Wearable sensor

Abstract

To provide a wearable sensor that can monitor sweat components, body surface temperature and body fluid temperature in real time with high accuracy.SOLUTION: A wearable sensor comprises: a substrate; a working electrode including an electrode, an inert layer and an ion selection membrane; a reference electrode including an electrode, an inert layer and a liquid junction layer; and a carrier. The carrier includes at least one or more kinds of polyurethane resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sensor device that detects any ion and measures body surface temperature and body fluid temperature, and relates to a wearable sensor that can be worn and carried around by a person. [Background technology]

[0002] In recent years, with the aging of the population, there has been growing interest in the prevention of adult diseases, health management, etc. Accordingly, various biological information devices that can easily measure blood pressure, pulse, body temperature, etc. at home or in the workplace, such as electronic thermometers and electronic blood pressure monitors, have been provided, and devices that comprehensively evaluate blood pressure, pulse, and body temperature have also been proposed.

[0003] In addition to biological information such as blood pressure, pulse rate, and body temperature, sweat components have been attracting attention as a non-invasive alternative to blood as a body fluid sample. However, in order to collect a sufficient amount of sweat required for quantitative measurement of sweat components, it has been necessary to subject the subject to some kind of thermal or chemical stimulus, such as by having the subject exercise, exposing them to a high-temperature environment, or administering a sweat-inducing agent, making it difficult to measure sweat components easily anytime, anywhere, and by anyone.

[0004] Against this background, Patent Document 2, for example, proposes a liquid collection device that can easily collect liquids such as sweat components from a subject as a technology for easily collecting sweat components. This liquid collection device collects sweat from the skin and detects the ions and lactic acid contained in the sweat, and the subject's skin is brought into contact with a porous body containing a salt-containing aqueous solution, which serves as a sweat extraction unit. Sweat is absorbed into the porous body by osmotic pressure, allowing sweat components to be detected simply, continuously, and with high accuracy.

[0005] However, the liquid collection device in Patent Document 1 was not evaluated for response reversibility, and there was a risk that it would be unable to measure increases and decreases in sweat component concentration with high accuracy without hysteresis. Furthermore, the liquid collection device in Patent Document 1 required several minutes or more from the time the subject's skin contacted the porous body (the sweat extraction unit) until the sweat components were detected, making it impractical for real-time sweat component measurement in wearable applications.

[0006] Although sweat sensors are also proposed in Non-Patent Document 1 and Patent Document 2, they are still not satisfactory and further improvements are required.

[0007] Improving the water resistance and moisture resistance of wearable sensors is said to be a challenge for measuring body surface temperature and body fluid temperature with high accuracy. In particular, to measure the temperature of body fluids, which are mostly water, it is essential that the sensors can be used stably underwater (100% humidity). The sensor in Non-Patent Document 2 was not designed for use underwater and was not suitable for underwater use. Furthermore, the protective layer of the sensors in Patent Documents 3 and 4 uses a polymer material that is highly soluble in water, and there is a risk that the protective layer will dissolve if it comes into direct contact with body fluids such as sweat, making them unsuitable for wearable applications. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 5-3857 [Patent Document 2] Japanese Patent Publication No. 2020-115103 [Patent Document 3] Japanese Patent Application Publication No. 2019-184289 [Patent Document 4] Japanese Patent Application Laid-Open No. 2019-184290 [Non-patent literature]

[0009] [Non-Patent Document 1] Tosoh Technical Report, Vol. 65, 2021, pp. 11-15 [Non-patent document 2] Scientific Reports,10,2467,2020. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a wearable sensor that is wearable and can monitor sweat components, body surface temperature, and body fluid temperature with high accuracy in real time. [Means for solving the problem]

[0011] As a result of extensive research into solving the above problems, the inventors have found that a specific wearable sensor can solve the above problems, and have completed the present invention.

[0012] The present invention has been proposed based on these findings, and specifically has the following configuration. [1] A wearable sensor comprising: a substrate; a working electrode comprising an electrode, an inert layer, and an ion-selective membrane; a reference electrode comprising an electrode, an inert layer, and a liquid junction layer; an insulating layer; and a carrier, wherein the carrier comprises at least one type of polyurethane resin or cellulose. [2] The wearable sensor according to [1], which contains one or more types of working electrodes. [3] The wearable sensor according to [1] or [2], wherein the ion-selective membrane is one or more selected from the group consisting of a sodium ion-selective membrane, a chloride ion-selective membrane, a potassium ion-selective membrane, a calcium ion-selective membrane, a magnesium ion-selective membrane, a hydrogen ion-selective membrane, an ammonium ion-selective membrane, and a nitrate ion-selective membrane.

[0013] [4] A wearable sensor comprising a substrate, an electrode, a temperature-sensitive layer, and a protective layer, wherein the protective layer contains at least one of metals, metal oxides, and water-insoluble polymers.

[0014] [5] The wearable sensor according to [4], which is a thermistor-type temperature sensor. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below.

[0016] The wearable sensor of the present invention is a wearable sensor (wearable sensor A) that includes a substrate; a working electrode that includes an electrode, an inert layer, and an ion-selective membrane; a reference electrode that includes an electrode, an inert layer, and a liquid junction layer; an insulating layer; and a carrier, wherein the carrier includes at least one type of polyurethane resin or cellulose; and a wearable sensor (wearable sensor B) that includes a substrate, an electrode, a temperature-sensitive layer, and a protective layer, wherein the protective layer includes at least one type of metal, metal oxide, or water-insoluble polymer.

[0017] First, the wearable sensor A will be described.

[0018] The substrate in the wearable sensor A supports the wearable sensor A. The number of layers is not particularly limited and may be either a single-layer structure or a multilayer structure. Examples of the substrate include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene; alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins; polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; phenolic resins; epoxy resins; silicone resins; polyvinyl chloride resins; fluororesins such as vinylidene fluoride; polyparaxylene; celluloses such as cellulose acetate and cellulose ethers; polyvinyl alcohols; polyvinylphenols; poly(melamine-co-formaldehyde) methylate; norbornene resins; glass; metal plates such as aluminum, stainless steel, and ferrotype plates; and ceramics. Preferred are polyester resins, polyurethane resins, polyimide resins, silicone resins, polyparaxylene, and cellulose, which have sufficient stretchability and conformability, and particularly preferred are polyester resins in terms of transparency, dimensional stability, heat resistance, etc.

[0019] The working electrode in the present invention includes an electrode, an inert layer, and an ion-selective membrane. The present invention can include one or more types of working electrode.

[0020] The electrode at the working electrode is used to acquire the sensed change in ion concentration as an electrical signal, and examples thereof include metals such as gold, silver, copper, platinum, aluminum, nickel, iron, stainless steel, titanium, and molybdenum; metal oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO); carbon; and conductive polymers such as polyacetylene, polythiophene, polypyrrole, and polyaniline. Metals are preferred, and gold, silver, copper, aluminum, and nickel are particularly preferred.

[0021] The inert layer on the working electrode is electrochemically inert and is interposed between the electrode and the ion-selective membrane or between the electrode and the liquid junction layer to improve adhesion between the electrode and the ion-selective membrane or between the electrode and the liquid junction layer. Examples of the inert layer include carbon such as carbon black and carbon graphite; oxides; nitrides; carbides; silicon; glass; and ceramics, with carbon being preferred and carbon black being particularly preferred. The arithmetic mean roughness (Ra) of the surface of the inert layer is preferably 100 nm or more, more preferably 200 nm or more, and particularly preferably 300 nm or more. The ion-selective membrane at the working electrode is a membrane that selectively allows the permeation of ions in a solution, and is a membrane that either hinders the flow of ions or allows them to pass through the membrane depending on the charge of the membrane. Examples of such membranes include sodium ion-selective membranes, chloride ion-selective membranes, potassium ion-selective membranes, calcium ion-selective membranes, magnesium ion-selective membranes, hydrogen ion-selective membranes, ammonium ion-selective membranes, and nitrate ion-selective membranes. One or more of these ion-selective membranes can be used, and preferred are sodium ion-selective membranes, potassium ion-selective membranes, hydrogen ion-selective membranes, ammonium ion-selective membranes, calcium ion-selective membranes, and chloride ion-selective membranes. Particularly preferred are sodium ion-selective membranes, potassium ion-selective membranes, and hydrogen ion-selective membranes.

[0022] The reference electrode of the present invention comprises an electrode, an inert layer, and a liquid junction layer.

[0023] The electrode and inert layer in the reference electrode can be the same as those in the working electrode.

[0024] The liquid junction layer in the reference electrode electrically connects sweat to the reference electrode, and may be a layer containing a polymer and a base.

[0025] Examples of the polymer include polymer surfactants such as polyvinyl chloride, polyvinyl butyral, 2,6-di(tert-butyl)-p-cresol, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), and polyvinylpyrrolidone, highly water-absorbent polymers, acrylic resins, silicone resins, and polyurethane resins, and preferably polyvinyl chloride, polyvinyl butyral, polyurethane resins, and polymer surfactants.

[0026] Examples of the base include sodium chloride, potassium chloride, silver / silver chloride, ionic liquid, and carbon nanotubes, with sodium chloride and potassium chloride being preferred.

[0027] The liquid junction layer is preferably a film in which a base is dispersed in the polymer.

