Patent Description:
For the electrically conductive composition, a mixture of poly(<NUM>,<NUM>-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT-PSS) and polyvinyl alcohol (PVA) has been known (ref: for example, Non-Patent Document <NUM>).

Other examples of electrically conductive polymeric compositions containing a conductive polymer component, a binder resin, a plasticizer and/or a crosslinking agent are disclosed in Patent Documents <NUM> to <NUM> and in Non-Patent Document <NUM>.

A biosensor containing containing a wiring containing a conducting polymer is disclosed in Patent Document <NUM>.

The mixture has excellent electrical conductivity and formability, and an electrically conductive object formed from this mixture (electrically conductive film) has excellent durability, tenacity, and flexibility.

However, even more excellently high tenacity (To be specific, achieving both tensile strength and tensile elongation (elongation)) and flexibility may be required for the electrically conductive object.

The present invention provides a biosensor including a connector prepared from a electrically conductive composition, wherein the connector has high tenacity and flexibility.

The present invention (<NUM>) discloses a biosensor including a wire layer, a probe that makes contact with a surface of a living body, and a connector that electrically connects the wire layer with the probe, wherein the connector includes the connector prepared from an electrically conductive composition comprising an electrical conductive polymer, a binder resin and a plasticizer,.

The electrically conductive composition used in the connector of the biosensor of the present invention contains a plasticizer and therefore an electrically conductive connector with excellently high tenacity and flexibility can be prepared.

The biosensor of the present invention has excellent connection reliability.

The electrically conductive composition used in the connector of the biosensor of the present invention contains an electrical conductive polymer, binder resin, and a plasticizer, wherein the plasticizer contains a polyol compound, and a ratio of the polyol compound relative to <NUM> parts by mass of the electrical conductive polymer is <NUM> parts by mass or more and <NUM> parts by mass or less.

The electrical conductive polymer can give electrical conductivity to the electrically conductive composition (furthermore, electrically conductive object to be described later). Examples of the electrical conductive polymer include a polythiophene compound, polypyrrole compound, and polyaniline compound (To be specific, polyaniline, etc.). These can be used singly, or can be used in combination of two or more.

Preferably, the polythiophene compound, more preferably, (<NUM>,<NUM>-ethylenedioxy thiophene)/poly (<NUM>-styrene sulfonic acid)(hereinafter, may be referred to as PEDOT-PSS)) is used. With the PEDOT-PSS, excellent electrical conductivity can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The ratio of the electrical conductive polymer relative to the electrically conductive composition is, for example, <NUM> mass% or more, preferably <NUM> mass% or more, and for example, <NUM> mass% or less, preferably <NUM> mass% or less. When the ratio is the above-described lower limit or more, excellent electrical conductivity can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later). When the ratio is the above-described upper limit or less, excellently high tenacity and flexibility can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The binder resin can give high tenacity to the electrically conductive composition (furthermore, electrically conductive object to be described later). Examples of the binder resin include a water-soluble polymer and water insoluble polymer. Preferably, in view of compatibility with other components in the electrically conductive composition, a water-soluble polymer is used. The water-soluble polymer does not completely dissolve in water, and includes polymers having hydrophilicity (hydrophilic polymer).

Examples of the water-soluble polymer include a hydroxyl group-containing polymer. For the hydroxyl group-containing polymer, for example, saccharides (agarose, etc.), for example, PVA, for example, polymer poly(acrylic acid-sodium acrylic acid) are used. Preferably, PVA is used. These can be used singly, or can be used in combination of two or more.

Examples of the PVA include polyvinyl alcohol, and for example, modified polyvinyl alcohol is used. Preferably, modified polyvinyl alcohol is used.

Examples of the modified polyvinyl alcohol include acetoacetyl group-containing poly vinyl alcohol, and diacetone acrylamide modified polyvinyl alcohol. Preferably, the acetoacetyl group-containing polyvinyl alcohol is used. The modified polyvinyl alcohol is described, for example, in <CIT>.

The ratio of the binder resin relative to the electrically conductive composition is, for example, <NUM> mass% or more, preferably <NUM> mass% or more, and for example, <NUM> mass% or less, preferably <NUM> mass% or less. When the ratio is the above-described lower limit or more, excellently high tenacity and flexibility can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later). When the ratio is the above-described upper limit or less, excellent electrical conductivity can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The cross-linking agent and plasticizer are high tenacity/flexibility additives that can give high tenacity and flexibility to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The high tenacity is characteristics that achieve both excellent strength and excellent elasticity. To be more specific, high tenacity means that strength and elasticity are both excellent in good balance, and does not include the case where one of the strength and elasticity is significantly excellent but the other is significantly low.

Flexibility is characteristics of suppressing generation of damages such as fractures to bending portions (fold, etc.) after bending (folding) the electrically conductive object (electrically conductive sheet).

The high tenacity/ flexibility additives can contain at least one of the cross-linking agent and plasticizer. That is, (<NUM>) the high tenacity/flexibility additive contains the cross-linking agent but contains no plasticizer, or (<NUM>) the high tenacity/flexibility additive contains the plasticizer but contains no cross-linking agent.

