JP2020146237A - Sticking type biological sensor - Google Patents

Abstract

To provide a sticking type biological sensor having excellent shock resistance.SOLUTION: A sticking type biological sensor 100 includes: a pressure-sensitive adhesive layer 110 having a sticking surface to be stuck onto a subject; an electrode having elasticity; a base material layer 120 superposed on an opposite surface of the sticking surface of the pressure-sensitive adhesive layer; an electronic device 150 provided on the base material layer for processing a biological signal acquired through the electrode; a circuit part 130 provided on the base material layer for connecting the electrode and the electronic device; and a connection part for connecting the electrode and the circuit part along the outer end part in a plane view of the electrode. The connection part includes a divided part that is divided in a direction along the outer end part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stick-on biosensor.

Conventionally, there is a biosensor using a biocompatible polymer substrate including a plate-shaped first polymer layer, a plate-shaped second polymer layer, an electrode, and a data acquisition module (see, for example, Patent Document 1). ).

Japanese Unexamined Patent Publication No. 2012-010978

When the biosensor is used as a medical device, it may be required to have impact resistance according to, for example, standards related to the medical device. In particular, there is a risk of breakage due to shear stress or the like at joints or the like of members having significantly different elasticity.

Therefore, it is an object of the present invention to provide a stick-on biosensor having good impact resistance.

The stick-type biological sensor according to the embodiment of the present invention is superposed on a pressure-sensitive adhesive layer having a sticking surface to be stuck to a subject, an elastic electrode, and the opposite surface of the sticking surface of the pressure-sensitive adhesive layer. A base material layer provided, an electronic device provided on the base material layer and processing a biological signal acquired via the electrode, and an electronic device provided on the base material layer to connect the electrode and the electronic device. A circuit portion and a joint portion for joining the electrode and the circuit portion along the outer end portion in a plan view of the electrode are included, and the joint portion is a divided portion divided in a direction along the outer end portion. Has.

It is possible to provide a stick-on biosensor having good impact resistance.

It is an exploded view which shows the sticking type biological sensor 100 of embodiment. It is a figure which shows the cross section of the completed state corresponding to the cross section of AA of FIG. It is a figure which shows the circuit structure of the sticking type biosensor 100. It is a figure which shows the probe 140 and the fixing tape 145. It is a figure which shows the result of the impact resistance test of the fixing tape 145 and the fixing tape 45 for comparison. It is a figure which shows the result of the fracture test at the time of using the cover 170 which has different thickness, elastic modulus, etc. It is a figure which shows the relationship between the elastic modulus and the thickness of a cover 170. It is a figure which shows the fixing tape 145M1 to 145M3 of a modification. It is an exploded view which shows the sticking type biosensor 100M4 of a modification.

Hereinafter, embodiments to which the stick-on biosensor of the present invention is applied will be described.

<Embodiment>
FIG. 1 is an exploded view showing the stick-on biosensor 100 of the embodiment. FIG. 2 is a diagram showing a cross section in a completed state corresponding to the cross section taken along the line AA of FIG. The stick-on biosensor 100 includes a pressure-sensitive adhesive layer 110, a base material layer 120, a circuit unit 130, a substrate 135, a probe 140, a fixing tape 145, an electronic device 150, a battery 160, and a cover 170 as main components. ..

In the following, the XYZ coordinate system will be defined and described. In the following, for convenience of explanation, the negative side of the Z axis is referred to as the lower side or the lower side, and the positive side of the Z axis is referred to as the upper side or the upper side, but does not represent a universal hierarchical relationship.

In the present embodiment, as an example, a stick-on biosensor 100 that is brought into contact with a living body as a subject to measure biological information will be described. The living body means a human body and an organism other than the human body, and is attached to the skin, scalp, forehead, or the like. Hereinafter, each member constituting the stick-on biosensor 100 will be described.

In the following, an electrode that comes into contact with a living body as a subject will be referred to as a probe 140, and a fixing tape 145 will be used as an example of a joint portion.

The stick-on biosensor 100 is a sheet-like member having a substantially elliptical shape in a plan view. The stick-on biosensor 100 has a cover 170 covering the upper surface opposite to the lower surface (the surface on the −Z direction side) to be attached to the skin 10 of the living body. The lower surface of the stick-on biosensor 100 is a stick-on surface.

The circuit unit 130 and the substrate 135 are mounted on the upper surface of the substrate layer 120. Further, the probe 140 is provided so as to be embedded in the pressure-sensitive adhesive layer 110 so as to be exposed from the lower surface 112 of the pressure-sensitive adhesive layer 110. The lower surface 112 is a sticking surface of the sticking type biosensor 100.

The pressure-sensitive adhesive layer 110 is a flat-plate adhesive layer. The pressure-sensitive adhesive layer 110 has a longitudinal direction in the X-axis direction and a lateral direction in the Y-axis direction. The pressure-sensitive adhesive layer 110 is supported by the base material layer 120 and is attached to the lower surface 121 of the base material layer 120.

As shown in FIG. 2, the pressure-sensitive adhesive layer 110 has an upper surface 111 and a lower surface 112. The upper surface 111 and the lower surface 112 are flat surfaces. The pressure-sensitive adhesive layer 110 is a layer in which the stick-on biosensor 100 comes into contact with the living body. Since the lower surface 112 has pressure-sensitive adhesiveness, it can be attached to the skin 10 of a living body. The lower surface 112 is the lower surface of the stickable biological sensor 100, and can be attached to the surface of the living body such as the skin 10.

