Stretchable device

Abstract

Provided is a stretchable device including a stretchable base material. The stretchable base material is provided with a main surface region extending along a direction different from the thickness direction of the stretchable base material, and an oil / fat barrier layer containing an oil / fat material is located in the main surface region.

Description

Technical Field

[0001] This disclosure relates to stretchable devices.

Background Art

[0002] Conventionally, stretchable devices having stretchable substrates have been known. Such stretchable devices can be used for, for example, living bodies or devices that require stretchability.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, stretchable devices include stretchable substrates made of resin. When such stretchable devices with stretchable substrates are used for living bodies or devices, foreign substances such as sebum, proteins derived from living bodies, or machine oil applied to the devices may adhere to the stretchable substrates. The inventor of the present application newly found that when such foreign substances adhere locally to the stretchable substrate, the stretchable substrate is likely to break at the adhesion site.

[0005] This disclosure has been made in view of the above problems. That is, the main object of this disclosure is to provide a stretchable device in which breakage of the stretchable substrate is preferably suppressed.

Means for Solving the Problems

[0006] The inventor of the present application attempted to solve the above problems not by following the prior art but by taking a new approach. As a result, the inventor arrived at an invention of a stretchable device in which the above main object was achieved.

[0007] The stretchable device according to this disclosure is Equipped with a stretchable base material, The stretchable substrate comprises a main surface region extending in a direction different from the thickness direction of the stretchable substrate, In the aforementioned main surface region, an oil and fat barrier layer containing an oil and fat material is positioned. [Effects of the Invention]

[0008] According to one embodiment of the stretchable device of this disclosure, the breakage of the stretchable substrate is suitably suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic perspective view showing the appearance of a stretchable device according to the first embodiment of this disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view showing the AA cross-section of the stretchable device shown in Figure 1. [Figure 3] Figure 3 is a schematic perspective view showing the appearance of a stretchable device equipped with stretchable wiring according to the first embodiment of this disclosure. [Figure 4] Figure 4 is a schematic cross-sectional view showing the BB cross-section of the expandable device shown in Figure 3. [Figure 5] Figure 5 is a schematic cross-sectional view showing a modified form of the stretchable device according to the first embodiment of this disclosure. [Figure 6] Figure 6 is a schematic cross-sectional view showing a modified form of the stretchable device according to the first embodiment of this disclosure. [Figure 7] Figure 7 is a schematic cross-sectional view showing a modified form of the stretchable device according to the first embodiment of this disclosure. [Figure 8] Figure 8 is a schematic perspective view illustrating a modified version of the stretchable device according to the first embodiment of this disclosure. [Figure 9] Figure 9 is a schematic cross-sectional view showing the CC cross-section of the stretchable device shown in Figure 8. [Figure 10] Figure 10 is a schematic cross-sectional view showing a modified form of the stretchable device according to the first embodiment of this disclosure. [Figure 11]FIG. 11 is a schematic cross-sectional view showing a modified aspect of the stretchable device according to the first embodiment of the present disclosure. [Figure 12] FIG. 12 is a schematic cross-sectional view showing the stretchable device according to the second embodiment of the present disclosure. [Figure 13] FIG. 13 is a schematic cross-sectional view showing the stretchable device according to the third embodiment of the present disclosure. [Figure 14A] FIG. 14A is a schematic cross-sectional view showing a modified aspect of the stretchable device according to the third embodiment of the present disclosure. [Figure 14B] FIG. 14B is a schematic cross-sectional view showing a modified aspect of the stretchable device according to the third embodiment of the present disclosure.

MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be specifically described. It should be noted that the applicant provides the following description and examples for those skilled in the art to fully understand the present disclosure, and does not intend to limit the subject matter described in the claims by these. That is, the present disclosure is not particularly limited to the preferred modes described below, and can be appropriately modified and implemented within the scope of its purpose. For the sake of easy explanation or understanding of the key points, it may be shown separately as embodiments or examples for convenience, but partial substitution and / or combination of the configurations shown in different embodiments are possible. In the description of such embodiments, duplicate explanations may be omitted for substantially the same matters, and only the different points may be explained. In particular, for the same operational effects due to the same configuration, they may not be sequentially mentioned for each embodiment.

[0011] In this specification, terms such as "thickness direction of the stretchable device", "thickness direction of the stretchable base material layer", "lamination direction of the stretchable base material", and "lamination direction" can be used interchangeably. Such a direction corresponds to the direction Y in the figure.

[0012] As used herein, the "cross-sectional view" or "cross-sectional shape" is based on the form viewed from a direction substantially perpendicular to the thickness direction of the stretchable device (specifically, the form when cut along a plane parallel to the thickness direction of the stretchable device). When the stretchable device has a laminated structure including a plurality of stretchable base material layers, the "cross-sectional view" or "cross-sectional shape" is based on the form viewed from a direction substantially perpendicular to the lamination direction of the stretchable base materials (specifically, the form when cut along a plane parallel to the lamination direction). Further, the "planar view" used herein is based on a schematic view of the object when viewed from above or below along the thickness direction (or lamination direction) of the stretchable device.

[0013] [[ID=*3]] In addition, in this specification, "above" a certain element includes not only the case of contacting the upper surface of the element but also the case of not contacting the upper surface of the element. That is, "above" a certain element means not only an upper position separated from the element, that is, an upper position via another object on the element or an upper position with a gap, but also a position directly above contacting the element. Further, "above" does not necessarily mean the upper side in the vertical direction. "Above" merely indicates the relative positional relationship of a certain element.

[0014] All kinds of numerical ranges referred to in this specification are intended to include the numerical values of the lower limit and the upper limit themselves unless otherwise specified. The term "about" means that it may include variations or differences of several percent, for example, ±10%.

[0015] As used herein, "vertical" and "substantially vertical" do not necessarily have to be completely "vertical", and may include a slightly deviated mode (for example, a range of ±10° from complete vertical, for example, a range up to ±5°).