In the case of (<NUM>), high tenacity, that is, both of tensile strength and tensile elongation (compared with Comparative Example (Comparative Example <NUM>) where high tenacity/flexibility additive does not contain cross-linking agent or plasticizer) can be improved. Furthermore, flexibility can also be improved.

In the case of (<NUM>), although tensile strength is slightly decreased (tensile strength is within acceptable range), the tensile elongation can be significantly improved. Therefore, overall, high tenacity can be improved. Furthermore, flexibility can also be improved.

Preferably, high tenacity/flexibility additive contains both of the cross-linking agent and plasticizer. When both of the cross-linking agent and plasticizer are contained in the electrically conductive composition, even more excellently high tenacity can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The cross-linking agent can crosslink binder resin. This improves high tenacity of the electrically conductive composition to be given by the binder resin.

The cross-linking agent has reactivity with the hydroxyl group when the binder resin is a hydroxyl group-containing polymer. To be specific, examples of the cross-linking agent include a zirconium compound (for example, zirconium salt, etc.), titanium compound (for example, titanium salt, etc.), boric acid compound (for example, boric acid, etc.), alkoxy group-containing compound, methylol group-containing compound, isocyanate compound (for example, blocked isocyanate, etc.), and aldehyde compound (for example, dialdehyde such as glyoxal, etc.).

These can be used singly, or can be used in combination of two or more. In view of reactivity and stability, preferably, the zirconium compound, isocyanate compound, and aldehyde compound are used.

The ratio of the cross-linking agent relative to <NUM> parts by mass of the binder resin is, for example, <NUM> part by mass or more, preferably <NUM> parts by mass or more, and for example, <NUM> parts by mass or less, preferably <NUM> parts by mass or less. When the ratio is the above-described lower limit or more, and the above-described upper limit or less, excellently high tenacity and excellent flexibility can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

The plasticizer plasticates the electrical conductive polymer. The plasticizer improves tensile elongation and flexibility of the electrically conductive composition. According to the present invention, the electrically conductive composition comprises a plasticizer, wherein the plasticizer contains a polyol compound, such as glycerine, ethylene glycol, propylene glycol, sorbitol, and polymers thereof.

These can be used singly, or can be used in combination of two or more.

The ratio of the plasticizer relative to <NUM> parts by mass of the electrical conductive polymer is <NUM> parts by mass or more, preferably <NUM> parts by mass or more, and <NUM> parts by mass or less, preferably <NUM> parts by mass or less. When the ratio of the plasticizer is the above-described lower limit or more, excellent flexibility can be reliably given to the electrically conductive composition (furthermore, electrically conductive object to be described later). When the ratio of the plasticizer is the above-described upper limit or less, excellently high tenacity and excellent flexibility can be given to the electrically conductive composition (furthermore, electrically conductive object to be described later).

To the electrically conductive composition, for example, additives such as a surfactant can be added at a suitable ratio. Examples of the surfactant include silicone surfactants.

To prepare the electrically conductive composition, the above-described components are blended at the above-described ratio, and they are mixed. At that time, as necessary, a solvent is used at a suitable ratio. Examples of the solvent include organic solvents, and water-based solvents such as, for example, water. Preferably, the water-based solvent is used. The electrical conductive polymer and/or binder resin (preferably, water-soluble polymer) can be prepared as an aqueous solution, in which the electrical conductive polymer and/or binder resin are dissolved in the water-based solvent.

The electrically conductive composition is prepared (produced) as an electrically conductive composition liquid (aqueous solution of electrically conductive composition) in this manner.

Thereafter, an electrically conductive object such as an electrically conductive sheet is prepared from the electrically conductive composition.

To be specific, the electrically conductive composition liquid is applied on the surface of a substrate (release sheet, breadboard, etc.), and thereafter, dried to remove the solvent.

In this manner, the electrically conductive object is formed as an electrically conductive sheet.

Thereafter, the electrically conductive object is further treated with heat.

The heat treatment conditions are those conditions that allow the cross-linking agent to react. To be specific, the electrically conductive object is heated at a temperature of, for example, <NUM> or more, preferably <NUM> or more, and for example, <NUM> or less, preferably <NUM> or less, for, for example, <NUM> minutes or more, preferably <NUM> minutes or more, and for example, <NUM> minutes or less, preferably <NUM> minutes or less.

The heat treatment allows crosslinking reaction of the binder resin by the cross-linking agent to progress.

The electrically conductive object (electrically conductive sheet) is produced in this manner.

The electrically conductive object is rubbery, and has both high tenacity and flexibility.

The electrically conductive object has a volume resistivity of, for example, <NUM> × <NUM>-<NUM>Ω · m or less, preferably <NUM> × <NUM>-<NUM>Ω · m or less. The volume resistivity measurement method is described in Examples later on.

High tenacity of the electrically conductive object (electrically conductive sheet) is evaluated by both of tensile strength and tensile elongation. The electrically conductive object (electrically conductive sheet) has a tensile strength of, for example, 2N/m<NUM> or more, preferably <NUM> N/m<NUM> or more. The electrically conductive object (electrically conductive sheet) has a tensile elongation of, for example, <NUM>% or more, preferably <NUM>% or more.

