WO2019167744A1

WO2019167744A1 - Sensor electrode and planar sensor using same

Info

Publication number: WO2019167744A1
Application number: PCT/JP2019/006275
Authority: WO
Inventors: 伊東　邦夫; 真治飯尾; 日比野　委茂
Original assignee: 住友理工株式会社
Priority date: 2018-02-28
Filing date: 2019-02-20
Publication date: 2019-09-06
Also published as: CN110612437A; JPWO2019167744A1; DE112019000033T5

Abstract

A sensor electrode according to the present invention is a fabric-like electrode comprising a woven fabric or knit fabric in which an electroconductive yarn and an insulating yarn are used, and has an insulating part formed including the insulating yarn, and electroconductive parts which are formed including the electroconductive yarn and which are disposed with the insulating part therebetween. The sensor electrode is flexible and not susceptible to breakage or an increase in electrical resistance when stretched. A planar sensor (1) is provided with a dielectric layer (10), and a front electrode (2) and a back electrode (3) disposed with the dielectric layer (10) therebetween in the thickness direction. The front electrode (2) and the back electrode (3) comprise sensor electrodes, and detection parts (D) are established in portions where electroconductive parts (01X-08X) of the front electrode (2) and electroconductive parts (01Y-08Y) of the back electrode (3) face each other via the dielectric layer (10).

Description

Electrode for sensor and planar sensor using the same

The present invention relates to a sensor electrode used for a flexible piezoelectric sensor, a capacitive sensor, and the like, and a planar sensor using the same.

A flexible capacitive sensor with an elastomeric dielectric layer between the electrodes has been developed. In this type of capacitance type sensor, the pressure is detected based on a change in capacitance caused by the dielectric layer being compressed by the load and the distance between the electrodes being reduced. The electrode that constitutes the sensor is required to be flexible enough to follow the deformation of the dielectric layer. As a material for forming a flexible electrode, for example, a conductive paint in which a conductive material such as carbon powder is blended into an elastomer can be cited (for example, see Patent Documents 1 and 2).

On the other hand, cloth-like electrodes using conductive yarn have been proposed. For example, Patent Document 3 describes a cloth-like electrode in which an electrode portion is formed by sewing a plurality of conductive threads on a non-conductive cloth by sewing a sewing machine. Patent Document 4 describes a conductive cloth obtained by plain weaving plated conductive fibers together with insulating fibers. Patent Document 5 describes a modified conductive knitted fabric in which conductive yarn is knitted. Patent Document 6 describes a metal-coated fabric in which a metal layer is formed on the surface of a fiber constituting the fabric.

JP2013-96716A Japanese Patent Laying-Open No. 2015-7756 JP 2009-42108 A JP 2007-262623 A JP-A-62-200701 JP 2008-266814 A

An electrode in which a conductive material is blended with an elastomer can be greatly expanded because the base elastomer is flexible. However, the contact between the conductive materials is likely to be cut off as much as it can be extended, which tends to cause a decrease in conductivity and breakage. In addition, since it is necessary to devise the shape of the conductive material in order to facilitate contact between the conductive materials or to maintain the contact even when the conductive material is stretched, the cost of the material is increased. In addition, it is difficult to uniformly disperse the conductive material in the elastomer polymer, and it is necessary to use a dispersant or a special dispersing device. For this reason, the process and labor required for manufacturing a conductive paint increase, and the manufacturing cost also increases. Furthermore, it is difficult to apply the conductive paint in a thin film with high dimensional accuracy.

Further, as described in Patent Document 3, according to the configuration in which the conductive thread is sewn on the non-conductive cloth, the conductive thread is alternately arranged up and down with the non-conductive cloth interposed therebetween. For this reason, when the cloth is arranged with a dielectric layer in between, the distance between the electrodes differs depending on the upper and lower positions of the conductive yarn, and the detection accuracy is reduced in the sensor that detects the capacitance based on the distance between the electrodes. To do. Further, since the conductive cloth or conductive knitted fabric described in Patent Documents 4 to 6 is entirely conductive, a sensor for measuring a load distribution that needs to specify a position where a load is applied. It is not suitable for an electrode.

The present invention has been made in view of such circumstances, and provides a sensor electrode that has flexibility and is less likely to cause an increase in electrical resistance and breakage when stretched, and a planar sensor that is flexible and highly durable. The task is to do.