[0028] The insulating layer in the present invention electrically insulates sweat from the electrodes and the inactive layer, and is made of, for example, polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene and polypropylene, alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins, polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; phenolic resins; epoxy resins; silicone resins; polyvinyl chloride resins; fluororesins such as polytetrafluoroethylene and vinylidene fluoride; polyvinyl butyral resins; polyparaxylene resins; Examples of suitable polymers include films containing polymers such as olefins; celluloses such as cellulose acetate and cellulose ether; polyvinyl alcohol; polyvinylphenol; poly(melamine-co-formaldehyde) methylate; norbornene resins; and photocrosslinkable resins containing photocrosslinkable groups such as cinnamate ester groups, cinnamic acid amide groups, chalconyl groups, coumarinyl groups, stilbenyl groups, cinnamylidene acetate ester groups, cinnamylidene acetophenyl groups, and maleimide groups. Preferred are films containing polyolefin resins, fluororesins, polyvinyl chloride resins, polyvinyl butyral resins, and photocrosslinkable resins, and particularly preferred are films containing polyolefin resins, fluororesins, polyvinyl butyral resins, and photocrosslinkable resins.

[0029] The thickness of the insulating layer is preferably 1 μm or more, and particularly preferably 10 μm or more.

[0030] The carrier in the present invention is intended to sequentially extract and absorb sweat and retain a certain amount of sweat on the surface of the insulating layer, the surface of the ion selective membrane, and the surface of the liquid junction layer, and preferably contains at least one type of polyurethane resin or cellulose, particularly preferably at least one type of polyurethane resin. The carrier is preferably porous.

[0031] The polyurethane resin is obtained by reacting a polyol (A), a polyol (B) other than the polyol (A), a polyisocyanate (C), and a chain extender (D) at room temperature (e.g., 25°C) or under heating (e.g., 40 to 150°C), and is characterized in that the polyol (A) is a polyethylene glycol having a number-average molecular weight of 800 to 3,500, and the content of polyethylene glycol in the resin is 30 mass% or more. The polyol (A) is polyethylene glycol from the viewpoint of imparting moisture permeability, and has a number-average molecular weight of 800 to 3,500, preferably 1,000 to 3,000. If the number-average molecular weight is below the lower limit, moisture permeability may decrease, and if it exceeds the upper limit, durability may decrease.

[0032] Next, the polyol (B) used in the polyurethane resin of the present invention will be described.

[0033] The polyol (B) used in the present invention is a polyol other than the polyol (A), and examples of the polyol (B) include polycarbonate polyols, polycaprolactone polyols, polyester polyols, polyether polyols, polyolefin polyols, acrylic polyols, silicone polyols, castor oil-based polyols, fluorine-based polyols, etc. Among these, polycarbonate polyols are preferred from the viewpoint of durability. <Polycarbonate polyol> Specific examples of polycarbonate polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, and ethylene oxide and propylene oxide of bisphenol A. Examples of such polycarbonate polyols include those obtained by dealcoholization or dephenolization reactions of one or more low-molecular-weight polyols, such as side adducts, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol, with dialkyl carbonates, such as dimethyl carbonate and diethyl carbonate, alkylene carbonates, such as ethylene carbonate and propylene carbonate, and diaryl carbonates, such as diphenyl carbonate, dinaphthyl carbonate, dianthryl carbonate, diphenanthryl carbonate, diindanyl carbonate, and tetrahydronaphthyl carbonate. Furthermore, from the viewpoint of imparting heat resistance, hydrolysis resistance, and weather resistance, polycarbonate polyols obtained by reacting 1,6-hexanediol with at least one selected from the group consisting of dialkyl carbonates, alkylene carbonates, and diaryl carbonates can be preferably used. <Polycaprolactone polyol> Specific examples of polycaprolactone polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexyl methylpropane, and the like. Examples of initiators that can be used include those obtained by ring-opening addition of either ε-caprolactone or alkyl-substituted ε-caprolactone, or both, to one or more low-molecular-weight polyols such as cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, ethylene oxide or propylene oxide adducts of bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol. <Polyester polyol> Specific examples of polyester polyols include those obtained by mixing one or more dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, sebacic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydromuconic acid, α-butyl-α-ethylglutaric acid, α,β-diethylsuccinic acid, maleic acid, and fumaric acid, or anhydrides thereof, with ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, and the like. Examples of suitable low-molecular-weight polyols include those obtained by condensation polymerization with one or more low-molecular-weight polyols having a molecular weight of 500 or less, such as hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, diol dimer acid, ethylene oxide or propylene oxide adducts of bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, and pentaerythritol. Polyester-amide polyols obtained by replacing a portion of the low-molecular-weight polyol with a low-molecular-weight polyamine or low-molecular-weight amino alcohol, such as hexamethylenediamine, isophoronedione, or monoethanolamine, can also be used. <Polyether polyol> Specific examples of polyether polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane, diethylene glycol, dipropylene glycol, neopentyl glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, bisphenol A, bis(β-hydroxyethyl)benzene, xylylene glycol, glycerin, trimethylolpropane, pentaerythritol, and the like. Examples of suitable polyether polyols include polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide using as an initiator a compound having two or more, preferably two to three, active hydrogen groups, such as low-molecular-weight polyols such as thuritol, or low-molecular-weight polyamines such as ethylene diamine, propylene diamine, toluene diamine, metaphenylenediamine, diphenylmethane diamine, and xylylene diamine; and polyether polyols obtained by ring-opening polymerization of cyclic ether monomers such as alkyl glycidyl ethers such as methyl glycidyl ether, aryl glycidyl ethers such as phenyl glycidyl ether, and tetrahydrofuran. <Polyolefin polyol> Specific examples of polyolefin polyols include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene. <Acrylic polyol> Examples of acrylic polyols include those obtained by copolymerizing an acrylic monomer with at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters (hereinafter referred to as "(meth)acrylic acid ester"), at least one selected from the group consisting of acrylic acid hydroxy compounds and methacrylic acid hydroxy compounds having at least one hydroxy group in the molecule that can serve as a reaction site (hereinafter referred to as "(meth)acrylic acid hydroxy compound"), and a polymerization initiator using thermal energy or light energy such as ultraviolet light or electron beams. <(Meth)acrylic acid ester> Specific examples of (meth)acrylic acid esters include alkyl esters having 1 to 20 carbon atoms. Specific examples of such (meth)acrylic acid esters include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, and dodecyl (meth)acrylate; esters of (meth)acrylic acid with alicyclic alcohols such as cyclohexyl (meth)acrylate; and allyl (meth)acrylic acid esters such as phenyl (meth)acrylate and benzyl (meth)acrylate. These (meth)acrylic acid esters can be used alone or in combination of two or more. <(Meth)acrylic acid hydroxy compound> Specific examples of (meth)acrylic acid hydroxy compounds have at least one hydroxyl group in the molecule that can serve as a reaction site with the polyisocyanate (C), and specific examples include acrylic acid hydroxy compounds such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 3-hydroxy-2,2-dimethylpropyl acrylate, and pentaerythritol triacrylate. Further examples include methacrylic acid hydroxy compounds such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 3-hydroxy-2,2-dimethylpropyl methacrylate, and pentaerythritol trimethacrylate. These acrylic acid hydroxy compounds and methacrylic acid hydroxy compounds can be used alone or in combination of two or more. <Silicone polyol> Specific examples of silicone polyols include vinyl group-containing silicone compounds obtained by polymerizing γ-methacryloxypropyltrimethoxysilane, and polysiloxanes having at least one terminal hydroxyl group in the molecule, such as α,ω-dihydroxypolydimethylsiloxane and α,ω-dihydroxypolydiphenylsiloxane. <Castor oil-based polyol> Specific examples of castor oil-based polyols include linear or branched polyester polyols obtained by reacting castor oil fatty acids with polyols. Dehydrated castor oil, partially dehydrated castor oil, and hydrogenated castor oil can also be used. <Fluorine-based polyol> Specific examples of fluorine-based polyols include linear or branched polyols obtained by copolymerization of a fluorine-containing monomer and a monomer having a hydroxyl group as essential components.Here, the fluorine-containing monomer is preferably a fluoroolefin, such as tetrafluoroethylene, chlorotrifluoroethylene, trichlorofluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, and trifluoromethyltrifluoroethylene.In addition, examples of monomers having a hydroxyl group include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and cyclohexanediol monovinyl ether, hydroxyalkyl allyl ethers such as 2-hydroxyethyl allyl ether, and hydroxyl group-containing vinyl carboxylates or allyl esters such as hydroxyalkyl vinyl crotonates.

[0034] Next, the polyisocyanate (C) used in the polyurethane resin of the present invention will be described.

[0035] Examples of the polyisocyanate (C) of the present invention include alicyclic polyisocyanates, aromatic polyisocyanates, aliphatic polyisocyanates, and araliphatic polyisocyanates, and from the viewpoint of yellowing resistance, alicyclic polyisocyanates are preferred. <Alicyclic polyisocyanate> Specific examples of alicyclic polyisocyanates include isophorone diisocyanate, cyclohexane diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated tetramethylxylene diisocyanate, etc. Among these alicyclic polyisocyanates, isophorone diisocyanate is particularly preferred from the viewpoints of yellowing resistance and productivity. <Aromatic polyisocyanate> Specific examples of aromatic polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate mixture, m-xylylene diisocyanate, p-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, a 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate mixture, 4,4'-diphenylmethane diisocyanate, Examples of suitable diisocyanates include terdiisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate. <Aliphatic polyisocyanate> Specific examples of aliphatic polyisocyanates include hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methyl-pentane-1,5-diisocyanate, 3-methyl-pentane-1,5-diisocyanate, lysine diisocyanate, and trioxyethylene diisocyanate. <Aromatic aliphatic polyisocyanate> Specific examples of aromatic aliphatic polyisocyanates include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or a mixture thereof, and ω,ω'-diisocyanato-1,4-diethylbenzene.

[0036] Next, the chain extender (D) used in the polyurethane resin of the present invention will be described.