Specifically, high tenacity is, for example, (<NUM>) tensile strength of 2N/m<NUM> or more, and tensile elongation of <NUM>% or more, and for example, (<NUM>) tensile strength of 5N/m<NUM> or more, and tensile elongation of <NUM>% or more. When the conditions of one of (<NUM>) and (<NUM>) is satisfied, the electrically conductive object (electrically conductive sheet) has high tenacity (has excellent high tenacity).

More preferably, high tenacity is (<NUM>) tensile strength is 5N/m<NUM> or more, and tensile elongation of <NUM>% or more.

The tensile strength and tensile elongation are described in Examples later on.

Flexibility is evaluated by, for example, two-fold test, and the fracture rate is, for example, less than <NUM>%, preferably less than <NUM>%.

Flexibility is described in Examples later on.

The electrically conductive object can be applied for use in which high tenacity and flexibility are required, for example, in a wearable sensor.

Next, description is given below of a wearable biosensor <NUM> as an example of the biosensor including a connector as an example of the electrically conductive object with reference to <FIG>.

In <FIG>, left-right direction on the sheet is longitudinal direction (first direction) of the wearable biosensor <NUM>. Right side on the sheet is longitudinal one side (one side in first direction), left side on the sheet is longitudinal other side (the other side in first direction).

In <FIG>, up-down direction on the sheet is transverse direction (direction orthogonal to longitudinal direction, width direction, second direction orthogonal to first direction) of the wearable biosensor <NUM>. Upper side on the sheet is one side in transverse direction (one side in width direction, one side in second direction), and lower side on the sheet is the other side in transverse direction (the other side in width direction, the other side in second direction).

In <FIG>, paper thickness direction on the sheet is up-down direction (thickness direction, third direction orthogonal to first direction and second direction) of the wearable biosensor <NUM>. Near side on the sheet is upper side (one side in thickness direction, one side in third direction), and far side on the sheet is lower side (the other side in thickness direction, the other side in third direction).

The directions are in accordance with the direction arrows described in the figures.

These definitions of the directions are not intended to limit the orientations of the wearable biosensor <NUM> at the time of production and use.

As shown in <FIG>, the wearable biosensor <NUM> has a substantially flat plate shape extending in longitudinal direction. The wearable biosensor <NUM> is a sheet having excellently high tenacity and flexibility. The wearable biosensor <NUM> includes a pressure-sensitive adhesive layer <NUM>, a substrate layer <NUM> disposed on an adhesive upper face of the pressure-sensitive adhesive layer <NUM>, a wire layer <NUM> disposed on the substrate layer <NUM>, a probe <NUM> disposed on an adhesive lower face <NUM> of the pressure-sensitive adhesive layer <NUM>, a connecter <NUM> as an example of the electrically conductive object that electrically connects the wire layer <NUM> with the probe <NUM>, and an electronic component <NUM> electrically connected with the wire layer <NUM>.

The pressure-sensitive adhesive layer <NUM> forms the lower face of the wearable biosensor <NUM>. The pressure-sensitive adhesive layer <NUM> is a layer that gives pressure-sensitive adhesiveness to the lower face of the wearable biosensor <NUM> for attaching the lower face of the wearable biosensor <NUM> to the surface of the living body (skin <NUM> shown by phantom line, etc.). The pressure-sensitive adhesive layer <NUM> forms the outline shape of the wearable biosensor <NUM>. The pressure-sensitive adhesive layer <NUM> has a flat plate shape extending in longitudinal direction. To be specific, the pressure-sensitive adhesive layer <NUM> has, for example, a band shape extending in longitudinal direction, with a longitudinal center portion bulging toward transverse both outsides. In the pressure-sensitive adhesive layer <NUM>, both end edges in transverse direction of the longitudinal center portion are positioned at transverse both outsides relative to the both end edges in transverse direction of other than the longitudinal center portion.

The pressure-sensitive adhesive layer <NUM> has an adhesive upper face <NUM> and an adhesive lower face <NUM>.

The adhesive upper face <NUM> has a flat face.

The adhesive lower face <NUM> is disposed to face each other at a lower side of the adhesive upper face <NUM> in spaced apart relation.

The pressure-sensitive adhesive layer <NUM> has two adhesion openings <NUM> at longitudinal both ends thereof. Each of the two adhesion openings <NUM> has a substantially ring shape in plan view.

The adhesion opening <NUM> penetrates the pressure-sensitive adhesive layer <NUM> in thickness direction. The adhesion opening <NUM> is filled with the connecter <NUM>.

The adhesive lower face <NUM> inside the adhesion opening <NUM> has adhesion grooves <NUM> in correspondence with the probe <NUM> (described later). The adhesion groove <NUM> is opened toward the lower side.

The material of the pressure-sensitive adhesive layer <NUM> is not particularly limited, as long as the material has pressure-sensitive adhesiveness.

The substrate layer <NUM> forms the upper face of the wearable biosensor <NUM> along with the electronic component <NUM> to be described later. The substrate layer <NUM> forms the outline shape of the wearable biosensor <NUM> along with the pressure-sensitive adhesive layer <NUM>.

