Biosensor

Abstract

This biosensor operates by the power supplied from a battery, and comprises: an electrode unit located on at least one terminal side of the battery; and an electroconductive adhesive tape that has electroconductive property and is provided between the one terminal and the electrode unit. The bending load per unit bending deflection of the electroconductive adhesive tape is 0.035 N / cm or less.

Description

Technical Field

[0001] The present invention relates to a biosensor.

Background Art

[0002] In medical institutions such as hospitals and clinics, nursing facilities, or homes, for example, a biosensor for measuring biological information such as electrocardiogram, pulse wave, electroencephalogram, or electromyogram is used. The biosensor includes a bioelectrode that comes into contact with the living body to acquire the biological information of the subject. When measuring the biological information, the biosensor is attached to the skin of the subject to bring the bioelectrode into contact with the skin of the subject. The biological information is measured by acquiring an electrical signal related to the biological information with the bioelectrode.

[0003] As such a biosensor, for example, there is disclosed a stick-on type biological device including a wiring board housed in a housing space defined by an upper exterior body and a lower exterior body, and a coin battery mounted on the wiring board, which supplies power from the coin battery to a wireless communication unit and transmits data acquired by the wireless communication unit (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A biosensor having a battery such as a coin cell or a control unit for controlling the operation of a biosensor inside, like a conventional sticking type biosensor for living bodies, may have an increase in the resistance of a conductive member such as wiring arranged between the battery and the control unit due to pressure bonding to the skin of a subject or movement of the living body (body movement) during use of the biosensor, and thus the supply voltage from the battery may decrease. In particular, when the supply voltage from the battery falls below the operable voltage of the control unit, the operation of the biosensor may stop and it may not be possible to measure biological information.

[0006] An object of one aspect of the present invention is to provide a biosensor capable of stably supplying a voltage from a battery to a control unit.

Means for Solving the Problems

[0007] One aspect of the biosensor according to the present invention is a biosensor that operates with electric power supplied from a battery, and includes an electrode portion located on at least one terminal side of the battery, and a conductive adhesive tape provided between the one terminal and the electrode portion and having conductivity, wherein the bending load per unit bending deflection amount of the conductive adhesive tape is 0.035 N / cm or less.

Effects of the Invention

[0008] One aspect of the biosensor according to the present invention can stably supply a voltage from a battery to a control unit.

Brief Description of the Drawings

[0009]

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MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail. For ease of understanding the description, the same reference numerals are assigned to the same components in each drawing, and redundant descriptions are omitted. Also, the scales of the respective members in the drawings may be different from the actual ones. In this specification, a three-dimensional orthogonal coordinate system in three axial directions (X-axis direction, Y-axis direction, Z-axis direction) is used. The short side direction of the biosensor is defined as the X-axis direction, the long side direction is defined as the Y-axis direction, and the height direction (thickness direction) is defined as the Z-axis direction. The direction opposite to the side (attachment side) where the biosensor is attached to the living body (subject) is defined as the +Z-axis direction, and the side (attachment side) where the biosensor is attached to the living body (subject) is defined as the -Z-axis direction. In the following description, for convenience of explanation, the +Z-axis direction side is referred to as the upper side or above, and the -Z-axis direction side is referred to as the lower side or below, but this does not represent a universal up-down relationship. In this specification, the tilde "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0011] <Biosensor> The biosensor according to this embodiment will be described. In this embodiment, as an example, the case of a patch-type biosensor that is brought into contact with a living body to measure biological information will be described. Note that the living body refers to a human body (person), as well as animals such as cows, horses, pigs, chickens, dogs, and cats. The biosensor is attached to a part of the living body (for example, the skin, scalp, or forehead, etc.). The biosensor can be preferably used for living bodies, especially for human bodies.

[0012] FIG. 1 is a perspective view showing the configuration of the biosensor according to the present embodiment, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a cross-sectional view taken along line I-I of FIG. 1. As shown in FIG. 1, the biosensor 1 is a plate-shaped (sheet-shaped) member formed in a substantially elliptical shape in plan view. As shown in FIGS. 2 and 3, the biosensor 1 includes a biological adhesive layer 10, a foamed sheet 20, a housing 30, an electrode 40, and a sensor unit 50, and is configured by laminating the biological adhesive layer 10, the foamed sheet 20, and the housing 30 in this order from the biological adhesive layer 10 side toward the housing 30 side. The biological adhesive layer 10, the foamed sheet 20, and the housing 30 have substantially the same outer shape in plan view. The electrode 40 is provided on the surface of the biological adhesive layer 10 on the side (-Z-axis direction) where it is attached to the skin 2. The sensor unit 50 is installed on the biological adhesive layer 10 and is housed in a storage space S formed by the foamed sheet 20 and the housing 30.

[0013] [Biological Adhesive Layer] As shown in FIG. 3, the biological adhesive layer 10 includes a base material 11, an adhesive layer 12 for attachment, and an adhesive layer 13 for the sensor.

[0014] (Base Material) As shown in FIG. 3, the base material 11 is provided on the adhesive layer 12 for attachment so that the surfaces on the foamed sheet 20 and housing 30 sides are exposed. The outer shapes on both sides in the width direction (X-axis direction) of the base material 11 are substantially the same as the outer shapes on both sides in the width direction (X-axis direction) of the foamed sheet 20 and the housing 30. The length (Y-axis direction) of the base material 11 is formed shorter than the lengths (Y-axis direction) of the foamed sheet 20 and the housing 30.

[0015] The base material 11 can be formed using a flexible resin having appropriate stretchability, flexibility, and toughness. As materials for forming the base material 11, for example, polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate; acrylic resins such as polyacrylic acid, polymethacrylic acid, methyl polyacrylate, polymethyl methacrylate (PMMA), ethyl polymethacrylate, butyl polyacrylate; polyolefin resins such as polyethylene, polypropylene; polystyrene resins such as polystyrene, imide-modified polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, imide-modified ABS resin, styrene-acrylonitrile copolymer (SAN) resin, acrylonitrile-ethylene-propylene-diene-styrene (AES) resin; polyimide resins; polyurethane resins; silicone resins; thermoplastic resins such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, etc. Among these, in particular, polyolefin resins and PET are preferably used. These thermoplastic resins have waterproof properties (low water permeability). Therefore, by forming the base material 11 using these thermoplastic resins, when the biosensor 1 is attached to the skin 2 of the living body, sweat or water vapor generated from the skin 2 can be prevented from penetrating through the base material 11 to the flexible substrate 51 side of the sensor unit 50.

[0016] Since the sensor unit 50 is installed on the upper surface of the base material 11, it is preferably formed in a flat plate shape.

[0017] The thickness of the base material 11 can be arbitrarily selected as appropriate. For example, it is preferably 1 μm to 300 μm, more preferably 5 μm to 100 μm, and even more preferably 10 μm to 50 μm.