Further, the pressure-sensitive adhesive layer 110 has a through hole 113. The through hole 113 has the same size and position as the through hole 123 of the base material layer 120 in a plan view, and communicates with the through hole 123.

The material of the pressure-sensitive adhesive layer 110 is not particularly limited as long as it has pressure-sensitive adhesiveness, and examples thereof include materials having biocompatibility. Examples of the material of the pressure-sensitive adhesive layer 110 include an acrylic pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive. Acrylic pressure-sensitive adhesives are preferable.

The acrylic pressure-sensitive adhesive contains an acrylic polymer as a main component.

Acrylic polymer is a pressure sensitive adhesive component. The acrylic polymer contains a (meth) acrylic acid ester such as isononyl acrylate and methoxyethyl acrylate as a main component, and a monomer component copolymerizing with a (meth) acrylic acid ester such as acrylic acid as an optional component. A polymer obtained by polymerizing the above can be used. The content of the main component in the monomer component is 70% by mass to 99% by mass, and the content of the optional component in the monomer component is 1% by mass to 30% by mass. As the acrylic polymer, for example, the (meth) acrylic acid ester-based polymer described in JP-A-2003-342541 can be used.

The acrylic pressure-sensitive adhesive preferably further contains a carboxylic acid ester.

The carboxylic acid ester contained in the acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive force adjusting agent that reduces the pressure-sensitive adhesive force of the acrylic polymer and adjusts the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer 110. The carboxylic acid ester is a carboxylic acid ester compatible with an acrylic polymer.

Specifically, the carboxylic acid ester is, for example, the trifatty acid glyceryl.

The content ratio of the carboxylic acid ester is preferably 30 parts by mass to 100 parts by mass, and more preferably 50 parts by mass to 70 parts by mass or less with respect to 100 parts by mass of the acrylic polymer.

The acrylic pressure-sensitive adhesive may contain a cross-linking agent, if necessary. The cross-linking agent is a cross-linking component that cross-links the acrylic polymer. Examples of the cross-linking agent include polyisocyanate 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. .. These cross-linking agents may be used alone or in combination. The cross-linking agent is preferably a polyisocyanate compound (polyfunctional isocyanate compound).

The content of the cross-linking agent is preferably, for example, 0.001 part by mass to 10 parts by mass, and more preferably 0.01 part by mass to 1 part by mass with respect to 100 parts by mass of the acrylic polymer.

The pressure-sensitive adhesive layer 110 preferably has excellent biocompatibility. For example, when the pressure-sensitive adhesive layer 110 is subjected to a keratin peeling test, the keratin peeling area ratio is preferably 0% to 50%, more preferably 1% to 15%. When the keratin exfoliation area ratio is in the range of 0% to 50%, the load on the skin 10 (see FIG. 2) can be suppressed even if the pressure-sensitive adhesive layer 110 is attached to the skin 10 (see FIG. 2). The keratin exfoliation test is measured by the method described in JP-A-2004-83425.

The moisture permeability of the pressure-sensitive adhesive layer 110 is preferably 300 (g / m ² / day) or more, more preferably 600 (g / m ² / day) or more, and 1000 (g / m ² / day) or more. Day) or more is more preferable. If the moisture permeability of the pressure-sensitive adhesive layer 110 is 300 (g / m ² / day) or more, even if the pressure-sensitive adhesive layer 110 is attached to the skin 10 (see FIG. 2), the skin 10 (see FIG. 2) Load can be suppressed.

The pressure-sensitive adhesive layer 110 satisfies at least one of the requirements that the keratin peeling area ratio in the keratin peeling test is 50% or less and the moisture permeability is 300 (g / m ² / day) or more. The pressure-sensitive adhesive layer 110 is biocompatible. It is more preferable that the material of the pressure-sensitive adhesive layer 110 satisfies both of the above requirements. As a result, the pressure-sensitive adhesive layer 110 is more stable and has high biocompatibility.

The thickness between the upper surface 111 and the lower surface 112 of the pressure-sensitive adhesive layer 110 is preferably 10 μm to 300 μm. When the thickness of the pressure-sensitive adhesive layer 110 is 10 μm to 300 μm, the stick-on biosensor 100 can be made thinner, and in particular, the area other than the electronic device 150 in the stick-on biosensor 100 can be made thinner.

The base material layer 120 is a support layer that supports the pressure-sensitive adhesive layer 110, and the pressure-sensitive adhesive layer 110 is adhered to the lower surface 121 of the base material layer 120. The circuit unit 130 and the substrate 135 are arranged on the upper surface side of the base material layer 120.

The base material layer 120 is a flat plate-shaped (sheet-shaped) member made of an insulator. The shape of the base material layer 120 in a plan view is the same as the shape of the pressure-sensitive adhesive layer 110 in a plan view, and they are aligned and overlapped in a plan view.

