Method of applying conductive material to the skin

Abstract

To provide a method for sticking a conductive substance more easily and with excellent reproducibility when sticking the conductive substance to the skin.SOLUTION: A method for sticking a conductive material to the skin includes: an arrangement step for arranging a laminate of the conductive material and a porous sheet on the skin so that the skin and the conductive material come in contact with each other; and a supply step for supplying water or an alcohol aqueous solution to the laminate from a surface side that does not come in contact with the skin, of the laminate arranged on the skin. The supply step is executed by a supply member removably provided on the surface side that does not come in contact with the skin of the laminate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for attaching a conductive substance to the skin.

Background Art

[0002] Flexible electronics, which forms electronic devices on a flexible substrate, has been studied, and research on its application to living bodies is also progressing. For example, a nano-mesh laminate in which a net-shaped substrate and a nano-mesh layer mainly composed of a polyvinyl alcohol (PVA)-based resin are laminated adjacent to each other has been proposed (see Patent Document 1).

[0003] The nano-mesh laminate disclosed in Patent Document 1 is obtained by coating one surface of a mesh of PVA nanofibers formed on a net-shaped substrate by an electrospinning method with a conductive metal or the like. After placing this nano-mesh laminate at a desired location, it is attached using water or the like, whereby a conductive substance layer is fixed. The fixed conductive substance layer follows the deformation of the skin or the like and can be applied to joints or the like, and can be used for sensing electrical signals of the skin, wiring to electrodes or various sensors that give stimuli from electrodes to the skin, and the like.

[0004] Furthermore, a method for attaching a nanofiber sheet provided with a nanofiber layer formed from nanofibers of a polymer compound and a substrate layer disposed on one surface side of the nanofiber layer to the surface of an object has been proposed (see Patent Document 2). The attachment method disclosed in Patent Document 2 has the feature that, in a state where the surface of the nanofiber layer or the surface of the object is wetted, the surface of the nanofiber sheet on the nanofiber layer side is brought into contact with the surface of the object.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] One example of a method for attaching a conductive material to the skin is the method disclosed in Patent Document 1. Specifically, this method involves placing a nanomesh laminate in a desired location, and then dissolving a water-soluble resin such as PVA nanofibers using water or the like to attach the conductive material to the skin surface. However, when using this method to attach a conductive material to the skin surface, the process must include steps such as placing the nanomesh laminate in the desired location and bringing the nanomesh laminate into contact with water or an aqueous alcohol solution. Because of these numerous attachment steps, a simpler method was desired.

[0007] Another example of a method for attaching a conductive material to the skin is the method disclosed in Patent Document 2. However, applying this method to attach conductive materials to the skin surface presents the following problems. If the surface of the nanomesh laminate is moistened before placing it in the desired location, the water-soluble resin contained in the nanomesh laminate dissolves, causing the nanomesh laminate to break down and become unhandling, making it difficult to attach to the skin. Also, if the skin is moistened beforehand, the nanomesh laminate comes into contact with the skin. When the nanomesh laminate is placed in a specific location, the water-soluble resin contained within it dissolves, making it prone to shifting and thus difficult to attach to the desired location.

[0008] This invention solves the above-mentioned problems that arise for the first time when conductive materials are applied to the skin. [Means for solving the problem]

[0009] The inventors of the present invention have made repeated improvements to solve the above problems and have found that the above problems can be solved by using a supply member when attaching a conductive material to the skin.

[0010] In other words, the present invention includes the following: [1] A method of attaching a conductive material to the skin, The arrangement step involves placing the laminate of the conductive material and the porous sheet on the skin so that the skin and the conductive material are in contact; A method comprising a supply step of supplying water or an aqueous alcohol solution to the laminate from the non-contact side of the laminate placed on the skin, wherein the supply step is supplied by a supply member detachably provided on the non-contact side of the laminate. [2] The method according to [1], wherein the porous sheet comprises a water-soluble resin mesh layer. [3] The method according to [2], wherein the porous sheet comprises a water-soluble resin nanomesh layer. [4] The method according to any one of [1] to [3], wherein the porous sheet comprises a mesh substrate. [5] The method according to any one of [1] to [4], wherein the supply member comprises a container for storing water or an aqueous alcohol solution. [6] The method according to any one of [1] to [5], wherein the supply member comprises a carrier on which water or an aqueous alcohol solution is supported. [7] The method according to any one of [1] to [5], wherein the supply member has a spraying device. [Effects of the Invention]

[0011] This invention makes it possible to apply conductive materials to the skin more easily than with conventional methods, and furthermore, it provides the advantage of being able to easily apply them to desired locations. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic cross-sectional view showing a laminate of one embodiment. [Figure 2] It is a schematic cross-sectional view showing a supply member of an embodiment. [Figure 3] It is a schematic cross-sectional view showing a state where a laminate is installed on a supply member of an embodiment. [Figure 4] It is a schematic cross-sectional view showing an embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, the present invention will be described in detail. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents, and various modifications can be made within the scope of the gist.

