JP2020146236A - Sticking type biological sensor - Google Patents

Abstract

To provide a sticking type biological sensor that achieves both flexibility and 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 exposed from the sticking surface of the pressure-sensitive adhesive layer; a base material layer 120 provided 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 battery provided on the base material layer for supplying power to the electronic device; a flattened layer 170 provided on the base material layer, which has a flat surface flattened by covering the electronic device and the battery; a hard layer provided superposed on the flattened layer, which includes a first surface superposed on the flat surface and a second surface on the side opposite to the first surface; and a shock absorbing layer provided superposed on the hard layer. The hard layer is harder than the shock absorbing layer.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

Since the biosensor is attached to the skin of the living body, it is required to have flexibility in order to obtain good wearability, but when it is used as a medical device, for example, it has impact resistance according to the standards related to the medical device. May be required to have. In order to ensure impact resistance, the biosensor has a certain level of strength, which may impair flexibility.

As described above, the flexibility of the biosensor and the strength for impact resistance are contradictory, and it is difficult to achieve both.

Therefore, it is an object of the present invention to provide a stick-on biosensor that has both flexibility and impact resistance.

The stick-on biosensor according to the embodiment of the present invention includes a pressure-sensitive adhesive layer having a stick-on surface to be attached to a subject, an electrode exposed from the stick-on surface of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer. A base material layer provided on the opposite surface of the sticking surface, 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. A battery that supplies power to the electronic device, a flattening layer provided on the base material layer and having a flat surface flattened by covering the electronic device and the battery, and a flattening layer overlaid on the flattening layer. The hard layer includes a hard layer provided and having a first surface overlapped with the flat surface, a second surface opposite to the first surface, and a shock absorbing layer provided superposed on the hard layer. Is harder than the shock absorbing layer.

It is possible to provide a stick-on biosensor that has both flexibility and 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 graph which shows the rigidity of a flattening layer 170. It is a graph which shows the rigidity of the deformation suppression layer 180. It is a graph which shows the rigidity of a cover 190.

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 has, as main components, 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 flattening layer 170. The deformation suppressing layer 180 and the cover 190 are included.

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 is referred to as a probe 140, a fixing tape 145 is used as an example of a joint, a deformation suppressing layer 180 is used as an example of a hard layer, and a cover 190 is used as an example of a shock absorbing layer. It will be described using.

The stick-on biosensor 100 is a sheet-like member having a substantially elliptical shape in a plan view. In the stick-on type biosensor 100, the upper surface side opposite to the lower surface (the surface on the −Z direction side) to be attached to the skin 10 of the living body is covered with the cover 190. 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, the base material layer 120, the flattening layer 170, and the deformation suppressing layer 180 are laminated in this order from the bottom to the top, and the pressure-sensitive adhesive layer 110, the base material layer 120, and the flattening layer are laminated in this order. The laminate of 170 and the deformation suppressing layer 180 is covered with a cover 190 together with a substrate 135, a fixing tape 145, an electronic device 150, and a battery 160.

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 on the −Z direction side.

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 of a living body (see FIG. 2), the skin 10 (FIG. 2). The load of (see) 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 and the battery 160 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 a rectangular annular shape in a plan view. 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 rectangular annular fixing tape 145 that covers the four end portions, with the four end portions 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 molded product of 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. Two terminals 151 are provided on the lower surface (−Z direction) of the electronic device 150. Examples of the material of the terminal 151 include solder and a conductive paste. As shown in FIG. 2, the two terminals 151 of the electronic device 150 are electrically connected to the two terminals 131A, respectively.

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, a lithium primary 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 two terminals (not shown) provided on its lower surface. The two terminals of the battery 160 are each electrically connected to the two terminals 131B. 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.

Next, the flattening layer 170, the deformation suppressing layer 180, and the cover 190 will be described. The stick-on biosensor 100 has both flexibility and impact resistance. Flexibility is the property of being soft, supple, and easily deformable. 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.

As for a wearable device to be attached to the skin 10 of a living body such as the attachment type biosensor 100, the higher the flexibility, the higher the wearability to the skin 10. This is because it is easy to follow the uneven shape of the skin 10 when the living body is stationary and the deformation of the surface shape of the skin 10 when the living body is exercising. The more flexible the device, the less mechanical irritation to the skin during wearing and the less likely it is to cause skin irritation.