The base material layer 120 has a lower surface 121 and an upper surface 122. The lower surface 121 and the upper surface 122 are flat surfaces. The lower surface 121 is in contact with the upper surface 111 of the pressure-sensitive adhesive layer 110 (pressure-sensitive adhesion). The base material layer 120 may be made of a flexible resin having appropriate elasticity, flexibility and toughness. For example, a polyurethane resin, a silicone resin, an acrylic resin, a polystyrene resin, or a vinyl chloride resin. , And a thermoplastic resin such as a polyester resin. The thickness of the base material layer 120 is preferably 1 μm to 300 μm, more preferably 5 μm to 100 μm, and even more preferably 10 μm to 50 μm.

The circuit unit 130 has a wiring 131, a frame 132, and a substrate 133. More specifically, the circuit unit 130 is connected to the electrode via the frame 132, and is connected to the electronic device 150 via the wiring 131. The stick-on biosensor 100 includes two such circuit units 130. The wiring 131 and the frame 132 are provided on the upper surface of the substrate 133 and are integrally formed. The wiring 131 connects the frame 132 with the electronic device 150 and the battery 160.

The wiring 131 and the frame 132 can be made of copper, nickel, gold, an alloy thereof, or the like. The thickness of the wiring 131 and the frame 132 is preferably 0.1 μm to 100 μm, more preferably 1 μm to 50 μm, and even more preferably 5 μm to 30 μm.

The two circuit units 130 are provided corresponding to the two through holes 113 and 123 of the pressure-sensitive adhesive layer 110 and the base material layer 120, respectively. The wiring 131 is connected to the electronic device 150 and the terminal 135A for the battery 160 via the wiring of the substrate 135. The frame 132 is a rectangular annular conductive member larger than the opening of the through hole 123 of the base material layer 120.

The substrate 133 has the same shape as the wiring 131 and the frame 132 in a plan view. The portion of the substrate 133 where the frame 132 is provided has a rectangular annular shape larger than the opening of the through hole 123 of the base material layer 120. The frame 132 and the rectangular annular portion of the substrate 133 on which the frame 132 is provided are provided so as to surround the through hole 123 on the upper surface of the base material layer 120. The substrate 133 may be made of an insulator, and for example, a polyimide substrate or a film can be used. Since the base material layer 120 has adhesiveness (tack), the substrate 133 is fixed to the upper surface of the base material layer 120.

The substrate 135 is an insulator-made substrate on which the electronic device 150 and the battery 160 are mounted, and is provided on the upper surface 122 of the base material layer 120. The substrate 135 is fixed by the tack (adhesiveness) of the substrate layer. As the substrate 135, a polyimide substrate or a film can be used as an example. Wiring and terminals 135A for the battery 160 are provided on the upper surface of the substrate 135. The wiring of the board 135 is connected to the electronic device 150 and the terminal 135A, and is also connected to the wiring 131 of the circuit unit 130.

The probe 140 is an electrode that comes into contact with a subject, and specifically, is an electrode that comes into contact with the skin 10 and detects a biological signal when the pressure-sensitive adhesive layer 110 is attached to the skin 10. The biological signal is, for example, an electric signal representing an electrocardiographic waveform, an electroencephalogram, a pulse, or the like.

The electrode used as the probe 140 is manufactured by using a conductive composition containing at least a conductive polymer and a binder resin as described later. Further, the electrode is manufactured by punching a sheet-shaped member obtained by using the conductive composition with a mold or the like, and is used as a probe.

The probe 140 has a rectangular shape in a plan view, is larger than the through holes 113 and 123 of the pressure-sensitive adhesive layer 110 and the base material layer 120, and has holes 140A arranged in a matrix. At the ends (parts of the four ends) of the probe 140 in the X and Y directions, the ladder-shaped sides of the probe 140 may protrude. The electrode used as the probe 140 may have a predetermined pattern shape. Examples of the predetermined electrode pattern shape include a mesh shape, a stripe shape, and a shape in which a plurality of electrodes are exposed from the sticking surface.

The fixing tape 145 is an example of the joint portion of the present embodiment. The fixing tape 145 is, for example, a copper tape and has four linear copper tapes. An adhesive is applied to the lower surface of the fixing tape 145. The fixing tape 145 is provided on the frame 132 so as to surround the four sides of the probe 140 outside the openings of the through holes 113 and 123 in a plan view, and fixes the probe 140 to the frame 132. The fixing tape 145 may be a metal tape other than copper.

The fixing tape 145 may be a non-conductive tape such as a resin tape composed of a non-conductive resin base material and an adhesive, in addition to a tape having a metal layer such as a copper tape. A conductive tape such as a metal tape is preferable because the probe 140 can be bonded (fixed) to the frame 132 of the circuit unit 130 and electrically connected.

The probe 140 is fixed to the frame 132 by a fixing tape 145 that covers the four end portions in a state where the four end portions are arranged on the frame 132. The fixing tape 145 is adhered to the frame 132 through a gap such as a hole 140A of the probe 140.

With the four ends of the probe 140 fixed to the frame 132 with the fixing tape 145 in this way, the pressure-sensitive adhesive layer 110A and the base material layer 120A are laminated on the fixing tape 145 and the probe 140 to form a pressure-sensitive adhesive layer. When the 110A and the base material layer 120A are pressed downward, the probe 140 is pushed along the inner walls of the through holes 113 and 123, and the pressure-sensitive adhesive layer 110A is pushed into the hole 140A of the probe 140.

