JP6821949B2 - Distortion sensor unit - Google Patents

Description

The present invention relates to a strain sensor unit and a strain measurement kit.

For example, various attempts have been made to detect the movement of a measurement target whose surface is flexible, such as the body of a human or an animal, with a sensor and convert it into numerical data.

As one method of detecting the movement of the human body, for example, a strain sensor unit in which a thin film strain sensor element capable of detecting expansion and contraction in the longitudinal direction is adhered to the surface of a base material such as gloves and adhesive plasters (the surface on the side not in contact with the human body). Has been proposed as a method for detecting the expansion and contraction of the skin due to the bending and stretching of joints and the like (see Japanese Patent Application Laid-Open No. 2011-47702).

The strain sensor element used in the strain sensor unit described in the publication uses a CNT film made of a plurality of carbon nanotubes oriented in a predetermined direction, and the CNT film can expand and contract relatively large, so that the strain is relatively large. Even if it is, it is said that it can be detected.

However, since the strain sensor unit described in the above-mentioned publication adheres the strain sensor element to a base material such as a glove or an adhesive plaster, if this base material cannot expand and contract accurately according to the movement of the human body, the movement of the human body is accurate. Cannot be detected. A base material such as a glove or an adhesive plaster may expand or contract differently from the measurement target portion directly under the strain sensor element due to movement other than the portion to which the strain sensor element is adhered. Therefore, the distortion sensor unit described in the above-mentioned publication may have insufficient detection accuracy.

Further, when the length of the strain sensor element is large, a measurement error may occur unless the strain sensor element expands and contracts evenly in the length direction. Since the skin of the human body and the like do not necessarily expand and contract evenly, measurement errors are likely to occur when a strain sensor unit using an adhesive plaster or the like is completely attached as described in the above-mentioned publication.

Japanese Unexamined Patent Publication No. 2011-47702

In view of the above inconvenience, it is an object of the present invention to provide a strain sensor unit and a strain measurement kit capable of measuring the movement of a human body or the like relatively accurately.

The strain sensor unit according to the present invention, which has been made to solve the above problems, is laminated with a thread-like or band-shaped strain sensor element that detects expansion and contraction in the longitudinal direction and both ends of one surface of the strain sensor element. It includes a pair of adhesive sheets having an average width larger than that of the strain sensor element and having adhesiveness on at least one surface.

The strain sensor unit is provided with a pair of adhesive sheets laminated on both ends of one surface of the strain sensor element, having an average width larger than that of the strain sensor element, and having adhesiveness on at least one surface. With this pair of adhesive sheets, both ends of the strain sensor element can be fixed to the measurement target. Therefore, in the strain sensor unit, the strain sensor element is not easily displaced, and the strain sensor element is relatively stable even if the surface of the measurement target portion in contact with the strain sensor element expands and contracts unevenly or forms wrinkles. Since it can be expanded and contracted evenly, the movement of the measurement target portion can be measured relatively accurately. The term "adhesive" means a property of being able to adhere without solidifying.

A pair of covering sheets laminated so as to cover the other surface side of both end portions of the strain sensor element may be further provided.

It is preferable that a pair of leads connected to both ends of the strain sensor element is further provided, and the leads have an adhesive portion that is partially widened and has adhesiveness on at least one surface.

It is preferable that the pressure-sensitive adhesive sheet has a base material layer and a pressure-sensitive adhesive layer laminated on one surface side of the base material layer.

Further, the strain measurement kit according to the present invention made to solve the above problems is laminated on the strain sensor unit and the release sheet, and transferred to one surface side of the base material layer of the strain sensor unit. It comprises a plurality of pressure-sensitive adhesive patches that form a pressure-sensitive adhesive layer.

As described above, the strain sensor unit and the strain measurement kit according to the present invention can measure the movement of the human body or the like relatively accurately.

It is a schematic plan view of the strain sensor unit of one Embodiment of this invention. It is a schematic cross-sectional view of the distortion sensor unit of FIG. It is a schematic perspective view of the strain measurement kit including the strain sensor unit of FIG. It is a schematic plan view of the distortion sensor unit of the embodiment different from FIG. 1 of this invention. It is a schematic sectional view of the distortion sensor unit of FIG. It is a schematic plan view of the strain sensor unit of the embodiment different from FIGS. 1 and 4 of this invention. It is a schematic sectional view of the distortion sensor unit of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First Embodiment]
The strain sensor unit according to the first embodiment of the present invention shown in FIGS. 1 and 2 includes a thread-like or band-shaped (strip-shaped in the illustrated example) strain sensor element 2 for detecting expansion and contraction in the longitudinal direction, and the strain sensor element 2. It is laminated on both ends of one surface (in the case where the strain sensor element is thread-like, a specific radial portion of the peripheral surface), has a larger average width than the strain sensor element 2, and is adhesive to at least one surface. It is provided with a pair of adhesive sheets 3 having the above.