[0014] One embodiment of the present invention is A method of attaching a conductive substance to the skin, An arrangement step of arranging a laminate of the conductive substance and a porous sheet on the skin so that the skin and the conductive substance are in contact; A supply step of supplying water or an aqueous alcohol solution to the laminate from a side of the laminate that is not in contact with the skin, which is supplied by a supply member detachably provided on a side of the laminate that is not in contact with the skin.

[0015] This embodiment will be described with reference to the drawings. FIGS. 1 to 4 show schematic cross-sectional views according to this embodiment.

[0016] FIG. 1 is a schematic cross-sectional view showing a laminate of an embodiment. The laminate 100 has a configuration in which a conductive substance layer 11 is laminated on a porous sheet 10. Further, the porous sheet 10 may have a water-soluble resin mesh layer on the side facing the conductive substance layer 11.

[0017] The porous sheet 10 is not particularly limited in its porosity as long as it can permeate liquids and vapors, but for quick application, a porosity of 55% to 80% is preferable in order to increase the permeability of water, aqueous alcohol solutions, water vapor, alcohol vapor, etc. On the other hand, when accuracy is required for the pattern of the conductive material layer to be transferred, for example when measuring resistance values, or when there are fine parts in the pattern to be transferred, for example, when a part of the pattern to be transferred has a thickness of 2 mm or less, and especially a width of 1 mm or less, in order to accurately transfer the pattern, the porosity of the porous sheet of the substrate is preferably 10% to 45%, more preferably 40% or less, and even more preferably 35% or less, in order to distribute the pressure applied to the laminate, especially the conductive material layer, during application and suppress damage to the laminate, especially the conductive material layer.

[0018] The material of the porous sheet 10 is not particularly limited, but commonly used thermoplastic resins are used, specifically, thermoplastic resins such as polyethylene, polypropylene, polyamide, polystyrene, and polyester. Preferably, it is a polyolefin resin such as polyethylene or polypropylene. Adhesion can also be imparted to the porous sheet by incorporating a water-soluble resin such as polyvinyl alcohol (PVA), polyacrylamide, carboxymethylcellulose, polyvinylpyrrolidone (PVP), polyglycolic acid (PGA), or polylactic acid (PLA).

[0019] The porous sheet 10 may have a water-soluble resin mesh layer. That is, the porous sheet may include a water-soluble resin mesh layer. In the laminate 100, it is preferable to have a water-soluble resin mesh layer between the porous sheet 10 and the conductive material layer 11. By providing a water-soluble resin mesh layer, the adhesive hardness when the conductive material is attached to the skin is increased. Examples of water-soluble resins used in the water-soluble resin mesh layer include polyvinyl alcohol (PVA), polyacrylamide, carboxymethylcellulose, polyvinylpyrrolidone (PVP), polyglycolic acid (PGA), and polylactic acid (PLA), with PVA being preferred. PVA may also be modified PVA, which has hydroxyl groups, acetate groups, acetoacetyl groups, etc., introduced into it.

[0020] The water-soluble resin mesh layer is preferably a nanomesh layer, as described in Patent Document 1. In other words, the porous sheet preferably contains a water-soluble resin nanomesh layer. This is because, when the water-soluble resin mesh layer is a nanomesh layer, water, an aqueous alcohol solution, etc., penetrates more quickly into the interior of the layer, not just the surface, when it comes into contact with the water-soluble resin nanomesh layer, thereby increasing the dissolution rate of the water-soluble resin nanomesh layer. As a result, the conductive substance adheres quickly to the skin.