(1) In order to solve the above-described problem, the sensor electrode of the present invention is a cloth-like sensor electrode made of a woven fabric or a knitted fabric using a conductive yarn and an insulating yarn, and includes the insulating yarn. And an electrically conductive portion that is formed to include the conductive yarn and is disposed with the insulating portion interposed therebetween.

The conductive yarn is a conductive yarn, and the insulating yarn is an insulating yarn. In this specification, the electrical resistance value per 100 mm in one yarn is measured. If it is less than 1 × 10 ¹⁰ Ω, it is a conductive yarn, and if it is 1 × 10 ¹⁰ Ω or more, it is an insulating yarn. .

The conductive part is a part having a surface resistance value of less than 1 × 10 ⁷ Ω, and the insulating part is a part having a surface resistance value of 1 × 10 ⁷ Ω or more. In this specification, the value measured by the following measuring method is adopted as the surface resistance value. First, a pair of electrodes (a front electrode and a back electrode) are arranged to face each other on the front and back surfaces of the measurement target part. The front electrode has a 10 mm square shape, and the back electrode has a 20 mm square shape. In addition, a square frame-shaped guard electrode is disposed 2 mm away from the surface electrode so as to surround the surface electrode. Then, the voltage V is applied to the guard electrode, the current I flowing from the guard electrode to the surface electrode is measured, and the surface resistance value Rs is calculated from the equation Rs = V / I.

(2) The planar sensor of the present invention includes a dielectric layer, and a front side electrode and a back side electrode arranged with the dielectric layer sandwiched in the thickness direction. The sensor electrode is characterized in that a detection portion is set at a portion where the conductive portion of the sensor electrode faces through the dielectric layer.

(1) The sensor electrode of the present invention is made of a woven fabric or a knitted fabric. For this reason, although it is flexible, it is hard to expand | extend largely compared with the conventional electrode which uses an elastomer as a base material. Therefore, it is difficult to cause a decrease in electrical conductivity or breakage at the time of extension, and the durability is high. Thereby, it is applicable also to the use which detects a heavy load. In addition, the heat resistance is higher than that of a conventional electrode using an elastomer as a base material. In addition, since no conductive paint is used, there is no need to consider the shape and dispersion method of the conductive material, problems during application of the conductive paint, and the like. The sensor electrode of the present invention can be easily manufactured by weaving or knitting a conductive yarn and an insulating yarn.

When a conductive paint is used, as described in

Patent Documents

1 and 2 described above, a conductive paint is applied on a resin base material to form an electrode. For this reason, when the sensor is configured, the air permeability and the moisture permeability are lowered, and there is a problem that when the sensor is disposed on a bed mattress, a car seat or the like, it is easily stuffy. In addition, there is a problem that the urethane layer disposed between the electrodes is easily hydrolyzed and the durability is lowered. In this respect, since the sensor electrode of the present invention is made of a woven fabric or a knitted fabric, it has excellent breathability and moisture permeability. Therefore, it is possible to reduce conventional problems such as dampness and a decrease in durability.

The sensor electrode of the present invention can be used as an electrode for a piezoelectric sensor having a piezoelectric layer in addition to a capacitive sensor having a dielectric layer. Here, the sensor electrode of the present invention has a conductive portion formed including a conductive yarn and an insulating portion formed including an insulating yarn. That is, as in the conductive cloth or conductive knitted fabric described in Patent Documents 4 to 6, the whole is not conductive, but part (only the conductive part) is conductive. It is. Further, the conductive portion is disposed with the insulating portion interposed therebetween. That is, at least a part of the conductive part is separated by the insulating part. Thereby, a conductive pattern is formed on the sensor electrode of the present invention. Therefore, the sensor electrode of the present invention is suitable as a sensor electrode for measuring a load distribution that requires specifying a position where a load is applied. And since the electrode for sensors of this invention is a textile fabric or a knitted fabric, an electroconductive part can be arrange | positioned with various forms only by changing the kind of thread | yarn. In other words, according to the sensor electrode of the present invention, various conductive patterns can be easily formed.

(2) The planar sensor of the present invention includes the sensor electrode of the present invention as a front side electrode and a back side electrode. For this reason, even if it repeats a deformation | transformation, the electroconductive fall in an electrode and a fracture | rupture do not produce easily and it is excellent in durability. Therefore, it can also be used for applications that detect large loads. In addition, a surface sensor capable of measuring the load distribution with high accuracy can be manufactured at a lower cost. Moreover, the planar sensor of this invention is excellent in air permeability and moisture permeability compared with the planar sensor using the conventional resin sheet. For this reason, it is suitable as a load distribution sensor disposed on a mattress of a bed, a seat of a car or wheelchair, a shoe sole, or the like.