However, if the wearable device is too flexible, the impact resistance may decrease. This is because if the structure is soft and easily deformed in order to realize high flexibility, it cannot absorb the impact and is easily damaged.

In this way, flexibility and impact resistance are contradictory (contradictory) properties, but in the stick-on biosensor 100, the flattening layer 170, the deformation suppressing layer 180, and the cover 190 are configured as follows. So, it has both flexibility and impact resistance.

The flattening layer 170 is smaller than the base material layer 120 in a plan view, and is provided on the upper surface of the base material layer 120. The flattening layer 170 is a layer that absorbs and flattens irregularities of the electronic device 150, the battery 160, and the like that project upward from the upper surface of the base material layer 120. The thickness (height) of the flattening layer 170 is larger than the height of all the components such as the electronic device 150 and the battery 160 arranged on the upper surface of the base material layer 120, and the flat surface 171 (see FIG. 2) is formed. Have.

The reason for providing such a flattening layer 170 is to flatten the base on which the deformation suppressing layer 180 and the cover 190 are arranged and to prevent stress from concentrating on the electronic device 150, the battery 160, etc. when an impact is applied. Is. Therefore, the thickness of the flattening layer 170 is made larger than the height of all the components such as the electronic device 150 and the battery 160 arranged on the upper surface of the base material layer 120, and the upper surface of the flattening layer 170 is It has a flat surface 171.

As the flattening layer 170, a flexible resin layer, an acrylic resin layer, or the like can be used. As the flexible resin layer, for example, Gummy Cast (registered trademark) of Nisshin Resin Co., Ltd. can be used. The gummy cast may be produced by mixing the liquid A and the liquid B with the base material layer 120 having the circuit unit 130, the electronic device 150, the battery 160 and the like mounted on the upper surface in a mold. The flattening layer 170 adheres to the unevenness of the circuit unit 130, the electronic device 150, the battery 160, etc. on the upper surface of the base material layer 120 by performing a light (UV) curing treatment, a thermosetting treatment, or the like. As the flexible resin layer, for example, a two-component mixed silicone resin can be used in addition to the gummy cast.

The deformation suppressing layer 180 has a size equal to that of the flattening layer 170 in a plan view, and is arranged on the flat surface 171 of the flattening layer 170 in a state of being aligned so as not to be displaced in a plane. .. The deformation suppressing layer 180 is provided to suppress the deformation of the cover 190 when the cover 190 receives an impact. If the cover 190 is significantly deformed, the pressure-sensitive adhesive layer 110, the base material layer 120, the circuit unit 130, the probe 140, the electronic device 150, the battery 160, the flattening layer 170, and the like may be damaged. The layer 180 suppresses the deformation of the cover 190 in the plane direction. The deformation suppressing layer 180 is a member that is less likely to be deformed than the cover 190, and is composed of a layer harder than the cover 190. The deformation suppressing layer 180 is an example of a hard layer. The lower surface of the deformation suppressing layer 180 in FIG. 2 is an example of the first surface, and the upper surface is an example of the second surface.

However, it is desirable that the deformation suppressing layer 180 has as much flexibility as possible even if it is harder than the cover 190. This is because the stick-on type biosensor 100 is attached to the skin 10 of the living body.

From this point of view, as the deformation suppressing layer 180, a film made of PET (Polyethylene terephthalate), a sheet made of a putty for molding, or the like can be used. As the putty for molding, for example, (Agusa Japan Co., Ltd. silicone rubber molding material Blue Mix II) can be used.

The cover 190 has a base 190A and a protrusion 190B protruding from the center of the base 190A in the + Z direction. The base portion 190A is a portion located around the cover 190 in a plan view, and is a portion lower than the protruding portion 190B. A recess 190C is provided on the lower side of the protrusion 190B. In the cover 190, the lower surface of the base 190A is adhered to the upper surface 122 of the base material layer 120, and covers the upper surface 122 of the base material layer 120 and the upper surface of the deformation suppressing layer 180. A substrate 135, an electronic device 150, a battery 160, a flattening layer 170, and a deformation suppressing layer 180 are housed in the recess 190C.