[0021] Furthermore, it is preferable that the porous sheet 10 includes a mesh-like substrate as described in Reference 1. Including a mesh-like substrate in the porous sheet makes it easier to install the laminate onto the supply member, and also reduces the likelihood of distortion in the laminate after installation. As a result, it is easier to attach it to the desired location, and distortion is less likely to occur during attachment. The material of the mesh substrate is not particularly limited, but commonly used thermoplastic resins include, specifically, thermoplastic resins such as polyethylene, polypropylene, polyamide, polystyrene, and polyester. Preferably, it is a polyolefin resin such as polyethylene or polypropylene. The mesh-like shape can be a grid shape, and examples of mesh-like grid shapes include a 60° staggered pattern, a single staggered pattern, a parallel pattern, a staggered pattern with oval holes, a parallel pattern with oval holes, a staggered pattern with square holes, a parallel pattern with square holes, a 60° hexagonal staggered pattern, a staggered pattern with rectangular holes, and a parallel pattern with rectangular holes. Among these, the parallel pattern with rectangular holes is preferred in terms of permeability to water or alcohol aqueous solutions.

[0022] The conductive material layer 11 is made of a conductive material. The conductive material is not particularly limited as long as it is conductive, but it is desirable that its volume resistivity is low enough not to hinder the transmission of electrical signals. Furthermore, if the volume resistivity of the conductive material is low, the resistance value can be kept within the desired range even if the conductive material layer is made thicker, thus improving durability while maintaining the resistance value of the conductive material layer within the desired range. The volume resistivity of the conductive material is usually 1 × 10⁻⁶. 12 It is less than or equal to Ωcm, and more preferably 1 × 10⁻⁶ 5 It is less than or equal to Ωcm, and particularly preferably 1 × 10⁻⁶ -1 It is less than Ωcm. Also, it is usually 1 × 10⁻⁶ -6 It is greater than Ωcm.

[0023] Specifically, metals or alloys thereof such as gold, platinum, silver, silver chloride, copper, titanium, palladium, chromium, or cobalt, or carbon can be used, and if transparency of the conductive material is desired, ITO (indium tin oxide) may be used. Other conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium zirconium oxide (IZO), titanium oxide, or zinc oxide may also be used. Conductive polymer materials such as PEDOT:PSS, which is a polythiophene derivative doped with polystyrene sulfonic acid, PEDOT:PTS, which is a polythiophene derivative doped with p-toluenesulfonic acid, or polypyrrole or polyaniline doped with iodine may also be used. Of these, considering application to living organisms, gold, carbon, titanium, PEDOT:PSS, and PEDOT:PTS are preferred, and gold is particularly preferred.

[0024] The method for forming the conductive material layer 11 on the porous sheet 10 is not particularly limited. For example, the conductive material layer 11 can be manufactured by vapor deposition or sputtering.

[0025] The thickness of the conductive material layer 11 can be set appropriately according to the purpose and is not particularly limited, but is usually 5 nm or more, may be 10 nm or more, and is usually 2 μm or less, may be 1 μm or less, and may be 500 nm or less. Furthermore, the resistance in the film thickness direction is preferably low enough not to hinder the transmission of electrical signals, and is usually 1000 Ω or less, more preferably 500 Ω or less, and particularly preferably 200 Ω or less. Furthermore, it is also desirable that the resistance in the in-plane direction be low, and the sheet resistance is usually 10000 Ω / L or less, preferably 1000 Ω / L or less, and particularly preferably 1000 Ω / L or less.

[0026] The conductive material layer 11 is preferably a mesh-like conductive material layer. The mesh-like structure of the conductive material layer 11 improves breathability when the conductive material is applied to biological skin. Furthermore, the mesh-like structure increases the number of conductive paths, thus reducing the risk of complete disconnection. The porosity in the cross-sectional area of ​​the mesh-like conductive material layer is not particularly limited, but is usually 90% or less, may be 70% or less, or may be 50% or less.

[0027] Although this embodiment is a laminate of a porous sheet and a conductive material layer, the porous sheet and the conductive material may also be integrated into a single structure. For example, by incorporating water-soluble resin fibers into the mesh structure constituting the conductive material layer, a conductive material can be formed in which the porous sheet and the conductive material are integrated. It may also be a water-soluble resin sheet.

[0028] Figure 2 is a schematic cross-sectional view showing a supply member of one embodiment. The supply member 200 has a mounting section 20 for the laminate. It may also have a container 21 and a carrier 22. The mounting section 20 includes a mounting mechanism for detachably mounting the mounting section to the porous sheet side of a laminate of conductive material and a porous sheet, and a supply mechanism that can supply water or an aqueous alcohol solution to the laminate when the conductive material is applied to the skin. Because the supply member has such a mounting section, previously it was necessary to include the steps of placing the laminate in the desired location and bringing the laminate into contact with water or an aqueous alcohol solution when applying the conductive material to the skin, but these two steps can now be performed in a single operation. As a result, the time required when applying a large number of conductive materials is significantly reduced.