[0016] In addition, as used herein, "substantially parallel" does not necessarily have to be completely "parallel", and may include a slightly deviated mode (for example, a range of ±10° from complete parallel, for example, a range up to ±5°).

[0017] [Basic Configuration of Stretchable Device] The structure of the stretchable device will be described with reference to Figures 1 and 2. Figure 1 is an illustrative perspective view of a stretchable device according to one embodiment of the present disclosure. Figure 2 is a cross-sectional view AA of the stretchable device of Figure 1. Note that the cross-sectional views in this specification are cross-sections parallel to the thickness direction Y of the stretchable device 1.

[0018] The main components included in the stretchable device of this disclosure will be described below with reference to Figures 1 and 2.

[0019] (Stretchable base material 10) The stretchable device 1 comprises at least a stretchable substrate 10. The stretchable substrate 10 (hereinafter also simply referred to as "substrate") may be a sheet-like or film-like stretchable substrate, and may be composed of, for example, a stretchable resin material. Here, in this specification, stretchability simply means the property of being able to stretch and contract, and can also be referred to as stretchability or stretchableness. More specifically, stretchability means the property of being able to stretch from a non-stretched state, which is the normal state in which no tensile stress is applied, by applying tensile stress, and being able to contract when released from the stretched state. Examples of resin materials used as the stretchable substrate 10 include thermoplastic polyurethane.

[0020] The stretchable substrate 10 has a main surface. In this specification, the "main surface" of the stretchable substrate is a surface that extends in a direction different from the thickness direction Y of the stretchable substrate, for example, a surface that extends in directions X and Z substantially perpendicular to the thickness direction Y of the stretchable substrate. The sheet-like or film-like stretchable substrate 10 may extend along the stretching direction of the stretchable device 1. In such a structure, the "main surface" of the stretchable substrate 10 can also be interpreted as a surface that extends along the stretching direction of the stretchable substrate 10. In embodiments that include stretchable wiring, which will be described later, it can also be interpreted as a surface that extends along the extending direction of the stretchable wiring (see Figure 3). Although the drawings show a stretchable device extending in a specific direction for clarity, the shape of the stretchable device is not particularly limited. The plan view shape of the stretchable device is also not particularly limited and can be various shapes such as quadrilaterals (e.g., squares, rectangles, etc.), polygons such as triangles; circles, ellipses, semicircles, crescent shapes, or irregular shapes.

[0021] The thickness of the stretchable substrate 10 is not particularly limited, but if the stretchability of the device is important, it is preferably 1 mm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. Furthermore, if the mechanical strength of the device is important, the thickness of the stretchable substrate 10 is preferably 1 μm or more. In addition, when a laminate is formed by multiple stretchable substrates, each of the multiple stretchable substrates to be laminated may have the same thickness, or they may have different thicknesses from each other.

[0022] (Stretchable wiring 20) The stretchable device 1 may further include stretchable wiring 20 arranged on a stretchable substrate 10 (see Figure 3). The stretchable wiring 20 (hereinafter also simply referred to as "wiring") contains conductive particles and resin. Examples of stretchable wiring 20 include a mixture consisting of metal powder such as Ag (silver), Cu (copper), or Ni (nickel) as conductive particles and an elastomer resin such as silicone resin. The average particle size of the conductive particles is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less. The shape of the conductive particles may be spherical.

[0023] Furthermore, although Figure 3 only shows the stretchable wiring 20 extending in a specific direction for clarity, the stretchable wiring 20 may extend in any direction on and / or inside the main surface of the stretchable base material 10. Preferably, the stretchable wiring 20 may extend along the extending direction of the main surface of the stretchable base material 10. Also, when viewed from the thickness direction Y of the stretchable base material 10, the stretchable wiring 20 does not necessarily have to be arranged in a straight line, but may be arranged in a curve, for example. Also, when viewed from the thickness direction Y, the stretchable wiring 20 does not necessarily have to extend in one direction. The number of stretchable wirings 20 is not particularly limited, and one or more wirings may be arranged.

[0024] [First Embodiment] Based on the main components of the stretchable device 1 described above, the characteristic features of the stretchable device 1 according to the first embodiment of this disclosure will be described below. As shown in Figures 1 and 2, the stretchable device 1 of this disclosure includes an oil and grease barrier layer 30 in the main surface region 12A of the stretchable substrate. The stretchable device 1 includes an oil and grease barrier layer 30 located in the main surface region 12A of the stretchable substrate. The oil and grease barrier layer 30 may be provided so as to cover the stretchable substrate 10 in the main surface region 12A. In other words, the main surface side of the stretchable substrate 10 may be covered by the oil and grease barrier layer 30.

[0025] In this specification, "main surface region," "side region," and "surface region" refer to the region on the surface of the stretchable substrate on the main surface, side, or surface including both the main surface and side, and the region inside the stretchable substrate within a depth of 3 μm along the thickness direction Y from said surface, respectively. In other words, "main surface region 12A" refers to the region on the main surface of the stretchable substrate 10 and the region inside the stretchable substrate within a depth of 3 μm along the thickness direction Y from said main surface. The oil barrier layer 30 may be located in the region on the main surface of the stretchable substrate 10, and / or in the surface region including the main surface of the stretchable substrate 10.

[0026] In this specification, the "oil and grease barrier layer 30" is, simply put, a layer located on the surface region of the stretchable substrate and mainly containing an oil and grease material. The oil and grease barrier layer 30 refers to a layer on the surface region of the stretchable substrate 10 in which an oil and grease material is located. More specifically, the oil and grease barrier layer 30 includes at least one of an oil and grease material impregnated into the interior of the stretchable substrate 10 and an oil and grease material located on the surface of the stretchable substrate 10, on the surface region of the stretchable substrate 10. The oil and grease barrier layer 30 may also be simply referred to as the "oil and grease layer" or "oil and grease-containing layer". Such an oil and grease barrier layer 30 is a layer located on the surface region that includes at least the main surface region 12A of the stretchable substrate, and is different from sebum that adheres locally, for example, by touching the stretchable device 1.

