Stretchable device

Abstract

This stretchable device comprises a first-layer device, a second-layer device, and a first adhesive layer. The first-layer device has a first stretchable substrate having a first strain gauge. The second-layer device has a second stretchable substrate having a second strain gauge. The first stretchable substrate has a plurality of first long hinge parts extending in a first direction. The second stretchable substrate has a plurality of second long hinge parts. The first long hinge parts have a plurality of first body parts that overlap the second long hinge parts when viewed from the thickness direction and a first hinge part that connects the plurality of first body parts to each other. The second long hinge parts have second body parts overlapping the first body part when viewed from the thickness direction and a second hinge part that connects the plurality of second body parts to each other.

Description

Stretchable Device

[0001] The present invention relates to a stretchable device.

[0002] The stretchable device has a stretchable substrate with excellent elasticity and flexibility. The stretchable substrate includes a resin substrate and an array layer disposed along the resin substrate. The stretchable substrate includes body portions arranged in a matrix and hinge portions connecting the body portions to each other. The hinge portions in Patent Document 1 have multiple arc portions and a meandering shape. When, for example, a tensile load acts on the stretchable substrate, the arc portions of the hinge portions expand. As a result, the body portions connected to both ends of the hinge portion separate from each other, and the stretchable substrate elongates. In addition, there are two types of hinge portions extending from one body portion. One is a vertical hinge portion that extends along the planar direction of the stretchable substrate. The other is a horizontal hinge portion that extends in the planar direction, perpendicular to the vertical hinge portion.

[0003] JP 2020-202208 A

[0004] Recently, in order to detect the load acting on a stretchable device, studies have been conducted to install strain gauges in the hinges to detect the strain (deformation) of the hinges. However, with conventional structures, the direction of the detected load is limited to the direction in which the vertical and horizontal hinges extend. Therefore, there is a need for the development of a stretchable device that has a high degree of freedom in the direction of the detected load.

[0005] An object of the present invention is to provide a stretchable device that has a high degree of freedom in the direction of the load to be detected.

[0006] A stretchable device according to one aspect of the present disclosure includes a first layer device, a second layer device stacked on the first layer device in a thickness direction, and a first adhesive layer disposed between the first layer device and the second layer device. The first layer device includes a first stretchable substrate having a first strain gauge and a first elastic resin covering the first stretchable substrate. The second layer device includes a second stretchable substrate having a second strain gauge and a second elastic resin covering the second stretchable substrate. The first stretchable substrate has a plurality of first elongated hinge portions extending in a first direction parallel to a planar direction in which the first stretchable substrate extends. The second stretchable substrate has a plurality of second elongated hinge portions extending in a first intersecting direction parallel to the planar direction and intersecting the first direction. The first elongated hinge portions are parallel to the planar direction and spaced apart in a direction intersecting the first direction. The second elongated hinge portions are parallel to the planar direction and are spaced apart in a direction intersecting the first intersecting direction. When viewed from the thickness direction, the first elongated hinge portions and the second elongated hinge portions intersect with one another. When viewed from the thickness direction, the first elongated hinge portions include a plurality of first body portions overlapping the second elongated hinge portions, and a first hinge portion connecting the first body portions and provided with the first strain gauge. When viewed from the thickness direction, the second elongated hinge portions include a second body portion overlapping the first body portion and a second hinge portion connecting the second body portions and provided with the second strain gauge.

[0007] FIG. 1 is a perspective view of a stretchable device according to the first embodiment. FIG. 2 is a perspective view of a first layer device according to the first embodiment. FIG. 3 is a schematic cross-sectional view of the first layer device according to the first embodiment cut in a second direction, more specifically, a cross-sectional view of the first layer device according to the first embodiment cut along line III-III in FIG. 2. FIG. 4 is an enlarged view of a portion of a first detection region of a first stretchable substrate according to the first embodiment. FIG. 5 is an enlarged view of a first hinge portion according to the first embodiment. FIG. 6 is an enlarged view of the first hinge portion according to the first embodiment when a tensile load acts in a first direction. FIG. 7 is a schematic diagram showing the circuit configuration of a strain detection circuit according to the first embodiment. FIG. 8 is a cross-sectional view of a stretchable device, more specifically, a cross-sectional view taken along line VIII-VIII in FIG. 11. FIG. 9 is a plan view of a portion of a second stretchable substrate according to the first embodiment. FIG. 10 is a plan view of a portion of a third stretchable substrate according to the first embodiment. Fig. 11 is a schematic diagram of a state in which the first long hinge portion, the second long hinge portion, and the third long hinge portion are overlapped in the first thickness direction in embodiment 1. Fig. 12 is a cross-sectional view of a stretchable device of a modified example taken in the thickness direction.