[0029] The water or alcohol aqueous solution supply mechanism is not particularly limited, but examples include a mechanism that provides a support body capable of supporting water or alcohol on a supply member, and supplies water or alcohol by bringing a laminate into contact with the support body, or a mechanism that provides a spraying device on a supply member and sprays water or alcohol.

[0030] The carrier 22 is a component for carrying water or an aqueous alcohol solution. Examples include cloth and sponge. Sponge is preferred because it has a large mass of water or aqueous alcohol solution that can be carried per unit volume of the carrier. The sponge may be a natural sponge or a synthetic sponge such as a urethane sponge or rubber sponge.

[0031] A spraying device is a component for spraying water or an alcohol aqueous solution. By using a spraying device as a means of supplying water or an alcohol aqueous solution, the entire laminate can be moistened with a small amount of water or an alcohol aqueous solution.

[0032] Unit area (1cm²) of the laminate placed on the skin 2The amount of water or alcohol aqueous solution supplied per unit is not particularly limited as long as it is sufficient to adhere the laminate to the skin, but is usually 1 mg or more, preferably 2 mg, more preferably 3 mg or more, and usually 15 mg or less, preferably 12 mg or less, and more preferably 10 mg or less. By setting the amount of water or alcohol aqueous solution supplied within this range, the water-soluble resin contained in the laminate dissolves in the water or alcohol aqueous solution and adheres to the skin. Furthermore, by setting the amount of water or alcohol aqueous solution supplied to 10 mg or less, drying after application is accelerated, which reduces the burden on the wearer.

[0033] The material and structure of the mounting part are not particularly limited, as long as the mounting mechanism allows for the detachable attachment of the laminate and the supply member. The mounting mechanism may be such that the laminate and the supply member are detachable by fitting them together with a screw mechanism, or by hooking a rib provided on one member onto the other member for fitting. It is preferable that the mounting part has cushioning properties in a direction perpendicular to the mounting surface. The cushioning properties of the mounting part ensure that the force applied to the laminate when the conductive material is attached to the skin is of an appropriate magnitude, thereby improving the reproducibility of the attachment. Furthermore, the cushioning properties of the mounting part make it easier to bring the carrier and the laminate attached to the mounting part into contact. Cushioning properties can be provided to the mounting part by using an elastomer or foam, or by using an elastic material in part of the mounting part's components.

[0034] Container 21 is a component for storing water, an alcohol solution, etc. The material of the container is not particularly limited, but commonly used thermoplastic resins are examples, specifically polyethylene, polypropylene, polyamide, polystyrene, polyester, etc. Having this feature improves the workability when continuously applying conductive materials to the skin.

[0035] Figure 3 is a schematic cross-sectional view showing one embodiment of the present invention. In state 300, where the laminate is installed on the supply member, the laminate of the conductive material layer 31 and the porous sheet 30 is installed on the installation part 32 by the installation mechanism of the installation part such that the porous sheet side of the laminate abuts against the installation part. The installation part also has a carrier 34 as a supply mechanism that can supply water or an alcohol aqueous solution to the laminate. Furthermore, water or an alcohol aqueous solution is supplied to the carrier from the container 33.

[0036] Figure 4 is a schematic cross-sectional view showing another embodiment of the present invention. In one embodiment 400, which includes a spraying device in the supply member, a laminate of a conductive material layer 41 and a porous sheet 40 is installed on the installation section 42 by the installation mechanism of the installation section such that the porous sheet side of the laminate abuts against the installation section. The installation section also has a spraying device 44 as a supply mechanism that can supply water or an aqueous alcohol solution to the laminate. Furthermore, water or an aqueous alcohol solution is supplied to the spraying device from a container 43. In this embodiment, a laminate of a conductive material and a porous sheet is placed on the skin 46 so that the skin and the conductive material are in contact, and water or an aqueous alcohol solution is supplied to the laminate by a spraying device while the laminate is pressed against the skin. The sprayed water or aqueous alcohol solution 45 comes into contact with the non-contact surface of the laminate and penetrates into the interior of the laminate, wetting the entire laminate. [Examples]

[0037] The present invention will be described in more detail below using examples, but it goes without saying that the scope of the present invention is not limited by the description of the examples.

[0038] (Example 1) [Creation of porous sheets] A mesh substrate (26% open area, parallel square-hole mesh, made of polypropylene, 240 μm thick) was mounted on the nanomesh forming section (on the drum) of a drum-type electrospinning machine manufactured by Kato Tech Co., Ltd.