[0027] The stretchable device 1 can be attached to various objects, including living organisms such as the human body or equipment. During use of the stretchable device 1, including the attachment process, various foreign substances, including sebum from the fingers, proteins, and / or machine oil applied to equipment, may adhere to the stretchable device 1 locally. The inventors of the present invention have newly discovered that such locally adhered foreign substances can cause damage to the stretchable device 1.

[0028] As described above, the stretchable substrate 10 provided in the stretchable device 1 is made of a resin material. When the stretchable substrate 10 is stretched, the molecules constituting the stretchable substrate 10 are pulled along the direction of stretching, and the distance between molecules constituting the stretchable substrate 10 increases compared to the normal state (i.e., the non-stretched state). In other words, the molecular structure of the stretchable substrate 10 becomes more sparse in the stretched state. In this state, if foreign matter adheres to the surface of the stretchable substrate 10, the foreign matter can get into the sparse molecular structure.

[0029] Foreign matter that penetrates the molecular structure can inhibit the movement of molecules constituting the stretchable substrate 10 or cause fracture of the molecular structure. When molecular movement is inhibited, the stretchability of the stretchable substrate 10 may decrease locally, and the uniform stretchability of the entire stretchable substrate 10 may be impaired. If the stretchability of the stretchable substrate 10 is uneven, stress tends to concentrate in areas with low stretchability, and as a result, the stretchable substrate 10 may fracture at those locations. In addition, if the molecular structure of the stretchable substrate 10 fractures partially, the mechanical strength of the stretchable substrate 10 decreases locally, which may cause the stretchable substrate 10 to fracture. Thus, when foreign matter adheres locally to the surface of the stretchable substrate 10, the adhered foreign matter penetrates the molecular structure constituting the stretchable substrate 10, making the stretchable substrate 10 more susceptible to damage at the point of foreign matter adhesion.

[0030] To address these challenges, the inventors of the present invention have newly discovered that by providing an oil and grease barrier layer 30 on the main surface region 12A of the stretchable substrate of the stretchable device 1, the occurrence of fracture of the stretchable substrate 10 due to the adhesion of foreign matter can be suppressed. As described above, fracture of the stretchable substrate 10 due to the adhesion of foreign matter can be caused by a localized decrease in the elasticity and / or mechanical strength of the stretchable substrate 10 at the site of foreign matter adhesion.

[0031] In the stretchable device 1 of this disclosure, the stretchable substrate 10 is pre-equipped with an oil and grease barrier layer 30, so that even if foreign matter adheres to the stretchable substrate during use, the intrusion of the foreign matter into the interior of the stretchable substrate 10 can be suppressed. Specifically, since the oil and grease material constituting the oil and grease barrier layer 30 is pre-disposed on the main surface region 12A of the stretchable substrate 10, even if foreign matter from the outside adheres to the main surface, the foreign matter cannot easily penetrate into the molecular structure of the stretchable substrate 10. As a result, local changes in the molecular structure of the stretchable substrate 10 are suppressed, and the stretchable substrate 10 as a whole can maintain more uniform stretchability and mechanical strength. In other words, according to the stretchable device 1 of this disclosure, local changes in the stretchability and / or mechanical strength of the stretchable substrate 10 caused by the adhesion of foreign matter can be suppressed, and as a result, the fracture of the stretchable substrate 10 can be suitably suppressed.

[0032] As described above, in the stretchable device 1 of this disclosure, the oil and grease barrier layer 30 contributes to protecting the stretchable substrate 10 from foreign matter, and may also be referred to as a "protective layer," "protective film," or "coating layer."

[0033] In a preferred embodiment, the grease barrier layer 30 may extend over the main surface region 12A of the stretchable substrate. More specifically, the grease barrier layer 30 may extend continuously along the main surface region 12A of the stretchable substrate. With such a structure, the main surface of the stretchable substrate 10 is suitably protected by the grease barrier layer 30 extending over the main surface region 12A. Therefore, it is possible to suitably suppress the arrival of foreign matter on the main surface of the stretchable substrate 10 and / or the penetration of foreign matter into the molecular structure of the stretchable substrate 10. This makes it possible to provide a stretchable device that can suppress the occurrence of damage to the stretchable substrate caused by the adhesion of foreign matter.

[0034] The oil and grease barrier layer 30 may be provided continuously as described above, or alternatively, it may be provided discontinuously. That is, the oil and grease barrier layer 30 may extend continuously across the surface area of ​​the stretchable substrate 10, or a plurality of discontinuous oil and grease barrier layers 30 may be provided on the surface of the stretchable substrate 10.

[0035] There may be areas in the main surface region 12A where the oil and grease barrier layer 30 is not located. In other words, the oil and grease barrier layer 30 may not be provided in some areas of the main surface region 12A. When viewed from the thickness direction Y of the stretchable substrate, the oil and grease barrier layer 30 may be located in an area that occupies 50% or more, 70% or more, or 90% or more of the area of ​​the main surface region 12A where the oil and grease barrier layer 30 is located. The presence of the oil and grease barrier layer 30 in the above-mentioned areas makes it possible to suitably suppress the fracture of the stretchable substrate 10. The area of ​​the main surface region 12A when viewed from the thickness direction of the stretchable substrate can also be referred to as the area of ​​the main surface.

[0036] The oil and grease barrier layer 30 is provided on at least the main surface region 12A of the stretchable substrate 10. In a sheet-like stretchable substrate 10, the main surface may be the surface with the largest area among the multiple surfaces constituting the stretchable substrate 10. The main surface, being a large surface, is more prone to the adhesion of foreign matter compared to other surfaces. Therefore, by providing the oil and grease barrier layer 30 on the main surface region 12A, it is possible to suitably suppress the breakage of the stretchable substrate 10 caused by the adhesion of foreign matter. Furthermore, as shown in Figures 1 and 2, the stretchable substrate 10 may have two main surface regions 12A that face each other. In such a structure, the oil and grease barrier layer 30 is located on at least one of the two main surface regions 12A that face each other. In other words, the oil and grease barrier layer 30 may be located on either one of the two main surface regions 12A, or alternatively, on both of the two main surface regions 12A.