The probe 140 is pushed down to a position where the central portion is substantially flush with the lower surface 112 of the pressure-sensitive adhesive layer 110 while the four end portions are fixed to the frame 132 by the fixing tape 145. Therefore, when the probe 140 is applied to the skin 10 of a living body (see FIG. 2), the pressure-sensitive adhesive layer 110A is adhered to the skin 10 and the probe 140 can be brought into close contact with the skin 10.

The thickness of the probe 140 is preferably thinner than the thickness of the pressure-sensitive adhesive layer 110. The thickness of the probe 140 is preferably 0.1 μm to 100 μm, more preferably 1 μm to 50 μm.

Further, the peripheral portion (rectangular annular portion) surrounding the central portion in the plan view of the pressure-sensitive adhesive layer 110A is located on the fixing tape 145. In FIG. 2, the upper surface of the pressure-sensitive adhesive layer 110A is substantially flat, but the central portion may be recessed below the peripheral portion. The base material layer 120A is superposed on a substantially flat upper surface of the pressure sensitive adhesive layer 110A.

Such the pressure-sensitive adhesive layer 110A and the base material layer 120A may be made of the same material as the pressure-sensitive adhesive layer 110 and the base material layer 120, respectively. Further, the pressure-sensitive adhesive layer 110A may be made of a material different from that of the pressure-sensitive adhesive layer 110. Further, the base material layer 120A may be made of a material different from that of the base material layer 120.

Although the thickness of each part is exaggerated in FIG. 2, in reality, the thickness of the pressure-sensitive adhesive layers 110 and 110A is 10 μm to 300 μm, and the thickness of the base material layers 120 and 120A is 1 μm to 300 μm. Is. The thickness of the wiring 131 is 0.1 μm to 100 μm, the thickness of the substrate 133 is about several hundred μm, and the thickness of the fixing tape 145 is 10 μm to 300 μm.

Further, as shown in FIG. 2, when the probe 140 and the frame 132 are in direct contact with each other to ensure an electrical connection, the fixing tape 145 may be a non-conductive resin tape or the like. Good.

Further, in FIG. 2, the fixing tape 145 covers the side surfaces of the frame 132 and the substrate 133 in addition to the probe 140, and reaches the upper surface of the base material layer 120. However, since the fixing tape 145 only needs to be able to bond the probe 140 and the frame 132, the fixing tape 145 does not have to reach the upper surface of the base material layer 120, does not have to cover the side surface of the substrate 133, and covers the side surface of the frame 132. It does not have to be covered.

Further, the substrate 133 and the two substrates 135 may be one integrated substrate. In this case, wiring 131, two frames 132, and terminal 135A are provided on the surface of one substrate, and the electronic device 150 and the battery 160 are mounted.

The electrode used as the probe 140 is preferably manufactured by thermosetting the following conductive composition and molding it. The conductive composition contains a conductive polymer, a binder resin, and at least one of a cross-linking agent and a plasticizer.

As the conductive polymer, for example, polythiophene, polyacetylene, polypyrrole, polyaniline, polyphenylene vinylene and the like can be used. These may be used alone or in combination of two or more. Among these, it is preferable to use a polythiophene compound. PEDOT / PSS doped with polystyrene sulfonic acid (poly4-styrene sulfonate; PSS) to poly 3,4-ethylenedioxythiophene (PEDOT) because it has lower contact impedance with the living body and has high conductivity. Is more preferable to use.

The content of the conductive polymer is preferably 0.20 parts by mass to 20 parts by mass with respect to 100 parts by mass of the conductive composition. When the content is within the above range, excellent conductivity, toughness and flexibility can be imparted to the conductive composition. The content of the conductive polymer is more preferably 2.5 parts by mass to 15 parts by mass, and further preferably 3.0 parts by mass to 12 parts by mass with respect to the conductive composition.

As the binder resin, a water-soluble polymer, a water-insoluble polymer, or the like can be used. As the binder resin, it is preferable to use a water-soluble polymer from the viewpoint of compatibility with other components contained in the conductive composition. The water-soluble polymer contains a polymer (hydrophilic polymer) that is completely insoluble in water and has hydrophilicity.

As the water-soluble polymer, a hydroxyl group-containing polymer or the like can be used. As the hydroxyl group-containing polymer, saccharides such as agarose, polyvinyl alcohol (PVA), modified polyvinyl alcohol, or a copolymer of acrylate and sodium acrylate can be used. These may be used alone or in combination of two or more. Among these, polyvinyl alcohol or modified polyvinyl alcohol is preferable, and modified polyvinyl alcohol is more preferable.

Examples of the modified polyvinyl alcohol include acetacetyl group-containing polyvinyl alcohol and diacetone acrylamide modified polyvinyl alcohol. As the diacetone acrylamide-modified polyvinyl alcohol, for example, a diacetone acrylamide-modified polyvinyl alcohol-based resin (DA-modified PVA-based resin) described in JP-A-2016-166436 can be used.

The content of the binder resin is preferably 5 parts by mass to 140 parts by mass with respect to 100 parts by mass of the conductive composition. When the content is within the above range, excellent conductivity, toughness and flexibility can be imparted to the conductive composition. The content of the binder resin is more preferably 10 parts by mass to 100 parts by mass, and further preferably 20 parts by mass to 70 parts by mass with respect to the conductive composition.

The cross-linking agent and the plasticizer have a function of imparting toughness and flexibility to the conductive composition. By imparting flexibility to the molded product of the conductive composition, an electrode having elasticity was obtained. As a result, the probe 140 having elasticity can be produced.