[0008] Modes (embodiments) for carrying out the present disclosure will be described in detail with reference to the drawings. The invention of the present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the invention are naturally included within the scope of the present invention. For clarity of explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each figure, components similar to those described above with reference to the previous figures are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] Furthermore, in this specification and claims, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0010] (Embodiment 1) Fig. 1 is a perspective view of a stretchable device according to embodiment 1. The stretchable device 1000 has a front surface 1001 and a back surface 1002 (not shown in Fig. 1; see Fig. 11) facing in the opposite direction to the front surface 1001. The stretchable device 1000 has a relatively thin thickness between the front surface 1001 and the back surface 1002. The stretchable device 1000 is a device that can detect a load in a planar direction parallel to the front surface 1001 (see, for example, F1 in Fig. 1). Hereinafter, the direction in which the front surface 1001 and the back surface 1002 are arranged will be referred to as the thickness direction.

[0011] The stretchable device 1000 is formed in a square (rectangular) shape when viewed in the thickness direction. Therefore, a surface 1001 of the stretchable device 1000 has a pair of first sides 1003 and a pair of second sides 1004. Hereinafter, a direction parallel to the planar direction and parallel to the first sides 1003 will be referred to as a first direction X, and a direction parallel to the second sides 1004 will be referred to as a second direction Y.

[0012] In a planar view, the stretchable device 1000 is divided into a detection area 1005 and a frame area 1006 other than the detection area 1005. The detection area 1005 is an area that detects a load input to the stretchable device 1000. The detection area 1005 in this embodiment is located in the center of the stretchable device 1000 and is formed in a rectangular shape in a planar view. The frame area 1006 is formed in a rectangular frame shape in a planar view, and the detection area 1005 is located inside it. Note that a boundary line L1 is drawn in FIG. 1 to make the boundary between the detection area 1005 and the frame area 1006 easier to understand.

[0013] The stretchable device 1000 is a device in which three devices are stacked in order and integrated with an adhesive layer. That is, the stretchable device 1000 has a first layer device 1, a first adhesive layer 2, a second layer device 101, a second adhesive layer 3, and a third layer device 201 stacked in order in the thickness direction. Note that, with respect to the thickness direction, the direction in which the first layer device 1 is arranged as viewed from the second layer device 101 is referred to as the first thickness direction Z1, and the direction in which the third layer device 201 is arranged is referred to as the second thickness direction Z2. In the following description, the first layer device 1, the second layer device 100, and the third layer device 200 may be collectively referred to as three devices. Next, each component of the stretchable device 1000 will be described.

[0014] Fig. 2 is a perspective view of the first layer device of embodiment 1. As shown in Fig. 2, the surface of the first layer device 1 in the first thickness direction Z1 constitutes the surface 1001 of the stretchable device 1000. In a plan view, the first layer device 1 is divided into a first detection region 5 overlapping with the detection region 1005 and a first frame region 6 overlapping with the frame region 1006. Note that a boundary line L2 is drawn in Fig. 2 to make the boundary between the first detection region 5 and the first frame region 6 easier to understand.

[0015] Fig. 3 is a cross-sectional view schematically illustrating a cross section of the first layer device of embodiment 1 cut in the second direction, more specifically, a cross-sectional view schematically illustrating a cross section cut along line III-III in Fig. 2. As shown in Fig. 2, the first layer device 1 includes a first elastic resin 8 and a first stretchable substrate 10.