The shape in plan view of the substrate layer <NUM> is the same as the shape in plan view of the pressure-sensitive adhesive layer <NUM>. The substrate layer <NUM> is disposed on the entire upper face of the pressure-sensitive adhesive layer <NUM> (but excluding the region where connecter <NUM> is provided). The substrate layer <NUM> is a support layer supporting the pressure-sensitive adhesive layer <NUM>. The substrate layer <NUM> has a flat plate shape extending in longitudinal direction. The substrate layer <NUM> has a substrate lower face <NUM> and a substrate upper face <NUM>.

The substrate lower face <NUM> has a flat face. The substrate lower face <NUM> is in contact with (pressure sensitive adhesion) the adhesive upper face <NUM> of the pressure-sensitive adhesive layer <NUM>.

The substrate upper face <NUM> is disposed to face each other at the upper side of the substrate lower face <NUM> in spaced apart relation. The substrate upper face <NUM> has a substrate groove <NUM> in correspondence with the wire layer <NUM>. The substrate groove <NUM> has the same pattern as that of the wire layer <NUM> in plan view. The substrate groove <NUM> is opened toward the upper side.

The substrate layer <NUM> has a substrate opening <NUM> in correspondence with the adhesion opening <NUM>. The substrate opening <NUM> communicates with the adhesion opening <NUM> in thickness direction. The substrate opening <NUM> has a substantially ring shape in plan view with the same shape and the same size as those of the adhesion opening <NUM>.

The material of the substrate layer <NUM> has, for example, a stretching property. The material of the substrate layer <NUM> has, for example, an insulating layer. For such a material, for example, resin such as polyurethane resin is used.

The substrate layer <NUM> has an elongation at break of, for example, <NUM>% or more, preferably <NUM>% or more, more preferably <NUM>% or more, and for example, <NUM>% or less. When the elongation at break is the above-described lower limit or more, the material of the substrate layer <NUM> can have excellent stretching property.

The wire layer <NUM> is embedded in, for example, the substrate groove <NUM>. To be specific, the wire layer <NUM> is embedded in the upper portion of the substrate layer <NUM> so as to be exposed from the substrate upper face <NUM> of the substrate layer <NUM>. The wire layer <NUM> has an upper face and a lower face disposed in spaced apart relation from each other, and side faces connecting their peripheral end edges. The entire lower face and the entire side face are in contact with the substrate layer <NUM>. The upper face is exposed from the substrate upper face <NUM> (excluding substrate groove <NUM>). The upper face of the wire layer <NUM> forms the upper face of the wearable biosensor <NUM> along with the substrate upper face <NUM> and the electronic component <NUM>.

The wire layer <NUM> has a wire pattern connecting the connecter <NUM>, an electronic component <NUM> (described later), and a battery <NUM> (described later). To be specific, the wire layer <NUM> independently includes a first wire pattern <NUM> and a second wire pattern <NUM>.

The first wire pattern <NUM> is disposed at longitudinal one side of the substrate layer <NUM>. The first wire pattern <NUM> includes a first wire 16A, and a first terminal 17A and a second terminal 17B continuous therefrom.

The first wire pattern <NUM> has a substantially letter T-shape in plan view. To be specific, the first wire pattern <NUM> extends from the longitudinal one end portion (the connecter <NUM> positioned at) of the substrate layer <NUM> toward longitudinal other side, splits at the longitudinal center portion of the substrate layer <NUM>, and extends toward transverse both outsides.

The first terminal 17A and the second terminal 17B each is disposed at transverse both end portions in longitudinal center portion of the substrate layer <NUM>. The first terminal 17A and the second terminal 17B each has a substantially rectangular shape in plan view (land shape). The first terminal 17A and the second terminal 17B each is continuous with both end portions of the first wire 16A extending in transverse both outsides at a longitudinal center portion of the substrate layer <NUM>.

The second wire pattern <NUM> is provided in spaced apart relation at longitudinal other side of the first wire pattern <NUM>. The second wire pattern <NUM> includes a second wire 16B and a third terminal 17C and a fourth terminal 17D continuous therefrom.

The second wire pattern <NUM> has a substantially letter T-shape in plan view. To be specific, the second wire pattern <NUM> extends from (the connecter <NUM> positioned at) the longitudinal other end portion of the substrate layer <NUM> toward longitudinal one side, splits at the longitudinal center portion of the substrate layer <NUM>, and extends toward transverse both outsides.

The third terminal 17C and the fourth terminal 17D each is disposed at transverse both end portions in longitudinal center portion of the substrate layer <NUM>. The third terminal 17C and the fourth terminal 17D each has a substantially rectangular shape in plan view (land shape). The third terminal 17C and the fourth terminal 17D each is continuous with both end portions of the second wire 16B extending in transverse both outsides at a longitudinal center portion of the substrate layer <NUM>.

For the material of the wire layer <NUM>, for example, conductors such as copper, nickel, gold, and alloys thereof are used. For the material of the wire layer <NUM>, preferably, copper is used.