The toughness is a property that achieves both excellent strength and elongation. The toughness does not include the property that one of the strength and the elongation is remarkably excellent, but the other is remarkably low, and includes the property of having an excellent balance of both strength and elongation.

Flexibility is a property that can suppress the occurrence of damage such as breakage in the bent portion after bending the molded body (electrode sheet) of the conductive composition.

The cross-linking agent cross-links the binder resin. By including the cross-linking agent in the binder resin, the toughness of the conductive composition can be improved. The cross-linking agent preferably has reactivity with a hydroxyl group. If the cross-linking agent has reactivity with a hydroxyl group, the cross-linking agent can react with the hydroxyl group of the hydroxyl group-containing polymer when the binder resin is a hydroxyl group-containing polymer.

Examples of the cross-linking agent include zirconium compounds such as zirconium salts; titanium compounds such as titanium salts; borides such as boric acid; isocyanate compounds such as blocked isocyanate; aldehyde compounds such as dialdehyde such as glyoxal; alkoxyl group-containing compounds and methylol groups. Examples include contained compounds. These may be used alone or in combination of two or more. Of these, a zirconium compound, an isocyanate compound, or an aldehyde compound is preferable from the viewpoint of reactivity and safety.

The content of the cross-linking agent is preferably 0.2 parts by mass to 80 parts by mass with respect to 100 parts by mass of the conductive composition. When the content is within the above range, excellent toughness and flexibility can be imparted to the conductive composition. The content of the cross-linking agent is more preferably 1 part by mass to 40 parts by mass, and more preferably 3.0 parts by mass to 20 parts by mass.

The plasticizer improves the tensile elongation and flexibility of the conductive composition. Examples of the plasticizer include glycerin, ethylene glycol, propylene glycol, sorbitol, and polyol compounds such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), NN'-dimethylacetamide (DMAc), and dimethyl sulfoxide. Examples thereof include aprotic compounds such as (DMSO). These may be used alone or in combination of two or more. Among these, glycerin is preferable from the viewpoint of compatibility with other components.

The content of the plasticizer is preferably 0.2 parts by mass to 150 parts by mass with respect to 100 parts by mass of the conductive composition. When the content is within the above range, excellent toughness and flexibility can be imparted to the conductive composition. The content of the plasticizer is more preferably 1.0 part by mass to 90 parts by mass, and further preferably 10 parts by mass to 70 parts by mass with respect to 100 parts by mass of the conductive polymer.

At least one of the cross-linking agent and the plasticizer may be contained in the conductive composition. By including at least one of the cross-linking agent and the plasticizer in the conductive composition, the molded product of the conductive composition can improve toughness and flexibility.

When the conductive composition contains a cross-linking agent but no plasticizer, the molded product of the conductive composition can further improve toughness, that is, both tensile strength and tensile elongation, and is flexible. It is possible to improve the sex.

When the conductive composition contains a plasticizer but does not contain a cross-linking agent, the tensile elongation of the molded product of the conductive composition can be improved, so that the molded product of the conductive composition is tough as a whole. Can be improved. In addition, the flexibility of the molded product of the conductive composition can be improved.

It is preferable that both the cross-linking agent and the plasticizer are contained in the conductive composition. By including both the cross-linking agent and the plasticizer in the conductive composition, the molded product of the conductive composition is imparted with even better toughness.

In addition to the above components, the conductive composition may contain a surfactant, a softener, a stabilizer, a leveling agent, an antioxidant, an antioxidant, a leavening agent, a thickener, a colorant, or, if necessary. Various known additives such as a filler can be appropriately contained in an arbitrary ratio. Examples of the surfactant include silicone-based surfactants.

The conductive composition is prepared by mixing the above-mentioned components in the above-mentioned ratios.

The conductive composition can appropriately contain a solvent in an arbitrary ratio, if necessary. As a result, an aqueous solution of the conductive composition (an aqueous solution of the conductive composition) is prepared.

As the solvent, an organic solvent or an aqueous solvent can be used. Examples of the organic solvent include ketones such as acetone and methyl ethyl ketone (MEK); esters such as ethyl acetate; ethers such as propylene glycol monomethyl ether; and amides such as N, N-dimethylformamide. Examples of the aqueous solvent include water; methanol, ethanol, propanol, alcohol for isopropanol, and the like. Among these, it is preferable to use an aqueous solvent.

Any one or more of the conductive polymer, the binder resin, and the cross-linking agent may be used as an aqueous solution dissolved in a solvent. In this case, the above-mentioned aqueous solvent is preferable as the solvent.

The electronic device 150 is installed on the upper surface 122 of the base material layer 120 and is electrically connected to the wiring 131. The electronic device 150 processes a biological signal acquired via an electrode used as a probe 140. The electronic device 150 has a rectangular shape in a cross-sectional view. Terminals are provided on the lower surface (-Z direction) of the electronic device 150. Examples of the material for the terminals of the electronic device 150 include solder, conductive paste, and the like.

As shown in FIG. 1, the electronic device 150 includes an ASIC (application specific integrated circuit) 150A, an MPU (Micro Processing Unit) 150B, a memory 150C, and a wireless communication unit 150D as an example, and includes a circuit unit. It is connected to the probe 140 and the battery 160 via 130.