[0016] The first stretchable resin 8 includes two plates, a back-side stretchable resin plate 60 and a front-side stretchable resin plate 70, which sandwich the first stretchable substrate 10 from both sides in the thickness direction. The back-side stretchable resin plate 60 and the front-side stretchable resin plate 70 have insulating properties, stretchability, and flexibility. Examples of resins used for the back-side stretchable resin plate 60 and the front-side stretchable resin plate 70 include acrylic elastomers. Note that the stretchable resin of the present disclosure is not limited to acrylic elastomers, and may be acrylic resin, epoxy resin, urethane resin, or the like, and is not particularly limited.

[0017] The back-side stretchable resin plate 60 and the front-side stretchable resin plate 70 are formed in a plate shape and extend in a planar direction. A frame portion 71 that protrudes in the second thickness direction Z2 is provided at the edge of the front-side stretchable resin plate 70. The frame portion 71 is formed in an annular shape in a planar view and surrounds the outer periphery of the first stretchable substrate 10. A surface 72 of the frame portion 71 in the second thickness direction Z2 is bonded to a surface of the back-side stretchable resin plate 60 in the first thickness direction Z1. As a result, the back-side stretchable resin plate 60 and the front-side stretchable resin plate 70 cooperate with each other to form a housing that houses the first stretchable substrate 10.

[0018] Figure 4 is an enlarged view of a portion of the first detection area of ​​the first stretchable substrate 10 in embodiment 1. As shown in Figure 4, a plurality of lightening holes 9 are provided in the first stretchable substrate 10 in an area overlapping with the first detection area 5. As shown in Figure 3, the lightening holes 9 penetrate the first stretchable substrate 10 in the thickness direction. The lightening holes 9 in the first stretchable substrate 10 are filled with a first elastic resin 8. For this reason, the first stretchable substrate 10 has low rigidity against loads in the planar direction.

[0019] The lightening holes 9 in this embodiment are filled with protrusions 73 (see FIG. 3 ) provided on the front-side stretchable resin plate 70. However, in the present disclosure, the lightening holes 9 may be filled with protrusions provided on the back-side stretchable resin plate 60, or may be filled with a stretchable resin different from the back-side stretchable resin plate 60 or the front-side stretchable resin plate 70, or may be left unfilled as empty spaces.

[0020] 4, in a plan view, the lightening holes 9 extend in the first direction X1. Therefore, the area of ​​the first stretchable substrate 10 that overlaps with the first detection area 5 is composed of a plurality of first long hinge portions 11 extending in the first direction X. Furthermore, the plurality of first long hinge portions 11 are arranged at equal intervals in a direction intersecting the first direction X (second direction Y). Therefore, the first stretchable substrate 10 does not have a portion that extends in the second direction Y in the area that overlaps with the first detection area 5.

[0021] The first long hinge portion 11 is divided into a plurality of first body portions 12 arranged at equal intervals in the first direction X, and a plurality of first hinge portions 13 extending in the first direction X in a serpentine manner.

[0022] 5 is an enlarged view of the first hinge portion of embodiment 1. The first body portion 12 is formed in a quadrangular shape in a plan view, and four corners are arranged to face the first direction X and the second direction Y. Note that, in the present disclosure, the shape of the first body portion 12 in a plan view is not limited to a quadrangular shape, and may be a circular shape or another polygonal shape.

[0023] The first hinge portion 13 has four bent portions 14 and extends in a serpentine manner in the first direction X. In this embodiment, each bent portion 14 is arc-shaped. Note that the bent portions of the present disclosure may be angular rather than arc-shaped. The number of bent portions is not limited to four.

[0024] The four bent portions 14 are a first arc portion 15, a second arc portion 16, a third arc portion 17, and a fourth arc portion 18, which are arranged in this order in the first direction X. The first arc portion 15 and the fourth arc portion 18 are quadrant-shaped and bent at 90 degrees. The second arc portion 16 and the third arc portion 17 are semicircular-shaped and bent at 180 degrees.

[0025] In addition, the first hinge portion 13 has a linear base portion 19a connecting the first body portion 12 and the first arc portion 15, and a linear base portion 19b connecting the first body portion 12 and the fourth arc portion 18.