The probe <NUM> is an electrode that allows sensing of electric signals, temperatures, vibrations, sweat, and metabolite from a living body, when the pressure-sensitive adhesive layer <NUM> is attached to the skin <NUM> by making contact with the skin <NUM>. The probe <NUM> is embedded in the pressure-sensitive adhesive layer <NUM> so as to be exposed from the adhesive lower face <NUM> of the pressure-sensitive adhesive layer <NUM>. That is, the probe <NUM> is embedded in the adhesion groove <NUM> of the pressure-sensitive adhesive layer <NUM> at the inside of the adhesion opening <NUM>. The probe <NUM> is disposed at the adhesive lower face <NUM> forming the adhesion groove <NUM>. That is, the probe <NUM> is embedded in the lower end portion of the pressure-sensitive adhesive layer <NUM> at the inside of the adhesion opening <NUM>. The probe <NUM> has a mesh shape, preferably, a substantially grid shape in plan view (or has a substantially mesh shape). In other words, the probe <NUM> has holes in spaced apart relation in the surface direction (longitudinal direction and transverse direction). The hole is filled with the pressure-sensitive adhesive layer <NUM>.

The probe <NUM> has a substantially rectangular shape in cross sectional view extending in a direction orthogonal thereto. The probe <NUM> has a probe lower face <NUM>, a probe upper face <NUM> disposed to face the upper side of the probe lower face <NUM> in spaced apart relation, and side faces connecting peripheral end edges of the probe lower face <NUM> and the probe upper face <NUM>.

The probe lower face <NUM> is exposed from the adhesive lower face <NUM> (excluding adhesion groove <NUM>) of the pressure-sensitive adhesive layer <NUM>. The probe lower face <NUM> is flush with the adhesive lower face <NUM>. The probe lower face <NUM> forms the lower face of the wearable biosensor <NUM> along with the adhesive lower face <NUM>.

The probe upper face <NUM> and the side face are covered with the pressure-sensitive adhesive layer <NUM>.

As shown in <FIG>, of the side faces of the probe <NUM>, the face positioned at the outermost side is an outer side face <NUM>. The outer side face <NUM> forms a virtual circle passing through the outer side face <NUM> in plan view.

For the material of the probe <NUM>, those materials given as Examples of the wire layer <NUM> (to be specific, conductor) are used.

The external size of the probe <NUM> is set so that the virtual circle passing through the outer side face <NUM> overlaps with the inner periphery defining the adhesion opening <NUM> in plan view.

The connector <NUM> is prepared from the above-described electrically conductive composition, and is an example of the electrically conductive connector to be formed. The connecter <NUM> is provided in correspondence with the substrate opening <NUM> and the adhesion opening <NUM>, and has the same shape as these. The connecter <NUM> penetrates (pass through) the substrate layer <NUM> and the pressure-sensitive adhesive layer <NUM> in thickness direction (up-down direction), and the substrate opening <NUM> and the adhesion opening <NUM> are filled with the connecter <NUM>. The connecter <NUM> has a no-end shape in plan view along the outer side face <NUM> of the probe <NUM>. To be specific, the connecter <NUM> has a substantially cylindrical shape with its axis line extending in thickness direction (along virtual circle passing through the outer side face <NUM>).

The inner side face of the connecter <NUM> is in contact with the outer side face <NUM> of the probe <NUM>.

The connecter <NUM> is allowed to adhere to the pressure-sensitive adhesive layer <NUM> outside the adhesion opening <NUM> and the pressure-sensitive adhesive layer <NUM> inside the adhesion opening <NUM> by pressure-sensitive adhesion. The connecter <NUM> is in contact with the substrate layer <NUM> outside the substrate opening <NUM> and the substrate layer <NUM> inside the substrate opening <NUM>.

The upper face of the connecter <NUM> is flush with the substrate upper face <NUM>. The lower face of the connecter <NUM> is flush with the adhesive lower face <NUM>.

As shown in <FIG>, of the two connecters <NUM>, the connecter <NUM> positioned at longitudinal one side is continuous with, at its upper end portion, longitudinal one end edge of the wire 16A positioned at longitudinal one side.

The connecter <NUM> positioned at longitudinal other side is continuous with, at its upper end portion, longitudinal other end edge of the wire 16B positioned at longitudinal other side.

That is, the connecter <NUM> is electrically connected with the wire layer <NUM>.

In this manner, the connecter <NUM> electrically connects the wire layer <NUM> with the probe <NUM>.

The connecter <NUM> and the wire layer <NUM> form a circuit portion <NUM> that electrically connects the probe <NUM> with the electronic component <NUM>. That is, the circuit portion <NUM> includes the wire layer <NUM> disposed on the substrate upper face <NUM> of the substrate layer <NUM>, and the connecter <NUM> passing through the substrate layer <NUM> and the pressure-sensitive adhesive layer <NUM>. Preferably, the circuit portion <NUM> is composed only of the wire layer <NUM> and the connecter <NUM>.

The connector <NUM> has a radial direction length (half the value of deduction of internal diameter from external diameter) of, for example, <NUM> or more, preferably <NUM> or more, and for example, less than <NUM>, preferably <NUM> or less, more preferably <NUM> or less.

Examples of the electronic component <NUM> include an analog front-end, microcomputer, and memory for processing and storing electric signals from a living body obtained by the probe <NUM>, and a communication IC and transmitter for converting electric signals to electro-magnetic waves and wirelessly transmitting them to an external receiver.