[0018] (Adhesive layer for attachment) As shown in FIG. 3, the adhesive layer 12 for attachment is provided on the lower surface of the base material 11 on the attachment side (-Z axis direction), and is a layer that comes into contact with the living body. The adhesive layer 12 for attachment preferably has moisture permeability. Water vapor and the like generated from the skin 2 to which the biosensor 1 is attached can escape to the foamed sheet 20 through the adhesive layer 12 for attachment. Furthermore, since the foamed sheet 20 has a bubble structure as described later, water vapor can be released to the outside of the biosensor 1 through the adhesive layer 22 for the housing. Thereby, it is possible to prevent sweat or water vapor from accumulating at the interface between the skin 2 on which the biosensor 1 is mounted and the adhesive layer 12 for attachment. As a result, it is possible to suppress the weakening of the adhesive force of the adhesive layer 12 for attachment due to the moisture accumulated at the interface between the skin 2 and the adhesive layer 12 for attachment, and to prevent the biosensor 1 from peeling off from the skin.

[0019] The adhesive layer 12 for attachment preferably has pressure-sensitive adhesiveness. By having pressure-sensitive adhesiveness, the adhesive layer 12 for attachment can be easily attached to the skin 2 by pressing the biosensor 1 against the skin 2 of the living body.

[0020] The material of the adhesive layer 12 for attachment is not particularly limited as long as it has pressure-sensitive adhesiveness, and examples thereof include materials having biocompatibility. Examples of the material for forming the adhesive layer 12 for attachment include acrylic pressure-sensitive adhesives and silicone pressure-sensitive adhesives. Preferably, an acrylic pressure-sensitive adhesive is mentioned.

[0021] The acrylic pressure-sensitive adhesive preferably contains an acrylic polymer as a main component. The acrylic polymer can function as a pressure-sensitive adhesive component. As the acrylic polymer, a polymer obtained by polymerizing a monomer component containing (meth)acrylate such as isononyl acrylate and methoxyethyl acrylate as a main component and containing a monomer copolymerizable with (meth)acrylate such as acrylic acid as an optional component can be used.

[0022] The acrylic pressure-sensitive adhesive preferably further contains a carboxylic acid ester. The carboxylic acid ester functions as a pressure-sensitive adhesive strength regulator that reduces the pressure-sensitive adhesive strength of the acrylic polymer and adjusts the pressure-sensitive adhesive strength of the adhesive layer 12 for sticking. As the carboxylic acid ester, a carboxylic acid ester compatible with the acrylic polymer can be used. As the carboxylic acid ester, glyceryl triradical fatty acid ester or the like can be used.

[0023] The acrylic pressure-sensitive adhesive may contain a crosslinking agent if necessary. The crosslinking agent is a crosslinking component that crosslinks the acrylic polymer. Examples of the crosslinking agent include polyisocyanate compounds (polyfunctional isocyanate compounds), epoxy compounds, melamine compounds, peroxide compounds, urea compounds, metal alkoxide compounds, metal chelate compounds, metal salt compounds, carbodiimide compounds, oxazoline compounds, aziridine compounds, amine compounds, and the like. Among these, polyisocyanate compounds are preferred. These crosslinking agents may be used alone or in combination.

[0024] The adhesive layer 12 for sticking preferably has excellent biocompatibility. For example, when the adhesive layer 12 for sticking is subjected to a horny layer peeling test, the horny layer peeling area ratio is preferably 0% to 50%, and more preferably 1% to 15%. If the horny layer peeling area ratio is within the range of 0% to 50%, even when the adhesive layer 12 for sticking is adhered to the skin 2, the load on the skin 2 can be suppressed.

[0025] The moisture permeability of the adhesive layer 12 for sticking is preferably 300 (g / m 2 ·day) or more, more preferably 600 (g / m 2 ·day) or more, and even more preferably 1000 (g / m 2 ·day) or more. Also, the moisture permeability of the adhesive layer 12 for sticking is 10000 (g / m 2 ·day) or less. When the moisture permeability of the adhesive layer 12 for sticking is 300 (g / m 2·If it is more than (days), even if the adhesive layer 12 for attachment is attached to the skin 2, sweat and the like generated from the skin 2 can be appropriately permeated from the base material 11 to the outside, so that the burden on the skin 2 can be reduced.

[0026] The thickness of the adhesive layer 12 for attachment can be appropriately and arbitrarily selected, and is preferably 10 μm to 300 μm. If the thickness of the adhesive layer 12 for attachment is 10 μm to 300 μm, the biological sensor 1 can be made thinner.

[0027] The adhesive layer 13 for the sensor is attached to the upper surface of the base material 11 and is a layer that adheres the base material 11 and the flexible substrate 51 of the sensor unit 50. As the material for forming the adhesive layer 13 for the sensor, a material having pressure-sensitive adhesiveness is preferable, the same material as the adhesive layer 12 for attachment can be used, and an acrylic pressure-sensitive adhesive is preferably used.

[0028] The thickness of the adhesive layer 13 for the sensor can be appropriately and arbitrarily set, and is preferably 10 μm to 300 μm. If the thickness of the adhesive layer 13 for the sensor is 10 μm to 300 μm, the biological sensor 1 can be made thinner.

[0029] [Foam sheet] The foam sheet 20 has a foam attachment layer 21 and a housing adhesive layer 22 provided on the upper surface thereof.

[0030] (Foam attachment layer) As shown in FIG. 3, the foam attachment layer 21 has a foam base material 211 and a base material adhesive layer 212 provided on the surface of the foam base material 211 on the biological side (-Z-axis direction). When the adhesion between the foam base material 211 and the adhesive layer 12 for attachment is sufficient, the foam attachment layer 21 may not include the base material adhesive layer 212, and the foam base material 211 may be adhered to the adhesive layer 12 for attachment.

[0031] ((Foam base material)) The foamed base material 211 can be formed using a foam having a structure of continuous bubbles, closed cells, or semi-closed cells, which has flexibility, waterproofness, and moisture permeability. Thereby, water vapor generated from a living body to which the biosensor 1 is attached, such as sweat, can be released to the outside of the biosensor 1 through the foamed base material 211.

[0032] As the material for forming the foamed base material 211, for example, thermoplastic resins such as polyurethane-based resins, polystyrene-based resins, polyolefin-based resins, silicone-based resins, acrylic-based resins, vinyl chloride-based resins, and polyester-based resins can be used. Among these, polyester-based resins are preferred, and PET is preferably used.

[0033] The thickness of the foamed base material 211 can be appropriately selected, and for example, it can be set to 0.5 mm to 1.5 mm.

[0034] ((Adhesive layer for base material)) As shown in FIG. 3, the adhesive layer 212 for the base material is provided by being attached to the lower surface of the foamed base material 211, and has a function of adhering the base material 11 and the foamed base material 211.

[0035] The adhesive layer 212 for the base material preferably has moisture permeability. Water vapor or the like generated from the skin 2 to which the biosensor 1 is attached can escape to the foamed base material 211 through the adhesive layer 212 for the base material. Furthermore, since the foamed base material 211 has a bubble structure as described above, water vapor can be released to the outside of the biosensor 1 through the adhesive layer 22 for the housing. Thereby, it is possible to prevent sweat or water vapor from accumulating at the interface between the skin 2 on which the biosensor 1 is worn and the adhesive layer 12 for attachment. As a result, it is possible to prevent the adhesive strength of the adhesive layer 12 for attachment from being weakened due to the moisture accumulated at the interface between the skin 2 and the adhesive layer 12 for attachment, and to prevent the biosensor 1 from peeling off from the skin 2.