The ASIC 150A includes an A / D (Analog to digital) converter. The electronic device 150 is driven by the electric power supplied from the battery 160 and acquires the biological signal measured by the probe 140. The electronic device 150 performs processing such as filtering and digital conversion on the biological signal, and the MPU 150B obtains the added average value of the biological signal acquired a plurality of times and stores the biological signal in the memory 150C. As an example, the electronic device 150 can continuously acquire biological signals for 24 hours or more. Since the electronic device 150 may measure a biological signal for a long time, it is devised to reduce power consumption.

The wireless communication unit 150D is a transceiver used when the test device of the evaluation test reads out the biological signal stored in the memory 150C in the evaluation test by wireless communication, and communicates at 2.4 GHz as an example. The evaluation test is, for example, a JIS 60601-2-47 standard test. The evaluation test is a test for confirming the operation performed after the completion of the biological sensor that detects a biological signal as a medical device. The evaluation test requires that the attenuation rate of the biological signal extracted from the biological sensor is less than 5% with respect to the biological signal input to the biological sensor. This evaluation test is performed on all finished products.

As shown in FIG. 2, the battery 160 is provided on the upper surface 122 of the base material layer 120. As the battery 160, a lead storage battery, a lithium ion secondary battery, or the like can be used. The battery 160 may be a button battery type. The battery 160 is an example of a battery. The battery 160 has terminals provided on its lower surface. The two terminals of the battery 160 are connected to the probe 140 and the electronic device 150 via the circuit unit 130. The capacity of the battery 160 is set so that the electronic device 150 can measure the biological signal for 24 hours or more, for example.

The cover 170 covers the base material layer 120, the circuit unit 130, the substrate 135, the probe 140, the fixing tape 145, the electronic device 150, and the battery 160. The cover 170 has a base 170A and a protrusion 170B protruding from the center of the base 170A in the + Z direction. The base portion 170A is a portion located around the cover 170 in a plan view, and is a portion lower than the protruding portion 170B. A recess 170C is provided on the lower side of the protrusion 170B. In the cover 170, the lower surface of the base 170A is adhered to the upper surface 122 of the base material layer 120. The substrate 135, the electronic device 150, and the battery 160 are housed in the recess 170C. The cover 170 is adhered to the upper surface 122 of the base material layer 120 with the electronic device 150, the battery 160, and the like housed in the recess 170C.

The cover 170 not only serves as a cover for protecting the circuit unit 130, the electronic device 150, and the battery 160 on the base material layer 120, but also provides internal components from the impact applied to the stickable biosensor 100 from the upper surface side. It has a role as a protective shock absorbing layer. As the cover 170, for example, silicone rubber, soft resin, urethane or the like can be used.

FIG. 3 is a diagram showing a circuit configuration of the stick-on biosensor 100. Each probe 140 is connected to the electronic device 150 and the battery 160 via the wiring 131 and the wiring 135B of the substrate 135. The two probes 140 are connected in parallel to the electronic device 150 and the battery 160.

Next, the details of the fixing tape 145 will be described. FIG. 4 is a diagram showing a probe 140 and a fixing tape 145. FIG. 4A shows the probe 140 and the fixing tape 145, and FIG. 4B shows the probe 140 and the fixing tape 45 for comparison. The fixing tape 45 for comparison is different from the fixing tape 145, which is divided into four parts, in that it is a rectangular annular copper tape in a plan view.

The stick-on biosensor 100 realizes high impact resistance by devising the structure of the fixing tape 145. Impact resistance is a property that retains its appearance and function without being damaged when an impact is applied from the outside, and impact is a large force that is momentarily applied.

The fixing tape 145 is a copper tape and has very low elasticity. On the other hand, the probe 140 has very high elasticity as described above. The fixing tape 145 is in direct contact with the probe 140 and fixes the probe 140 to the frame 132.

When a large impact is applied from above the stick-on biosensor 100, a force is applied to the probe 140 and the fixing tape 145 in the shearing direction (XY plane plane direction). This is because the probe 140 and the fixing tape 145 are crushed.

When such a force in the shearing direction is applied, the probe 140 having a very large elasticity is greatly deformed in the shearing direction, but the fixing tape 145 having a very small elasticity is hardly deformed in the shearing direction.

Here, if the rectangular annular fixing tape 45 shown in FIG. 4B is used instead of the fixing tape 145 divided for each of the four sides, the fixing tape 45 can be used when an impact from above is applied. Since there is almost no displacement, damage such as disconnection of the probe 140 and / or the fixing tape 45 may occur at the boundary between the probe 140 and the fixing tape 45.

On the other hand, the fixing tape 145 can be displaced in the shearing direction independently and independently without the four fixing tapes 145 pulling each other when a large impact is applied from above and a force in the shearing direction is applied. At the same time, it can be deformed in the shearing direction.

Therefore, at the boundary between the probe 140 and the fixing tape 145, damage such as disconnection of the probe 140 and the fixing tape 145 can be suppressed. As a result, the high impact resistance of the stick-on biosensor 100 can be realized.

Next, the results of the impact resistance test of the fixing tape 145 and the fixing tape 45 for comparison will be described with reference to FIG. FIG. 5 is a diagram showing the results of impact resistance tests of the fixing tape 145 and the fixing tape 45 for comparison.