It is a permeation | transmission top view of the planar sensor of 1st embodiment. It is II-II sectional drawing of the same surface sensor. It is a top view of the front side electrode which comprises the same surface sensor. FIG. 4 is an enlarged view of a circle IV in FIG. 3. It is a top view of the back side electrode which comprises the planar sensor of 2nd embodiment. FIG. 6 is an enlarged view of a circle VI in FIG. 5. It is a top view of the front side electrode which shows another arrangement | positioning form of an electroconductive part.

Next, embodiments of the sensor electrode and the planar sensor of the present invention will be described. In the first and second embodiments, the sensor electrode of the present invention is embodied as a front side electrode and a back side electrode of a planar sensor. In the following drawings, the vertical direction corresponds to the thickness direction of the dielectric layer.

<First embodiment>
[Configuration of surface sensor]
First, the configuration of the planar sensor of this embodiment will be described. In FIG. 1, the permeation | transmission top view of the planar sensor of this embodiment is shown. FIG. 2 shows a II-II cross-sectional view of the same surface sensor. FIG. 3 shows a top view of the front electrode constituting the same surface sensor. FIG. 4 shows an enlarged view of the circle IV in FIG. For convenience of explanation, in FIG. 1, the detection unit is shown with dotted hatching.

As shown in FIGS. 1 and 2, the planar sensor 1 includes a dielectric layer 10, a front side electrode 2, and a back side electrode 3. The dielectric layer 10 is made of urethane foam (urethane rubber foam) and has a rectangular sheet shape with a thickness of 4 mm. The dielectric layer 10 is substantially the same size as the front electrode 2 and the back electrode 3 except for the thickness.

The front electrode 2 is disposed on the upper surface of the dielectric layer 10. The front-side electrode 2 is a rectangular twill fabric in which a conductive yarn and an insulating yarn are twilled. As shown in FIG. 3, the front electrode 2 has eight conductive portions 01X to 08X and an insulating portion 20. For convenience of explanation, in FIG. 3, the conductive portions are shown hatched. The conductive portions 01X to 08X each have a strip shape with a width of 10 mm. The conductive portions 01X to 08X each extend in the front-rear direction. The conductive portions 01X to 08X are arranged in parallel to each other with a spacing of 3 mm in the left-right direction. The surface resistance values of the conductive portions 01X to 08X are 1 × 10 ² to 10 ³ Ω.

The warp yarns constituting the conductive portions 01X to 08X are conductive yarns, and the weft yarns are insulating yarns. The conductive yarn is obtained by subjecting the surface of an acrylic fiber to copper sulfate plating, and has a thickness of 370 dtex. The electric resistance value per 100 mm length of the conductive yarn is 1 × 10 ⁴ to 10 ⁵ Ω. The insulating yarn is made of polyethylene terephthalate (PET) fiber and has a thickness of 333 dtex. The electric resistance value per 100 mm length of the insulating yarn is 1 × 10 ¹³ to 10 ¹⁴ Ω. As shown in an enlarged view in FIG. 4, the conductive portions 01X to 08X have a single weft (insulating yarn) after the warp (conductive yarn) passes over two wefts (insulating yarn). It has a twill structure that passes under In FIG. 4, the insulating yarn is indicated by a thin line, and the warp passing over the weft is hatched. Of the warp yarns, the conductive yarn is indicated by a right-up hatching, and the insulating yarn is indicated by a right-down hatching.

The insulating part 20 is disposed on both sides in the left-right direction of the individual conductive parts 01X to 08X. In other words, the conductive portions 01X to 08X are arranged so as to be separated from each other by the insulating portion 20 having a width of 3 mm. The surface resistance value of the insulating portion 20 is 1 × 10 ⁹ to 10 ¹⁰ Ω. The warp and weft constituting the insulating portion 20 are both made of the same PET fiber as the insulating yarn constituting the conductive portions 01X to 08X. As shown in FIG. 4 in an enlarged manner, in the insulating portion 20 as well as the conductive portions 01X to 08X, the warp yarn (insulating yarn) passes over the two weft yarns (insulating yarn). , Having a twill structure that passes under one weft (insulating thread).

Metal eyelets 21 are attached to the front ends of the conductive portions 01X to 08X, respectively. The conductive portions 01X to 08X are connected to the front-side wirings 01x to 08x via the eyelet 21. The front side wirings 01x to 08x are electrically connected to the control device via a connector (not shown).