The size of the recess 190C of the cover 190 in a plan view is matched to the size of the flattening layer 170 and the deformation suppressing layer 180 in a plan view, and the height of the recess 190C to the upper surface is the upper surface of the base material layer 120. It is adjusted to the height from 122 to the upper surface of the deformation suppressing layer 180. The cover 190 is configured such that when the lower surface of the base 190A is adhered to the upper surface 122 of the base material layer 120, the flattening layer 170 and the deformation suppressing layer 180 are fitted in the recess 190C. Therefore, the flattening layer 170 and the deformation suppressing layer 180 are housed in the recess 190C without a gap, and are fixed in the recess 190C.

The cover 190 protects the lower component from the impact applied to the stickable biosensor 100 from the upper surface side. The cover 190 is an example of a shock absorbing layer. More specifically, the cover 190 protects the internal components by alleviating the impact applied to the stickable biosensor 100 from the upper surface side in the plane direction. The cover 190 is a protective cover for the stick-on biosensor 100. As the cover 190, 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 rigidity of the flattening layer 170, the deformation suppressing layer 180, and the cover 190 will be described. Here, as the impact resistance test of the flattening layer 170, the deformation suppressing layer 180, and the cover 190, the results of the impact resistance test specified on page 15 of JIS T0601-1 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 50 MPa or more and 130 MPa or less, 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. is there. 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 130 MPa or less is applied at 50 MPa or more, and a color sample when a pressure greater than 130 MPa is applied. The color changes to the darkest color and the pressure sensitive paper itself is dented or torn. 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, it was confirmed in three stages (○, △, ×) whether or not to pass. ◯ indicates that there is no abnormality such as damage or cracks in the appearance after dropping the metal ball. Δ indicates a case where the pressure can be measured with the pressure sensitive paper even if the appearance is damaged or cracked after the metal ball is dropped. X indicates a case where an abnormality such as damage or cracks occurs in the appearance after the metal ball is dropped, and the pressure cannot be measured with the pressure sensitive paper. ○ and △ were considered to have passed the impact resistance test, and × was considered to have failed.

The rigidity of the flattening layer 170, the deformation suppressing layer 180, and the cover 190 was calculated using the following equations (1) and (w). 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 ).
l = ab3 / 12 (1)
k _B = EL / a = Eb3 / 12 (2)

FIG. 4 is a graph showing the rigidity of the flattening layer 170. Five types of flattening layer 170 are used: human skin gel (ultra-soft urethane resin), gummy cast (3 mm), gummy cast (4 mm), gummy cast (5 mm), and acrylic resin (UVR55G, 3 mm manufactured by Kiyohara Co., Ltd.). Using. The number in parentheses is the thickness.

A PET film having a thickness of 300 μm was used as the deformation suppressing layer 180, and a silicone rubber sheet having a hardness of 30 (elastic modulus 0.58 MPa, thickness 2 mm) was used as the cover 190.

As shown in FIG. 4, the human skin gel was ×, the gummy cast (3 mm), the gummy cast (4 mm), the gummy cast (5 mm) was Δ, and the acrylic resin was ◯. Therefore, the human skin gel failed the impact resistance test, and the gummy cast (3 mm), gummy cast (4 mm), gummy cast (5 mm), and acrylic resin passed the impact resistance test.

Here, when the rigidity of the passed gummy cast (3 mm), gummy cast (4 mm), gummy cast (5 mm), and acrylic resin was calculated using the equations (1) and (2), the gummy cast (3 mm) was 0. .3N ・ mm ² , gummy cast (4mm) and gummy cast (5mm) were larger than 0.3N ・ mm ² , and acrylic resin was 0.9N ・ mm ² .

Therefore, it was found that if the rigidity of the flattening layer 170 is 0.3 N · mm ² or more, the impact resistance test is passed. The upper limit of the rigidity of the planarizing layer thickness of the acrylic resin layer is available as 170 are the 5000N · mm ² approximately, the rigidity of the planarization layer 170 is 0.3 N · mm ² or more, 5000N · mm can be ^two or less, preferably, 0.9N · mm ² or more, as long 2500N · mm ² or less.

The defined maximum rigidity of the planarization layer 170 to 5000N · mm ² is impaired flexibility of the patch-type biometric sensor 100 and larger than 5000N · mm ^2, because the fit to the skin 10 not as good Is. Further, the more preferable upper limit is set to 2500 N ・ mm ² , because the rigidity of the acrylic resin having a thickness of 3.0 mm is 2250 N ・ mm ² , so that a margin of about 10% is included in 2500 N ・ mm ^2. It is set to.