[0036] As the material for forming the adhesive layer 212 for the base material, it is preferably a material having pressure-sensitive adhesiveness, and the same material as the adhesive layer 12 for attachment can be used. As the material for forming the adhesive layer 212 for the base material, it is preferable to use an acrylic-based pressure-sensitive adhesive.

[0037] The moisture permeability of the adhesive layer 212 for the base material is preferably 1 (g / m 2 ·day) or more, and more preferably 10 (g / m 2 ·day) or more. Also, the moisture permeability of the adhesive layer 212 for the base material is 10000 (g / m 2 ·day) or less. If the moisture permeability of the adhesive layer 212 for the base material is 10 (g / m 2 ·day) or more, when the adhesive layer 12 for attachment is attached to the skin 2, sweat and the like transmitted from the adhesive layer 10 for living body can be permeated outward, so the load on the skin 2 can be suppressed.

[0038] The thickness of the adhesive layer 212 for the base material can be set arbitrarily as appropriate, and is preferably 10 μm to 300 μm. If the thickness of the adhesive layer 212 for the base material is 10 μm to 300 μm, the bio-sensor 1 can be made thinner.

[0039] (Adhesive layer for the housing) As shown in FIG. 3, the adhesive layer 22 for the housing is provided in a state of being attached to the upper surface of the foamed base material 211. The adhesive layer 22 for the housing is attached to a position corresponding to the flat surface on the attachment side (-Y axis direction) of the housing 30 among the upper surface of the foamed base material 211, and has a function of adhering the foamed base material 211 and the housing 30.

[0040] As the material for forming the adhesive layer 22 for the housing, a silicone-based adhesive, a silicone tape, or the like can be used.

[0041] The adhesive layer 22 for the housing preferably has moisture permeability. Since the foamed base material 211 has an open-cell structure, water vapor that has penetrated through the adhesive layer 22 for the housing can be released to the outside of the bio-sensor 1.

[0042] The thickness of the adhesive layer 22 for the housing can be set as appropriate, for example, it can be 0.5 mm to 1.5 mm.

[0043] The moisture permeability of the adhesive layer 22 for the housing is preferably 65 (g / m 2 ·day) to 4000 (g / m 2 ·day), more preferably 90 (g / m 2 ·day) to 2000 (g / m 2 ·day), even more preferably 800 (g / m 2 ·day) to 1700 (g / m 2 ·day), and most preferably 850 (g / m 2 ·day) to 1660 (g / m 2 ·day). If the moisture permeability of the adhesive layer 22 for the housing is within the above preferred range, the stress at the interface between the adhesive layer 12 provided on the surface on the sticking side (-Z-axis direction) of the base material 11 and the skin 2 can be relaxed, so that the biological sensor 1 can be prevented from peeling off from the skin 2.

[0044] (Housing) As shown in FIG. 3, the housing 30 is adhered to the upper surface of the foamed sheet 20. The housing 30 has a protruding portion 31 protruding substantially dome-shaped in the height direction (+Z-axis direction) of the biological sensor 1 at the central portion in the longitudinal direction (Y-axis direction). Further, the lower surface (the sticking side surface) of the housing 30 is formed flat. A storage space S for storing the sensor portion 50 is formed inside (the sticking side) of the protruding portion 31.

[0045] As the material for forming the housing 30, for example, a material having flexibility such as silicone rubber, fluororubber, urethane rubber, etc. can be used. It can protect the sensor portion 50 disposed in the storage space S of the housing 30 and absorb the impact applied to the biological sensor 1 from the upper surface side to reduce the impact applied to the sensor portion 50.

[0046] The thickness of the upper surface and the side walls of the protruding portion 31 of the housing 30 is preferably greater than the thickness of the flat portions 32a and 32b provided on both ends of the housing 30 in the longitudinal direction L. Thereby, the flexibility of the protruding portion 31 can be made lower than the flexibility of the flat portions 32a and 32b, and the sensor portion 50 can be protected from an external force applied to the biological sensor 1.

[0047] The thickness of the upper surface and the side walls of the protruding portion 31 is preferably 1.5 mm to 3 mm, and the thickness of the flat portions 32a and 32b is preferably 0.5 mm to 1 mm.

[0048] Since the flat portions 32a and 32b with a small thickness have higher flexibility than the protruding portion 31, when the biological sensor 1 is attached to the skin 2, it can be easily deformed following the deformation of the surface of the skin 2 due to body movements such as stretching, bending, and twisting. Thereby, the stress applied to the flat portions 32a and 32b when the surface of the skin 2 is deformed can be relieved, and the biological sensor 1 can be made difficult to peel off from the skin 2.

[0049] The outer peripheral portions of the flat portions 32a and 32b preferably have a shape in which the thickness gradually decreases toward the ends. Thereby, the flexibility of the outer peripheral portions of the flat portions 32a and 32b can be further increased, and the wearing feeling when the biological sensor 1 is attached to the skin 2 can be improved as compared with the case where the thickness of the outer peripheral portions of the flat portions 32a and 32b is not reduced.

[0050] (Electrode) As shown in FIG. 3, the electrode 40 is attached to the lower surface of the adhesion layer 12 for attachment provided on the lower surface (the -Z axis direction) of the substrate 11 on the attachment side. When the biological sensor 1 is attached to the skin 2, the electrode 40 contacts the skin 2, so that a biological signal can be detected. The biological signal is, for example, an electrical signal representing an electrocardiogram waveform, an electroencephalogram, a pulse, or the like. Note that the electrode 40 may be buried in a state where it is exposed to be in contact with the skin on the substrate 11.

[0051] The electrode 40 can be formed using an electrode sheet formed in a sheet shape from a cured product of a conductive composition containing a conductive polymer and a binder resin, a metal, an alloy, or the like.

[0052] As the conductive polymer, for example, polythiophene-based conductive polymers, polyaniline-based conductive polymers, polypyrrole-based conductive polymers, polyacetylene-based conductive polymers, polyphenylene-based conductive polymers and their derivatives, and composites thereof can be used. These may be used alone or in combination of two or more. Among these, a composite in which polyaniline is doped as a dopant into polythiophene is preferable. Among the composites of polythiophene and polyaniline, PEDOT / PSS doped with polystyrene sulfonic acid (poly 4-styrene sulfonate; PSS) is more preferable because it has a lower contact impedance with a living body and higher conductivity.

[0053] Also, the electrode 40 may be embedded in the lower surface of the adhesive layer 12 for attachment in a state of being exposed so as to be able to contact the living body.

[0054] Furthermore, the electrode 40 may have a plurality of through holes on the contact surface with the skin 2. Thereby, in a state where the electrode 40 is attached to the adhesive layer 12 for attachment, the adhesive layer 12 for attachment can be exposed to the attachment side from the through holes, so that the adhesion between the electrode 40 and the skin 2 can be enhanced.