To be more specific, when the wearable biosensor <NUM> is a wearable electrocardiograph, the changes in cardiac potential obtained at the probe <NUM> is converted to digital data at an analog front-end, and the changes in the cardiac potential is stored in the memory. For example, changes in the cardiac potential are stored in the memory with <NUM> bit, at a data rate of <NUM>. To decrease the memory size, sometimes resolving power of data and data rate have to be decreased. After detaching the wearable biosensor <NUM> after the measurement, the stored data is taken out from the memory and analyzed. The communication IC has functions to send the signals obtained at the probe <NUM> to outside wirelessly. This function works when connected under normal communication, the wearable biosensor <NUM> is attached to the skin <NUM>, and when it can be confirmed that data acquisition is normal, and a message that the data acquisition is normal is intermittently sent to outside, to check if the wearable biosensor <NUM> is working normally.

The electronic component <NUM> can have some or all of the above-described components. The electronic component <NUM> is in contact with the substrate upper face <NUM>. The electronic component <NUM> has a substantially rectangular flat plate shape in cross sectional view. Two terminals <NUM> are provided at the lower face of the electronic component <NUM>. Two terminals <NUM> of the electronic component <NUM> are electrically connected with the first terminal 17A and the third terminal 17C, respectively. The electronic component <NUM> is harder than, for example, the pressure-sensitive adhesive layer <NUM> and the substrate layer <NUM>.

Next, description is given below of the method for producing a wearable biosensor <NUM>.

As shown in <FIG>, in this method, first, the substrate layer <NUM> and wire layer <NUM> are prepared.

For example, the substrate layer <NUM> and wire layer <NUM> are prepared so that the wire layer <NUM> is embedded in the substrate groove <NUM> by the method described in <CIT> and <CIT>.

As shown in <FIG>, then, the pressure-sensitive adhesive layer <NUM> is disposed on the substrate lower face <NUM>.

To dispose the pressure-sensitive adhesive layer <NUM> on the substrate lower face <NUM>, for example, first, an application liquid containing the materials for the pressure-sensitive adhesive layer <NUM> is prepared, and then the application liquid is applied on the upper face of the first release sheet <NUM>, and thereafter, they are dried by heating. In this manner, the pressure-sensitive adhesive layer <NUM> is disposed on the upper face of the first release sheet <NUM>. The first release sheet <NUM> has, for example, a substantially flat plate shape extending in longitudinal direction. For the material of the first release sheet <NUM>, for example, resin such as polyethylene terephthalate is used.

Then, the pressure-sensitive adhesive layer <NUM> and the substrate layer <NUM> are bonded by, for example, a laminator. To be specific, the adhesive upper face <NUM> of the pressure-sensitive adhesive layer <NUM> is brought into contact with the substrate lower face <NUM> of the substrate layer <NUM>.

At this point, the substrate layer <NUM> or the pressure-sensitive adhesive layer <NUM> has no substrate opening <NUM> or adhesion opening <NUM>.

As shown in <FIG>, then, the opening <NUM> is formed in the substrate layer <NUM> and the pressure-sensitive adhesive layer <NUM>.

The opening <NUM> penetrates the substrate layer <NUM> and pressure-sensitive adhesive layer <NUM>. The opening <NUM> is a hole having a generally circular shape in plan view (through opening) defined by an outer peripheral face defining the substrate opening <NUM> and an outer peripheral face defining the adhesion opening <NUM>. The opening <NUM> is opened toward the upper side. Meanwhile, the lower end of the opening <NUM> is closed by the first release sheet <NUM>.

To form the opening <NUM>, the pressure-sensitive adhesive layer <NUM> and substrate layer <NUM> are subjected to, for example, punching or half etching.

Then, the probe member <NUM> is prepared, and inserted into the opening <NUM>.

As shown in <FIG>, to prepare the probe member <NUM>, first, the probe-containing sheet <NUM> is prepared.

The probe-containing sheet <NUM> includes a second release sheet <NUM>, a probe pattern <NUM> formed on the second release sheet <NUM>, a pressure-sensitive adhesive layer <NUM> formed on the second release sheet <NUM> and in which the probe pattern <NUM> is embedded, and a substrate layer <NUM> disposed on the adhesive upper face <NUM> of the pressure-sensitive adhesive layer <NUM>.

The second release sheet <NUM> has the same configuration as that of the above-described first release sheet <NUM>.

The probe pattern <NUM> has the same pattern as that of the probe <NUM>, and the material of the probe pattern <NUM> is the same as the material of the probe <NUM>. The probe pattern <NUM> has a flat area larger than the virtual circle passing through the outer side face <NUM> of the probe <NUM>.

The pressure-sensitive adhesive layer <NUM> and substrate layer <NUM> of the probe-containing sheet <NUM> has the same configuration as that of the above-described pressure-sensitive adhesive layer <NUM> and substrate layer <NUM>.

The probe-containing sheet <NUM> is prepared, for example, by the method described in <CIT> and <CIT>.

Although not shown, to be specific, after forming a seed layer composed of copper on the upper face of a release layer composed of stainless steel, a photoresist is laminated on the entire upper face of the seed layer. Then, the photoresist is exposed to light and developed, thereby forming the photoresist into a reverse pattern of the probe pattern <NUM>. Then, after the probe pattern <NUM> is formed on the upper face of the seed layer by electrolytic plating, the photoresist is removed. Thereafter, an application liquid containing the material of the pressure-sensitive adhesive layer <NUM> is applied to cover the probe pattern <NUM>, and cured to form the pressure-sensitive adhesive layer <NUM>. Then, the substrate layer <NUM> is bonded to the upper face of the pressure-sensitive adhesive layer <NUM> by, for example, a laminator. Then, the release layer is removed from the lower face of the seed layer, and then the seed layer is removed. Thereafter, as necessary, the second release sheet <NUM> is bonded to the lower face of the pressure-sensitive adhesive layer <NUM>.