The back electrode 3 is disposed on the lower surface of the dielectric layer 10. The back side electrode 3 is a twill fabric having the same rectangular shape as that of the front side electrode 2, and has eight conductive portions 01 Y to 08 Y and an insulating portion 30. The back side electrode 3 is arranged in a state in which the front side electrode 2 is rotated 90 ° clockwise. The conductive portions 01Y to 08Y each have a strip shape with a width of 10 mm. The conductive portions 01Y to 08Y each extend in the left-right direction. The conductive portions 01Y to 08Y are arranged in parallel to each other with a spacing of 3 mm in the front-rear direction. The insulating part 20 is disposed on both sides in the front-rear direction of the individual conductive parts 01Y to 08Y. In other words, the conductive portions 01Y to 08Y are each separated by the insulating portion 30 having a width of 3 mm. The configurations of the conductive portions 01Y to 08Y and the insulating portion 30 are the same as the configurations of the conductive portions 01X to 08X and the insulating portion 20 of the front side electrode 2. When viewed from above, the conductive portions 01X to 08X of the front electrode 2 and the conductive portions 01Y to 08Y of the back electrode 3 are arranged substantially orthogonally and are arranged in a lattice pattern. A plurality of detection units D are set in a portion where the conductive portions 01X to 08X and the conductive portions 01Y to 08Y overlap (a portion facing through the dielectric layer 10). A total of 64 detectors D are set.

A metal eyelet 31 is attached to the left end of each of the conductive portions 01Y to 08Y. The conductive portions 01Y to 08Y are connected to the back side wirings 01y to 08y through the eyelet 31. The back side wirings 01y to 08y are electrically connected to the control device via a connector (not shown).

[Motion of planar sensor]
Next, the movement of the planar sensor 1 of the present embodiment will be described. First, voltage is applied to the conductive portions 01X to 08X of the front-side electrode 2 and the conductive portions 01Y to 08Y of the back-side electrode 3 before a load is applied to the planar sensor 1 (initial state). The capacitance C is calculated. Subsequently, after the load is applied to the planar sensor 1, the electrostatic capacitance C is calculated for each detection unit D in the same manner. In the detection portion D at the portion where the load is applied, the distance between the conductive portions 01X to 08X and the conductive portions 01Y to 08Y arranged with the dielectric layer 10 interposed therebetween is small. Thereby, the electrostatic capacitance C of the said detection part D becomes large. Based on the change amount ΔC of the capacitance C, the surface pressure for each detection unit D is calculated. In this way, the load distribution can be measured.

[Function and effect]
Next, the function and effect of the front side electrode 2, the back side electrode 3, and the planar sensor 1 of this embodiment will be described. In addition, since the front side electrode 2 and the back side electrode 3 have the same structure, here, the front side electrode 2 is described on behalf of both.

The front-side electrode 2 is made of a twill fabric in which a conductive yarn and an insulating yarn are twilled. For this reason, it is flexible and highly flexible. In addition, the conductivity is not easily lowered or broken, and the durability is high. Furthermore, since the thread | yarn which has a copper sulfate plating layer is used as an electroconductive thread | yarn, the oxidative degradation of an electroconductive thread | yarn is suppressed and the time-dependent change of electroconductivity is small. In the front-side electrode 2, the warp yarn is a conductive yarn and the weft yarn is an insulating yarn. Therefore, the conductive portions 01X to 08X and the insulating portion 20 can be woven by simply changing the warp from the conductive yarn to the insulating yarn (or vice versa). Therefore, even when the front electrode 2 has a large area, it can be easily manufactured using a loom. In addition, the conductive portion can be arranged in various forms simply by changing the type of yarn. That is, various conductive patterns can be easily formed.

According to the front-side electrode 2, there is no need to consider the shape of the conductive material, the dispersion method, problems during application of the conductive paint, and the like due to the use of the conductive paint. Therefore, the front side electrode 2 and by extension, the planar sensor 1 can be manufactured at a lower cost.

The front electrode 2 is excellent in air permeability and moisture permeability. For this reason, even if it arrange | positions the planar sensor 1 to seats, such as a mattress of a bed or a car, it is hard to be steamed. Further, since the hydrolysis of the dielectric layer 10 is suppressed, the durability is not easily lowered.