[0055] (Sensor section) FIG. 4 is a plan view showing the configuration of the sensor unit 50, and FIG. 5 is an exploded perspective view of a part of the sensor unit 50. The broken line in FIG. 4 indicates the outer diameter of the housing 30. As shown in FIGS. 4 and 5, the sensor unit 50 includes a flexible substrate 51 on which various components for acquiring biological information are mounted, a sensor body 52, wirings 53a and 53b respectively connected to the sensor body 52 in the longitudinal direction of the sensor body 52, a battery 54, a positive electrode pattern (first electrode portion) 55, a negative electrode pattern (second electrode portion) 56, and a conductive adhesive tape 57. Between the pad portion 522a and the pad portion 522b of the sensor unit 50, the positive electrode pattern 55, the conductive adhesive tape 57, the battery 54, the conductive adhesive tape 57, and the negative electrode pattern 56 are laminated in this order from the pad portion 522a side to the pad portion 522b side. In this embodiment, the positive terminal of the battery 54 is in the -Z-axis direction and the negative terminal is in the +Z-axis direction, but the reverse may also be used, that is, the positive terminal may be in the +Z-axis direction and the negative terminal may be in the -Z-axis direction.

[0056] The flexible substrate 51 is a resin substrate, and the sensor body 52, and the wirings 53a and 53b are integrally formed on the flexible substrate 51.

[0057] One end of each of the wirings 53a and 53b is connected to the electrode 40 as shown in FIG. 3. As shown in FIG. 4, the other end of the wiring 53a is connected to a switch or the like mounted on the component mounting portion 521 along the outer periphery of the sensor body 52. The other end of the wiring 53b is also connected to a switch or the like mounted on the component mounting portion 521 in the same manner as the wiring 53a. The wirings 53a and 53b may be formed on either the front side or the back side wiring layer of the flexible substrate 51.

[0058] As shown in FIG. 4, the sensor body 52 has a component mounting portion 521 which is a control unit, and a battery mounting portion 522.

[0059] The component mounting part 521 has various components mounted on the flexible substrate 51, such as a CPU and an integrated circuit that process biological signals acquired from a living body to generate biological signal data, a switch that activates the biological sensor 1, a flash memory that stores biological signals, a light-emitting element, etc. Note that a circuit example by the various components is omitted. The component mounting part 521 operates with the power supplied from the battery 54 mounted on the battery mounting part 522.

[0060] The component mounting part 521 transmits to an external device such as an operation confirmation device that confirms the initial operation and a reading device that reads biological information from the biological sensor 1, either wired or wirelessly.

[0061] The battery mounting part 522 supplies power to an integrated circuit or the like mounted on the component mounting part 521. As shown in FIG. 5, the battery 54 is mounted on the battery mounting part 522.

[0062] An explanatory diagram showing the layout of the sensor part 50 in FIG. 4 is shown in FIG. 6. As shown in FIG. 6, the battery mounting part 522 is disposed between the wiring 53a and the component mounting part 521, and has pad parts 522a and 522b and a constricted part 522c.

[0063] As shown in FIG. 6, the pad part 522a is provided between the wiring 53a and the component mounting part 521, is located on the positive terminal side of the battery 54, and has a positive electrode pattern 55 to which the positive terminal is connected.

[0064] As shown in FIG. 6, the pad part 522b is provided at a predetermined interval from the pad part 522a in a direction orthogonal to the longitudinal direction with respect to the pad part 522a (the upper direction in FIG. 3). The pad part 522b is located on the negative terminal (second terminal) side of the battery 54 and has a negative electrode pattern 56 to which the negative terminal is connected.

[0065] As shown in FIG. 6, the constricted part 522c is disposed between the pad parts 522a and 522b and connects the pad parts 522a and 522b to each other.

[0066] As shown in FIG. 5, the battery 54 is disposed between the positive electrode pattern 55 and the negative electrode pattern 56. The battery 54 has a positive electrode terminal and a negative electrode terminal, and a known battery can be used. As the battery 54, for example, a coin-type battery such as CR2025 can be used.

[0067] The positive electrode pattern 55 is located on the positive electrode terminal side of the battery 54 and is connected to the positive electrode terminal. As shown in FIG. 6, the positive electrode pattern 55 has a rectangular shape with chamfered corners.

[0068] The negative electrode pattern 56 is located on the negative electrode terminal side of the battery 54 and is connected to the negative electrode terminal. As shown in FIG. 6, the negative electrode pattern 56 has a shape that substantially corresponds to the size of the circular shape of the negative electrode terminal of the battery 54. The diameter of the negative electrode pattern 56 is, for example, equal to the diameter of the battery 54 and has a size that is substantially equal to the length of the diagonal of the positive electrode pattern 55.

[0069] The conductive adhesive tape 57 is an adhesive having conductivity and is disposed between the battery 54 and the positive electrode pattern 55 and between the battery 54 and the negative electrode pattern 56, respectively. Note that the conductive adhesive tape is generally also referred to as a conductive adhesive sheet, a conductive adhesive film, or the like.

[0070] The conductive adhesive tape 57 has a bending load per unit bending deflection amount of 0.035 N / cm or less. The inventor of the present application has reduced the rigidity of the conductive adhesive tape 57 that joins the battery and the positive electrode pattern 55 or the negative electrode pattern 56, and if the bending load per unit bending deflection amount is a predetermined value or less, even when a load is applied to the conductive adhesive tape 57, the change in the size of the conductive path can be suppressed. The inventor of the present application has found that when the bending load per unit bending deflection amount of the conductive adhesive tape 57 is 0.035 N / cm or less, even when a load is applied to the conductive adhesive tape 57, the resistance fluctuation is suppressed and the conduction is stabilized.

[0071] Here, the bending load per unit bending deflection amount can be obtained by calculating the bending load per unit bending deflection amount using a three-point bending test in accordance with JIS K7171. Specifically, the conductive adhesive tape 57 is set to a predetermined size (for example, width 2 cm × length 15 cm), and both sides of the conductive adhesive tape 57 are sandwiched and reinforced with PET films (thickness: 38 μm) to produce a laminate in which the conductive adhesive tape 57 is sandwiched between PET films. A three-point bending test is performed using the laminate. Among the bending amount-load curves obtained with the bending amount (unit: cm) on the X-axis and the load (unit: N) on the Y-axis, up to a bending amount of 1 cm is regarded as the initial slope, and the slope of the laminate is calculated. The obtained slope of the laminate is obtained as the bending load per unit bending deflection amount of the conductive adhesive tape 57. Further, when a plurality (for example, nine) of laminates are produced, the bending load per unit bending deflection amount may be the average value of the bending loads per unit bending deflection amount of the plurality (for example, nine) of laminates. Note that the distance between the two fulcrums where the conductive adhesive tape 57 is installed and the lowering (compression) speed of the indenter can be appropriately selected according to the size of the laminate, etc. For example, when the size of the conductive adhesive tape 57 is width 2 cm × length 15 cm, the distance between the fulcrums is 5 cm and the compression speed is 1 cm / min.

[0072] The conductive adhesive tape 57 includes a first conductive adhesive tape 57A disposed between the positive electrode terminal of the battery 54 and the positive electrode pattern 55, and a second conductive adhesive tape 57B disposed between the negative electrode terminal of the battery 54 and the negative electrode pattern 56. In the following description, the first conductive adhesive tape 57A and the second conductive adhesive tape 57B may be simply referred to as the conductive adhesive tape 57 collectively.

[0073] FIG. 7 is a partial cross-sectional view taken along line II-II of FIG. 4. As shown in FIG. 7, the first conductive adhesive tape 57A is provided between the positive electrode terminal of the battery 54 and the positive electrode pattern 55, and electrically connects the positive electrode terminal and the positive electrode pattern 55. The second conductive adhesive tape 57B is provided between the negative electrode terminal of the battery 54 and the negative electrode pattern 56, and electrically connects the second terminal and the negative electrode pattern 56.