In this manner, the probe-containing sheet <NUM> is prepared.

As shown in <FIG>, then, a cutting line <NUM> is formed on the probe pattern <NUM>, pressure-sensitive adhesive layer <NUM>, and substrate layer <NUM> into a generally circular shape in plan view. The cutting line <NUM> is formed, for example, by punching. The cutting line <NUM> divides the probe pattern <NUM>, pressure-sensitive adhesive layer <NUM>, and substrate layer <NUM> into inner portions and outer portions, but the cutting line <NUM> is not formed on the second release sheet <NUM>. The size of the cutting line <NUM> is the same as the internal diameter of the adhesion opening <NUM> and substrate opening <NUM>. That is, the cutting line <NUM> coincides with the virtual circle passing through the outer side face <NUM>.

By forming the cutting line <NUM>, the probe member <NUM> is formed.

In the probe member <NUM>, the outer side face <NUM> of the probe <NUM> is flush with the outer side face of the pressure-sensitive adhesive layer <NUM>. In the probe member <NUM>, the outer side face <NUM> is exposed to the outside in radial direction from the outer side face of the pressure-sensitive adhesive layer <NUM>.

Then, as shown in the arrow in <FIG>, the probe member <NUM> is pulled out from the second release sheet <NUM>. To be specific, the adhesive lower face <NUM> and probe lower face <NUM> of the probe member <NUM> are released from the second release sheet <NUM>.

Thereafter, as shown by the arrow in <FIG>, the probe member <NUM> is inserted in the opening <NUM>.

At this time, a gap is created between the pressure-sensitive adhesive layer <NUM>, substrate layer <NUM>, and probe <NUM> of the probe member <NUM>, and the pressure-sensitive adhesive layer <NUM> and substrate layer <NUM> surrounding the opening <NUM>. That is, the probe member <NUM> is inserted into the opening <NUM> so as to form the substrate opening <NUM> and the adhesion opening <NUM>.

Thereafter, as shown in <FIG>, the connecter <NUM> is provided in the substrate opening <NUM> and the adhesion opening <NUM>.

To be specific, the electrically conductive resin composition (electrically conductive composition liquid) is injected (or applied) to the substrate opening <NUM> and adhesive opening <NUM>. Thereafter, the electrically conductive resin composition (electrically conductive composition liquid) is heated to remove the solvent, and to crosslink the binder resin with the cross-linking agent.

In this manner, the biosensor laminate <NUM> including the first release sheet <NUM>, pressure-sensitive adhesive layer <NUM>, substrate layer <NUM>, wire layer <NUM>, probe <NUM>, and connecter <NUM> is produced. The biosensor laminate <NUM> is distributed singly, and is an industrially applicable device. To be specific, the biosensor laminate <NUM> can be distributed singly, separately from the electronic component <NUM> and battery <NUM> (ref: phantom line in <FIG>) to be described later. That is, the biosensor laminate <NUM> is not mounted with the electronic component <NUM> or battery <NUM>, and is a component for producing a wearable biosensor <NUM>.

As shown in <FIG>, thereafter, the two terminals <NUM> of the electronic components <NUM> are electrically connected with the first terminal 17A and the third terminal 17C. At this time, the lower face of the electronic component <NUM> is allowed to contact the substrate upper face <NUM>.

In this manner, the wearable biosensor <NUM> is produced.

The wearable biosensor <NUM> includes a pressure-sensitive adhesive layer <NUM>, a substrate layer <NUM>, a wire layer <NUM>, a probe <NUM>, a connecter <NUM>, an electronic component <NUM>, and a first release sheet <NUM>, and preferably, is composed only of these. As shown in <FIG>, the wearable biosensor <NUM> may be composed only of the pressure-sensitive adhesive layer <NUM>, substrate layer <NUM>, wire layer <NUM>, probe <NUM>, connecter <NUM>, and electronic component <NUM> without including the first release sheet <NUM>.

Next, description is given below of a method of using the wearable biosensor <NUM>.

To use the wearable biosensor <NUM>, first, the battery <NUM> is mounted on the wearable biosensor <NUM>.

The battery <NUM> has a substantially flat plate (box) shape extending in surface direction. The battery <NUM> has two terminals (not shown) provided at its lower face.

To allow the battery <NUM> to be mounted on the wearable biosensor <NUM>, the two terminals (not shown) of the battery <NUM> are electrically connected with the second terminal 17B and fourth terminal 17D.

At that time, the lower face of the battery <NUM> is allowed to contact the substrate upper face <NUM>.

Then, the first release sheet <NUM> (ref: arrow and phantom line of <FIG>) is released from the pressure-sensitive adhesive layer <NUM> and probe <NUM>.