[0026] Fig. 6 is an enlarged view of the first hinge portion of the first embodiment when a tensile load in a first direction acts on the first hinge portion. As shown in Fig. 6, when a tensile load in the first direction X (see arrow W in Fig. 6) acts on the first hinge portion 13 (first long hinge portion 11), the first arc portion 15, the second arc portion 16, the third arc portion 17, and the fourth arc portion 18 are deformed so that their curvatures become smaller. As a result, the distance from one end to the other end of the first hinge portion 13 increases, and the first body portions 12 are separated from each other.

[0027] Furthermore, although not shown, when a compressive load in the first direction X acts on the first hinge portion 13, the first arc portion 15, the second arc portion 16, the third arc portion 17, and the fourth arc portion 18 are deformed so that the curvature thereof increases. As a result, the distance from one end to the other end of the first hinge portion 13 decreases, and the first body portions 12 move closer to each other.

[0028] The above has described the first detection region 5 of the first stretchable substrate 10. Meanwhile, the area of ​​the first stretchable substrate 10 that overlaps with the first frame region 6 is formed in a frame shape, although not particularly shown. Note that the area of ​​the first stretchable substrate 10 that overlaps with the first frame region 6 may be formed in a frame shape by connecting multiple body portions and multiple hinge portions, and is not particularly limited in the present disclosure.

[0029] 2, the first stretchable substrate 10 has a resin base material 20 and an array layer 21. The resin base material 20 is a base material for producing the array layer 21, and has stretchability, flexibility, and insulating properties. The resin base material 20 is made of a resin material such as polyimide.

[0030] The array layer 21 is provided on a surface of the resin base material 20 in the first thickness direction Z1. The array layer 21 has a plurality of insulating layers (not shown) stacked in the thickness direction, and an electric circuit (strain detection circuit) whose insulation from the outside is ensured by the plurality of insulating layers. Next, the strain detection circuit included in the array layer 21 will be described in detail.

[0031] Fig. 7 is a schematic diagram showing the circuit configuration of the strain detection circuit of embodiment 1. As shown in Fig. 7, the portion of the array layer 21 that is arranged in the first detection region 5 includes a first strain gauge 30, a transistor 40, a gate line 41, a signal line 42, a current supply line 43, a connection portion 50 (see Fig. 2), a gate line driving circuit 51 (see Fig. 2), a signal line selection circuit 52 (see Fig. 2), and a reference current line 53 (see Fig. 2).

[0032] The first strain gauge 30 is provided in the first hinge portion 13 and is a detection element that expands and contracts in response to strain generated in the first hinge portion 13, increasing or decreasing its resistance value. One end 31 and the other end 32 of the first strain gauge 30 are separated and arranged in two first body portions 12 adjacent to each other in the first direction X1. Note that, although the first strain gauge 30 in the embodiment is configured as a single strain gauge, the present disclosure may also be configured as two strain gauges, in other words, a strain gauge that extends from the first body portion 12 to the first hinge portion 13 and then folds back and returns to the first body portion 12. This allows for a greater amount of strain to be detected than when configured as a single strain gauge, resulting in higher detection sensitivity.

[0033] The transistors 40 are switching elements and are arranged in each first body portion 12. The gate lines 41, signal lines 42, and current supply lines 43 are arranged across the multiple first hinge portions 13 and the multiple first body portions 12, and extend in the first direction X. The same number of gate lines 41 as the number of transistors 40 are provided for each first elongated hinge portion 11. That is, one end of each of the multiple gate lines 41 extends to the first body portion 12 in which the corresponding transistor 40 is provided, and is connected to the gate electrode of the transistor 40.

[0034] One signal line 42 and one current supply line 43 are provided for each long hinge portion. The signal line 42 is connected to the other end 32 of the first strain gauge 30 at each body portion. The current supply line 43 is connected to the drain electrode of the transistor 40 at each body portion. The source electrode of the transistor 40 is connected to one end 31 of the first strain gauge 30.