[0037] The chain extender (D) may be an aliphatic glycol. <Aliphatic glycol> Examples of aliphatic glycols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 3-methyl-1,5-pentanediol, dimethylolheptane, diethylene glycol, dipropylene glycol, and neopentyl glycol. 1,4-butanediol is preferred for its flexibility, durability, and processability. Examples of celluloses include methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and carboxymethyl cellulose.

[0038] The polyurethane resin or cellulose has excellent permeability to sweat components, etc., and has a moisture permeability of 150 g / (m 2 The moisture permeability is preferably at least 1 / 24 h. The moisture permeability is measured by the cup method (JIS Z 0208).

[0039] The carrier of the present invention may be formed by combining the polyurethane resin or cellulose with one or more polymers selected from the following. Examples of the polymer include agarose, gelatin, xanthan gum, gellan gum, sclerotium gum, gum arabic, tragacanth gum, karaya gum, cellulose gum, tamarind gum, guar gum, locust bean gum, glucomannan, chitosan, carrageenan, quince seed, galactan, mannan, starch, dextrin, curdlan, casein, pectin, collagen, fibrin, peptides, chondroitin sulfates such as sodium chondroitin sulfate, hyaluronic acid (mucopolysaccharides) and hyaluronates such as sodium hyaluronate, alginic acid, alginates, and derivatives thereof; and poly(meth)acrylic acids such as polyacrylic acid, polymethacrylic acid, and acrylic acid-alkyl methacrylate copolymers. and their salts; synthetic polymers such as polyvinyl alcohol, polyethylene glycol di(meth)acrylate polymers (PPEGDA, PPEGDM), polyhydroxyethyl methacrylate, polyacrylamide, poly(N,N-dimethylacrylamide), poly2-acrylamido-2-methylpropanesulfonic acid, poly(N-isopropylacrylamide), polyvinylpyrrolidone, polystyrene sulfonic acid, polyethylene glycol, carboxyvinyl polymers, alkyl-modified carboxyvinyl polymers, maleic anhydride copolymers, polyalkylene oxide resins, crosslinked products of poly(methyl vinyl ether-alt-maleic anhydride) and polyethylene glycol, crosslinked products of polyethylene glycol, N-vinylacetamide crosslinked products, acrylamide crosslinked products, and crosslinked products of starch-acrylate graft copolymers; polyvinyl butyral resins; pulp; paper, etc.

[0040] The mass ratio of the polymer to the polyurethane resin or cellulose is not particularly limited, but is preferably 0.001 to 99 mass %, more preferably 0.001 to 95 mass %, and even more preferably 0.001 to 90 mass %.

[0041] The thickness of the carrier is preferably 1000 μm or less, more preferably 500 μm or less, and particularly preferably 100 μm or less.

[0042] The wearable sensor A of the present invention is a wearable sensor comprising a substrate; a working electrode comprising an electrode, an inert layer, and an ion-selective membrane; a reference electrode comprising an electrode, an inert layer, and a liquid junction layer; an insulating layer; and a carrier, the carrier comprising at least one type of polyurethane resin. A specific structure is shown in FIG. 1.

[0043] Wearable sensor A of the present invention may include materials other than a substrate; a working electrode including an electrode, an inert electrode, and an ion-selective membrane; a reference electrode including an electrode, an inert electrode, and a liquid junction layer; an insulating layer; and a carrier. Materials other than the substrate; the working electrode including an electrode, an inert electrode, and an ion-selective membrane; the reference electrode including an electrode, an inert electrode, and a liquid junction layer; the insulating layer; and the carrier may include a support for physically fixing the carrier to the surface of the substrate, the surface of the insulating layer, the surface of the liquid junction layer, and the surface of the ion-selective membrane, a flow path for draining excess sweat outside the element, an adhesive layer for physically fixing the skin and the element, and other sensors and devices capable of measuring biological information. A specific structure is shown in Figure 2.

[0044] Examples of the flow path include a resin processed body such as a silicone resin processed body such as polydimethylsiloxane, an acrylic resin processed body, or a urethane resin processed body; and a porous body such as paper or sponge. The support is not particularly limited as long as it can fix the carrier to the surface of the substrate, the surface of the insulating film, the surface of the ion-selective membrane, or the surface of the liquid junction layer, and examples thereof include a resin pin and a resin support frame that is arranged to cover the side of the carrier or the vicinity of the side of the carrier.

[0045] Examples of the adhesive layer include a pressure-sensitive adhesive film having a base material such as an acrylic resin, a silicone resin, a urethane resin, etc. The adhesive layer can also function as a flow path and a support by being made into a resin-processed formed body.

[0046] The method for manufacturing the wearable sensor A of the present invention will be described with reference to FIG.

[0047] In the electrode formation process for forming an electrode on the substrate 1, an electrode containing the metal can be formed as the electrode 2 on the substrate 1 by the electrode formation process.

[0048] Examples of the electrode formation process to be used include dry processes such as photolithography, vapor deposition, and sputtering; coating methods such as dip coating, spin coating, bar coating, blade coating, slit coating, spray coating, nozzle coating, casting, and dispensing; printing methods using various printers such as offset printing, gravure printing, flexographic printing, screen printing, gravure offset printing, reverse offset printing, inkjet printing, and adhesion contrast printing; plating; and lamination. Preferred are coating methods, printing methods, plating, and lamination, and particularly preferred are coating methods, printing methods, and plating.

[0049] In the inert layer formation process, an inert layer is formed to cover a portion of the electrode surface. Following the electrode formation process, a solution containing carbon (e.g., carbon black, carbon graphite, etc.); oxides; nitrides; carbides; silicon; glass; or ceramics, preferably carbon, particularly carbon black, is dropped onto the electrode, and the solvent is heated to evaporate, forming the inert layer 3. The solvent used in the solution is not particularly limited as long as it dissolves carbon, oxides, nitrides, carbides, silicon, glass, or ceramics. Examples of the solvent include propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, aromatic mixed hydrocarbons (petroleum naphtha), trimethylbenzene, cumene, xylene, N-methylpyrrolidone, and α-terpineol. Preferred are propylene glycol monomethyl ether acetate and N-methylpyrrolidone. The solution concentration is preferably 60% by mass or less, and particularly preferably 30% by mass or less.

[0050] The process for forming the inactive layer can be the same as the process for forming the electrodes, and is preferably a coating method, a printing method, or a lamination method, and particularly preferably a coating method or a printing method.

[0051] Furthermore, the temperature at which the solvent is heated to evaporate after the inactive layer formation process is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 60°C or higher, particularly preferably 100°C or higher.

[0052] The insulating layer is made of polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene; alicyclic polyolefin resins; polycarbonate resin; acrylic resin; methacrylic resin; polyurethane resin; polyamide resin; polyimide resin; polyarylate resin; polyacetal resin; polysulfone; polyethersulfone; polyetherketone; phenolic resin; epoxy resin; silicone resin; polyvinyl chloride resin; fluororesin such as polytetrafluoroethylene and vinylidene fluoride; polyvinyl butyral resin; polyparaxyl A solution containing a polymer such as polyethylene; cellulose such as cellulose acetate or cellulose ether; polyvinyl alcohol; polyvinylphenol; poly(melamine-co-formaldehyde) methylate; norbornene resin; or a photocrosslinkable resin containing a photocrosslinkable group such as a cinnamate ester group, a cinnamic acid amide group, a chalconyl group, a coumarinyl group, a stilbenyl group, a cinnamylidene acetate ester group, a cinnamylidene acetophenyl group, or a maleimide group is dropped onto the surface of the substrate near the working electrode 8 and the reference electrode 9, and also dropped so as to cover part of the surface of the electrode 2 and part of the surface of the inactive layer 3, and the solvent is heated to evaporate, thereby forming the insulating layer 4. The solvent used for the solution is not particularly limited as long as it dissolves the polymer, and examples thereof include water, methanol, ethanol, isopropanol, diacetone alcohol, butanol, N,N-dimethylformamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate, cyclohexanone, anisole, dimethoxybenzene, perfluorotributylamine, perfluoroamine, ethyl nonafluorobutyl ether, and octafluoropentanol, with ethanol, propylene glycol monomethyl ether acetate, perfluorotributylamine, and octafluoropentanol being preferred. The concentration of the solution is preferably 30% by mass or less, and particularly preferably 10% by mass or less.

[0053] The insulating layer forming process may be the same as the electrode forming process, and among these, coating, printing and laminating are preferred, with coating and printing being particularly preferred.

[0054] Furthermore, the temperature at which the solvent is heated to evaporate after the insulating layer formation process is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 60°C or higher, and particularly preferably 100°C or higher.

[0055] The ion-selective membrane covering the surface of the inactive layer of the working electrode can be formed by an ion-selective membrane formation process in which a solution of a composition containing an ionophore, an anion-excluder, a polymer, a plasticizer, and a solvent is dropped onto the inactive layer 3, and the solvent is heated and evaporated to form an ion-selective membrane 5 on top of the inactive layer 3.

[0056] Examples of ionophores include sodium ionophores, chlorine ionophores, potassium ionophores, calcium ionophores, magnesium ionophores, hydrogen ionophores, ammonium ionophores, and nitrate ionophores, with sodium ionophores, potassium ionophores, and hydrogen ionophores being preferred.

[0057] Examples of anion-removing materials include sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, sodium tetraphenylborate, and potassium tetrakis(4-chlorophenyl)borate, and preferred are sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate and potassium tetrakis(4-chlorophenyl)borate.