[0039] PVA (unmodified, 88 mol% saponification, 10% by weight aqueous solution viscosity 860 mPa·s) was used as the water-soluble resin. This PVA was dissolved in pure water to prepare a 10% by weight PVA aqueous solution, which was used as the spinning solution. Four mL of the spinning solution was added to a syringe in an electrospinning apparatus equipped with the mesh substrate prepared above. An electrode was attached to the non-beveled 18G needle (manufactured by Terumo Corporation) at the tip of the syringe, and electrospinning was performed to produce a fiber with a diameter of 260 nm and a basis weight of 1.1 g / m². 2 A water-soluble resin nanomesh layer was fabricated to obtain a porous sheet. The settings for the electrospinning apparatus were as follows.

[0040] <Conditions for forming nanomesh layers> Target speed: 5m / min Traverse speed: 10cm / min Syringe speed: 0.10~0.15 mm / min Voltage: 15~20kV Film forming time: 30min

[0041] With a metal mask having three 4mm x 30mm openings spaced 2.5mm apart placed on the water-soluble resin nanomesh layer side of the porous sheet manufactured as described above, the deposition time was adjusted using a ULVAC EX-400 vacuum deposition machine to achieve a thickness of 100nm in the openings. A thin gold film (conductive material layer) was formed, and a laminate with conductive material measuring 3.5 × 3 cm was obtained.

[0042] [Evaluation of adherence to skin] A supply member was prepared, consisting of a mounting section from which the sheet shown in Figure 1 can be attached and detached, a container capable of holding the supply liquid, and a carrier capable of holding the supply liquid. The laminate obtained above was set in the supply member with the mesh substrate facing the mounting section. An alcohol aqueous solution composed of 80% by weight of ethyl alcohol and 20% by weight of water was used as the supply liquid for the supply member. The carrier of the supply member had an area (16 cm²) that covered the porous sheet. 2 It is made of a sponge having ). The laminate, set in the above-mentioned supply member, was placed on the skin so that the conductive material layer side was in contact with the relatively flat, unmoistened skin on the inside of the forearm of a subject with a body temperature of approximately 36°C. In an indoor environment of approximately 23°C, 100 mg of an alcohol aqueous solution was supplied through the supply member from the side not in contact with the skin, and pressed down for 1 minute. After that, the supply member was slowly removed from the skin, and the shape of the conductive material was maintained before and after application, confirming good adhesion to the skin.

[0043] (Example 2) The adhesion to the skin was evaluated using the same method as in Example 1, except that the supply solution was 100% water by weight and the supply amount was 80 mg. Compared to Example 1, localized peeling of the conductive material was observed, possibly due to a slower drying rate, but the shape of the conductive material was maintained before and after application, and a satisfactory level of adhesion to the skin was confirmed.

[0044] (Comparative Example 1) Adhesion to the skin was evaluated using the same method as in Example 1, except that the subject's skin was pre-moistened with water. Because the laminate was placed on the subject's skin while it was moist, the conductive material shifted position before it could adhere to the skin, making it impossible to maintain the shape of the conductive material and adhere it to the skin. [Explanation of Symbols]

[0045] 100-layer structure 10, 30, 40 porous sheets 11, 31, 41 Conductive material layer 200 Supply Members 20, 32, 42 Installation section 21, 33, 43 containers 22, 34 Carrier 300 The laminated body is installed on the supply member. 400 One embodiment in which a spraying device is provided on the supply member 44 Spraying device 45. Sprayed water or alcohol aqueous solution 46 Skin

Claims

1. A method of attaching a conductive material to the skin, The arrangement step involves placing the laminate of the conductive material and the porous sheet on the skin so that the skin and the conductive material are in contact; A method comprising: a supply step of supplying water or an aqueous alcohol solution to the laminate from the non-contact side of the laminate placed on the skin, wherein the supply step is supplied by a supply member detachably provided on the non-contact side of the laminate, and the supply member has a spraying device.

2. The method according to claim 1, wherein the porous sheet includes a water-soluble resin mesh layer.

3. The method according to claim 2, wherein the porous sheet includes a water-soluble resin nanomesh layer.

4. The method according to any one of claims 1 to 3, wherein the porous sheet includes a mesh-like substrate.

5. The method according to any one of claims 1 to 3, wherein the supply member comprises a container for storing water or an aqueous alcohol solution.

6. The method according to any one of claims 1 to 3, wherein the supply member comprises a carrier supporting water or an aqueous alcohol solution.

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