[0035] Therefore, when the gate line 41 is scanned, the transistor 40 is turned ON. As a result, the current supply line 43 and one end 31 of the first strain gauge 30 are electrically connected, and a predetermined amount of current flows through the first strain gauge 30. Thereafter, a current (electrical signal) is input to the signal line 42 connected to the other end 32 of the first strain gauge 30. Note that the first strain gauges 30 provided in one first elongated hinge portion 11 share one signal line 42. Therefore, the multiple gate lines 41 provided in one first elongated hinge portion 11 need to be selected sequentially.

[0036] 2, a connection section 50, a gate line driving circuit 51, a signal line selection circuit 52, and a reference current wiring 53 are arranged in a portion of the array layer 21 that is arranged in the first frame region 6. The connection section 50 is for connecting to a driving IC (Integrated Circuit) arranged outside the stretchable device 1000.

[0037] The gate line driving circuit 51 is a circuit that drives the multiple gate lines 41 based on various control signals from the driving IC. The gate line driving circuit 51 selects the multiple gate lines 41 and supplies gate driving signals to the selected gate lines 41. The signal line selection circuit 52 is a switch circuit that selects the multiple signal lines 42. The signal line selection circuit 52 is, for example, a multiplexer. The signal line selection circuit 52 connects the selected signal line 42 to the driving IC based on a selection signal supplied from the driving IC. The reference current wiring 53 is a wiring that supplies a predetermined amount of current to the current supply line 43 and extends along the first frame region 6. The reference current wiring 53 is connected to the driving IC via a connection portion 50, and a predetermined amount of current flows through it.

[0038] As described above, according to the first layer device 1, when a load is applied in the first direction X, the first hinge portion 13 deforms. This causes strain in the first strain gauge 30, changing the resistance value of the first strain gauge 30. The current value input to the signal line 42 differs depending on whether or not strain is occurring in the first strain gauge 30. Therefore, the driving IC detects the amount of strain (input load) of the first strain gauge 30 from the amount of change in the current value.

[0039] Next, the second layer device 101 and the third layer device 201 will be described.

[0040] Figure 8 is a cross-sectional view of the stretchable device, specifically a cross-sectional view taken along line VIII-VIII in Figure 11. As shown in Figure 8, the second layer device 101 includes a second stretchable substrate 120 and a second elastic resin 108 covering the second stretchable substrate 120.

[0041] The second stretchable resin 108 has the same configuration as the first stretchable resin 8. On the other hand, the second stretchable substrate 120 differs from the first stretchable substrate 10 in that the orientation of the second elongated hinge portion 111 (see FIG. 9 ) provided on the second stretchable substrate 120 is different from that of the first elongated hinge portion 11. The following description of the second layer device 101 will focus on the difference from the first layer device 1 (the second elongated hinge portion 111).

[0042] 9 is a plan view of a portion of the second stretchable substrate of embodiment 1. The second long hinge portion 111 is arranged so as to intersect with the first long hinge portion 11 (first direction X) in plan view. More specifically, the second long hinge portion 111 extends in the second direction Y. Therefore, in plan view, the angle at which the second long hinge portion 111 intersects with the first long hinge portion 11 is 90°. Hereinafter, the direction in which the second long hinge portion 111 extends may be referred to as the first intersecting direction.

[0043] The multiple second body portions 112 included in one second elongated hinge portion 111 are arranged at equal intervals in the second direction Y (first intersecting direction). Furthermore, the multiple second hinge portions 113 included in the second elongated hinge portion 111 extend in a serpentine manner in the second direction Y (first intersecting direction). In other words, the resistance value of the second strain gauge 130 included in the second hinge portion 113 changes when the second hinge portion 113 is deformed by a load in the second direction Y. Therefore, the second layer device 101 is a device that can detect a load in the second direction Y.

[0044] As shown in FIG. 8, the third layer device 201 includes a third stretchable substrate 220 and a third stretchable resin 208 covering the third stretchable substrate 220 .

[0045] The third stretchable resin 208 has the same configuration as the first stretchable resin 8. On the other hand, the third stretchable substrate 220 differs from the first stretchable substrate 10 in that the orientation of a third elongated hinge portion 211 (see FIG. 10 ) provided on the third stretchable substrate 220 is different from that of the first elongated hinge portion 11. The following description of the third layer device 201 will focus on the difference from the first layer device 1 (the third elongated hinge portion 211).