[0058] Examples of polymers include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene; alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins; polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; phenolic resins; epoxy resins; silicone resins; polyvinyl chloride resins; fluororesins such as polytetrafluoroethylene and vinylidene fluoride; polyparaxylene; cellulose acetate Examples of the resin include celluloses such as acetate and cellulose ether; polyvinyl alcohol; norbornene resins; polyvinyl butyral resins; and photocrosslinkable resins containing photocrosslinkable groups such as cinnamate ester groups, cinnamic acid amide groups, chalconyl groups, coumarinyl groups, stilbenyl groups, cinnamylidene acetate groups, cinnamylidene acetophenyl groups, and maleimide groups. Preferred are polyolefin resins, acrylic resins, fluororesins, polyvinyl chloride resins, polyvinyl butyral resins; photocrosslinkable resins, and the like, and particularly preferred are polyolefin resins, fluororesins, vinyl chloride resins, polyvinyl butyral resins; photocrosslinkable resins, and the like.

[0059] Examples of plasticizers include octyl ether-based plasticizers; phthalate ester-based plasticizers; aliphatic dibasic acid ester-based plasticizers; trimellitate ester-based plasticizers; adipate ester-based plasticizers; sebacate ester-based plasticizers; phosphate ester-based plasticizers; biphenyltetracarboxylic acid tetraalkyl ester-based plasticizers; polyester-based polymer plasticizers; epoxy-based plasticizers; chlorinated fatty acid esters; and process oils such as paraffin-based process oils, naphthene-based process oils, and aromatic process oils, with sebacate ester-based plasticizers being particularly preferred.

[0060] In the composition, the mass ratio of the polymer to the plasticizer is preferably 9:1 to 1:9, and particularly preferably 4:1 to 1:4; the mass ratio of the total mass of the polymer and the plasticizer to the ionophore is preferably 95:5 to 99.99:0.01, and particularly preferably 98:2 to 99.99:0.01; and the mass ratio of the total mass of the polymer and the plasticizer to the anion-removing material is preferably 95:5 to 99.99:0.01, and particularly preferably 98:2 to 99.99:0.01.

[0061] The solvent is not particularly limited as long as it dissolves the ionophore, anion-removing material, polymer, and plasticizer, and examples thereof include tetrahydrofuran, cyclohexanone, anisole, dimethoxybenzene, etc., with cyclohexanone being preferred. The concentration of the solution is preferably 50% by mass or less, and particularly preferably 34% by mass or less.

[0062] The ion-selective membrane forming process may be the same as the electrode forming process, and among these, coating, printing and laminating are preferred, with coating and printing being particularly preferred.

[0063] After the ion-selective membrane formation process, the temperature at which the solvent is heated to evaporate is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 30°C or higher, and particularly preferably 50°C or higher.

[0064] In this manner, the working electrode 8 can be manufactured.

[0065] A liquid junction layer covering the surface of the inactive layer of the reference electrode can be formed on top of the inactive layer 3 by a liquid junction layer formation process in which a solution of a composition containing a polymer, a base, and a solvent is dropped onto the inactive layer 3 and the solvent is heated to evaporate, thereby forming a liquid junction layer 6 on top of the inactive layer 3.

[0066] Examples of polymers include polyvinyl chloride, polyvinyl butyral, polymer surfactants such as 2,6-di(tert-butyl)-p-cresol, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol), and polyvinylpyrrolidone, highly water-absorbent polymers, acrylic resins, silicone resins, and polyurethane resins, with polyvinyl chloride, polyvinyl butyral, polyurethane resins, and polymer surfactants being preferred. Examples of bases include sodium chloride, potassium chloride, silver / silver chloride, ionic liquids, and carbon nanotubes, with sodium chloride and potassium chloride being preferred.

[0067] The content of the base relative to the polymer in the composition is preferably 50% by mass or less, particularly preferably 25% by mass or less.

[0068] The solvent may be any solvent that dissolves the polymer and the base, and examples thereof include water, methanol, ethanol, isopropanol, diacetone alcohol, butanol, acetone, methyl ethyl ketone, formamide, N,N-dimethylformamide, N-methylpyrrolidone, xylene, mesitylene, cyclohexanone, propylene glycol monomethyl ether acetate, anisole, dimethoxybenzene, etc., with water, methanol, ethanol, etc. being preferred. The concentration of the solution is preferably 50% by mass or less, and particularly preferably 34% by mass or less.

[0069] The liquid junction layer can be formed by the same process as the electrode formation process, preferably by coating, printing or laminating, and particularly preferably by coating or printing.

[0070] Furthermore, the temperature at which the solvent is heated to evaporate after the liquid junction layer formation process is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 30°C or higher, particularly preferably 50°C or higher.

[0071] In this manner, the reference electrode 9 can be manufactured.

[0072] Finally, in a carrier formation process, a solution containing a polyurethane resin is applied to the surfaces of the working electrode 8 and the reference electrode 9 so as to cover the working electrode 8 and the reference electrode 9, and the solvent is then heated to evaporate, thereby forming the carrier 7. There are no particular limitations on the solvent used as long as it dissolves the polyurethane resin, and examples include methanol, ethanol, isopropanol, diacetone alcohol, butanol, acetone, methyl ethyl ketone, formamide, N,N-dimethylformamide, and N-methylpyrrolidone. The concentration of the solution is preferably 50% by mass or less, and particularly preferably 30% by mass or less.

[0073] The carrier formation process to be used may be a process similar to the electrode formation process, or a method of laminating a film containing polyurethane resin onto the surfaces of the working electrode 8 and the reference electrode 9, preferably a coating method, a printing method, or a lamination method.

[0074] Furthermore, the temperature at which the solvent is heated to evaporate after the carrier formation process is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 30°C or higher, particularly preferably 50°C or higher.

[0075] Next, the wearable sensor B will be described.

[0076] The substrate of wearable sensor B may be the same as that of wearable sensor A.

[0077] The electrodes are used to acquire the sensed temperature change as an electrical signal, and examples of the electrodes include metals such as gold, silver, copper, platinum, aluminum, nickel, iron, stainless steel, titanium, and molybdenum; metal oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO); carbon; and conductive polymers such as polyacetylene, polythiophene, polypyrrole, and polyaniline. Metals are preferred, and gold, silver, copper, aluminum, and nickel are particularly preferred.

[0078] The temperature-sensitive layer is a layer whose electrical resistance value changes in response to a temperature change, and is a film containing a temperature-sensitive material. Examples of the temperature-sensitive material include carbon such as carbon black, fullerene, graphene, graphite, carbon nanobelts, and carbon nanotubes; metals such as metal nanoparticles and metal nanowires; metal oxides such as iron oxide, manganese oxide, nickel oxide, cobalt oxide, copper oxide, and zinc oxide; poly(styrene sulfonate)-doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS), poly(styrene sulfonate)-doped polyaniline (PANI:PSS), poly(styrene sulfonate)-doped polypyrrole, poly(styrene sulfonate)-doped polythiophene, polycarboxylic acid-doped poly(3,4-ethylenedioxythiophene), and polycarboxylic acid-doped polyaniline. Examples of the polymer semiconductor include polyaniline doped with a polycarboxylic acid, polypyrrole doped with a polycarboxylic acid, polythiophene doped with a polycarboxylic acid, poly(3,4-ethylenedioxythiophene) having a sulfonate group in the side chain (SELFTRON®), polyaniline having a sulfonate group in the side chain, polypyrrole having a sulfonate group in the side chain, polythiophene having a sulfonate group in the side chain, poly(3,4-ethylenedioxythiophene) having a carboxy group in the side chain, polyaniline having a carboxy group in the side chain, polypyrrole having a carboxy group in the side chain, polythiophene having a carboxy group in the side chain, polyacetylene, polyaniline, polypyrrole, and polythiophene, and preferably a film containing carbon or a polymer semiconductor.

[0079] The protective layer is a layer for electrically insulating, moisture-proofing, and waterproofing the electrodes and the temperature-sensitive layer, and contains at least one of metals, metal oxides, and water-insoluble polymers. Examples of metals include gold, silver, copper, platinum, aluminum, nickel, iron, stainless steel, titanium, and molybdenum. Examples of metal oxides include indium tin oxide (ITO), indium zinc oxide (IZO), aluminum oxide, copper oxide, iron oxide, chromium oxide, and nickel oxide. Examples of water-insoluble polymers include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene; alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins; polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; Examples of the polymer include films containing water-insoluble polymers such as phenol resins; epoxy resins; silicone resins; polyvinyl chloride resins; fluororesins such as polytetrafluoroethylene and vinylidene fluoride; polyvinyl butyral resins; polyparaxylene; celluloses such as cellulose acetate and cellulose ether; polyvinyl alcohol; polyvinylphenol; poly(melamine-co-formaldehyde) methylate; norbornene resins; and photocrosslinkable resins containing photocrosslinkable groups such as cinnamate ester groups, cinnamate amide groups, chalconyl groups, coumarinyl groups, stilbenyl groups, cinnamylidene acetate ester groups, cinnamylidene acetophenyl groups, and maleimide groups. Preferred are films containing silver, copper, aluminum, polyolefin resins, fluororesins, polyvinyl chloride resins, polyvinyl butyral resins, and photocrosslinkable resins, and particularly preferred are films containing silver, copper, aluminum, polyolefin resins, polyvinyl butyral resins, and photocrosslinkable resins.

[0080] The thickness of the protective layer is preferably 1 μm or more, and particularly preferably 10 μm or more.

[0081] The protective layer in the present invention may be formed by combining two or more materials selected from the above metals, metal oxides, and water-insoluble polymers.

[0082] The method for manufacturing the wearable sensor B of the present invention will be described with reference to FIG.

[0083] In the electrode formation process for forming an electrode on the substrate 1, an electrode containing the above-mentioned metal can be formed as the electrode 2 on the substrate 1 by the electrode formation process.