The conductive portions 01X to 08X are adjacent to each other with the insulating portion 20 interposed therebetween. Thereby, a conductive pattern having a vertical stripe pattern is formed on the front electrode 2. In the front side electrode 2, the whole is not conductive, but only the region where the conductive portions 01X to 08X are disposed has conductivity. The strip-shaped conductive portions 01X to 08X are arranged in parallel across the entire surface of the dielectric layer 10 with the insulating portion 20 interposed therebetween. Similarly, in the back electrode 3, the strip-like conductive parts 01Y to 08Y are arranged in parallel across the entire surface of the dielectric layer 10 with the insulating part 30 interposed therebetween. The detection unit D is arranged using the intersections of the front-side electrodes 01X to 08X and the back-side electrodes 01Y to 08Y. By doing so, the detection part D can be easily dispersed on the entire surface of the dielectric layer 10. Further, even when measuring the load distribution in a wide area, it is not necessary to dispose the conductive portion for each site where it is desired to detect the load.

In the planar sensor 1, the conductive portions 01X to 08X of the front electrode 2 and the front wirings 01x to 08x were connected using the eyelet 21. As a result, the connection between the conductive portions 01X to 08X and the front-side wirings 01x to 08x can be performed easily, reliably, and at low cost.

<Second embodiment>
The difference between the planar sensor of the present embodiment and the planar sensor of the first embodiment is that the front side electrode and the back side electrode are not woven but knitted. Here, the difference will be mainly described. In FIG. 5, the top view of the back side electrode which comprises the planar sensor of this embodiment is shown. FIG. 6 shows an enlarged view of the circle VI in FIG. 5 corresponds to FIG. 1 described above, and the same parts as those in FIG. 1 are denoted by the same reference numerals. In FIG. 6, the insulating yarn is indicated by a thin dotted line.

The back side electrode 3 is disposed on the lower surface of the dielectric layer 10 (see FIG. 1). The back-side electrode 3 is a rectangular flat knitted fabric in which conductive yarns 301 and insulating yarns 300 are alternately flat-knitted in the front-rear direction. As shown in FIG. 5, the back-side electrode 3 has eight conductive portions 01Y to 08Y and an insulating portion 30. For convenience of explanation, in FIG. 5, the conductive portions are hatched. The conductive portions 01Y to 08Y each have a strip shape with a width of 10 mm. The conductive portions 01Y to 08Y each extend in the left-right direction. The conductive portions 01Y to 08Y are arranged in parallel to each other with a spacing of 3 mm in the front-rear direction. The surface resistance values of the conductive portions 01Y to 08Y are 1 × 10 ² to 10 ³ Ω. The insulating part 30 is arranged on both sides in the front-rear direction of the individual conductive parts 01Y to 08Y. In other words, the conductive portions 01Y to 08Y are each separated by the insulating portion 30 having a width of 3 mm. The surface resistance value of the insulating portion 30 is 1 × 10 ⁹ to 10 ¹⁰ Ω.

As shown in FIG. 6 in an enlarged manner, the conductive portions 01Y to 08Y have a flat knitting structure with the conductive yarn 301. As in the first embodiment, the conductive yarn 301 is obtained by performing copper sulfate plating on the back surface of the acrylic fiber and has a thickness of 370 dtex. The electric resistance value per 100 mm length of the conductive yarn 301 is 1 × 10 ⁴ to 10 ⁵ Ω. The insulating portion 30 has a flat knitting structure with the insulating yarn 300. The insulating yarn 300 is made of PET fiber as in the first embodiment, and has a thickness of 333 dtex. The electric resistance value per 100 mm length of the insulating yarn 300 is 1 × 10 ¹³ to 10 ¹⁴ Ω.

The front side electrode 2 is the same rectangular flat knitted fabric as the back side electrode 3, and is arranged on the upper surface of the dielectric layer 10 with the back side electrode 3 rotated 90 ° counterclockwise. The configurations of the conductive portions 01X to 08X and the insulating portion 20 of the front side electrode 2 are the same as those of the back side electrode 3.

The planar sensor of the present embodiment has the same function and effect with respect to parts having the same configuration as the planar sensor of the first embodiment. According to this embodiment, the front side electrode 2 and the back side electrode 3 consist of a flat knitted fabric. For this reason, the front side electrode 2 and the back side electrode 3 are more flexible and excellent in elasticity. Since the front-side electrode 2 and the back-side electrode 3 have the same configuration, when the back-side electrode 3 is described on behalf of both, only changing the knitting yarn from the conductive yarn 301 to the insulating yarn 300 (or vice versa) The conductive portions 01Y to 08Y and the insulating portion 30 can be knitted separately. Therefore, even when the back side electrode 3 has a large area, it can be easily manufactured using a knitting machine. Further, since the conductive portions 01Y to 08Y can be arranged in various forms only by changing the type of yarn, various conductive patterns can be easily formed.

