintain conformal contact with it, as well as stretch in different directions, it is still hoped that the deformation amplitude of the stretchable sensor can be as small as possible to meet the needs of long-term high reliability.

[0034] In the disclosed technology, the improvement of electronic skin can be reflected in improving the stretching ability of the stretchable sensor, such as the stretching deformation rate, the number of repeated stretching times, etc. For example, the stretchable sensor is set as a paper-cut structure, and the stretching amount is provided by the deformation of the opening shape; or the stretchable sensor is set as a pleated paper structure, and the deformation effect is achieved by using the three-dimensional change in the structure; or the stretchable sensor is set as an elastic structure, and the stretching effect is achieved by the elastic properties of the material.

[0035] However, the above-mentioned improvements to electronic skin will cause the stretchable sensor to produce a certain amount of deformation as the skin's traction changes, which is not conducive to the stability of the electronic skin in recording physiological signals; at the same time, the friction between the stretchable sensor and the skin surface may generate static electricity, affecting the accuracy of the electronic skin generating physiological signals.

[0036] Figure 1 The following is a schematic diagram of a stretchable substrate provided by the disclosed technology. Based on the above technical problems, the disclosed technology proposes to set the substrate of the electronic skin as an elastic stretchable substrate. Figure 1 As shown, the stretchable substrate includes an island area 1 and a bridge area 2, wherein the island area 1 is a non-deformable area, and the bridge area 2 is a deformable area, i.e., a stretchable area; the sensor in the electronic skin is set in the island area 1, and the bridge area 2 is set with a wiring connecting the sensors on the adjacent island area 1, so that the sensor is not affected by the traction of the skin and maintains a fixed shape to ensure its working state. However, when the electronic skin is stretched, there will be an obvious stress accumulation problem at the boundary between the island area 1 and the bridge area 2, which will affect the service life of the electronic skin.

[0037] In order to solve at least one of the above technical problems, an embodiment of the present disclosure provides a stretchable substrate for application in electronic skin.

[0038] Figure 2 A schematic plan view of a stretchable substrate provided in an embodiment of the present disclosure, Figure 3 A schematic diagram of a stretchable substrate provided in an embodiment of the present disclosure is shown in FIG. Figure 2 , 3 As shown, the stretchable substrate includes a plurality of island regions 1 and a bridge region 2 connecting adjacent island regions 1 . The stretchable substrate includes a substrate 3 and a conductive structure 4 and a sensor element 5 located on the substrate 3 .

[0039] Among them, the sensor element 5 is located in the island area 1; the conductive structure 4 is located in the bridge area 2, the conductive structure 4 connects the sensor elements 5 on the adjacent island area 1, the conductive structure 4 includes a buffer pattern 41 and a connection pattern 42, the buffer pattern 41 is connected between the connection pattern 42 and the sensor element 5; the buffer pattern 41 includes a grid pattern, and the connection pattern 42 includes at least one connection line 42a.

[0040] In the stretchable substrate provided by the embodiment of the present disclosure, the sensor element 5 is fixed on the island area 1 and can maintain a fixed shape to ensure its working state; the conductive structure 4 connects adjacent sensor elements 5, and the buffer pattern 41 on the side of the conductive structure 4 close to the sensor element 5 is a grid pattern, that is, the conductive structure 4 connecting the island area 1 and the bridge area 2 in the stretchable substrate is a grid pattern, so as to reduce the stress concentration problem at the boundary between the island area 1 and the bridge area 2, and improve the reliability of the stretchable substrate.

[0041] The material of the above-mentioned conductive structure 4 may include metal, alloy, metal nitride, conductive metal oxide, transparent conductive material, etc. In one example, the conductive structure 4 may be a single layer composed of metal, such as a layer of gold, silver, aluminum, etc.; in another example, the conductive structure 4 may also be a multilayer composed of metal, such as a Mo / Al / Mo composite layer or a Ti / Al / Ti composite layer. In addition, the thickness of the conductive structure 4 is between 0.6-1μm. For example, 0.6μm, 0.8μm or 1μm. In the disclosed embodiment, the material and thickness of the conductive structure 4 are not specifically limited.

[0042] The sensor element 5 provided in the island area 1 is used to detect physiological signals, so it can be a sensor for detecting human blood pressure, heartbeat, body temperature and other data, or a sensor for sensing different types of pressure, or a sensor for sensing air and water flow. It can be flexibly set in specific applications, and the embodiments of the present disclosure are not limited to this.