[0046] 10 is a plan view of a portion of the third stretchable substrate of embodiment 1. The third long hinge portion 211 extends in an oblique direction in plan view and is disposed so as to intersect with both the first long hinge portion 11 (first direction X) and the second long hinge portion 111. Therefore, in plan view, the third long hinge portion 211 intersects with both the second long hinge portion 111 and the first long hinge portion 11 at an angle of 45°. Hereinafter, the direction in which the third long hinge portion 211 extends may be referred to as the second intersecting direction.

[0047] The multiple third body portions 212 included in one third elongated hinge portion 211 are arranged at equal intervals in the diagonal direction (second intersecting direction). The multiple third hinge portions 213 included in the second elongated hinge portion 111 extend in the diagonal direction in a meandering manner. That is, the resistance value of the third strain gauge 230 included in the third hinge portion 213 changes when the third hinge portion 213 is deformed by a load in the diagonal direction. Therefore, the third layer device 201 is a device that can detect a load in the diagonal direction.

[0048] 11 is a schematic diagram illustrating the state in which the first long hinge portion, the second long hinge portion, and the third long hinge portion overlap in the first thickness direction in embodiment 1. As shown in Fig. 11 , the first body portion 12, the second body portion 112, and the third body portion 212 are arranged to overlap each other in the thickness direction. Therefore, in a plan view, it appears that three types of hinge portions (the first hinge portion 13, the second hinge portion 113, and the third hinge portion 213) extend from one body.

[0049] As shown in Figure 8, the first layer device 1 has a first surface 1a facing the second layer device 101. The second layer device 101 has a second surface 101a facing the first layer device 1. A first adhesive layer 2 bonds the first surface 1a and the second surface 101a together. The second layer device 101 has a third surface 101b facing the third layer device 201. The third layer device 201 has a fourth surface 201a facing the second layer device 101. A second adhesive layer 3 bonds the third surface 101b and the fourth surface 201a together. The surface of the third layer device 201 facing the second thickness direction Z2 constitutes the back surface 1002.

[0050] As described above, according to the stretchable device 1000 of embodiment 1, when a tensile load (see F1 in Figure 1) is applied to both ends of the stretchable device 1000, the three devices are integrated by the two adhesive layers, and the load acts on each of the three devices.

[0051] Here, when a load acts on the stretchable device 1000 in the first direction X, the first hinge portion 13 of the first layer device 1 and the third hinge portion 213 of the third layer device 201 are deformed. On the other hand, the second hinge portion 113 of the second layer device 101 is not deformed. Furthermore, when a load acts on the stretchable device 1000 in the second direction Y, the second hinge portion 113 and the third hinge portion 213 are deformed, but the first hinge portion 13 is not deformed. Furthermore, when a load acts on the stretchable device 1000 in an oblique direction, the first hinge portion 13, the second hinge portion 113, and the third hinge portion 213 are deformed.

[0052] From the above, the difference between a load in the first direction X and a load in an oblique direction can be determined by the presence or absence of deformation of the second hinge portion 113. In other words, if the second hinge portion 113 is not deformed, the direction of the load applied to the stretchable device 1000 can be determined to be the first direction X. Therefore, the driving IC can accurately determine the load in the first direction X by performing calculations based on the signal sent from the first strain gauge 30 arranged on the first hinge portion 13.

[0053] Furthermore, the difference between a load in the second direction Y and a load in an oblique direction can be determined by the presence or absence of deformation of the first hinge portion 13. In other words, if the first hinge portion 13 is not deformed, the direction of the load applied to the stretchable device 1000 can be determined to be the second direction Y. Therefore, the driving IC can accurately determine the load in the second direction Y by performing calculations based on the signal sent from the second strain gauge 130 arranged on the second hinge portion 113.

[0054] Furthermore, in the case of a diagonal load, this can be determined based on the presence or absence of deformation in both the first hinge portion 13 and the second hinge portion 113. In other words, if both the first hinge portion 13 and the second hinge portion 113 are deformed, the direction of the load applied to the stretchable device 1000 can be determined to be diagonal. Therefore, the driving IC can accurately determine the diagonal load by performing calculations based on the signal sent from the third strain gauge 230 arranged in the third hinge portion 213.