[0074] The first conductive adhesive tape 57A is composed of an adhesive layer 71A, and the second conductive adhesive tape 57B is composed of an adhesive layer 71B. Both the first conductive adhesive tape 57A and the second conductive adhesive tape 57B are so-called double-sided adhesive type conductive adhesive tapes in which both sides of the adhesive layers 71A and 71B are adhesive surfaces. Note that the surfaces of the adhesive layers 71A and 71B may be referred to as adhesive surfaces. Also, the first conductive adhesive tape 57A and the second conductive adhesive tape 57B are so-called substrate-less conductive double-sided adhesive tapes that do not include a conductive substrate such as a metal foil.

[0075] 〔Adhesive layer〕 The adhesive layers 71A and 71B provide the adhesive surfaces of the conductive adhesive tape and have conductivity (electrical conductivity). When the adhesive surfaces of the adhesive layers 71A and 71B are attached to an adherend such as a conductor, electrical conduction between the adherend and the adhesive layers 71A and 71B is ensured.

[0076] As shown in FIG. 7, the adhesive layers 71A and 71B have an adhesive resin 711 and conductive fine particles (conductive filler) 712. Note that the adhesive layers 71A and 71B may contain other components (additives) as long as the purpose of the conductive adhesive tape 57 is not impaired.

[0077] The thickness of the adhesive layers 71A and 71B is preferably 20 μm to 80 μm, more preferably 30 μm to 70 μm, and even more preferably 35 μm to 60 μm. If the thickness of the adhesive layers 71A and 71B is within the above preferred range, the conductive adhesive tape 57 can be made thinner, so that the flexibility can be enhanced.

[0078] (Adhesive resin) The adhesive resin 711 has a function of ensuring the adhesive force of the adhesive layers 71A and 71B. The adhesive resin 711 is formed using a pressure-sensitive polymer. Examples of the pressure-sensitive polymer include acrylic polymers, silicone polymers, urethane polymers, rubber polymers, vinyl alkyl ether polymers, polyester polymers, polyamide polymers, fluorine polymers, epoxy polymers, and the like. Among these, acrylic polymers are preferably used from the viewpoints of ease of polymer design, ease of adjusting the adhesive force, and ensuring the dispersibility of conductive particles. Note that the pressure-sensitive polymer may be used alone or in combination of two or more. In the following description, the case where the pressure-sensitive polymer is made of an acrylic polymer or contains an acrylic polymer will be described.

[0079] The content (lower limit value) of the adhesive resin 711 is preferably 20% by mass or more, more preferably 25% by mass or more, and still more preferably 30% by mass or more with respect to the total mass (100% by mass) of the adhesive layers 71A and 71B. Also, the content (upper limit value) of the adhesive resin 711 is preferably 60% by mass or less, more preferably 55% by mass or less with respect to the total mass (100% by mass) of the adhesive layers 71A and 71B.

[0080] When the adhesive resin 711 is formed including an acrylic polymer, the content (lower limit value) of the acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more with respect to the total mass (100% by mass) of the adhesive resin 711. Also, the content (upper limit value) of the acrylic polymer is preferably 100% by mass or less, more preferably 90% by mass or less with respect to the total mass (100% by mass) of the resin component.

[0081] The acrylic polymer is not particularly limited. For example, it is preferably an acrylic polymer composed of a (meth)acrylic acid alkyl ester having a linear or branched alkyl group with 1 to 20 carbon atoms (hereinafter simply referred to as (meth)acrylic acid alkyl ester) and a polar group-containing monomer as monomer components. In this specification, "(meth)acrylic" means either one or both of "acrylic" and "methacrylic".

[0082] The weight average molecular weight (Mw) of the acrylic polymer is preferably 300,000 to 1,000,000, more preferably 400,000 to 800,000, in terms of being able to more effectively exhibit the effects of the pressure-sensitive adhesive resin 711. The weight average molecular weight (Mw) can be controlled by the types and amounts of polymerization initiators and chain transfer agents, the temperature and time during polymerization, as well as the monomer concentration, monomer dropping rate, etc. The weight average molecular weight can be measured, for example, by the gel permeation chromatography (GPC) method.

[0083] [Conductive particles] As shown in FIG. 7, the conductive fine particles 712 are contained in a dispersed state in the pressure-sensitive adhesive resin 711.

[0084] As the conductive fine particles 712, particles having conductivity such as metal powder are used. Examples of the material for forming the conductive particles include particles (powders) made of conductive materials such as metals such as nickel, iron, chromium, cobalt, aluminum, antimony, molybdenum, copper, silver, platinum, gold, alloys or oxides thereof, and carbon materials such as carbon black; coated particles in which the surfaces of particles such as polymer beads, glass, and ceramics are coated with a conductive material. The coated particles also include particles in which the surface of particles made of a conductive material is coated with another type of conductive material. Among these, preferably, they are metals and coated particles, and as the metal, it is preferable to use nickel and silver.

[0085] The shape of the conductive fine particles 712 is spherical, spike-shaped (like a chestnut), flake-shaped (thin plate-shaped), filamentous, etc., and is appropriately selected. When the conductive fine particles 712 are spherical, it becomes easier for the conductive fine particles 712 to be uniformly dispersed in the adhesive resin 711. Therefore, it becomes easier to ensure the adhesive force, and it becomes easier to form a conductive path by the conductive fine particles 712 in the adhesive layer 71. Therefore, the shape of the conductive fine particles 712 is preferably spherical.

[0086] The aspect ratio of the conductive fine particles 712 is preferably 1.0 to 1.5, more preferably 1.0 to 1.1. The aspect ratio of the conductive fine particles 712 can be measured, for example, with a scanning electron microscope (SEM).

[0087] The particle size d of the conductive fine particles 712 50 is preferably smaller than the thicknesses of the adhesive layers 71A and 71B. That is, it is preferably in the relationship of "the thicknesses of the adhesive layers 71A and 71B > d 50 ". d 50 is the 50% cumulative value (median diameter) in the particle size distribution. d 50 is measured, for example, by the laser diffraction / scattering method. When two or more types of conductive fine particles 712 are contained in the adhesive layers 71A and 71B, d 50 is calculated from the distribution in which all types of conductive fine particles 712 are mixed.

[0088] d 50 being in the above relationship enables the adhesive layers 71A and 71B to have higher conductivity and better adhesiveness. When d 50 is greater than or equal to the thickness of the adhesive layer 71, more than half of the conductive fine particles 712 will be larger than the thicknesses of the adhesive layers 71A and 71B, forming protrusions on the surfaces of the adhesive layers 71A and 71B. Therefore, there is a possibility that the contact area between the adhesive layers 71A and 71B and the adherend will decrease and the adhesiveness will decrease, and there is also a possibility that the appearance will be poor. 50 The specific range of d is preferably 2 μm to 20 μm, more preferably 3 μm to 15 μm, and even more preferably 4 μm to 10 μm.