[0043] In some embodiments, Figure 3 As shown, the stretchable substrate also includes a protective layer 6, and the sensor element 5 and the conductive structure 4 are located between the protective layer 6 and the substrate 3. The protective layer 6 can isolate water vapor and protect the stretchable substrate from water vapor erosion. In some embodiments, the protective layer 6 can be made of inorganic materials, such as silicon oxide, silicon nitride, etc.; or organic materials, such as acrylic acid, polyimide film, or a combination of the above two organic materials, so that the protective layer 6 has a certain degree of stretchability. The embodiments of the present disclosure are not limited to this.

[0044] In some embodiments, the buffer pattern 41 includes a plurality of grid groups pointing in the direction of the island area 1 along the bridge area 2, each grid group includes a plurality of grids, each grid has a plurality of edges, that is, the shape of the grid pattern in the buffer pattern 41 can be various, and it should be noted that the plurality of grids in the buffer pattern 41 are connected together. Since the stress is mainly concentrated at the boundary between the island area 1 and the bridge area 2, for any two grid groups in the same buffer pattern 41, the number of edges of the grid in the grid group close to the island area 1 is greater than the number of edges of the grid in the grid group far from the island area 1, so that the stress generated between the island area 1 and the bridge area 2 is gradually decomposed through the step-by-step dense grid pattern to avoid local stress accumulation.

[0045] Among them, multiple grids in each grid group can be arranged into multiple rows, and the multiple rows of grids are arranged along the direction from the bridge area 2 to the island area 1 (referred to as the first direction), and multiple grids in the same row are arranged along the second direction, for example, the second direction is perpendicular to the first direction.

[0046] In some embodiments, Figure 2 As shown, the buffer pattern 41 includes a first grid group 411 and a second grid group 412, and the second grid group 412 is located between the first grid group 411 and the connection pattern 42; the grids in the first grid group 411 are hexagonal patterns; and the grids in the second grid group 412 are quadrilateral patterns.

[0047] It should be noted that the grid groups in the buffer pattern 41 are multiple groups, which can be set as follows: Figure 2 The two grid groups shown in the figure can also be set to three, four or more grid groups. When the grid groups in the buffer pattern 41 are two groups, the following can be set: Figure 2 As shown, the grids in the first grid group 411 are set to a hexagonal pattern, and the grids in the second grid group 412 are set to a quadrilateral pattern, so that the conductive structure between the two islands forms a grid pattern consisting of a hexagonal pattern, a quadrilateral pattern, a connecting line, a quadrilateral pattern, and a hexagonal pattern in sequence; the grids in the first grid group 411 can also be set to a pentagonal pattern, and the grids in the second grid group 412 are set to a quadrilateral pattern, so that the conductive structure between the two islands forms a grid pattern consisting of a pentagonal pattern, a quadrilateral pattern, a connecting line, a quadrilateral pattern, and a pentagonal pattern in sequence. When there are three grid groups in the buffer pattern 41, that is, the buffer pattern 41 may also include a third grid group located in the direction away from the island area from the second grid group, in this case, the grids in the first grid group 411 may be set to a hexagonal pattern, the grids in the second grid group 412 may be set to a pentagonal pattern, and the grids in the third grid group may be set to a quadrilateral pattern, so that the conductive structure between the two island areas forms a grid pattern composed of a hexagonal pattern, a pentagonal pattern, a quadrilateral pattern, a connecting line, a quadrilateral pattern, a pentagonal pattern, and a hexagonal pattern in sequence. In other words, in the embodiment of the present disclosure, there is no specific limitation on the number of grid groups in the buffer pattern 41 and the pattern shape of the grids in each grid group. It is only necessary to ensure that the number of edges of the grids in the grid group close to the island area is greater than the number of edges of the grids in the grid group far away from the island area.

[0048] In addition, the number of polygonal patterns in the first grid group 411 and the second grid group 412 can be set to any number of 1-5 groups, which is not limited in the embodiment of the present disclosure. Figure 2As shown, the first grid group 411 includes two groups of hexagonal grids, that is, two columns of hexagonal grids are arranged in the direction from the island area 1 to the bridge area 2; the second grid group 412 includes five groups of quadrilateral grids, that is, five columns of quadrilateral grids are arranged in the direction from the island area 1 to the bridge area 2.

[0049] In one example, if Figure 2 As shown, the shape of the hexagonal grids in the first grid group 411 can be set to a regular hexagon with a side length of a, where a is between 8-12 μm, for example, 10 μm; the shape of the quadrilateral grids in the second grid group 412 can be set to a rhombus with a side length of b, where b is between 8-12 μm, for example, 10 μm, and the present disclosure does not make specific limitations on this.