[0084] The thermosensitive layer 14 that overlaps the electrodes 2 can be formed by a thermosensitive layer formation process in which a solution of a composition containing a thermosensitive material, a water-insoluble polymer, a crosslinking agent, and a surfactant is dropped onto the substrate 1 and the electrodes 2 so that the electrodes 2 overlap, and the solvent is heated to evaporate, thereby forming the thermosensitive layer 14 on the substrate 1 and on top of the electrodes 2.

[0085] Examples of the temperature-sensing body include carbon such as carbon black, fullerene, graphene, graphite, carbon nanobelts, and carbon nanotubes; metals such as metal nanoparticles and metal nanowires; metal oxides such as iron oxide, manganese oxide, nickel oxide, cobalt oxide, copper oxide, and zinc oxide; poly(styrene sulfonate)-doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS), poly(styrene sulfonate)-doped polyaniline (PANI:PSS), poly(styrene sulfonate)-doped polypyrrole, poly(styrene sulfonate)-doped polythiophene, and polycarboxylic acid-doped poly(3,4-ethylenedioxythiophene). These include polyaniline doped with polycarboxylic acid, polypyrrole doped with polycarboxylic acid, polythiophene doped with polycarboxylic acid, poly(3,4-ethylenedioxythiophene) (SELFTRON (registered trademark)) having a sulfonate group in the side chain, polyaniline having a sulfonate group in the side chain, polypyrrole having a sulfonate group in the side chain, polythiophene having a sulfonate group in the side chain, poly(3,4-ethylenedioxythiophene) having a carboxy group in the side chain, polyaniline having a carboxy group in the side chain, polypyrrole having a carboxy group in the side chain, polythiophene having a carboxy group in the side chain, and polymer semiconductors such as polyacetylene, polyaniline, polypyrrole, and polythiophene.

[0086] The surfactant is not particularly limited, but examples thereof include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, fluorine-based surfactants, and silicone-based surfactants.

[0087] The crosslinking agent is not particularly limited, but examples thereof include a glycidyl group or an amino group. Examples of the silane compounds include silane compounds such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, and 3-phenylaminopropyltrimethoxysilane; and blocked isocyanate compounds such as various amine-blocked hexamethylene diisocyanate trimers (e.g., diisopropylamine), SU-268A manufactured by Meisei Chemical Industry Co., Ltd., the Fixer series manufactured by Murayama Chemical Research Institute, and the Elastron (registered trademark) BN series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0088] Examples of water-insoluble polymers include polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene; alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins; polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; phenolic resins; epoxy resins; silicone resins; polyvinyl chloride resins; fluororesins such as polytetrafluoroethylene and vinylidene fluoride; and polyvinyl butyral resin; polyparaxylene; cellulose such as cellulose acetate and cellulose ether; polyvinyl alcohol; polyvinylphenol; poly(melamine-co-formaldehyde) methylate; norbornene resin; photocrosslinkable resin containing a photocrosslinkable group such as a cinnamic acid ester group, a cinnamic acid amide group, a chalconyl group, a coumarinyl group, a stilbenyl group, a cinnamylidene acetate group, a cinnamylidene acetophenyl group, or a maleimide group, and preferred are polyolefin resin, fluororesin, polyvinyl chloride resin, polyvinyl butyral resin, photocrosslinkable resin, etc.

[0089] In the composition, the mass ratio of the temperature sensor, surfactant, and crosslinking agent is preferably 2:1:0.1 to 2:1:100, and particularly preferably 2:1:0.1 to 2:1:70, and the mass ratio of the total mass of the temperature sensor, surfactant, and crosslinking agent to the polymer is preferably 99.99:0.01 to 0.01:99.99, and particularly preferably 99.9:0.1 to 0.1:99.9.

[0090] The solvent is not particularly limited as long as it dissolves or disperses the temperature-sensing body, polymer, crosslinking agent, and surfactant, and examples thereof include water, methanol, ethanol, isopropanol, diacetone alcohol, butanol, acetone, methyl ethyl ketone, formamide, N,N-dimethylformamide, N-methylpyrrolidone, xylene, mesitylene, cyclohexanone, propylene glycol monomethyl ether acetate, anisole, dimethoxybenzene, perfluorotributylamine, perfluoroamine, ethyl nonafluorobutyl ether, octafluoropentanol, etc. The concentration of the solution is preferably 70% by mass or less, and particularly preferably 50% by mass or less.

[0091] The process for forming the temperature-sensitive layer can be the same as the process for forming the electrodes, and among these, coating, printing and laminating are preferred, with coating and printing being particularly preferred.

[0092] Furthermore, after the temperature-sensitive layer formation process, the temperature at which the solvent is heated to evaporate is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 60°C or higher, particularly preferably 100°C or higher.

[0093] In this way, it is possible to manufacture the temperature-sensitive layer 14. The temperature-sensitive layer 14 may cover the electrode 2 entirely or partially.

[0094] The protective layer 15 covering the temperature-sensitive layer 14 is formed by a protective layer formation process using a material selected from the group consisting of metals such as gold, silver, copper, platinum, aluminum, nickel, iron, stainless steel, titanium, and molybdenum; metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum oxide, copper oxide, iron oxide, chromium oxide, and nickel oxide; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyolefin resins such as polystyrene, polyethylene, and polypropylene, and alicyclic polyolefin resins; polycarbonate resins; acrylic resins; methacrylic resins; polyurethane resins; polyamide resins; polyimide resins; polyarylate resins; polyacetal resins; polysulfones; polyethersulfones; polyetherketones; and phenols. The protective layer 15 can be formed by dropping a solution containing a polymer such as vinyl resin; epoxy resin; silicone resin; polyvinyl chloride resin; fluororesin such as polytetrafluoroethylene or vinylidene fluoride; polyvinyl butyral resin; polyparaxylene; cellulose such as cellulose acetate or cellulose ether; polyvinyl alcohol; norbornene resin; or photocrosslinkable resin containing photocrosslinkable groups such as cinnamate ester group, cinnamic acid amide group, chalconyl group, coumarinyl group, stilbenyl group, cinnamylidene acetate ester group, cinnamylidene acetophenyl group, or maleimide group onto the surface of the substrate in the vicinity of the electrode 2 and the temperature-sensitive layer 14, and also dropping the solution so as to cover part of the surface of the electrode 2 and the temperature-sensitive layer 14, and then heating and evaporating the solvent.

[0095] The solvent used for the solution is not particularly limited as long as it disperses or dissolves the metal oxide or the polymer, and examples thereof include water, methanol, ethanol, isopropanol, diacetone alcohol, butanol, N,N-dimethylformamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate, cyclohexanone, anisole, dimethoxybenzene, perfluorotributylamine, perfluoroamine, ethyl nonafluorobutyl ether, and octafluoropentanol, with ethanol, propylene glycol monomethyl ether acetate, perfluorotributylamine, and octafluoropentanol being preferred. The concentration of the solution is preferably 30% by mass or less, and particularly preferably 10% by mass or less.

[0096] Furthermore, the temperature at which the solvent is heated to evaporate after the insulating layer formation process is not particularly limited as long as it is a temperature at which the solvent evaporates, and is preferably 60°C or higher, and particularly preferably 100°C or higher.

[0097] The protective layer 15 can also be formed by laminating a film containing one or more selected from the water-insoluble polymers, metals, and metal oxides.

[0098] The protective layer can be formed by the same process as the electrode formation process, and among these, coating, printing, and lamination are preferred.

[0099] As shown in FIG. 5, two or more protective layers may be formed.

[0100] The uses of wearable sensors A and B of the present invention are not particularly limited as long as they can measure biological information such as sweat components, body surface temperature, body fluid temperature, respiratory status, and heart rate. Examples of such uses include temperature sensors, piezoelectric sensors, atmospheric pressure sensors, acceleration sensors, strain sensors, brain wave sensors, sensors that continuously record various data in fields such as fitness and sports, pulse oximeters that irradiate light toward a biological part and measure the oxygen saturation level in the blood based on the amount of light that is transmitted through or reflected by the biological part, and communication devices equipped with these, and these may also be combined.

[0101] Wearable sensor A is suitable as a wearable sensor that can monitor sweat components in real time with high accuracy.

[0102] Wearable sensor B is suitable as a temperature sensor. There are no particular limitations on the type of temperature sensor as long as it can measure body surface temperature and body fluid temperature, and examples include contact-type temperature sensors such as thermocouples, resistance thermometers, and thermistors; and non-contact temperature sensors that measure temperature by detecting infrared rays, with thermistor-type temperature sensors being particularly preferred.

[0103] Wearable sensor A and wearable sensor B of the present invention may be combined, and a specific structure is shown in Figure 7. Insulating layer 4 of wearable sensor A and first protective layer 15 or second protective layer 16 of wearable sensor B may be shared by each other, or may be formed using the same resin and forming process. [Brief explanation of the drawings]

[0104] [Figure 1] 1 is an example of a wearable sensor A of the present invention. [Figure 2] 1 is an example of a wearable sensor A of the present invention. [Figure 3] The response evaluation method and evaluation results. [Figure 4] 1 is an example of a wearable sensor B of the present invention. [Figure 5] 1 is an example of a wearable sensor B of the present invention. [Figure 6] The response evaluation method and evaluation results. [Figure 7] 1 is an example of a combination of wearable sensor A and wearable sensor B of the present invention. [Figure 8] 1 shows a photograph of an example of a wearable sensor of the present invention and a method for evaluating response. [Figure 9] 10 shows the results of an evaluation of the responsiveness of the wearable sensor of the present invention. [Example]

[0105] The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to these examples. (Wearable Sensor A) Example 1 Silver nanoparticle ink (solution) (Harima Chemicals, NPS-JL) was printed by inkjet printing (Fujifilm, Dimatix DMP2831) on a polyethylene naphthalate film (PEN film, 100 μm thick, Teonex, manufactured by Toyobo Co., Ltd.) substrate, and baked at 120°C for 30 minutes to obtain silver electrodes for working electrode 8 and reference electrode 9. Carbon black ink (solution) (JELCON CH-8, manufactured by Jujo Chemical Co., Ltd.) was applied to the top of the silver electrodes of working electrode 8 and reference electrode 9 to form a circle with a diameter of 3 mm, and the solvent was evaporated at 120°C for 30 minutes to form an inactive layer on the top of the silver electrodes.