[0089] The upper limit of the content of the conductive fine particles 712 is preferably 70% by mass or less, preferably 65% by mass or less, and more preferably 60% by mass or less with respect to the total mass (100% by mass) of the adhesive layers 71A and 71B. Also, the lower limit of the content of the conductive fine particles 712 is preferably 15% by mass or more, preferably 20% by mass or more, and more preferably 25% by mass or more. When the content of the conductive fine particles 712 is within the above preferred range, the conductivity of the adhesive layers 71A and 71B can be ensured without reducing the adhesive force of the adhesive layers 71A and 71B.

[0090] As shown in FIG. 8, the adhesive layers 71A and 71B may contain conductive fibers 713 as a conductive filler.

[0091] The conductive fibers 713 may be any that have conductivity, and known ones can be used. As the conductive fibers 713, metal fibers such as gold, silver, platinum, copper, nickel, tin, zinc, palladium, indium tin oxide, copper sulfide, etc., carbon fibers such as carbon nanotubes, fibers made of conductive polymers, fibers made of polymers in which fibrous or granular conductive fillers are dispersed, and conductive coated fibers in which the surface of a fiber substrate is coated with a conductive material can be used. As the fiber substrate, known fibers can be used regardless of whether they have conductivity. For example, synthetic fibers such as polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, vinyl chloride fibers, aramid fibers, polysulfone fibers, polyether fibers, polyurethane fibers, etc., natural fibers such as cotton, hemp, silk, etc., semi-synthetic fibers such as acetate, and regenerated fibers such as rayon and cupra can be used. These fibers may be used alone or in combination of two or more. Examples of the conductive material for coating the surface of the fiber substrate include metals and conductive polymers. As the metal, the same metals as those used for the metal fibers can be used. Among them, metals are preferable from the viewpoints of conductivity, durability, flexibility, etc. Examples of the method for coating the metal include vapor deposition, sputtering, electroplating, electroless plating, etc.

[0092] The fiber diameter of the conductive fiber 713 is preferably less than 1.1 μm, more preferably 300 nm to 1.0 μm, and even more preferably 400 nm to 700 nm. If the content of the conductive fiber 713 is within the above preferred range, the conductivity of the adhesive layer 71 can be ensured without reducing the adhesive force of the adhesive layers 71A and 71B.

[0093] The fiber length of the conductive fiber 713 is not particularly limited and can be appropriately selected according to the types, thicknesses, volumes, etc. of the adhesive layers 71A and 71B. The fiber diameter and fiber length of the conductive fiber 713 can be measured by a scanning electron microscope.

[0094] As shown in FIG. 9, the adhesive layers 71A and 71B may include a conductive substrate. A conductive double-sided adhesive tape having a conductive substrate in the adhesive layers 71A and 71B is called a so-called conductive double-sided adhesive tape with a substrate. That is, the conductive adhesive tape 57 may be configured by providing the adhesive layers 71 on both sides of the conductive substrate 714, respectively.

[0095] In addition, the adhesive layer 71 may include other layers such as an intermediate layer and an undercoat layer in addition to the conductive fiber and the conductive substrate as long as the purpose of the conductive adhesive tape 57 is not impaired.

[0096] When the battery 54 is attached to the biosensor 1, the first conductive adhesive tape 57A and the second conductive adhesive tape 57B are respectively attached to the entire positive electrode pattern 55 and negative electrode pattern 56. Then, the positive electrode terminal and the negative electrode terminal of the battery 54 are respectively attached to the positive electrode pattern 55 and the negative electrode pattern 56 via the first conductive adhesive tape 57A and the second conductive adhesive tape 57B, so that the battery 54 is attached to the battery mounting portion 522. Note that the sensor body 52 shown in FIG. 4 shows a state in which the battery 54 is attached to the battery mounting portion 522 in a state where the constricted portion 522c is bent and the battery 54 is sandwiched between the positive electrode pattern 55 and the negative electrode pattern 56.

[0097] As shown in FIG. 3, in order to protect the biological adhesive layer 10 and the electrode 40 on the attachment surface side (-Z axis direction), it is preferable to attach the release paper 60 to the biological sensor 1 until the biological sensor 1 is attached to the living body. During use, by peeling the release paper 60 from the biological adhesive layer 10 and the electrode 40, the adhesive force of the adhesive layer 12 for attachment of the biological adhesive layer 10 can be maintained.

[0098] FIG. 10 is an explanatory diagram showing a state in which the biological sensor 1 of FIG. 1 is attached to the chest of the living body P. For example, the biological sensor 1 is attached to the skin of the subject P with the longitudinal direction (Y-axis direction) aligned with the sternum of the subject P, one electrode 40 on the upper side and the other electrode 40 on the lower side. The biological sensor 1 obtains a biological signal such as an electrocardiogram signal from the subject P with the electrode 40 crimped to the skin of the subject P by attaching the biological sensor 1 to the skin of the subject P by the adhesive layer 12 for attachment in FIG. 3. The biological sensor 1 stores the acquired biological signal data in a non-volatile memory such as a flash memory mounted on the component mounting portion 521.

[0099] Thus, the biological sensor 1 includes a positive electrode pattern 55 and a negative electrode pattern 56, and a conductive adhesive tape 57 disposed between these electrode patterns and the battery 54, and the bending load per unit bending deflection amount of the conductive adhesive tape 57 is set to 0.035 N / cm or less. Thereby, when a strong load is applied to the surface of the conductive adhesive tape 57, the increase in resistance can be suppressed, so that stable conduction can be achieved. Therefore, even when crimping to the skin 2 of the subject or body movement occurs during use of the biological sensor 1, the biological sensor 1 can suppress an increase in the resistance of the conductive adhesive tape 57, and thus can suppress a decrease in the supply voltage from the battery 54 to the component mounting portion 521. Therefore, the biological sensor 1 can stably supply voltage from the battery 54 to the component mounting portion 521 by suppressing a decrease in the supply voltage from the battery 54 to the component mounting portion 521.

[0100] Therefore, even when the subject's skin is pressed or the subject moves during the use of the biosensor 1, the operation of the component mounting portion 521 can be prevented from stopping, so that biological information can be stably measured from the skin 2.

[0101] Further, the biosensor 1 may include a positive electrode pattern 55 and a negative electrode pattern 56 as electrode portions in the sensor portion 50, and may include a first conductive adhesive tape 57A and a second conductive adhesive tape 57B as the conductive adhesive tape 57. When the positive electrode terminal and the negative electrode terminal of the battery 54 are provided in opposite directions, the biosensor 1 may dispose the first conductive adhesive tape 57A between the positive electrode terminal of the battery 54 and the positive electrode pattern 55, and may dispose the second conductive adhesive tape 57B between the negative electrode terminal of the battery 54 and the negative electrode pattern 56. Thereby, the biosensor 1 can form a laminate in which the positive electrode pattern 55, the first conductive adhesive tape 57A, the battery 54, the second conductive adhesive tape 57B, and the negative electrode pattern 56 are laminated in this order between the pad portion 522a and the pad portion 522b of the sensor portion 50. Therefore, when the battery 54 is a battery in which the positive electrode terminal and the negative electrode terminal are arranged in opposite directions like a button-type battery or the like, the biosensor 1 can compactly accommodate the sensor portion 50 in the biosensor 1, and even when a load is applied to the inside of the housing due to pressing on the subject's skin or body movement during use, an increase in the resistance of the conductive adhesive tape 57 can be suppressed.