FIG. 5 is a graph showing the rigidity of the deformation suppressing layer 180. When the deformation suppressing layer 180 is not used (without the deformation suppressing layer 180), the deformation suppressing layer 180 includes PET (0.05 mm), PET (0.1 mm), a putty for molding (1.5 mm), and molding. Putty (2 mm) and PET (0.3 mm) were used. Although not shown in FIG. 5, PET (0.5 mm) was also used as the deformation suppressing layer 180. The number in parentheses is the thickness.

A gummy cast having an elastic modulus of 0.18 MPa and a thickness of 4 mm was used as the flattening layer 170, and a silicone rubber sheet having a hardness of 30 (elastic modulus of 0.58 MPa and a thickness of 2 mm) was used as the cover 190.

Deformation suppression layer 180 None, PET (0.05 mm), PET (0.1 mm), Molding putty (1.5 mm) is ×, Molding putty (2 mm) is Δ, PET (0.3 mm) , PET (0.5 mm) was ◯. Therefore, without the deformation suppressing layer 180, PET (0.05 mm), PET (0.1 mm), and the putty for molding (1.5 mm) failed the impact resistance test, and the putty for molding (2 mm). ), PET (0.3 mm) and PET (0.5 mm) passed the impact resistance test.

Here, when the rigidity of the passed mold-making putty (2 mm), PET (0.3 mm), and PET (0.5 mm) was calculated using the equations (1) and (2), the mold-molding putty was calculated. (2mm) is ^{4.0N · mm 2, PET (0.3mm} ) is ^{6.0N · mm 2, PET (0.5mm} ) was 30N · mm ^2. The rigidity of the rejected PET (0.05 mm), PET (0.1 mm), and putty for molding (1.5 mm) was less than 4.0 N · mm ² .

Therefore, it was found that if the rigidity of the deformation suppressing layer 180 is 4.0 N · mm ² or more, the impact resistance test is passed. The upper limit of the stiffness of the PET available thickness as a modified suppression layer 180 are the 10000 N · mm ² approximately, the rigidity of the deformation suppressing layer 180 is 4.0 N · mm ² or more, 10000 N · mm ² or less as long, preferably, 6.0 N · mm ² or more, as long 30 N · mm ² or less. The more preferable upper limit of the stiffness of the anti-deformation layer 180 was set to 30 N · mm ² are that fit the sticking type biometric sensor 100 if 30 N · mm ² or less is better, 0 little thicker. This is because the rigidity of the PET of 5 mm is 30 N · mm ² .

FIG. 6 is a graph showing the rigidity of the cover 190. As the cover 190, silicone rubber with a hardness of 15 (silicone 15), tango + (resin), urethane rubber with a hardness of 30 (urethane 30), tango + 2 (resin), silicone rubber with a hardness of 30 (silicone rubber 30), FLX9960 + 3 (Rubber-like resin), urethane rubber having a hardness of 60 (urethane 60), urethane rubber having a hardness of 50 (urethane 50), and NBR60 (nitrile rubber 60) were used.

A gummy cast having an elastic modulus of 0.18 MPa and a thickness of 4 mm was used as the flattening layer 170, and a silicone rubber sheet having a hardness of 30 (elastic modulus of 0.58 MPa and a thickness of 2 mm) was used as the cover 190.

In addition, tango + and FLX9960 are rubber-like acrylic resins for 3D printers. tango + 2 is a mixture of tango + and FLX9960. FLX9960 + 3 is a mixture of FLX9960 and RGD8630, an acrylic resin for 3D printers.

Silicone 15, tango +, urethane 60, and NBR60 were x, urethane 30 and urethane 50 were Δ, tango + 2, silicone rubber 30, and FLX9960 + 3 were ◯. Therefore, silicone 15, tango +, urethane 60, and NBR60 failed the impact resistance test, and urethane 30, tango + 2, silicone rubber 30, FLX9960 + 3, and urethane 50 passed the impact resistance test.

Here, when the rigidity of the passed urethane 30, tango + 2, silicone rubber 30, FLX9960 + 3, and urethane 50 was calculated using the equations (1) and (2), the rigidity of the urethane 30 was the lowest, and 0. It was 1 N · mm ² , and the rigidity of urethane 50 was the highest, 1.0 N · mm ² .

The rigidity of tango + 2, silicone rubber 30, and FLX9960 + 3 was 0.2 N · mm ² for tango + 2 and 0.3 N · mm ² for FLX9960 + 3.