[0037] As shown in Figures 1 and 2, the grease barrier layer 30 may be provided on the main surface region 12A of the stretchable substrate without stretchable wiring. In the stretchable device 1 of this disclosure, the grease barrier layer 30 is applicable regardless of the presence or absence of stretchable wiring and can suitably suppress the breakage of the stretchable substrate 10. In such a structure, the grease barrier layer 30 may be provided so as to cover at least the central portion of the main surface region 12A when viewed from the thickness direction Y of the stretchable substrate.

[0038] Alternatively, as shown in Figure 3, the oil and grease barrier layer 30 may be provided on a stretchable substrate 10 equipped with stretchable wiring 20. The stretchable substrate 10 may be equipped with stretchable wiring 20 arranged inside it, and may be equipped with an oil and grease barrier layer 30 on at least the main surface region 12A. Preferably, the oil and grease barrier layer 30 may be provided in a region that overlaps with the stretchable wiring 20 when viewed from the thickness direction Y of the stretchable substrate. In other words, the stretchable wiring 20 and the oil and grease barrier layer 30 may be arranged to overlap each other when viewed from the thickness direction Y of the stretchable substrate. In the stretchable device 1 of this disclosure, by arranging the oil and grease barrier layer 30 in a region that overlaps with the stretchable wiring 20 when viewed from the thickness direction Y, the stretchable substrate 10 located in the region overlapping with the stretchable wiring 20 can be suitably protected from the adhesion of foreign matter. Generally, in the use of the stretchable device 1, electrical signals are transmitted via the stretchable wiring 20 arranged on the stretchable substrate 10. If the stretchable substrate 10 breaks in an area overlapping with the stretchable wiring 20, the stretchable wiring 20 may be damaged as a result of the break, potentially causing abnormalities in the transmission of electrical signals. In the stretchable device 1 of this disclosure, an oil barrier layer 30 is placed in at least an area overlapping with the stretchable wiring 20 when viewed from the thickness direction Y, thereby protecting the stretchable substrate 10 covering the stretchable wiring 20 and effectively suppressing damage to the stretchable wiring 20.

[0039] Preferably, the oil and grease barrier layer 30 may be provided over the entire main surface of the stretchable substrate 10. In other words, the entire main surface of the stretchable substrate 10 may be covered by the oil and grease barrier layer 30. This effectively protects the entire main surface of the stretchable substrate 10 from the adhesion of foreign matter, thereby more effectively suppressing the breakage of the stretchable substrate 10.

[0040] The oil and grease barrier layer 30 can exist in at least one of the following: the surface region inside the stretchable substrate 10, and the region on the surface outside the stretchable substrate 10. In other words, the oil and grease barrier layer 30 may comprise at least one of the layers located on the inside of the stretchable substrate 10 and the layer located on the outside of the stretchable substrate 10. The oil and grease barrier layer 30 located on the inside of the stretchable substrate 10, which contains an oil and grease material impregnated into the inside of the stretchable substrate 10, will be referred to below as the "first oil and grease layer" (see Figures 1 to 4). The first oil and grease layer may also be referred to as the "internal oil and grease layer" or the "impregnated oil and grease layer". Furthermore, the oil and grease barrier layer 30 located on the surface of the stretchable substrate 10, which contains an oil and grease material, will be referred to below as the "second oil and grease layer" (see Figure 5). The second oil and grease layer may also be referred to as the "external oil and grease layer" or the "coated oil and grease layer". In other words, the stretchable device 1 of this disclosure may include an oil barrier layer comprising at least one of a first oil layer and a second oil layer.

[0041] As shown in Figure 4, by providing a first oily layer 30 containing impregnated oily material, the oily material can be positioned within the molecular structure located on the surface of the stretchable substrate 10. Because the oily material is pre-positioned within the molecular structure, the penetration of locally attached foreign matter into the molecular structure can be suppressed. Although this should not be interpreted as being limited to a specific theory, it is presumed that this is because, on the surface of the stretchable substrate 10, the oily material constituting the oily barrier layer 30 is interposed within the molecular structure of the stretchable substrate 10, thereby blocking the entry routes of foreign matter. Therefore, it is thought that local changes in the elasticity and / or mechanical strength of the stretchable substrate 10 can be suppressed, and as a result, the fracture of the stretchable substrate 10 can be suitably suppressed.

[0042] Furthermore, as shown in Figure 5, the second oily layer 30, which contains an oily material and is placed on the surface of the stretchable substrate 10, can suppress foreign matter adhering to the stretchable device 1 from reaching the stretchable substrate 10. In other words, the penetration of foreign matter into the surface of the stretchable substrate can be prevented by the second oily layer. This prevents foreign matter from locally entering the molecular structure of the stretchable substrate, thus effectively suppressing fracture of the stretchable substrate caused by localized adhesion of foreign matter.

[0043] Preferably, the oil and grease barrier layer 30 comprises at least a first oil and grease layer. By comprising at least a first oil and grease layer, the penetration of foreign matter into the interior of the stretchable substrate 10 can be suitably avoided. For example, the oil and grease barrier layer 30 may comprise only the first oil and grease layer 30a (see Figure 4), or alternatively, it may comprise both the first oil and grease layer 30a and the second oil and grease layer 30b (see Figure 6). When viewed from the thickness direction of the oil and grease barrier layer 30, the first oil and grease layer 30a and the second oil and grease layer 30b may overlap in at least a portion. When viewed from the thickness direction of the oil and grease barrier layer 30, the region in which the first oil and grease layer 30a and the second oil and grease layer 30b overlap corresponds to a configuration in which an additional oil and grease material is applied to the surface of the stretchable substrate 10, which is impregnated with an oil and grease material on its surface layer. As a result, the first oil layer 30a suppresses the intrusion of foreign matter into the interior of the stretchable substrate 10, and the second oil layer 30b also suppresses the arrival of foreign matter on the surface of the stretchable substrate. This allows for more favorable suppression of localized stress concentration in the stretchable substrate 10 caused by the adhesion of foreign matter.