[0050] In some embodiments, the substrate 3 includes a first portion located in the island area 1 and a second portion located in the bridge area 2. Since the sensor element 5 is fixed in the island area 1, which is a non-stretchable area, and the bridge area 2 is a stretchable area, the hardness of the first portion is greater than the hardness of the second portion, so that the bridge area 2 can achieve the stretchability of the stretchable substrate through the deformation of the grid pattern in the buffer pattern 41.

[0051] In one example, a substrate 3 with uniform hardness may be provided first, and then a surface treatment may be performed on the area corresponding to the island region 1 on the substrate 3 to form a first portion with greater hardness and a second portion with less hardness on the same substrate 3 .

[0052] In some embodiments, the substrate 3 may be made of an elastic material, such as styrene-ethylene-butylene-styrene block copolymer.

[0053] In some embodiments, the thickness of the substrate 3 is between 3 μm and 10 μm, for example, the thickness of the substrate 3 is 5 μm, thereby improving the stretchability of the substrate 3 while ensuring the supporting capacity of the substrate 3 .

[0054] In some embodiments, a hollow portion may be further provided on the substrate 3, and the hollow portion is located in an area outside the bridge area and the island area 1, for example, Figure 4 As shown, the island areas 1 are arranged in multiple rows and columns, and a bridge area is provided between two adjacent island areas in the same row and between two adjacent island areas 1 in the same column. A hollow portion W is provided between two adjacent bridge areas in the same row and between two adjacent bridge areas in the same column.

[0055] In some embodiments, the connection line 42a in the connection pattern 42 is a wavy line or a broken line. Figure 4 A schematic plan view of a stretchable substrate in a natural state provided by an embodiment of the present disclosure, Figure 5 A schematic plan view of a stretchable substrate in a stretched state provided by an embodiment of the present disclosure. Specifically, Figure 4In the figure, the connection line 42a in the connection pattern 42 of the stretchable substrate in the natural state is a wavy line; Figure 5 In the embodiment, the connecting line 42a of the stretchable substrate is a broken line in the stretched state. The natural state refers to the state in which the stretchable substrate is not deformed without being subjected to external force.

[0056] like Figure 4 , Figure 5 As shown, during the stretching process of the stretchable substrate, the connecting line 42a provides the largest deformation, the multiple groups of quadrilateral patterns in the second grid group 412 provide a slightly smaller deformation, and the multiple groups of hexagonal patterns in the first grid group 411 provide the smallest deformation. The three together form a conductive structure 4, which gradually decomposes the stress generated at the boundary between the island area 1 and the bridge area 2 to avoid local stress accumulation.

[0057] In some embodiments, the buffer pattern 41 includes a plurality of meshes, each mesh has a plurality of edges, the connection line 42 a is connected to the vertex positions of the meshes, and the vertices connected by the connection line 42 a do not contact other meshes.

[0058] Specifically, in some embodiments, Figure 2 , Figure 4 , Figure 5 As shown, the connection pattern 42 includes a plurality of connection lines 42a, the plurality of connection lines 42a are spaced apart from each other, each connection line 42a is correspondingly connected to a grid, and different connection lines 42a are connected to different grids. Figure 6 This is a planar structural diagram of another stretchable substrate provided in an embodiment of the present disclosure. In other embodiments, the connection pattern 42 may also include only one connection line 42a, and the two ends of the connection line 42a are respectively connected to the grids in the buffer pattern 41. In other words, the number of connection lines 42a in the connection pattern 42 can be flexibly set, and the embodiment of the present disclosure is not limited to this.

[0059] In some embodiments, at least one bridge region 2 is provided with a plurality of stacked conductive structures 4 , each conductive structure 4 is connected to a sensor element 5 in an adjacent island region 1 , and two adjacent conductive structures 4 are separated by an insulating layer 7 .

[0060] The material of the insulating layer 7 may include silicon oxynitride, silicon oxide, silicon nitride, silicon oxycarbide, silicon carbide nitride, aluminum oxide, aluminum nitride, tantalum oxide, hafnium oxide, zirconium oxide, titanium oxide, and the like.