Moreover, the rigidity of the rejected silicone 15 and tango + was less than 0.1 N · mm ² . Tango + is more rigid than Silicone 15.

The rigidity of urethane 50 and NBR60 was 1.5 N · mm ² or more. NBR60 has higher rigidity than urethane 50.

From this, it was found that if the rigidity of the cover 190 is 0.1 N · mm ² or more and 1.0 N · mm ² or less, the impact resistance test is passed. It was found that preferably 0.2 N · mm ² or more and 0.3 N · mm ² or less are sufficient.

As described above, in the stick-on biosensor 100 of the embodiment, in order to suppress the concentration of stress on the electronic device 150, the battery 160, etc. when an impact is applied, the electronic device 150 and the battery are placed on the upper surface of the base material layer 120. A flattening layer 170 that covers 160 and the like and absorbs unevenness to flatten the surface is included.

Further, the stick-on biosensor 100 suppresses the deformation of the cover 190 between the flattening layer 170 and the cover 190, and the pressure-sensitive adhesive layer 110, the base material layer 120, the circuit unit 130, the probe 140, the electronic device 150, and the battery. Includes 160 and a deformation suppressing layer 180 that suppresses breakage of the flattening layer 170 and the like.

Therefore, it is possible to provide a stick-on biosensor 100 that has both flexibility and impact resistance.

Although the configuration in which the wiring 131 and the frame 132 are provided on the substrate 133 has been described above, the wiring 131 and the frame 132 may be provided on the upper surface 122 of the base material layer 120. In this case, a groove may be provided on the upper surface 122 of the base material layer 120, and the wiring 131 and the frame 132 may be provided inside the groove.

Further, although the form in which the cover 190 has the base portion 190A and the projecting portion 190B has been described above, the cover 190 may have an equal thickness as a whole. In this case, the cover 190 does not have the protrusion 190B.

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 135 Substrate 140 Probe 145 Fixing tape 150 Electronic device 160 Battery 170 Flattening layer 180 Deformation suppression layer 190 Cover

Claims (10)

A pressure-sensitive adhesive layer with a sticking surface that can be stuck to the subject,
An electrode exposed from the sticking surface of the pressure-sensitive adhesive layer and
A base material layer provided on the opposite surface of the pressure-sensitive adhesive layer to the sticking surface, and
An electronic device provided on the base material layer and processing a biological signal acquired via the electrode.
A battery provided on the substrate layer and supplying electric power to the electronic device,
A flattening layer provided on the base material layer and having a flat surface flattened by covering the electronic device and the battery.
A hard layer provided on the flattening layer and having a first surface overlapped with the flat surface and a second surface opposite to the first surface.
Including a shock absorbing layer provided on the hard layer.
The hard layer is a stick-on biosensor that is harder than the shock absorbing layer. The flattening layer and the hard layer are smaller than the base material layer in a plan view.
The shock absorbing layer has a recess for accommodating the electronic device, the battery, the flattening layer, and the hard layer, and the electronic device, the battery, the flattening layer, and the hard layer are placed in the recess. The stick-on biosensor according to claim 1, which is adhered to the base material layer in a stored state. The stick-on biosensor according to claim 2, wherein the shock absorbing layer has a base portion and a protruding portion that protrudes from the base portion and has the recessed portion inside, and the base portion is adhered to the base material layer. The stick-on biosensor according to claim 2 or 3, wherein the hard layer has a size corresponding to the size of the recess in a plan view and is fitted inside the recess. The stick-on biosensor according to any one of claims 1 to 4, wherein the rigidity of the shock absorbing layer is 0.1 N · mm ² or more and 1.0 N · mm ² or less. The stick-on biosensor according to any one of claims 1 to 5, wherein the rigidity of the hard layer is 4.0 N · mm ² or more. The patch-type biosensor according to any one of claims 1 to 6, wherein the flattening layer has a rigidity of 0.3 N · mm ² or more. A circuit unit provided on the base material layer and connecting the electrode and the electronic device,
The stick-on biosensor according to any one of claims 1 to 7, further comprising a substrate on which the circuit portion is formed and provided on the base material layer. The stick-on biosensor according to claim 8, wherein the electronic device and the battery are mounted on the substrate. The stick-on biosensor according to any one of claims 1 to 8, further comprising a second substrate on which the electronic device and the battery are mounted and provided on the base material layer.

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