Here, as the impact resistance test, the result of the impact resistance test specified on JIS T0601-1 on page 15 will be described. In this impact resistance test, a 500 g metal ball is dropped only once from a height of 130 cm with respect to a stick-on biosensor 100 in which a pressure-sensitive paper is placed on the floor and the lower surface 112 is placed on the pressure-sensitive paper with the bottom surface 112 facing the pressure-sensitive paper. , I checked if I passed.

The pressure that can be measured with the pressure sensitive paper is from 50 MPa to 130 MPa, and within this range, the circuit unit 130, the probe 140, the electronic device 150, and the battery 160 are not damaged, and the biological signal can be acquired. .. The pressure-sensitive paper does not discolor when a pressure of less than 50 MPa is applied, changes to a color distinguishable from a color sample when a pressure of 50 MPa or more and 130 MPa or less is applied, and a color sample when a pressure greater than 130 MPa is applied. The color changes to a color that is not found in the color (darker than the color sample). Therefore, if the pressure sensitive paper is used, it is possible to determine whether the applied pressure is less than 50 MPa, 50 MPa or more and 130 MPa or less, or 130 MPa or more.

Here, the results of the impact resistance test are shown in two stages of ○ (no damage, passing the impact resistance test) and × (damaged, failing the impact resistance test). No damage means that the appearance is not damaged or cracked after the metal ball is dropped. The term “damaged” means that the appearance of the metal ball is damaged or cracked after being dropped.

The rigidity of the fixing tape 145 and the fixing tape 45 for comparison was calculated using the following equations (1) and (2). Here, a is the width (mm), b is the thickness (mm), E is the elastic modulus (Mpa), I is the moment of inertia of area (m ⁴ ), and k _B is the rigidity (N · mm ² ). The width a of the fixing tape 145 is the width in the lateral direction, and the width a of the fixing tape 45 for comparison is the width of the rectangular annular copper tape. The elastic modulus E is the value of the cover 170. The width a was set to 10 mm and the thickness b was set to 0.060 mm.
l = ab3 / 12 (1)
k _B = EL / a = Eb3 / 12 (2)

The impact resistance test was performed by setting the thickness of the cover 170 to 0 mm, 0.3 mm, 0.5 mm, and 1 mm. When the thickness of the cover 170 is 0 mm, it means that the cover 170 is not attached.

The comparative fixing tape 45 failed the covers 170 of all thicknesses. On the other hand, the fixing tape 145 passed when the thickness of the cover 170 was 0 mm, 0.3 mm, and 0.5 mm, and failed when the thickness was 1 mm. The reason why the cover 170 was rejected in the case of 1 mm was that because the cover 170 was thick, the amount of displacement of the cover 170 in the shearing direction was large due to the impact from above, and the stress applied to the boundary between the probe 140 and the fixing tape 145 was large. it is conceivable that.

FIG. 6 is a diagram showing the thickness, material (type of resin), elastic modulus (MPa), breaking elongation and rigidity of the resin, pressure measured with pressure-sensitive paper, presence / absence of breakage, and wearability of the cover 170. As shown in FIG. 4A, the fixing tape 145 was divided into four parts, and the damage and the wearing feeling when various covers 170 were used were evaluated.

The cover 170 was set to the value shown in FIG. 6 within the range of 0.008 mm to 3.0 mm in thickness, and urethane rubber, silicone rubber (hardness 15 or 30), and natural rubber (hardness 90) were used as the material. .. In these cases, the elastic modulus is the value shown in FIG. 6 in the range of 0.025 MPa to 8.00 MPa, the elongation at break of the resin is the value shown in FIG. 6 in the range of 1600 to 570, and the rigidity is The value shown in FIG. 6 was obtained in the range of 1.1 × ^10-9 to 18.0, and the pressure measured with the pressure sensitive paper was the value shown in FIG. 6 in the range of 45 MPa to 110.

The results of the impact resistance test are shown in two stages: ○ (no damage, passed the impact resistance test) and × (damaged, failed the impact resistance test). In addition, although the wearing feeling is a subjective judgment, a very good one is indicated by ⊚, a good one is indicated by ○, and a not bad one is indicated by Δ.

The ones that did not break were urethane rubber with a thickness of 0.008 mm, silicone rubber with a thickness of 0.3 mm (hardness 15), silicone rubber with a thickness of 0.3 mm (hardness 30), and silicone with a thickness of 0.5 mm. It was rubber (hardness 30), natural rubber having a thickness of 0.3 mm (hardness 90), natural rubber having a thickness of 0.5 mm (hardness 90), and natural rubber having a thickness of 1.0 mm (hardness 90).

Of these, urethane rubber with a thickness of 0.008 mm and silicone rubber with a thickness of 0.3 mm (hardness 15) had a very good fit, and those with a thickness of 0.3 mm were good. Silicone rubber (hardness 30) and silicone rubber (hardness 30) having a thickness of 0.5 mm, and the natural rubber had a feeling of wearing Δ.

FIG. 7 is a diagram showing the relationship between the elastic modulus and the thickness of the cover 170. The result of the impact resistance test is indicated by a round marker, and the result of the impact resistance test is indicated by a square marker.