[0044] Furthermore, in an oil barrier layer 30 comprising both a first oil layer 30a and a second oil layer 30b, the first oil layer 30a and / or the second oil layer 30b may be positioned discontinuously. For example, the first oil layer 30a may extend continuously while the second oil layer 30b is discontinuous. Alternatively, the first oil layer 30a may be positioned discontinuously while the second oil layer 30b extends continuously. Or, both the first oil layer 30a and the second oil layer 30b may extend continuously. In yet another embodiment, both the first oil layer 30a and the second oil layer 30b may be positioned discontinuously. When viewed from the thickness direction of the oil barrier layer 30, the discontinuous first oil layer 30a and the second oil layer 30b may overlap in at least a portion. This may result in the formation of a continuously extending oil and grease barrier layer 30 when viewed macroscopically. For example, the surface area of ​​the stretchable substrate may be covered by at least one of the first oil and grease layer 30a and the second oil and grease layer 30b.

[0045] In cross-sectional view, the thickness T1 of the first oil layer may be, for example, 1 μm or more, 1.5 μm or more, or 3 μm or more (see Figure 4). Note that "thickness of the first oil layer" can be understood as the depth of the first oil layer extending from the surface of the stretchable substrate 10 toward the interior of the stretchable substrate 10. By having the thickness T1 of the first oil layer within the above range, the localized penetration of foreign matter into the interior of the stretchable substrate 10 can be suitably suppressed. For example, the thickness of sebum adhering to the skin of the human body is generally about 0.5 μm. Therefore, if the lower limit of the thickness T1 of the first oil layer is as described above, the stretchable substrate 10 can be suitably protected from sebum that may locally adhere to the stretchable device 1 as a result of skin contact with the stretchable device 1. Furthermore, if the overall stretchability of the stretchable substrate 10 is important, the thickness T1 of the first oil layer may be 100 μm or less, 70 μm or less, or 40 μm or less.

[0046] Furthermore, in cross-sectional view, the thickness T2 of the second oil layer may be, for example, 1 μm or more, 1.5 μm or more, or 3 μm or more (see Figure 5). By having the thickness T2 of the second oil layer within the above range, the arrival of foreign matter on the surface of the stretchable substrate 10 can be suitably suppressed. Also, if the overall stretchability of the stretchable substrate 10 is important, the thickness T2 of the second oil layer may be 100 μm or less, 70 μm or less, or 40 μm or less.

[0047] Furthermore, as shown in Figure 7, the stretchable substrate 10 has a side surface connecting two main surfaces that are positioned opposite each other. The oil and grease barrier layer 30 may be positioned from the main surface to the side surface of the stretchable substrate 10. In other words, the oil and grease barrier layer 30 may extend from the main surface region 12A to the side surface region 12B of the stretchable substrate 10. Specifically, the oil and grease barrier layer 30 may be provided so as to cover the entire main surface region 12A and at least a part of the side surface region 12B. In such a structure, if the stretchable substrate 10 has a rectangular sheet shape in cross-section, the oil and grease barrier layer 30 may be positioned so as to cover the edges and / or corners of the stretchable substrate 10. This makes it possible for the oil and grease barrier layer 30 to protect not only the main surface of the stretchable substrate 10 but also the edges and / or corners where stress tends to concentrate. Therefore, according to the above structure, damage to the stretchable substrate 10 can be more effectively suppressed. Furthermore, by forming the oil and grease barrier layer 30 across multiple surfaces of the stretchable substrate 10, the oil and grease barrier layer 30 can be more effectively retained by the stretchable substrate 10 compared to a configuration where the oil and grease barrier layer 30 is formed on only a single surface.

[0048] In one preferred embodiment, the grease barrier layer 30 is positioned to cover the entire outer surface of the stretchable substrate 10 (see Figures 8 to 11). That is, the grease barrier layer 30 may be provided so as to surround the stretchable substrate 10. In other words, the stretchable substrate 10 may be covered by the grease barrier layer 30 located in the surface region including the main surface region 12A and the side region 12B of the stretchable substrate 10. Such a configuration can also be understood as a configuration in which the grease barrier layer 30 extends along the outer contour of the stretchable substrate 10. For example, the grease barrier layer 30 may be continuously formed over all surfaces of the stretchable substrate 10. In such a configuration, all corners 14 and ridges 16 of the stretchable substrate 10 can be covered by the grease barrier layer 30 (see Figure 8). This protects the entire stretchable substrate 10 from the grease barrier layer 30, and more effectively suppresses damage to the stretchable substrate 10 caused by the adhesion of foreign matter.

[0049] The oily material contained in the oily barrier layer 30 provided throughout the stretchable substrate 10 may be applied to the surface of the stretchable substrate 10 in the main surface region 12A and the side surface region 12B of the stretchable substrate (see Figure 9), or it may be impregnated into the interior of the stretchable substrate 10 (see Figure 10). Alternatively, the oily barrier layer 30 may comprise both a first oily layer 30a and a second oily layer 30b. In other words, the oily barrier layer 30 may comprise at least one of the first oily layer 30a and the second oily layer 30b. Furthermore, the oily barrier layer 30 provided in the main surface region 12A and the side surface region 12B does not necessarily have to have a uniform structure. For example, the oily barrier layer 30 may have different thicknesses in the main surface region 12A and the side surface region 12B. Furthermore, for example, the main surface region 12A may have both the first oil layer 30a and the second oil layer 30b, while the side surface region 12B may have only the first oil layer 30a, thus forming oil barrier layers 30 with different structures in the main surface region 12A and the side surface region 12B.

[0050] The oil and fat material contained in the oil and fat barrier layer 30 can be any oil and fat material used in fields such as food, animal feed, cosmetics, pharmaceuticals, and industry. For example, the oil and fat material contained in the oil and fat barrier layer 30 may be at least one selected from the group consisting of vegetable oils, animal oils, mineral oils, and synthetic oils. Furthermore, the oil and fat material may be in liquid or solid form.