[0055] Furthermore, in the stretchable device 1000 of this embodiment, the first body 12, the second body 112, and the third body 212 are integrated in the thickness direction. This makes it possible to detect a load acting on a part of the first detection area 5, rather than on both ends of the stretchable device 1000 (see F1 in FIG. 1). In other words, as shown in FIG. 11, even when a load F3 acts on the two bodies, the first body 12, the second body 112, and the third body 212 all move in the load direction, making it possible to detect the direction of the load.

[0056] As described above, according to the stretchable device 1000 of the first embodiment, devices each having a long hinge portion extending in a direction in which a load is to be detected are stacked on top of each other. Therefore, the direction in which the load can be detected is not limited to the first direction X and the second direction Y. As described above, according to the stretchable device 1000 of the present embodiment, there is a high degree of freedom in the direction in which the load is detected.

[0057] The above has described the first embodiment. Next, a modified example in which the stretchable device 1000 of the first embodiment is partially modified will be described. The following description will focus on the differences from the first embodiment.

[0058] 12 is a cross-sectional view of a stretchable device according to a modified example taken in the thickness direction. As shown in Fig. 12, the stretchable device 1000A according to the modified example differs from that according to the first embodiment in the range where the first adhesive layer 2A and the second adhesive layer 3A are bonded.

[0059] The first adhesive layer 2A bonds together the portions of the first surface 1a and the second surface 101a that overlap the frame region 1006 (see FIG. 1 ) when viewed from the thickness direction and the portions that overlap the first body portion 12 and the second body portion 112. The second adhesive layer 3A bonds together the portions of the third surface 101b and the fourth surface 201a that overlap the frame region 1006 when viewed from the thickness direction and the portions that overlap the first body portion 12, the second body portion 112, and the third body portion 212.

[0060] As described above, according to the modified example, it is possible to detect loads on both ends of the stretchable device 1000A (see F1 in FIG. 1) and loads acting on a part of the first detection area 5 (see F3 in FIG. 11). Note that although it is preferable that the first adhesive layer 2A and the second adhesive layer 3A have a lower elastic modulus, they may also be formed from a resin with a high elastic modulus.

[0061] Although the embodiments and modifications have been described above, the present disclosure is not limited to the examples shown in the embodiments and modifications. While the embodiments and modifications include three devices, the present disclosure requires at least two or more devices.

[0062] Furthermore, in the embodiment, the second long hinge portion 111 extends in the second direction Y and has an intersecting direction (first intersecting direction) with respect to the first long hinge portion 11 at an angle of 90°, but the intersecting angle may be other than 90°. In other words, in the present disclosure, the intersecting angle is not particularly important as long as the second long hinge portion 111 intersects with the first long hinge portion 11 in a plan view. Although the third long hinge portion 211 has an intersecting direction (second intersecting direction) with respect to each of the first long hinge portion 11 and the second long hinge portion 111 at an angle of 45°, the present disclosure is not limited to this. In other words, in the present disclosure, the intersecting angle is not particularly important as long as the third long hinge portion 211 intersects with each of the first long hinge portion 11 and the second long hinge portion 111 in a plan view. Therefore, for example, the second long hinge portion 111 may extend in a direction that forms an angle of 30° with respect to the first long hinge portion 11, and the third long hinge portion 211 may extend in a direction that forms an angle of 60° with respect to the first long hinge portion 11. Furthermore, according to the present disclosure, since only one-directional strain gauges are provided in the long hinge portion, fewer gate lines and the like are provided in the long hinge portion, and the width of the long hinge portion can be designed to be narrower.