As shown in the phantom line in <FIG>, then, the adhesive lower face <NUM> of the pressure-sensitive adhesive layer <NUM> is allowed to contact, for example, a skin <NUM> of a human body. To be specific, the pressure-sensitive adhesive layer <NUM> is allowed to pressure-sensitively adhere to a surface of the skin <NUM>.

Then, the probe lower face <NUM> of the probe <NUM> makes contact with the surface of the skin <NUM>, by allowing the adhesive lower face <NUM> to pressure-sensitively adhere (attaching) to the skin <NUM>.

Then, the probe <NUM> senses electric signals from the living body, and the electric signals sensed at the probe <NUM> are inputted to the electronic component <NUM> through the connecter <NUM> and wire layer <NUM>. The electronic component <NUM> processes the electric signal based on the electric power supplied from the battery <NUM>, and store that information. Furthermore, as necessary, the electric signals are converted to electro-magnetic waves, and they are wirelessly transmitted to an external receiver.

Examples of the wearable biosensor <NUM> include devices that can sense electric signals of a living body and monitor conditions of a living body, and to be specific, a wearable electrocardiograph, wearable electroencephalograph, wearable sphygmomanometer, wearable pulse meter, wearable electromyograph, wearable thermometer, and wearable accelerometer. These devices can be individual devices, or can be a device including the plurality of these devices.

The wearable biosensor <NUM> is preferably used as a wearable electrocardiograph. In the wearable electrocardiograph, the probe <NUM> senses cardiac action potential as electric signals.

The living body includes a human body and a living thing other than the human body, but preferably, the living body is a human body.

In the wearable biosensor <NUM>, the connector <NUM> is prepared from the above-described electrically conductive composition, and therefore it flexibly conforms to the contraction of the skin <NUM>, and also has excellent durability. Therefore, in the wearable biosensor <NUM>, connection reliability with the connector <NUM> is excellent, and sensing reliability is excellent.

In the above-described description, the connector <NUM> is cylindrical, but the shape is not particularly limited, and for example, it can have a prism shape.

The specific numerical values of mixing ratio (content), physical property value, and parameter used in the description below can be replaced with the upper limit values (numerical values defined with "or less" or "below") or lower limit values (numerical values defined with "or more" or "more than") of the corresponding numerical values of mixing ratio (content), physical property value, and parameter described in "DESCRIPTION OF EMBODIMENTS" above.

The components used in Examples are shown below.

<NUM> of PEDOT-PSS (electrical conductive polymer) aqueous solution (Clevious PH1000, manufactured by Heraeus Holding), <NUM> of <NUM>% aqueous solution of modified polyvinyl alcohol) (Gohsenx Z-<NUM>, manufactured by The Nippon Synthetic Chemical Industry Co. ), <NUM> of <NUM>% aqueous solution (Safelink SPM-<NUM>, manufactured by The Nippon Synthetic Chemical Industry Co. ) of cross-linking agent (zirconium compound), <NUM> of plasticizer (glycerine, manufactured by Wako Pure Chemical Industries, Ltd. ), and <NUM> of surfactant (SILFACE SAG503A, manufactured by Nissin Chemical co. ) were blended, and mixed for <NUM> minutes in an ultrasonic bath, thereby preparing a homogenous electrically conductive composition aqueous solution.

Then, the electrically conductive composition aqueous solution was applied on a PET (polyethylene terephthalate) film using an applicator, and thereafter, dried in a drying oven at <NUM> for <NUM> minutes, and then heated at <NUM> for <NUM> minutes to be subjected to crosslinking, thereby forming an electrically conductive sheet (prepared).

The electrically conductive sheet was blue black and rubbery.

An electrically conductive sheet was formed (prepared) in the same manner as in Example <NUM>, except that the formulation of the components was changed in accordance with Table <NUM>.

The volume resistivity of the electrically conductive sheet was measured and calculated with <NUM> terminal sensing method using a digital multimeter (manufactured by ADVANTEST R6552).

The electrically conductive sheet was subjected to tensile test with the following conditions, and tensile strength and tensile elongation were calculated by the fracture point stress value.

Then, tensile strength and tensile elongation were evaluated based on the criteria below, and then overall high tenacity was evaluated based on the results.

The electrically conductive sheet having a width of <NUM>, length of <NUM>, and thickness of <NUM> was folded into two so that the fold was along the width direction. Ten electrically conductive sheets were folded in this manner. Then, the fracture rate (for example, fracture rate is <NUM>% when two electrically conductive sheets out of the ten fractured) of the fold of the electrically conductive sheet folded into two was determined, and flexibility was evaluated based on the following.

While the illustrative embodiments of the present invention are provided in the above description, such is for illustrative purpose only and it is not to be construed as limiting in any manner. Modification and variation of the present invention that will be obvious to those skilled in the art is to be covered by the following claims.

Claim 1:
A biosensor comprising:
a wire layer,
a probe that makes contact with a surface of a living body, and
a connector that electrically connects the wire layer with the probe,
wherein the connector is prepared from an electrically conductive composition comprising an electrical conductive polymer, a binder resin, and a plasticizer, wherein
the plasticizer contains a polyol compound, and
a ratio of the polyol compound relative to <NUM> parts by mass of the electrical conductive polymer is <NUM> parts by mass or more and <NUM> parts by mass or less.