[0106] A solution of polytetrafluoroethylene (Teflon (registered trademark) AF1600, manufactured by DuPont-Mitsui Fluorochemicals) dissolved at 5 wt % in perfluorotributylamine (Fluorinert (registered trademark) FC-43, manufactured by 3M) was applied to the vicinity of the working electrode 8 and the reference electrode 9, and the solvent was evaporated at 120°C for 30 minutes to form an insulating layer.

[0107] To fabricate an ion-selective membrane covering the inactive surface of the working electrode, the ionophore 4-tert-Butylcalix[4]arene-tetraacetic acid tetraethyl ester (sodium ionophore X) (1 mg, Sigma-Aldrich), the anion-excluding agent sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (0.55 mg, Sigma-Aldrich), polyvinyl chloride (33 mg, Sigma-Aldrich), the sebacate ester plasticizer bis(2-ethylhexyl) sebacate (71.9 μL, Tokyo Chemical Industry Co.), and the solvent cyclohexanone (350 μL, Sigma-Aldrich) were mixed to prepare a composition. A 4 μL solution of the composition was dropped onto the surface of the working electrode 8 and dried at 50 °C for 30 minutes to form a sodium ion-selective membrane on top of the inactive layer.

[0108] Next, to prepare a liquid junction layer covering the inactive surface of the reference electrode, a polymer, polyvinyl butyral (79.1 mg, manufactured by Sigma-Aldrich), a base, sodium chloride (50 mg, manufactured by Fujifilm Wako Pure Chemical Industries), and a solvent, methanol (1 mL, manufactured by Fujifilm Wako Pure Chemical Industries), were mixed to prepare a composition. 4 μL of the composition solution was dropped onto the surface of the reference electrode 9, and the mixture was dried at 50°C for 30 minutes to form a liquid junction layer of polyvinyl butyral containing sodium chloride on top of the inactive layer. <Preparation of carrier film> Polyethylene glycol (104.7 g, average molecular weight 2000, manufactured by Tokyo Chemical Industry Co., Ltd.) as polyol (A), polypropylene glycol (59.2 g, Sannix PP-200, average molecular weight 200, manufactured by Sanyo Chemical Industries Co., Ltd.) as polyol (B), 1,6-hexanediol (15 g, manufactured by Tokyo Chemical Industry Co., Ltd.) as chain extender (D), and methyl ethyl ketone (300 g, manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as solvent were charged into a separable flask, mixed and dissolved at 45°C for 30 minutes, and then the polyisocyanate was added. A mixture of 2,4'-diphenylmethane diisocyanate / 4,4'-diphenylmethane diisocyanate (121.1 g, Millionate MT, Tosoh Corporation), which is the catalyst (C), and bismuth tris(2-ethylhexanoate) (0.1 g, Neostan U600, Nitto Kasei Co., Ltd.), which is a bismuth-based reaction catalyst, were added and reacted at 75°C for 10 hours. After this, methyl ethyl ketone (400 g, Fujifilm Wako Pure Chemical Industries, Ltd.) was added and mixed to dissolve, yielding a solution containing a polyurethane resin with a concentration of 30% by mass. This solution was coated onto the surface of a release paper using a bar coater and then dried at 50°C for 30 minutes to produce a 90 μm thick carrier film. The moisture permeability of the 90 μm thick polyurethane resin was 165 g / (m 2 24h).

[0109] Finally, a carrier film having an area of ​​1 cm x 1 cm was laminated to cover the surfaces of the working electrode 8 and the reference electrode 9, thereby producing a wearable sensor.

[0110] Example 2 To produce the ion-selective membrane, the potassium ionophore valinomycin (potassium ionophore I) (2 mg, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the ionophore, the anion-excluding material potassium tetrakis(4-chlorophenyl)borate (0.5 mg, manufactured by Sigma-Aldrich), polyvinyl chloride (32.7 mg, manufactured by Sigma-Aldrich), the sebacate ester plasticizer bis(2-ethylhexyl) sebacate (71 μL, manufactured by Tokyo Chemical Industry Co., Ltd.), and the solvent cyclohexanone (350 μL, manufactured by Sigma-Aldrich) were mixed to prepare a composition, and a potassium ion-selective membrane was obtained. A wearable sensor was produced in the same manner as in Example 1, except that the composition was adjusted to obtain a potassium ion-selective membrane.

[0111] Example 3 To produce the ion-selective membrane, the hydrogen ionophore tridodecylamine (hydrogen ionophore I) (1 mg, Sigma-Aldrich), the anion-excluding material potassium tetrakis(4-chlorophenyl)borate (0.5 mg, Sigma-Aldrich), polyvinyl chloride (33 mg, Sigma-Aldrich), the sebacate ester plasticizer bis(2-ethylhexyl) sebacate (71.9 μL, Tokyo Chemical Industry Co., Ltd.), and the solvent cyclohexanone (350 μL, Sigma-Aldrich) were mixed to prepare a composition, and a wearable sensor was fabricated in the same manner as in Example 1, except that a hydrogen ion-selective membrane was obtained.

[0112] Comparative Example 1 A wearable sensor was prepared in the same manner as in Example 1, except that a 100 μm thick agarose carrier film not containing polyurethane resin was prepared by mixing agarose (2 wt%), which is a sweat extraction material described in Patent Document 2 (JP 2020-115103 A), pure water (48 wt%) as a solvent, and glycerin (50 wt%) as a moisturizer as the carrier. This solution was then blade coated onto a glass plate and dried at room temperature for 3 minutes. <Response evaluation> The wearable sensors obtained in Example 1 and Comparative Example 1 were connected to a voltmeter (ALS model 612E, manufactured by BAS), and the potential difference between the working electrode 8 and the reference electrode 9 was measured. As shown in Figure 3(a), approximately 90 μL of a 10 mM sodium chloride aqueous solution was drop-cast onto the surface of the support, and the potential difference between the working electrode 8 and the reference electrode 9 was measured for 100 seconds. After that, the 10 mM sodium chloride aqueous solution on the support surface was wiped off with a rag. Next, approximately 90 μL of a 100 mM sodium chloride aqueous solution was drop-cast onto the surface of the support, and the potential difference between the working electrode 8 and the reference electrode 9 was measured for 100 seconds. After that, the 100 mM sodium chloride aqueous solution on the support surface was wiped off with a rag to remove the droplets. This cycle was repeated for a total of five cycles. Figure 3(b) shows the waveform of the potential difference obtained by the measurement shown in Figure 3(a).

[0113] The potential difference changed with increasing and decreasing sodium chloride concentration. This change in potential difference is expressed by the Nernst equation E = E 0 +RT / nF ln(a i ) (where a i is the activity of Na+ ions), and the sensitivity of Na+ ions calculated from this Nernst equation is approximately 60mV / dec. For example, when the Na+ ion concentration in the solution changes from 10mM to 100mM, the ideal change in potential between the working electrode 8 and the reference electrode 9 should be 60mV.

[0114] Compared to a carrier containing conventional agarose (Comparative Example 1), when a carrier containing a polyurethane resin composition was used, a change of 60 mV was observed, which is almost the ideal change calculated using the Nernst equation, and the response time was short at approximately 20 seconds. The hysteresis was small, less than a few percent of the potential change, demonstrating excellent reversibility of the response. These results suggest that, compared to conventional agarose carriers, this sensor can measure increases and decreases in ion concentration with high accuracy, making it a practical wearable sensor for real-time sweat component measurement in wearable applications. (Wearable Sensor B) Example 4 Electrode 2 was formed on a substrate 1, a polyethylene naphthalate film (PEN film, 100 μm thick, Teonex, manufactured by Toyobo Co., Ltd.), using an inkjet printing method (Fujifilm, Dimatix DMP2831) with silver nanoparticle ink (solution) (Harima Chemicals, NPS-JL) and baking at 120°C for 30 minutes.

[0115] To form the thermosensitive layer 14 overlapping the electrodes 2, a 1.3 wt% solution of the thermosensitive material poly(3,4-ethylenedioxythiophene) (SELFTRON® S grade, manufactured by Tosoh Corporation) containing sulfonate groups in its side chains was mixed with a 0.5 mL solution of the surfactant 4-(1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton® X-100, manufactured by Sigma-Aldrich) at a concentration of 1.3 wt%, and a 67.1 μL crosslinker (3-glycidyloxypropyl)trimethoxysilane (manufactured by Sigma-Aldrich) was mixed. The solution was applied to the electrodes 2 overlapping each other using a dispenser (manufactured by Musashi Engineering Co., Ltd.). The solvent was evaporated at 150°C for 30 minutes to form the thermosensitive layer 14 covering a portion of the substrate 1 and a portion of the electrodes 2.

[0116] To form the first protective layer 15 covering the temperature-sensitive layer 14, a composition was prepared by dissolving 4 wt% polyvinyl butyral (Sigma-Aldrich) in a solution made by mixing ethanol (Fujifilm Wako Pure Chemical Industries) and octafluoropentanol (Tokyo Chemical Industry Co., Ltd.) in a 1:1 (volume ratio). The composition solution was dripped onto the surface of the substrate 1 in the vicinity of the electrode 2 and the temperature-sensitive layer 14, and also onto a portion of the surface of the electrode 2, and then dried at 120°C for 10 minutes to form the first protective layer 15 made of polyvinyl butyral.