[0102] Furthermore, the biosensor 1 may include an adhesive layer 71 in which the conductive adhesive tape 57 contains an adhesive resin 711 and conductive fine particles 712. By configuring the conductive adhesive tape 57 with the adhesive layer 71, the rigidity of the conductive adhesive tape 57 mainly depends on the adhesive layer 71, so that it is easy to reduce the bending load per unit bending deflection amount of the conductive adhesive tape 57. Therefore, even when a load is applied to the inside of the housing due to pressing on the subject's skin or body movement during the use of the biosensor 1, the biosensor 1 can more easily suppress an increase in the resistance of the conductive adhesive tape 57.

[0103] In addition, the biosensor 1 can be configured such that the conductive adhesive tape 57 is composed of an adhesive resin 711 without a base material. As a result, since it is easier to enhance the flexibility of the adhesive resin 711, the conductive adhesive tape 57 can have reduced rigidity. Therefore, when a load is applied to the surface of the conductive adhesive tape 57, it is more likely to deform, so that an increase in the resistance of the conductive adhesive tape 57 can be more stably suppressed.

[0104] In addition, the biosensor 1 can be configured to include conductive fibers in the conductive adhesive tape 57. A plurality of conductive fibers can be dispersed while being easily brought into contact with each other within the adhesive resin 711. Therefore, even when a load is applied to the surface of the conductive adhesive tape 57 of the biosensor 1, the conductive adhesive tape 57 can easily maintain its conductivity and more stably suppress an increase in resistance.

[0105] At this time, it is preferable that the average fiber diameter of the conductive fibers included in the conductive adhesive tape 57 of the biosensor 1 is less than 1.1 μm. Thereby, the conductivity of the adhesive layer 71 can be ensured without reducing the adhesive force of the adhesive layer 71. Therefore, the conductive adhesive tape 57 can more stably suppress resistance fluctuations while maintaining the adhesive force and conductivity.

[0106] In addition, the biosensor 1 can be configured such that the thickness of the adhesive layer 71 included in the conductive adhesive tape 57 is 20 μm to 80 μm. As a result, the conductive adhesive tape 57 can be made thinner, so that the conductive adhesive tape 57 has reduced rigidity and can be easily deformed. Also, the conductive adhesive tape 57 can be made thinner. Therefore, when a load is applied to the surface of the conductive adhesive tape 57, an increase in resistance can be more easily suppressed, and the conductive adhesive tape 57 can be formed thinner.

[0107] As described above, since the biosensor 1 can stably supply a voltage from the battery to the control unit as described above, it can be suitably used, for example, in a healthcare wearable device such as a biosensor.

[0108] In addition, in the present embodiment, the bending load per unit bending deflection amount of the first conductive adhesive tape 57A and the second conductive adhesive tape 57B is not set to 0.035 N / cm or less, and the bending load per unit bending deflection amount of the first conductive adhesive tape 57A or the second conductive adhesive tape 57B may be set to 0.035 N / cm or less.

[0109] In the present embodiment, the conductive adhesive tape 57 may be disposed only on one side between the positive electrode terminal of the battery 54 and the positive electrode pattern 55 and between the negative electrode terminal of the battery 54 and the negative electrode pattern 56, and a conductive adhesive or the like may be used on the other side.

Example

[0110] Hereinafter, the embodiments will be described in more detail by showing examples and comparative examples, but the embodiments are not limited to these examples and comparative examples.

[0111] <Example 1> [Preparation of Conductive Adhesive Tape] A conductive adhesive tape 1 (trade name "9707", manufactured by 3M Japan Co., Ltd.) was prepared. The conductive adhesive tape 1 is an adhesive tape containing conductive fine particles (material: Ag, average particle diameter: 5 μm, filling rate: 56 wt%) dispersed in an adhesive resin, and is a substrate-free conductive adhesive tape.

[0112] (Measurement of Thickness of Conductive Adhesive Tape) Using a dial gauge specified in JIS B 7503, the thickness of the adhesive layer was measured. The contact surface of the dial gauge was flat and the diameter was 5 mm. Using a test piece with a width of 150 mm, the thickness at 5 points at equal intervals in the width direction was measured with a dial gauge with a scale of 1 / 1000 mm, and the average value of the measurement results was taken as the thickness of the adhesive layer. Since the conductive adhesive tape 1 is composed of an adhesive layer, the thickness of the adhesive layer was taken as the thickness of the conductive adhesive tape 1.

[0113] (Measurement of Bending Load per Unit Bending Deflection Amount) The size of the conductive adhesive tape 1 was 2 cm in width × 15 cm in length. Both sides of the conductive adhesive tape 1 were sandwiched and reinforced with PET films (thickness: 38 μm), and nine test pieces in which the conductive adhesive tape 1 was laminated with the PET films sandwiched were prepared. Using the test pieces, a three-point bending test in accordance with JIS K7171 was carried out at 23°C using a small measuring device (EZ-Test, Shimadzu Corporation). An example of the three-point bending test is shown in Fig. 11. As shown in Fig. 11, the test piece 80 was placed on two fulcrums 81 so that the central portion of the test piece 80 was in the middle between the two fulcrums 81, and a pressure head 82 was placed on the central portion of the test piece 80. The distance L between the fulcrums 81 was 5 cm, and the lowering (compression) speed of the pressure head was 1 cm / min. The pressure head was lowered to bend the test piece 80. When the amount of deflection (unit: cm) was taken as the X-axis and the load (unit: N) was taken as the Y-axis, among the obtained deflection amount (X)-load (Y) curves, up to a deflection amount of 1 cm was regarded as the initial slope, and the slope of the test piece 80 was calculated. The obtained slope was taken as the bending load per unit bending deflection amount. The bending load per unit bending deflection amount was the average value of the bending loads per unit bending deflection amount of the nine test pieces 80.

[0114] (Calculation of resistance variation value) The size of the test piece of the conductive adhesive tape 1 was 1 cm in width × 1 cm in length. With a current of about 50 mA flowing through the test piece, an iron ball weighing 33 g was dropped from a position 30 cm directly above the conductive adhesive tape 1. The resistance variation was calculated from the voltage variation when the iron ball collided with the test piece, and the peak resistance value was measured. The resistance variation value was calculated from the difference between the peak resistance value and the resistance value before the ball drop. When the resistance variation value of the conductive adhesive tape was 1.60 Ω or less, it was evaluated that the voltage stability of the conductive adhesive tape was good (marked as A in Table 1), and when the resistance variation value of the conductive adhesive tape exceeded 1.60 Ω, it was evaluated that the voltage stability of the conductive adhesive tape was poor (marked as B in Table 1).

[0115] [Fabrication of biosensor] The sensor unit was fabricated by adhering both terminals of the battery and two electrode pads formed on the flexible substrate via a conductive adhesive tape 1. Also, an adhesive layer for attachment was formed on the attachment surface side of the base material, and a biological adhesive layer with an adhesive layer formed on the surface opposite to the attachment surface side of the base material was prepared. Furthermore, a foamed sheet provided with a housing adhesive layer on the upper surface of a foamed attachment layer formed by laminating a foamed base material and a base material adhesive layer was prepared. Then, after attaching a pair of electrodes to the attachment surface side of the biological adhesive layer, the sensor unit was installed on the upper surface of the biological adhesive layer. The biological sensor was fabricated by installing the foamed sheet and the housing on the upper surface of the biological adhesive layer so that the sensor unit was disposed within the space formed by the foamed sheet and the housing.