<Other forms>
The embodiments of the sensor electrode and the planar sensor of the present invention have been described above. However, the embodiment is not limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

[Sensor electrode]
The sensor electrode of the present invention is a cloth-like electrode made of a woven fabric or a knitted fabric using a conductive yarn and an insulating yarn. In the case of a woven fabric, the weaving method is not particularly limited. What is necessary is just to select suitably the weaving method from which a desired characteristic is acquired from a plain weave, a twill weave, a satin weave, etc. For example, in the case of plain weave, it is strong and excellent in durability, but the flexibility is slightly lowered. In the case of twill weave, there are many options for organization, and it is flexible and flexible. In the case of a knitted fabric, the knitting method is not particularly limited. A weaving method such as flat knitting, rubber knitting, pearl knitting, and knit knitting, or warp knitting such as tricot or double raschel knitting may be appropriately selected. For example, flat knitting has a structure in which loops are continuous in the weft direction. For this reason, it is easy to make it thin and excellent in the stretchability in the weft direction. Rubber knitting is more stretchable because the front and back are the same stitches. The binding knitting has a structure in which two front and back knitted fabrics are connected by a binding yarn. Therefore, for example, when a knitted fabric having an electrode protection function is employed on at least one of the front and back surfaces, the electrode can be protected from the outside. Double raschel knitting has a structure in which loops are continuous in the warp direction. For this reason, it becomes a stable knitted fabric and can be made into a three-dimensional structure. In the case of a three-dimensional structure, the air permeability increases and the elasticity of the fabric increases, so that the conductive yarn can be protected. The knitted fabric is more flexible than the woven fabric. Whether it is woven or knitted, the weaving or knitting method may be changed in one electrode.

The conductive yarn may be any conductive yarn, and the material thereof is A) metal fiber, B) carbon fiber, C) synthetic fiber is subjected to plating treatment, coating treatment, sputtering treatment, etc. to make it conductive. Examples thereof include fibers provided, D) fibers obtained by kneading a conductive material in synthetic fibers, and E) conductive polymer fibers. Hereinafter, specific examples of each fiber, suitable materials, and the like are listed.
A) Metal fibers: fibers such as gold, silver, copper, stainless steel, tungsten, molybdenum, beryllium, and amorphous wires.
B) Carbon fiber: Polyacrylonitrile (PAN) -based carbon fiber, pitch-based carbon fiber.
C) Plating material: aluminum, copper, silver, gold, palladium, copper sulfate, copper sulfide, copper nickel.
Coating material: Carbon paint, metal oxide paint, conductive polymer paint in which carbon nanotubes or conductive carbon black are dispersed.
Sputtering materials: chromium, copper, titanium, silver, platinum, gold, stainless steel, nickel-chromium alloy, copper-zinc alloy.
D) Conductive material: conductive carbon black, carbon nanotube, metal powder.
Synthetic fibers used in C) and D): polyester fibers such as PET, polytrimethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon and aramid, polyimide fibers, polyolefin fibers such as polyethylene and polypropylene, vinylon fibers and vinylidene fibers , Polyvinyl chloride fiber, acrylic fiber, polyurethane fiber, polyclar fiber, fluorine fiber, novoloid fiber, polyetherester fiber, polylactic acid fiber, polyarylate fiber, ultra high strength polyethylene fiber, polyacetal fiber.

For example, when a synthetic fiber is plated, a conductive thread can be easily manufactured. Among these, yarns having a copper sulfate plating layer or a copper sulfide plating layer have the advantages that they are softer and less likely to break than metal fibers and carbon fibers, and the plating layer suppresses oxidative degradation and has little change over time in conductivity. .

As long as the electrical resistance value per 100 mm in length is less than 1 × 10 ¹⁰ Ω, the conductive yarn may be a mixture of the conductive yarn made of the fiber and the insulating yarn. Alternatively, a conductive yarn coated with resin may be used. The conductive yarn may be one type or a combination of two or more types.

The insulating yarn may be an insulating yarn, and examples of the material include a) synthetic fiber, b) semi-synthetic fiber, c) regenerated cellulose fiber, d) natural fiber, e) inorganic fiber, and the like. . Specific examples of each fiber are listed below. In addition, the synthetic fiber of a) is as having enumerated in description of an electroconductive thread | yarn. The insulating yarn may be one type or a combination of two or more types.
b) Semi-synthetic fiber: acetate, triacetate, promix.
c) Regenerated cellulose fiber: rayon, vorinosic.
d) Natural fibers: plant fibers such as cotton, kabok, acund, hemp, kenaf, and animal fibers such as wool, silk, angora, cashmere, and mohair.
e) Inorganic fiber: glass fiber, ceramic fiber.