[0063] 1 First layer device 1a First surface 2, 2A First adhesive layer 3, 3A Second adhesive layer 8 First elastic resin 9 Lightening hole 10 First stretchable substrate 11 First long hinge portion 12 First body portion 13 First hinge portion 20 Resin base material 21 Array layer 30 First strain gauge 101 Second layer device 101a Second surface 101b Third surface 108 Second elastic resin 111 Second long hinge portion 112 Second body portion 113 Second hinge portion 120 Second stretchable substrate 130 Second strain gauge 201 Third layer device 201a Fourth surface 208 Third elastic resin 211 Third long hinge portion 212 Third body portion 213 Third hinge portion 220 Third stretchable substrate 230 Third strain gauge 1000, 1000A Stretchable device 1005 Detection area 1006 Frame area

Claims

1. A device comprising: a first layer device; a second layer device stacked on top of the first layer device in a thickness direction; and a first adhesive layer disposed between the first layer device and the second layer device; wherein the first layer device comprises: a first stretchable substrate having a first strain gauge; and a first elastic resin covering the first stretchable substrate; wherein the second layer device comprises: a second stretchable substrate having a second strain gauge; and a second elastic resin covering the second stretchable substrate; wherein the first stretchable substrate has a plurality of first elongated hinge portions extending in a first direction parallel to a planar direction in which the first layer device extends; and the second stretchable substrate has a plurality of second elongated hinge portions extending in a first intersecting direction parallel to the planar direction and intersecting the first direction; and the plurality of first elongated hinge portions are parallel to the planar direction and are spaced apart in a direction intersecting the first direction, a stretchable device, wherein the second elongated hinge portions are parallel to the planar direction and are spaced apart in a direction intersecting the first intersecting direction; the first elongated hinge portions and the second elongated hinge portions intersect with each other when viewed from the thickness direction; the first elongated hinge portions have: a plurality of first body portions overlapping with the second elongated hinge portions when viewed from the thickness direction; and a first hinge portion connecting the plurality of first body portions and provided with the first strain gauge; and the second elongated hinge portion has: a second body portion overlapping with the first body portion when viewed from the thickness direction; and a second hinge portion connecting the plurality of second body portions and provided with the second strain gauge.

2. A device comprising: a third layer device stacked on the second layer device on the opposite side to the first layer device; and a second adhesive layer arranged between the second layer device and the third layer device; wherein the third layer device comprises: a third stretchable substrate having a third strain gauge provided thereon; and a third elastic resin covering the third stretchable substrate; wherein the third stretchable substrate has a plurality of third long hinge portions that are parallel to the planar direction and extend in a second intersecting direction that intersects with both the first direction and the first intersecting direction; the third long hinge portions are parallel to the planar direction and are arranged at intervals in a direction intersecting with the second intersecting direction; when viewed from the thickness direction, the first long hinge portions and the second long hinge portions intersect with each other; and the third long hinge portions have: a plurality of third body portions that overlap the first body portion and the second body portion when viewed from the thickness direction; The stretchable device according to claim 1 , further comprising: a third hinge portion that connects the plurality of third body portions together and that is provided with the third strain gauge.

3. The stretchable device of claim 1, wherein the first layer device has a first surface facing the second layer device, the second layer device has a second surface facing the first layer device, and the first adhesive layer adheres all of the first and second surfaces.

4. The stretchable device of claim 1, wherein, when viewed from the thickness direction, the stretchable device is divided into a detection area in which the first long hinge portion and the second long hinge portion are arranged, and a frame-shaped frame area surrounding the outside of the detection area, the first layer device has a first surface facing the second layer device, the second layer device has a second surface facing the first layer device, and the first adhesive layer bonds together portions of the first surface and the second surface that overlap with the frame area when viewed from the thickness direction and portions that overlap with the first body portion and the second body portion.

5. The stretchable device of claim 2, wherein the second layer device has a third surface facing the third layer device, the third layer device has a fourth surface facing the second layer device, and the second adhesive layer adheres both the third surface and the fourth surface.

6. The stretchable device of claim 2, wherein, when viewed from the thickness direction, the stretchable device is divided into a detection area in which the first long hinge portion, the second long hinge portion, and the third long hinge portion are arranged, and a frame-shaped frame area surrounding the outside of the detection area; the second layer device has a third surface facing the third layer device; the third layer device has a fourth surface facing the second layer device; and the second adhesive layer bonds together the portions of the third surface and the fourth surface that overlap with the frame area when viewed from the thickness direction and the portions that overlap with the first body portion, the second body portion, and the third body portion.

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