[0116] (Evaluation of Power Supply Voltage Fluctuation) Two seconds after starting to flow a current from the coin-type battery of the biological sensor, a load (pressure: 20 N / cm 2 ) was applied in the attachment direction to the housing located above the coin-type battery for about 6.5 seconds, and then the pressurization was stopped. The fluctuation of the power supply voltage during this period was measured. The measurement results of the power supply voltage are shown in FIG. 12. In FIG. 12, the power supply voltage of the battery is indicated by a thick solid line, and the voltage applied to the component mounting portion (control portion) such as the CPU where the sensor unit is installed is indicated by a thin solid line.

[0117] <Examples 2 to 6> In Example 1, the same procedure as in Example 1 was performed except that the conductive adhesive tape 1 was changed to the following conductive adhesive tapes 2 to 6. In Examples 2 to 6, the measurement results of the power supply voltage fluctuations of the biological sensors fabricated using the conductive adhesive tapes 2 to 6 are shown in FIGS. 13 to 17. · Conductive Adhesive Tape 2 (Trade Name "CN4490", manufactured by 3M Japan Ltd.) · Conductive Adhesive Tape 3 (Trade Name "9725", manufactured by 3M Japan Ltd.) · Conductive Adhesive Tape 4 (Trade Name "9720S", manufactured by 3M Japan Ltd.) · Conductive Adhesive Tape 5 (Trade Name "No. 7025", manufactured by Teraoka Seisakusho Co., Ltd.) · Conductive Adhesive Tape 6 (Trade Name "T4420W", manufactured by Dexerials Corporation)

[0118] <Comparative Examples 1 to 3> In Example 1, the procedure was the same as in Example 1, except that the conductive adhesive tape 1 was changed to the following conductive adhesive tapes 7 to 9. The results of measuring the fluctuations in the power supply voltage of the biosensors fabricated using the conductive adhesive tapes 7 to 9 in Comparative Examples 1 to 3 are shown in FIGS. 18 to 20. · Conductive adhesive tape 7 (trade name "No. 792", manufactured by Teraoka Seisakusho Co., Ltd.) · Conductive adhesive tape 8 (trade name "X7001", manufactured by 3M Japan Ltd.) · Conductive adhesive tape 9 (trade name "Al-25DC", manufactured by 3M Japan Ltd.)

[0119] Table 1 shows the types of the obtained conductive adhesive tapes, the measurement results of the resistance fluctuation values, and the evaluation results of the voltage stability in each Example and Comparative Example.

[0120]

Table 1

[0121] In Examples 1 to 6, as shown in Table 1, the resistance fluctuation value of the conductive adhesive tape was 0.23 Ω or less. As shown in FIGS. 12 to 17, the power supply voltage was in the range of 2.7 V to 2.9 V, the voltage applied to the control unit was about 2.1 V, and the voltage stability was good. On the other hand, in Comparative Examples 1 to 3, as shown in Table 1, the resistance fluctuation value of the conductive adhesive tape was about 1.7 Ω or more. As shown in FIGS. 18 to 20, the power supply voltage fluctuated within the range of 2.1 V to 2.8 V, the voltage applied to the control unit fluctuated within the range of 2.1 V to 2.5 V, and the voltage stability was poor.

[0122] Therefore, unlike the conductive adhesive tapes of Comparative Examples 1 to 3, the conductive adhesive tapes of Examples 1 to 6 can suppress the variation in resistance by setting the bending load per unit bending deflection amount to 0.02 N / cm or less. Accordingly, when the biological sensor according to the present embodiment uses a predetermined conductive adhesive tape for connecting a battery (electric cell) and a substrate, an increase in the resistance value can be suppressed. Thus, it can be said that the contact impedance between the biological sensor and a living body can be kept low, and an electric signal obtained from the living body can be detected stably with high sensitivity. Therefore, it can be said that the biological sensor can be effectively used for stably measuring an electrocardiogram continuously for a long time (for example, 24 hours) while being in close contact with the skin of a subject.

[0123] As described above, the embodiments have been described. However, the above embodiments are presented as examples, and the present invention is not limited by the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

[0124] This application claims priority based on Japanese Patent Application No. 2020-059656 filed with the Japan Patent Office on March 30, 2020, and incorporates the entire contents of Japanese Patent Application No. 2020-059656 into this application.

Explanation of Reference Numerals

[0125] 1 Biological sensor 2 Skin 10 Adhesive layer for living body 11 Base material 12 Adhesive layer for attachment 13 Adhesive layer for sensor 20 Foam sheet 21 Foam attachment layer 211 Foam base material 212 Adhesive layer for base material 22 Adhesive layer for housing 30 Housing 40 Electrode 50 Sensor unit 51 Flexible substrate (resin substrate) 52 Sensor body 521 Component mounting part (control part) 522 Battery mounting part 54 Battery 55 Positive electrode pattern (first electrode part) 56 Negative electrode pattern (second electrode part) 57 Conductive adhesive tape 57A First conductive adhesive tape 57B Second conductive adhesive tape 71A, 71B Adhesive layer 711 Adhesive resin 712 Conductive fine particles (conductive filler) 713 Conductive fiber

Claims

1. A biosensor that operates using electric power supplied from a battery, comprising: an electrode portion located on at least one terminal side of the battery; a conductive adhesive tape having conductivity provided between the one terminal and the electrode portion; and wherein the bending load per unit bending deflection amount of the conductive adhesive tape is 0.035 N / cm or less, the bending load per unit bending deflection amount is the slope of the deflection amount-load curve showing the relationship between the deflection amount and the load of a test piece obtained by laminating the conductive adhesive tape having a size of width 2 cm × length 15 cm with a PET film having a thickness of 38 μm sandwiched therebetween and performing a three-point bending test in accordance with JIS K7171 until the deflection amount reaches 1 cm, in the three-point bending test, the test piece is installed such that the central portion of the test piece is in the middle between the two fulcrums on the two fulcrums, the distance between the fulcrums is 5 cm in an environment of 23°C, and the indenter installed on the central portion of the test piece is lowered at a rate of 1 cm / min to bend the test piece. A biosensor.

2. The electrode portion includes: a first electrode portion located on the first terminal side of the battery; a second electrode portion located on the second terminal side of the battery; and wherein the conductive adhesive tape includes: a first conductive adhesive tape provided between the first terminal and the first electrode portion; a second conductive adhesive tape provided between the second terminal and the second electrode portion; The biosensor according to claim 1, comprising.

3. The biosensor according to claim 1 or 2, wherein the conductive adhesive tape includes an adhesive layer containing an adhesive resin and conductive fine particles dispersed in the adhesive resin.

4. The biosensor according to claim 3, wherein the adhesive resin does not contain a base material.

5. The biosensor according to claim 3 or 4, wherein the conductive adhesive tape includes conductive fibers in which the surface of a fiber base material is coated with a conductive material in the adhesive resin.

6. The biosensor according to claim 5, wherein the average fiber diameter of the conductive fibers is less than 1.1 μm.

7. The biosensor according to any one of claims 1 to 6, wherein the thickness of the conductive adhesive tape is 20 μm to 80 μm.

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