[0051] Examples of vegetable oils include, but are not limited to, soybean oil, corn oil, cottonseed oil, rapeseed oil, sesame oil, perilla oil, rice bran oil, sunflower oil, peanut oil, olive oil, palm oil, palm kernel oil, rice germ oil, wheat germ oil, brown rice germ oil, Job's tears oil, garlic oil, macadamia nut oil, avocado oil, evening primrose oil, flower oil, camellia oil, coconut oil, castor oil, linseed oil, cocoa oil, wood wax, jojoba oil, and grapeseed oil, either individually or in mixtures, or processed oils obtained by hardening, fractionating, or transesterifying these oils.

[0052] Examples of animal fats and oils, though not particularly limited, include fish oil, chicken oil, beef tallow, pork tallow, milk fat, horse oil, snake oil, egg oil, egg yolk oil, turtle oil, mink oil, and processed products of these fats and oils (margarine, shortening, butter, etc.).

[0053] Examples of mineral oils, though not limited to them, include rust-preventive oils, cutting oils, engine oils, gear oils, and greases.

[0054] Examples of synthetic oils, though merely illustrative, include non-polar oils such as hydrocarbon oils, silicone oils, and ester oils. Specifically, examples include hydrocarbon oils such as petrolatum, solid paraffin, and liquid paraffin; silicone oils such as cyclopentasiloxane; and ester oils such as cetyl ethylhexanoate, ethylhexyl palmitate, isopropyl myristate, isopropyl palmitate, caprylic / capric triglyceride, and triethylhexanoin.

[0055] For example, when the stretchable device 1 is applied to the human body, it is preferable that the oily material contained in the oily barrier layer 30 is an oily material with excellent biocompatibility. Also, for example, when the stretchable device 1 is used in industrial equipment, it is preferable that the oily barrier layer 30 contains the same type of oily material as the oily material used as machine oil. As a result, even if machine oil adheres locally when the stretchable device 1 is used, the machine oil is equivalent to the components contained in the oily barrier layer 30, and therefore, local changes in the stretchability and mechanical strength of the stretchable base material 10 can be effectively suppressed.

[0056] (Method for fabricating stretchable devices) The following describes an exemplary method for fabricating a stretchable device according to one embodiment of this disclosure.

[0057] First, prepare the stretchable substrate. After preparing the stretchable substrate layer, stretchable wiring may be formed on the main surface of the stretchable substrate layer.

[0058] The formation of stretchable wiring may be carried out by printing a conductive paste (for example, a conductive paste containing a mixture of silver and resin) onto a stretchable substrate using methods such as screen printing or inkjet printing. This makes it possible to obtain the desired circuit pattern.

[0059] After forming a circuit pattern for the stretchable wiring 20 on the stretchable substrate 10, the stretchable wiring 20 can be formed on the stretchable substrate 10 by drying and curing a conductive paste for stretchable wiring. Printing may be performed on both sides of the stretchable substrate 10, including the opposite main surface, rather than just one main surface. Furthermore, if necessary, components such as electronic components can be mounted on the stretchable wiring 20.

[0060] Next, another stretchable substrate 10 may be stacked in the thickness direction Y so as to cover the stretchable wiring 20 arranged on the stretchable substrate 10. After that, the stacked stretchable substrates 10 may be bonded together by pressing them under predetermined temperature conditions. This makes it possible to obtain a stretchable substrate 10 with stretchable wiring 20 inside.

[0061] Subsequently, an oily barrier layer 30 is formed by applying an oily material to the outer surface of the stretchable substrate 10. For example, an oily material that can impregnate the stretchable substrate 10 may be applied to the outer surface of the stretchable substrate 10 and left for a predetermined time (e.g., 1 second or more) to impregnate the surface layer of the stretchable substrate 10 with the oily material. The method of applying the oil is not particularly limited, and known application methods can be applied. For example, the application method may be a roll coater method, a spray method, a dip method, etc.

[0062] In one embodiment, all of the applied oily material may be impregnated into the surface layer of the stretchable substrate 10. Alternatively, the oily material may not be impregnated into the stretchable substrate 10, but rather retained on the surface of the stretchable substrate 10. In other words, only a first oily layer may be formed so that the stretchable substrate 10 contains only the impregnated oily material (see Figure 9), or only a second oily layer may be formed by retaining the oily material on the surface without impregnation (see Figure 10). For example, a second oily layer may be formed by applying an oily material that does not impregnate the stretchable substrate 10 to the surface of the stretchable substrate 10. Alternatively, some of the applied oily material may remain on the stretchable substrate 10 without impregnation. Or, both a first oily layer and a second oily layer may be formed (see Figure 11).

[0063] (Second Embodiment) Next, the stretchable device 1B according to the second embodiment will be described. The stretchable device 1B differs from the stretchable device 1 according to the first embodiment in that the stretchable wiring 20 is arranged on the surface of the stretchable substrate 10 rather than inside the stretchable substrate 10, and an oil barrier layer 30 is provided so as to cover the stretchable wiring 20.

[0064] Figure 12 is a cross-sectional view of a stretchable device 1B according to a second embodiment. As shown, the stretchable device 1B may include stretchable wiring 20 arranged on the outer surface of a stretchable substrate 10. In such a structure, the oil and grease barrier layer 30 may be provided to cover the stretchable wiring 20 located on the stretchable substrate 10. The stretchable wiring 20 may have the oil and grease barrier layer 30 on its outer surface 20A that is not in contact with the stretchable substrate 10. The oil and grease barrier layer 30 may integrally surround the stretchable substrate 10 and the stretchable wiring 20 located on the stretchable substrate 10. Similar to the stretchable substrate 10, if the stretchability and mechanical strength of the stretchable wiring 20 changes locally due to the adhesion and intrusion of foreign matter, fracture due to stress concentration may occur. According to the above configuration, by providing an oil and grease barrier layer 30 covering the stretchable wiring 20, the stretchable wiring 20 located outside the stretchable substrate 10, rather than inside the stretchable substrate 10, can also be suitably protected from the adhesion of foreign matter.