Assuming that the elastic modulus of the cover 170 is X (MPa) and the thickness is Y (mm), those that pass the impact resistance test (○) are thicker than those that fail (×). It was found that Y (mm) and elastic modulus X (MPa) satisfy the relationship expressed by the following equation (3).
Y ≤ 0.19 ln (X) +0.60 (3)
Further, since the thickness variation of the cover 170 was ± 20%, it is considered that the cover 170 passed the impact resistance test up to the thickness of + 20%. Therefore, the condition of the equation (3) was relaxed by 20%, and the following equation ( 4) is obtained.
Y ≤ 0.23 ln (X) + 0.72 (4)
Therefore, if the thickness Y (mm) of the cover 170 and the elastic modulus X (MPa) satisfy the relationship of the formula (3) or the formula (4), the stick-on biosensor 100 that passes the impact resistance test can be obtained.

As described above, the stick-on biosensor 100 of the embodiment has a configuration in which the fixing tape 145 is divided around the probe 140 in order to suppress damage to the boundary between the probe 140 and the fixing tape 145 when an impact is applied. did. Therefore, the stress applied to the boundary between the probe 140 and the fixing tape 145 can be reduced, and the boundary between the probe 140 and the fixing tape 145 can be suppressed from being damaged.

Therefore, it is possible to provide a stick-on biosensor 100 having good impact resistance.

In the above, the configuration in which the fixing tape 145 is divided into four around the probe 140 has been described. However, the fixing tape 145 is not limited to such a configuration, and may have a configuration as shown in FIG. FIG. 8 is a diagram showing fixing tapes 145M1 to 145M3 of a modified example.

Like the fixing tape 145M1 shown in FIG. 8A, the probe 140 may be divided at only one place. The fixing tape 145M1 is divided by the dividing portion 145MA1.

Further, as in the fixing tape 145M2 shown in FIG. 8B, a U-shaped configuration may be provided on three of the four sides around the probe 140. The fixing tape 145M2 is divided by the dividing portion 145MA2.

Further, when the probe 140M3 is arranged in a circular region as shown in FIG. 8C, the probe 140M3 is provided in an arc shape around the probe 140 and is divided only at one place like the fixing tape 145M3. It may be. The fixing tape 145M3 is divided by the dividing portion 145MA3.

As in the fixing tapes 145M1 to 145M3 shown in FIGS. 8A to 8C, the configuration may be such that the divided portions 145MA1 to 145MA3 are provided.

Further, although the form in which the electronic device 150 has the wireless communication unit 150D has been described above, the configuration as shown in FIG. 9 may be used. FIG. 9 is an exploded view showing a stick-on biosensor 100M4 of a modified example.

The stick-on biosensor 100M4 includes an electronic device 150M4 and a cover 170M4 instead of the electronic device 150 and the cover 170 shown in FIG.

The electronic device 150M4 includes an ASIC 150A, an MPU 150B, a memory 150C, and a connector 150MD4. The electronic device 150M4 has a connector 150MD4 instead of the wireless communication unit 150D of the electronic device 150 shown in FIG.

Further, the cover 170M4 has a through hole 170MD4 provided directly above the connector 150MD4. The through hole 170MD4 is provided in the protruding portion 170MB, and the connector of the test device for the evaluation test is inserted and connected to the connector 150MD4.

In the stick-on biosensor 100M4, in the evaluation test, the biological signal stored in the memory 150C is read out by the test apparatus via the connector 150MD4. The through hole 170MD4 of the cover 170M4 may be filled with the same material as the cover 170M4 after the evaluation test is completed.

Although the stick-on biosensor of the exemplary embodiment of the present invention has been described above, the present invention is not limited to the specifically disclosed embodiment and deviates from the scope of claims. It is possible to make various modifications and changes.

100 Stick-on biosensor 110 Pressure-sensitive adhesive layer 120 Base material layer 130 Circuit part 140 Probe 150 Electronic device 160 Battery 170 Cover

Claims (8)

A pressure-sensitive adhesive layer with a sticking surface that can be stuck to the subject,
With elastic electrodes
A base material layer provided on the opposite surface of the pressure-sensitive adhesive layer to which it is attached,
An electronic device provided on the base material layer and processing a biological signal acquired via the electrode.
A circuit unit provided on the base material layer and connecting the electrode and the electronic device,
Including a joint portion for joining the electrode and the circuit portion along the outer end portion in a plan view of the electrode.
The joint portion is a stick-on biosensor having a divided portion divided in a direction along the outer end portion. Further including a cover covering the electrode, the electronic device, the circuit part, and the joint part.
The stick-on biosensor according to claim 1, wherein the elastic modulus of the cover is X (MPa), and the thickness of the cover is Y (mm), which is represented by the following formula (1).
Y ≤ 0.23 ln (X) + 0.72 (1) The stick-on biosensor according to claim 2, wherein the thickness of the cover is Y (mm), which is represented by the following formula (2).
Y ≤ 0.19 ln (X) +0.60 (2) The stick-on biosensor according to any one of claims 1 to 3, wherein the electrode is integrated with at least a part of the stick-on surface of the pressure-sensitive adhesive layer. The stick-on biosensor according to any one of claims 1 to 4, wherein the electrode has a predetermined pattern shape. The stick-on biosensor according to any one of claims 1 to 5, wherein the circuit portion is formed and further includes a substrate provided on the base material layer. The stick-on biosensor according to claim 6, wherein the electronic device is mounted on the substrate. The stickable biosensor according to any one of claims 1 to 7, wherein the electronic device is mounted and further includes a second substrate provided on the base material layer.

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