[0117] As the second protective layer 16 covering a part of the first protective layer 15, polytetrafluoroethylene (Teflon (registered trademark)) adhesive tape (ASF-110FR, manufactured by Chukoh Chemical Industry Co., Ltd.) was laminated by roller pressing under heating at 50°C, and then annealed at 80°C for 1 minute to form a protective layer with a total thickness of 90 μm, including the thickness of the first protective layer and the second protective layer, thereby producing a wearable sensor.

[0118] Example 5 The first protective layer 15 covering the temperature-sensitive layer 14 was formed by laminating a polyolefin film (Parafilm (registered trademark) PM996, manufactured by Bemis) by roller pressing under heating at 50°C so as to cover the temperature-sensitive layer 14 and part of the electrode 2, and then annealing at 80°C for 1 minute.Next, the second protective layer 16 covering part of the first protective layer 15 was formed by laminating an aluminum foil by roller pressing under heating at 50°C, and then annealing at 80°C for 1 minute, thereby forming a protective layer with a total thickness of 140 μm, consisting of the first protective layer 15 and the second protective layer 16.A wearable sensor was produced in the same manner as in Example 4.

[0119] Example 6 To form the thermosensitive layer 14 overlapping the electrodes 2, a solution of 1 wt% poly(3,4-ethylenedioxythiophene) (SELFTRON® A grade, manufactured by Tosoh Corporation), a thermosensitive substance containing sulfonate groups in its side chains, dissolved in cyclohexanone (manufactured by Sigma-Aldrich) was mixed with a solution of 0.1 wt% polyaniline (emeraldine base) (manufactured by Sigma-Aldrich) in cyclohexanone (manufactured by Sigma-Aldrich) in a volume ratio of 10:4 to prepare a composition. The composition solution was applied to the electrodes 2 overlapping each other using a dispenser (manufactured by Musashi Engineering Co., Ltd.), and the solvent was evaporated at 150°C for 30 minutes to form a thermosensitive layer covering part of the substrate 1 and part of the electrodes 2.

[0120] Next, to form the first protective layer 15 covering the temperature-sensitive layer 14, a polytetrafluoroethylene (Teflon (registered trademark)) adhesive tape (ASF-110FR, manufactured by Chukoh Chemical Industry Co., Ltd.) was laminated by roller pressing under heating at 50°C so as to cover part of the surface of the electrode 2 and the temperature-sensitive layer 14, and then annealed at 80°C for 1 minute, thereby forming a protective layer with a total thickness of 80 μm.A wearable sensor was produced in the same manner as in the example.

[0121] Comparative Example 2 A wearable sensor was fabricated in the same manner as in Example 4, except that a first protective layer 15 covering the temperature-sensitive layer 14 was formed by dripping a solution of CYTOP (registered trademark) (CTX-809A), a protective layer material described in Non-Patent Document 3, onto the temperature-sensitive layer 14 using a dispenser (manufactured by Musashi Engineering), dripping onto the surface of the substrate 1 near the electrode 2 and the temperature-sensitive layer 14, and dripping onto a portion of the surface of the electrode 2, and drying at 120°C for 10 minutes to form a protective layer with a total thickness of 20 μm. <Response evaluation> 6(a), the wearable sensors obtained in Examples 4, 5, and 6 and Comparative Example 2 were connected to a resistance meter (IM3536, manufactured by Hioki E.E. Corporation), and the wearable sensors were immersed in water in a beaker whose temperature was controlled by a hot plate to measure the electrical resistance of the temperature-sensitive layer 14. The temperature was changed within the range of 20°C to 50°C, which is the range of temperatures that the body surface and body fluids can reach.

[0122] Figure 6(b) shows the waveform of the resistance value obtained by the measurement shown in Figure 6(a). The resistance value changed as the temperature rose and fell. Compared to Comparative Example 2, which used a conventional protective layer, the wearable sensors obtained in Examples 4, 5, and 6 could be used stably underwater and exhibited high moisture resistance and water resistance. From the above, it was suggested that the wearable sensors can measure the rise and fall of body fluid temperature, which is mostly water, with high sensitivity, and are practical for measuring body surface temperature and sweat temperature in real time in wearable applications. (Example of a wearable sensor that combines wearable sensor A and wearable sensor B) <Integration of wearable sensor A and wearable sensor B> Example 7 A solution of polyvinylphenol (Sigma Aldrich) dissolved at 5 wt% in propylene glycol monomethyl ether acetate (Fujifilm Wako Pure Chemical Industries, Ltd.) and a solution of poly(melamine-co-formaldehyde) methylate (Sigma Aldrich) dissolved at 5 wt% in propylene glycol monomethyl ether acetate (Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed at a volume ratio of 1:1 to prepare a composition. The composition solution was applied by spin coating to a polyethylene naphthalate film (PEN film, 100 μm thick, Teonex, Toyobo Co., Ltd.), which serves as a first substrate 17 shown in FIG. 7, and baked at 150°C for 30 minutes to form a second substrate 18 shown in FIG. 7.

[0123] An electrode 2 was formed on the second substrate 18 by inkjet printing (Fujifilm, Dimatix DMP2831) using silver nanoparticle ink (solution) (Harima Chemicals, NPS-JL) and baking at 150° C. for 30 minutes.

[0124] A solution prepared by mixing propylene glycol monomethyl ether acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and carbon black ink (solution) (JELCON CH-8 manufactured by Jujo Chemical Co., Ltd.) in a 1:1 (volume ratio) was applied to the top of electrode 2 using a dispenser device (manufactured by Musashi Engineering Co., Ltd.) to form a circle with a diameter of 2 mm.The solvent was then evaporated at 150°C for 15 minutes to form an inactive layer 3 on the top of electrode 2.

[0125] To form the temperature-sensitive layer 14, we mixed 1 mL of a 1.3 wt% aqueous solution of the thermosensor poly(3,4-ethylenedioxythiophene) (SELFTRON® S grade, manufactured by Tosoh Corporation) containing sulfonate groups in its side chains, 0.5 mL of a 1.3 wt% aqueous solution of the surfactant 4-(1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton® X-100, manufactured by Sigma-Aldrich), and 67.1 μL of the crosslinker (3-glycidyloxypropyl)trimethoxysilane (manufactured by Sigma-Aldrich). The solution was applied to the electrodes 2 of the wearable sensor B26 shown in Figure 7 using a dispenser (manufactured by Musashi Engineering Co., Ltd.) so that they overlapped. The solvent was then evaporated at 150°C for 30 minutes to form the temperature-sensitive layer 14.

[0126] Next, a composition was prepared by dissolving 10 wt % of a photocrosslinkable resin containing cinnamic acid ester groups (described in Example 1 of WO2022 / 210326) and 0.3 wt % of 4,4'-bis(diethylamino)benzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) in octafluoropentanol (manufactured by Tokyo Chemical Industry Co., Ltd.). The composition solution was applied using a dispenser device (manufactured by Musashi Engineering Co., Ltd.) near the first working electrode 22, the second working electrode 23, the third working electrode 24, and the reference electrode 9 of wearable sensor A25, so as to cover the temperature-sensitive layer 14 of wearable sensor B26 and to cover part of electrode 2. The solvent was then evaporated at 125°C for 30 minutes, and the coating was then exposed to light (wavelength 365 nm, exposure dose 300 mJ / cm2) using an exposure device (UPE-1605MA, manufactured by Ushio Lighting Co., Ltd.) to form the insulating layer 4 of wearable sensor A25 and the first protective layer 15 of wearable sensor B26.

[0127] The second protective layer 16 was formed by laminating polytetrafluoroethylene (Teflon (registered trademark)) adhesive tape (ASF-110FR, manufactured by Chukoh Chemical Industries, Ltd.) by roller pressing under heating at 50°C so as to cover a portion of the electrode 2 of the wearable sensor B26 and a portion of the first protective layer 15.

[0128] To fabricate the sodium ion-selective membrane 19 covering the surface of the inactive layer 3, the ionophore 4-tert-Butylcalix[4]arene-tetraacetic acid tetraethyl ester (sodium ionophore X) (1 mg, Sigma-Aldrich), the anion-excluding agent sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (0.55 mg, Sigma-Aldrich), polyvinyl chloride (33 mg, Sigma-Aldrich), the sebacate ester plasticizer bis(2-ethylhexyl) sebacate (71.9 μL, Tokyo Chemical Industry Co., Ltd.), and the solvent cyclohexanone (350 μL, Sigma-Aldrich) were mixed to prepare a composition. 1.2 μL of the composition solution was dropped onto the surface of the inactive layer 3 and dried at 40°C for 15 minutes to form the sodium ion-selective membrane 19 on top of the inactive layer 3, forming a first working electrode 22.

[0129] To fabricate the potassium ion-selective membrane 20 covering the surface of the inactive layer 3, a composition was prepared by mixing the following: valinomycin (potassium ionophore I) (2 mg, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), potassium tetrakis(4-chlorophenyl)borate (0.5 mg, manufactured by Sigma-Aldrich), an anion-excluder; polyvinyl chloride (32.7 mg, manufactured by Sigma-Aldrich); bis(2-ethylhexyl) sebacate (71 μL, manufactured by Tokyo Chemical Industry Co., Ltd.), a sebacate ester-based plasticizer; and cyclohexanone (350 μL, manufactured by Sigma-Aldrich), a solvent. 1.2 μL of the composition solution was dropped onto the surface of the inactive layer 3 and dried at 40° C. for 15 minutes to form the potassium ion-selective membrane 20 on top of the inactive layer 3, forming a second working electrode 23.