[0065] For example, the surface layer of the expandable wiring 20, which is arranged on the outer surface of the expandable substrate, may also be impregnated with the oily material that constitutes the oily barrier layer 30. This allows the oily barrier layer 30 to be suitably held on the expandable wiring and to suitably protect the expandable wiring 20 from foreign matter.

[0066] (Third embodiment) Next, the stretchable device 1C according to the third embodiment will be described. The stretchable device 1C differs from the stretchable device 1 according to the first embodiment in that it comprises a laminate 50 in which a plurality of stretchable substrates 10 are stacked.

[0067] Figures 13, 14A, and 14B are schematic cross-sectional views of a stretchable device 1C according to a third embodiment. The stretchable substrates 10 may be stacked on top of each other in the thickness direction Y. More specifically, a multilayer structure may be formed in which multiple stretchable substrates 10 are stacked with their main surfaces facing each other. In other words, multiple stretchable substrates 10 may be stacked in the thickness direction Y of the stretchable substrates to form a laminate 50. The number of stretchable substrates 10 to be stacked is not particularly limited.

[0068] In such a structure, the oil and grease barrier layer 30 may be positioned in the main surface region 50A of the stretchable substrate constituting the outer surface of the laminate 50. More specifically, the oil and grease barrier layer 30 may be positioned in the upper main surface region of the stretchable substrate 10 located at the top of the laminate 50, and / or in the lower main surface region of the stretchable substrate located at the bottom of the laminate 50. In other words, the oil and grease barrier layer 30 can be understood as being positioned in the main surface region 50A of the outer surface of the laminate 50. With such a structure, since the main surface region 50A of the laminate 50 is protected by the oil and grease barrier layer 30, damage to the stretchable substrate 10 caused by the adhesion of foreign matter can be suitably suppressed.

[0069] The grease barrier layer 30 may be placed in the side region of the stretchable substrate 10 that constitutes the outer surface of the laminate 50 (see Figures 14A and 14B). The grease barrier layer 30 may extend from the main surface region 50A of the stretchable substrate 10 located at the top and / or bottom to the side region 50B that is continuous with the main surface region 50A. Preferably, the entire laminate 50 may be covered by the grease barrier layer 30 that is continuously provided across the outer surface of the laminate 50. Such a grease barrier layer 30 can also be understood as constituting the outermost layer of the stretchable device by continuously covering the outer surface of the laminate 50. According to the above structure, it is possible to suitably reduce the effects of foreign matter adhesion throughout the entire stretchable device 1C comprising the laminate 50.

[0070] The oil and grease barrier layer 30 may comprise at least one of a first oil and grease layer (see Figure 14A) containing an oil and grease material impregnated into the interior of the surface of the stretchable substrate 10 constituting the outer surface of the laminate 50, and a second oil and grease layer (see Figure 14B) containing an oil and grease material present on the outer surface of the laminate 50. Preferably, the oil and grease barrier layer 30 covering the laminate 50 may comprise at least the first oil and grease layer. For example, the oil and grease material contained in the first oil and grease layer may penetrate into the gaps between adjacent stretchable substrates 10 on the outer surface side of the laminate 50. This effectively suppresses localized reductions in the elasticity and / or mechanical strength of the stretchable substrates 10 caused by the intrusion of foreign matter from the gaps between the laminated stretchable substrates 10.

[0071] The embodiments of this disclosure have been described above, but these are merely typical examples. Those skilled in the art will readily understand that this disclosure is not limited thereto, and various embodiments are conceivable without altering the gist of this disclosure.

[0072] For example, the stretchable device may include portions of the main surface area of ​​the stretchable substrate 10 (or, if the stretchable device has a laminated structure, the main surface area of ​​the laminate) that do not have the oil and grease barrier layer 30. For example, the oil and grease barrier layer 30 does not need to be provided in portions of the stretchable substrate 10 where the stretchability is locally reduced, such as portions that overlap with components that have less stretchability than the stretchable substrate 10, such as electronic components, when viewed from the thickness direction Y of the stretchable substrate. In other words, the oil and grease barrier layer 30 may be located in the main surface area of ​​the stretchable substrate 10, excluding portions that overlap with components such as electronic components provided on the stretchable substrate 10, when viewed from the thickness direction Y of the stretchable substrate. With such a configuration, damage to the stretchable substrate 10 caused by the adhesion of foreign matter can be suitably suppressed in the stretchable substrate 10 around electronic components.

[0073] Furthermore, the oil and grease barrier layer 30 may have the effect of slightly reducing the elasticity of the stretchable substrate 10. Therefore, for stretchable devices whose elasticity has been locally reduced due to component mounting, etc., by providing the oil and grease barrier layer 30 in areas other than those with low elasticity, the elasticity of the stretchable substrate 10 in the areas where the oil and grease barrier layer 30 is provided can be slightly reduced. As a result, the difference in elasticity of the stretchable substrate 10 between areas with and without components is reduced, and the localized reduction in the elasticity of the stretchable substrate 10 at the component mounting area can be mitigated. In other words, by selecting the placement of the oil and grease barrier layer according to the difference in elasticity of the stretchable device, the overall elasticity of the stretchable device can be adjusted. This makes it possible for the stretchable device to have more uniform elasticity as a whole, and the occurrence of damage to the stretchable substrate 10 caused by localized reduction in elasticity can be suitably suppressed.