The thickness of the conductive yarn and the insulating yarn is not particularly limited. The thinner the thread, the thinner the electrode can be, and the sensitivity of the sensor can be improved, but there is a problem that it becomes easier to cut. For example, the thickness of the yarn may be 55.5 dtex (50 denier) or more and 1332 dtex (1200 denier) or less. It is more preferable to set it to 165 dtex (150 denier) or more and 660 dtex (600 denier) or less. When using carbon fiber as the conductive yarn, use a product of 1K (1000 filaments per bundle) or more and 60K (60,000 filaments per bundle) or less, more preferably 1K or more and 6K or less. Is desirable.

The cross-sectional shapes of the conductive yarn and the insulating yarn are not particularly limited, and various shapes such as a circle, an ellipse, a rectangle, a trapezoid, and a triangle can be adopted. The conductive yarn and the insulating yarn may be hollow fibers. The conductive yarn and the insulating yarn may be made of a single fiber, a blended yarn or a twisted yarn. In the case of a twisted yarn, since the strength of the yarn is high, there is an advantage that it is difficult to cut when making a woven fabric. Further, when making a woven fabric, a laundry paste or the like may be applied to the yarn. By doing so, friction can be reduced and cutting of the yarn can be suppressed.

The sensor electrode of the present invention has a conductive portion and an insulating portion. The surface resistance value of the conductive portion is less than 1 × 10 ⁷ Ω, more preferably less than 1 × 10 ⁶ Ω. The conductive portion is formed including the conductive yarn described above. That is, the conductive portion may be formed only from the conductive yarn, or may be formed using both the conductive yarn and the insulating yarn. For example, when the sensor electrode is a woven fabric, one of the warp and the weft can be a conductive yarn, and the other can be an insulating yarn to form the conductive portion. The number and shape of the conductive portions are not particularly limited. The arrangement form of the conductive part is not particularly limited as long as part or all of the conductive part is arranged via the insulating part. For example, when the sensor is configured, the conductive portion may be arranged in an island shape only in the portion that becomes the detection portion. Or as shown as the electroconductive part 22 in FIG. 7, the strip | belt-shaped electroconductive parts arrange | positioned in parallel in 1st embodiment may be connected by the edge part of a longitudinal direction, and you may make it continue in one stroke. In FIG. 7, a part of the conductive portion 22 is disposed with the insulating portion 20 interposed therebetween. Since the sensor electrode of the present invention is a woven fabric or a knitted fabric, the conductive portion can be arranged in various forms only by changing the type of the yarn. In other words, according to the sensor electrode of the present invention, it is easy to form various conductive patterns.

The surface resistance value of the insulating portion is 1 × 10 ⁷ Ω or more, more preferably 1 × 10 ⁸ Ω or more. The insulating portion is formed including the above-described insulating yarn. The number, shape, and arrangement form of the insulating portions are not particularly limited.

[Surface sensor]
The planar sensor of the present invention includes a dielectric layer, and a front-side electrode and a back-side electrode that are arranged with the dielectric layer sandwiched in the thickness direction and are formed of the sensor electrode of the present invention. For the dielectric layer, an elastomer or a resin (both including a foam) having a relatively high relative dielectric constant may be used. Elastomers include cross-linked rubbers and thermoplastic elastomers. For example, those having a relative dielectric constant of 5 or more (measurement frequency 100 Hz) are suitable. Such elastomers include urethane rubber, silicone rubber, nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, natural rubber, isoprene rubber, ethylene-propylene copolymer rubber, butyl rubber, styrene-butadiene rubber, fluorine rubber, epichlorohydrin rubber, Examples include chloroprene rubber, chlorinated polyethylene, and chlorosulfonated polyethylene. Examples of the resin include polyethylene, polypropylene, polyurethane, polystyrene (including cross-linked foamed polystyrene), polyvinyl chloride, vinylidene chloride copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-acrylic ester copolymer, and the like. Can be mentioned.

The shape of the dielectric layer is not particularly limited, but it is desirable that the dielectric layer is thinner from the viewpoint of improving the sensitivity of the sensor. For example, the thickness of the dielectric layer is desirably 10 mm or less, and more desirably 5 mm or less. Further, a dielectric layer may be configured by laminating a plurality of layers having different materials and shapes.