[0130] To fabricate the hydrogen ion-selective membrane 21 covering the surface of the inactive layer 3, a composition was prepared by mixing the hydrogen ionophore tridodecylamine (hydrogen ionophore I) (1 mg, Sigma-Aldrich), the anion-excluding material potassium tetrakis(4-chlorophenyl)borate (0.5 mg, Sigma-Aldrich), polyvinyl chloride (33 mg, Sigma-Aldrich), the sebacate ester-based plasticizer bis(2-ethylhexyl) sebacate (71.9 μL, Tokyo Chemical Industry Co., Ltd.), and the solvent cyclohexanone (350 μL, Sigma-Aldrich). 1.2 μL of the composition solution was dropped onto the surface of the inactive layer 3 and dried at 40° C. for 15 minutes to form the hydrogen ion-selective membrane 21 on the inactive layer 3, and a third working electrode 24 was formed.

[0131] To prepare the liquid junction layer 6 covering the surface of the inactive layer 3, a polymer (79.1 mg, Sigma-Aldrich), a base (50 mg, Fujifilm Wako Pure Chemical Industries, Ltd.), a polymer surfactant (2,6-di(tert-butyl)-p-cresol), poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (Pluronic® F-127, 2 mg, Sigma-Aldrich), a solvent (0.85 mL, Fujifilm Wako Pure Chemical Industries, Ltd.), and a solvent (0.15 mL) of water were mixed to prepare a composition. 1.2 μL of the composition solution was dropped onto the surface of the inactive layer 3 and dried at 40 °C for 15 minutes to form a liquid junction layer 6 of polyvinyl butyral containing sodium chloride on top of the inactive layer 3, forming a reference electrode 9. <Formation of carrier> The solution containing the 30% by mass polyurethane resin obtained in Example 1 was mixed with N-methylpyrrolidone at a 1:1 (volume ratio) ratio to prepare a solution containing polyurethane resin. 2 mL of this solution was drop-cast onto the bottom of a 10 cm diameter glass Petri dish so that it evenly covered the bottom surface, and then the Petri dish was steamed at 85°C for 5 minutes with the lid closed. Then, with the lid open, the solvent was dried at 125°C for 15 minutes to obtain a 10 cm diameter film containing polyurethane resin. Next, 20 mL of pure water was drop-cast into the Petri dish, and while the film containing polyurethane resin had absorbed water, it was punched using a metal die to produce a carrier film containing polyurethane resin with a diameter of 0.8 cm and a thickness of 20 μm. The moisture permeability of the 20 μm thick polyurethane resin was 217 g / (m 2 24h).

[0132] A carrier film containing polyurethane resin with a diameter of 0.8 cm and a thickness of 20 μm was laminated onto the surfaces of the first working electrode 22, the second working electrode 23, the third working electrode 24, and the reference electrode 9 via an aqueous solution (2 μL) containing 0.5 wt % of photocrosslinkable polyvinyl alcohol resin (BIOSURFINE (registered trademark) AWP-MRH, manufactured by Toyo Gosei Co., Ltd.). After drying the solvent at 40°C for 5 minutes, the film was exposed to light (wavelength 365 nm, exposure dose 300 mJ / cm) using an exposure device (UPE-1605MA, manufactured by Ushio Lighting Co., Ltd.). 2 ) to form carrier 7. <Formation of adhesive layer> An acrylic resin double-sided adhesive tape (200A5020, manufactured by Kyodo Giken Chemical Co., Ltd.) with cut-out patterns of circular (1 cm diameter) and linear flow channels (1.5 mm width, 3 mm length) was laminated near the first working electrode 22, the second working electrode 23, the third working electrode 24, and the reference electrode 9 so as to cover the second protective layer 16 of the wearable sensor B26, thereby forming an adhesive layer 12, and the wearable sensor shown in Figures 8(a) and (b) was produced. <Response evaluation> 8(c), the wearable sensor A25 obtained in Example 7 was connected to a voltmeter (ALS model 612E, manufactured by BAS), and the wearable sensor was immersed in an aqueous electrolyte solution in a beaker controlled at room temperature to measure the potential difference between the first working electrode 22 and the reference electrode 9, the potential difference between the second working electrode 23 and the reference electrode 9, and the potential difference between the third working electrode 24 and the reference electrode 9. The electrolyte concentrations of the aqueous electrolyte solution were varied within the ion concentration range that can be absorbed by sweat (sodium ions: 10 to 100 mM, potassium ions: 1 to 10 mM, pH value: 3 to 8). Aqueous sodium chloride solutions with concentrations of 10 mM, 33 mM, and 100 mM were prepared in beakers, and the wearable sensor was immersed in the solutions in the order of 10 mM, 33 mM, 100 mM, 33 mM, 10 mM, 33 mM, and 100 mM, and the potential difference between the first working electrode 22 and the reference electrode 9 was measured for 50 seconds at each concentration. Aqueous potassium chloride solutions with concentrations of 1 mM, 3.3 mM, and 10 mM were prepared in beakers, and the wearable sensor was immersed in the solutions in the order of 1 mM, 3.3 mM, 10 mM, 3.3 mM, 1 mM, 3.3 mM, and 10 mM, and the potential difference between the second working electrode 23 and the reference electrode 9 was measured for 50 seconds at each concentration. McIlvaine buffer solutions of pH 3, pH 4, pH 5, pH 6, pH 7, and pH 8 were prepared in beakers, and the wearable sensor was immersed in the solutions in the following order: pH 8, pH 7, pH 6, pH 5, pH 4, pH 3, pH 4, pH 5, pH 6, pH 7, pH 8, pH 7, pH 6, pH 5, pH 4, and pH 3. The potential difference between the third working electrode 24 and the reference electrode 9 was measured for 50 seconds at each pH value.

[0133] Figures 9(a), (b), and (c) respectively show the waveform of the potential difference between the first working electrode 22 and the reference electrode 9 (the response of the sodium ion sensor to sodium ions), the waveform of the potential difference between the second working electrode 23 and the reference electrode 9 (the response of the potassium ion sensor to potassium ions), and the waveform of the potential difference between the third working electrode 24 and the reference electrode 9 (the response of the hydrogen ion sensor to hydrogen ions) obtained by the measurement shown in Figure 8(c). The potential difference changed in response to increases and decreases in the concentration of specific ions. This change in potential difference is expressed by the Nernst equation E = E 0 +RT / nF ln(a i ) (where a iThe sensitivity of the wearable sensor of the present invention is defined as the activity of a certain ion, and the ideal sensitivity for monovalent ions is approximately 60 mV / dec. The wearable sensor of the present invention observed a change of approximately 60 mV, which is almost the ideal change calculated using the Nernst equation. It was also found to have a short response time of approximately 20 seconds, and a small hysteresis of less than a few percent of the potential change, demonstrating excellent reversibility of response. These findings suggest that the sensor can measure increases and decreases in ion concentration with high accuracy, making it a practical wearable sensor for real-time sweat component measurement in wearable applications.

[0134] 8(d), the wearable sensor B26 obtained in Example 7 was connected to a resistance meter (IM3536, manufactured by Hioki E.E. Corporation), and the wearable sensor was immersed in water in a beaker whose temperature was controlled by a hot plate to measure the electrical resistance value of the temperature-sensitive layer 14. The temperature was changed within the range of 20°C to 50°C, which is the range of temperatures that the body surface and body fluids can reach.

[0135] Figure 9(d) shows the waveform of the resistance value (the temperature sensor's response to temperature) obtained by the measurement shown in Figure 8(d). The resistance value changed as the temperature rose and fell. The wearable sensor obtained in Example 7 could be used stably underwater and exhibited high moisture resistance and water resistance. From the above, it was suggested that the sensor can measure the rise and fall of body fluid temperature, which is mostly water, with high sensitivity, and is a practical wearable sensor for measuring body surface temperature and sweat temperature in real time in wearable applications. [Explanation of symbols]

[0136] 1: Base material 2: Electrode 3: Inactive layer 4: Insulation layer 5: Ion selective membrane 6: Liquid junction layer 7: Carrier 8: Working electrode 9:Reference pole 10:Support 11: Flow path 12: Adhesive layer 13: Temperature sensor 14: Temperature sensitive layer 15: 1st protective layer 16:Second protective layer 17: First base material 18:Second base material 19: Sodium ion selective membrane 20: Potassium ion selective membrane 21: Hydrogen ion selective membrane 22: 1st working electrode 23:Second working electrode 24: Third working electrode 25: Wearable Sensor A 26: Wearable Sensor B

Claims

1. A wearable sensor comprising: a substrate; a working electrode comprising an electrode, an inert layer, and an ion-selective membrane; a reference electrode comprising an electrode, an inert layer, and a liquid junction layer; an insulating layer; and a carrier, wherein the carrier comprises at least one type of polyurethane resin or cellulose.

2. The wearable sensor according to claim 1 , comprising one or more types of working electrodes.

3. 3. The wearable sensor according to claim 1, wherein the ion-selective membrane is one or more selected from the group consisting of a sodium ion-selective membrane, a chloride ion-selective membrane, a potassium ion-selective membrane, a calcium ion-selective membrane, a magnesium ion-selective membrane, a hydrogen ion-selective membrane, an ammonium ion-selective membrane, and a nitrate ion-selective membrane.

4. A wearable sensor comprising a substrate, an electrode, a temperature-sensitive layer, and a protective layer, wherein the protective layer contains at least one of a metal, a metal oxide, and a water-insoluble polymer.

5. The wearable sensor according to claim 4, which is a thermistor-type temperature sensor.

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