[0061] In one example, at least one island region 1 is provided with n stacked sensor elements 5; the bridge region 2 adjacent to the n sensor elements 5 is provided with n stacked conductive structures 4; the n sensor elements 5 and the n conductive structures 4 are connected in a one-to-one correspondence, and n is an integer greater than 1. Figure 7 is a schematic structural diagram of another stretchable substrate according to an embodiment of the present disclosure, such as Figure 7 As shown, n is 2, that is, the island area 1 is provided with two layers of sensor elements 5, and the adjacent bridge area is correspondingly provided with two layers of conductive structures 4.

[0062] In the above-mentioned stacked n sensor elements 5, n specifically refers to the number of layers of the sensor elements 5. That is, the above description does not consider the situation where a plurality of sensor elements 5 spaced apart from each other are arranged in the same layer, and the sensor elements 5 located in the same layer are regarded as a whole.

[0063] Specifically, the sensor element 5 arranged on the island area 1 may have only one layer or may be stacked in multiple layers. Then, in the bridge area 2 connected to the island area 1 , there are conductive structures 4 with the same number of stacked layers as the sensor elements 5 in the island area 1 .

[0064] like Figure 7 As shown, the insulating layer 7 is located between two adjacent layers of sensor elements 5 and extends to the bridge region 2 . The two adjacent layers of conductive structures 4 in the bridge region 2 are separated by the insulating layer 7 .

[0065] It should be noted that when the island area 1 is provided with a plurality of stacked sensor elements 5 , the stacking number of the conductive structures 4 provided in the adjacent bridge area 2 may also be different from the stacking number of the sensor elements 5 , which is not limited in the embodiments of the present disclosure.

[0066] The disclosed embodiment also provides an electronic skin, comprising the above-mentioned stretchable substrate.

[0067] Since the sensor element in the stretchable substrate is fixed on the island area, it can maintain a fixed shape to ensure its working state; the conductive structure connects adjacent sensor elements, and the buffer pattern on the side close to the sensor element in the conductive structure is a grid pattern, that is, the conductive structure connecting the island area and the bridge area in the stretchable substrate is a grid pattern to reduce the stress concentration problem at the boundary between the island area and the bridge area, improve the reliability of the stretchable substrate, so as to improve the accuracy and stability of the electronic skin in detecting physiological signals.

[0068] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A stretchable substrate, characterized in that: The stretchable substrate comprises a plurality of island regions and a bridge region connecting adjacent island regions, and the stretchable substrate comprises a substrate and a sensor element and a conductive structure located on the substrate; The sensor element is located in the island area; The conductive structure is located in the bridge area, the conductive structure connects the sensor elements on the adjacent island areas, the conductive structure includes a buffer pattern and a connection pattern, and the buffer pattern is connected between the connection pattern and the sensor element; The buffer pattern includes a grid pattern, and the connection pattern includes at least one connection line.

2. The stretchable substrate according to claim 1, characterized in that The buffer pattern includes a plurality of grid groups pointing along the bridge area to the island area, each grid group includes a plurality of grids, and each grid has a plurality of edges; For any two grid groups in the same buffer pattern, the number of edges of the grids in the grid group close to the island area is greater than the number of edges of the grids in the grid group far from the island area.

3. The stretchable substrate according to claim 2, characterized in that The plurality of grid groups include a first grid group and a second grid group, wherein the second grid group is located between the first grid group and the connection pattern; The grids in the first grid group are hexagonal patterns; The grids in the second grid group are quadrilateral patterns.

4. The stretchable substrate according to claim 1, characterized in that At least one of the bridge regions is provided with a plurality of stacked conductive structures, each conductive structure is connected to one of the sensor elements in the adjacent island region, and two adjacent layers of conductive structures are separated by an insulating layer.

5. The stretchable substrate according to any one of claims 1 to 4, characterized in that The stretchable substrate further comprises a protective layer, The sensor element and the conductive structure are located between the protection layer and the substrate.

6. The stretchable substrate according to any one of claims 1 to 4, characterized in that The substrate includes a first portion located in the island region and a second portion located in the bridge region, The hardness of the first portion is greater than the hardness of the second portion.

7. The stretchable substrate according to any one of claims 1 to 4, characterized in that The connecting line is a wavy line or a broken line in a natural state.

8. The stretchable substrate according to any one of claims 1 to 4, characterized in that The connection pattern includes a plurality of connection lines, and the plurality of connection lines are spaced apart from each other.

9. The stretchable substrate according to any one of claims 1 to 4, characterized in that The buffer pattern includes a plurality of grids, each grid has a plurality of edges, and the connection lines are connected to the vertex positions of the grids.

10. An electronic skin, characterized in that: A stretchable substrate comprising any one of claims 1-9.

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