Examples of the planar sensor using the sensor electrode of the present invention include a piezoelectric sensor in addition to the capacitive sensor of the above embodiment. Also in the case of a piezoelectric sensor, a configuration including a piezoelectric layer, and a front side electrode and a back side electrode that are arranged with the piezoelectric layer sandwiched in the thickness direction and are formed of the sensor electrode of the present invention may be used. The piezoelectric layer may include an elastomer and piezoelectric particles.

In the above embodiment, the conductive portion and the wiring are connected using eyelets. However, the connection form between the conductive portion and the wiring is not particularly limited. For example, you may connect by soldering, a conductive adhesive, etc. Moreover, you may use a part of electroconductive part as a part of wiring.

The planar sensor of the present invention may be used as it is in the first embodiment, but may be used by being housed in an exterior cover. When housed in the exterior cover, it is possible to reduce a sense of incongruity when the planar sensor contacts the human body, and safety, antifouling properties, and design are improved. Suitable materials for the exterior cover include resins and elastomers such as vinyl chloride and thermoplastic polyurethane (TPU), elastic fabrics using elastic fibers such as polyurethane and polyester, and laminates of elastomers and elastic fabrics. The sensor electrode and the outer cover of the present invention may be directly bonded together. However, when the outer cover is an insulating cloth, the sensor electrode and the outer cover are integrally woven by double face weaving. May be.

Since the sensor electrode and the surface sensor of the present invention can be applied to a stretched or bent part, it can be applied to mattresses for medical use, nursing care, etc., car or wheelchair seats, shoe soles, artificial skin of robots, etc. It is suitable for a pressure sensor to be arranged or a wearable biological information sensor. Moreover, it is suitable also for the use of sensing a motion by three-dimensionally winding a sensor around an arm or a leg.

1: Planar sensor, 10: Dielectric layer, 2: Front side electrode, 20: Insulating part, 21: Eyelet, 22: Conductive part, 3: Back side electrode, 30: Insulating part, 31: Eyelet, 300: Insulation 301: conductive yarn, 01X to 08X: conductive portion, 01x to 08x: front side wiring, 01Y to 08Y: conductive portion, 01y to 08y: back side wiring, D: detection portion.

Claims

A cloth-like sensor electrode comprising a woven fabric or a knitted fabric using a conductive yarn and an insulating yarn,
An insulating portion formed including the insulating yarn;
A conductive portion formed including the conductive yarn and disposed across the insulating portion;
A sensor electrode characterized by comprising:
The sensor electrode according to claim 1, wherein the fabric has at least one structure selected from a plain weave, a twill weave, and a satin weave.
The sensor electrode according to claim 1, wherein the woven fabric is a plain woven fabric, a twill woven fabric, or a satin woven fabric.
Made of the fabric,
4. The sensor electrode according to claim 1, wherein one of the warp and the weft in the conductive portion is the conductive yarn, and the other is the insulating yarn. 5.
2. The sensor electrode according to claim 1, wherein the knitted fabric has at least one structure selected from flat knitting, rubber knitting, binding knitting, and double raschel knitting.
2. The sensor electrode according to claim 1, wherein the knitted fabric is a flat knitted fabric, a rubber knitted fabric, a bound knitted fabric, or a double raschel knitted fabric.
The sensor electrode according to any one of claims 1 to 6, wherein the conductive yarn includes a yarn having a plating layer on a surface thereof.
The sensor electrode according to claim 7, wherein the plating layer is a copper sulfate plating layer or a copper sulfide plating layer.
The sensor electrode according to any one of claims 1 to 8, wherein the sensor electrode has a plurality of the conductive portions that are band-shaped and arranged in parallel with the insulating portion interposed therebetween.
A dielectric layer;
A front-side electrode and a back-side electrode arranged with the dielectric layer sandwiched in the thickness direction;
With
The front-side electrode and the back-side electrode are sensor electrodes according to any one of claims 1 to 9, and a detection unit is provided at a portion where the conductive portion of the sensor electrode faces through the dielectric layer. Is a planar sensor.
The front-side electrode and the back-side electrode each have a plurality of the conductive portions arranged in parallel with each other having a strip shape and sandwiching the insulating portion,
The planar sensor according to claim 10, wherein the conductive portion of the front electrode and the conductive portion of the back electrode are disposed substantially orthogonal to each other when viewed from the thickness direction of the dielectric layer.