[0074] Furthermore, the above-described embodiment of the present disclosure includes the following preferred embodiments. <1> Equipped with a stretchable base material, The stretchable substrate comprises a main surface region extending in a direction different from the thickness direction of the stretchable substrate, A stretchable device in which an oil barrier layer containing an oil material is positioned in the main surface region. <2> The oil barrier layer extends along the main surface region. <1> The stretchable device described. <3> The oil and grease barrier layer comprises a first oil and grease barrier layer located on the inner side of the stretchable substrate, The first oil barrier layer includes an oil material impregnated into the interior of the stretchable substrate. <1> or <2> The stretchable device described. <4> In cross-sectional view, the thickness of the first oil barrier layer is 1 μm or more and 100 μm or less. <3> The stretchable device described. <5> The oil and grease barrier layer comprises a second oil and grease barrier layer located on the outer surface of the stretchable substrate, The second oil barrier layer includes an oil material positioned on the outer surface of the stretchable substrate. <1> ~ <4> A stretchable device as described in any of the following. <6> In cross-sectional view, the thickness of the second oil barrier layer is 1 μm or more and 100 μm or less. <5> The stretchable device described. <7> The aforementioned stretchable substrate further comprises stretchable wiring, Viewed from the thickness direction of the stretchable substrate, the oil barrier layer is positioned in the main surface region that overlaps with at least the stretchable wiring. <1> ~ <6> A stretchable device as described in any of the following. <8> The oil barrier layer is positioned over the entire surface area of ​​the main surface region. <1> ~ <7> A stretchable device as described in any of the following. <9> The stretchable substrate comprises two main surface regions facing each other and a side surface region located between the two main surface regions. The oil barrier layer extends from the main surface region to the side surface region. <1> ~ <8> A stretchable device as described in any of the following. <10> The oil barrier layer is continuous over the entire outer surface region of the stretchable substrate. <1> ~ <9> A stretchable device as described in any of the following. <11> The stretchable substrate is surrounded by the oil barrier layer. <1> ~ <10> A stretchable device as described in any of the following. <12> The main surface region further comprises stretchable wiring arranged on the outer surface of the stretchable substrate, The oil barrier layer integrally covers the main surface region and the expandable wiring. <1> ~ <11> A stretchable device as described in any of the following. <13> The laminate comprises a plurality of the stretchable substrates stacked on top of each other, The oil barrier layer is positioned in the main surface region of the stretchable substrate that constitutes the outer surface of the laminate, among the plurality of stretchable substrates. <1> ~ <12> A stretchable device as described in any of the following. <14> Among the plurality of stretchable substrates, the stretchable substrate having a surface constituting the outer surface of the laminate has a continuous oil and grease barrier layer extending across the entire surface constituting the outer surface. <13> The stretchable device described. <15> The laminate is surrounded by the oil barrier layer. <13> or <14> The stretchable device described. <16> The oil barrier layer comprises at least one oil material selected from the group consisting of vegetable oils, animal oils, mineral oils, and synthetic oils. <1> ~ <15> A stretchable device as described in any of the following.

[0075] It should be noted that the effects described above are merely examples. Therefore, this disclosure is not limited to the matters described above, and there may be additional effects. [Explanation of Symbols]

[0076] 1: Stretchable device 10: Stretchable base material 12A: Main surface area of ​​the stretchable substrate 12B: Side region of stretchable substrate 14: Corner 16: Ridge section 20:Stretchable wiring 30: Oil and fat barrier layer 50: Laminate 50A: Main surface area of ​​the laminate 50B: Side region of the laminate

Claims

1. Equipped with a stretchable base material, The stretchable substrate comprises a main surface region extending in a direction different from the thickness direction of the stretchable substrate, A stretchable device in which an oil barrier layer containing an oil material is positioned in the main surface region.

2. The stretchable device according to claim 1, wherein the oil barrier layer extends along the main surface region.

3. The oil and grease barrier layer comprises a first oil and grease barrier layer located on the inner side of the stretchable substrate, The stretchable device according to claim 1, wherein the first oil barrier layer includes an oil material impregnated into the interior of the stretchable substrate.

4. The stretchable device according to claim 3, wherein, in cross-sectional view, the thickness of the first oil barrier layer is 1 μm or more and 100 μm or less.

5. The oil and grease barrier layer comprises a second oil and grease barrier layer located on the outer surface of the stretchable substrate, The stretchable device according to claim 1, wherein the second oil barrier layer includes an oil material positioned on the outer surface of the stretchable substrate.

6. The stretchable device according to claim 5, wherein, in cross-sectional view, the thickness of the second oil barrier layer is 1 μm or more and 100 μm or less.

7. The aforementioned stretchable substrate further comprises stretchable wiring, The stretchable device according to claim 1, wherein, viewed from the thickness direction of the stretchable substrate, the oil barrier layer is positioned in the main surface region that overlaps with at least the stretchable wiring.

8. The stretchable device according to claim 1, wherein the oil barrier layer is positioned over the entire surface area of ​​the main surface region.

9. The stretchable substrate comprises two main surface regions facing each other and a side surface region located between the two main surface regions. The stretchable device according to claim 1, wherein the oil barrier layer extends from the main surface region to the side surface region.

10. The stretchable device according to claim 1, wherein the oil barrier layer is continuous over the entire outer surface region of the stretchable substrate.

11. The stretchable device according to claim 1, wherein the stretchable substrate is surrounded by the oil barrier layer.

12. The main surface region further comprises stretchable wiring arranged on the outer surface of the stretchable substrate, The stretchable device according to claim 1, wherein the oil barrier layer integrally covers the main surface region and the stretchable wiring.

13. The laminate comprises a plurality of the stretchable substrates stacked on top of each other, The stretchable device according to claim 1, wherein the oil barrier layer is positioned in the main surface region of the stretchable substrate that constitutes the outer surface of the laminate, among the plurality of stretchable substrates.

14. The stretchable device according to claim 13, wherein, among the plurality of stretchable substrates, the stretchable substrate having a surface constituting the outer surface of the laminate comprises the oil and grease barrier layer that extends continuously over the entire surface constituting the outer surface.

15. The stretchable device according to claim 13, wherein the laminate is surrounded by the oil barrier layer.

16. The stretchable device according to claim 1, wherein the oil barrier layer comprises at least one oil material selected from the group consisting of vegetable oils, animal oils, mineral oils, and synthetic oils.

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