In the following description, "one surface" and "one surface side" mean "measurement target side surface" and "measurement target side" in the strain sensor unit, and are based on the front and back sides of the measurement target. It is synonymous with "back side" and "back side" in the direction of measurement. Therefore, "the other surface side" means "the side opposite to the measurement target" and is synonymous with "the surface side".

The strain sensor unit 1 has a pair of adhesive sheets 3 directly attached to the surface (skin) of a measurement target portion such as a joint of a human body, whereby the adhesive sheet 3 on the surface of the measurement target portion is attached 2 By measuring the change in length along the surface of the measurement target between points, it can be used to detect the movement of the measurement target site.

<Distortion sensor element>
The strain sensor element 2 may have elasticity (elasticity) and its electrical characteristics change according to expansion and contraction, but a strain resistance element whose electrical resistance changes due to expansion and contraction is preferably used. Among them, as the strain sensor element 2, a CNT strain sensor using carbon nanotubes (hereinafter, may be referred to as CNT) is particularly preferably used.

The strain sensor unit 1 measures the resistance value between both ends of the strain sensor element 2 composed of the strain resistance element by a detection circuit (not shown), so that the surface of the measurement target portion changes according to the movement of the measurement target portion (the surface of the measurement target portion ( Detects an increase or decrease in the length of the skin).

The CNT strain sensor can be configured to include, for example, a stretchable sheet-shaped support film, a CNT film laminated on the surface side of the support film, and a protective film that protects the CNT film.

It should be noted that the front and back surfaces of the layer structure of the CNT strain sensor are for convenience, and do not limit the stacking order in the manufacturing process, the vertical relationship at the time of manufacturing, etc., and the strain sensor element 2 in the strain sensor unit 1 It does not limit the direction of.

The lower limit of the average thickness of the support film and the protective film of the CNT strain sensor is preferably 10 μm, more preferably 50 μm. On the other hand, as the upper limit of the average thickness of the support film, 1 mm is preferable, and 0.5 mm is more preferable. If the average thickness of the support film is less than the lower limit, the strength may be insufficient and damage to the CNT film may not be prevented. On the contrary, when the average thickness of the support film exceeds the upper limit, the elastic modulus of the strain sensor element 2 increases, which may hinder the expansion and contraction of the surface of the measurement target and may give the subject a sense of discomfort. ..

The material of the support film and the protective film is not particularly limited as long as it has flexibility, and examples thereof include synthetic resin, rubber, and non-woven fabric.

Examples of the synthetic resin include phenol resin (PF), epoxy resin (EP), melamine resin (MF), urea resin (ureia resin, UF), unsaturated polyester (UP), alkyd resin, polyurethane (PUR), and heat. Curable Polyethylene (PI), Polyethylene (PE), High Density Polyethylene (HDPE), Medium Density Polyethylene (MDPE), Low Density Polyethylene (LDPE), Polypropylene (PP), Polyvinyl Chloride (PVC), Polyvinylidene Chloride, Polystyrene (PS), Polyvinyl acetate (PVAc), Acrylonitrile butadiene styrene resin (ABS), Acrylonitrile styrene resin (AS), Polymethylmethacrylic (PMMA), Polyethylene (PA), Polyacetal (POM), Polycarbonate (PC), Modified Examples thereof include polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), cyclic polyolefin (COP) and the like.

Examples of the rubber include natural rubber (NR), butyl rubber (IIR), isoprene rubber (IR), ethylene / propylene rubber (EPDM), butadiene rubber (BR), urethane rubber (U), and styrene / butadiene rubber (SBR). , Silicone rubber (Q), chloroprene rubber (CR), chlorosulfonized polyethylene rubber (CSM), acrylonitrile butadiene rubber (NBR), chlorinated polyethylene (CM), acrylic rubber (ACM), epichlorohydrin rubber (CO, ECO), Fluoro rubber (FKM), polydimethylsiloxane (PDMS) and the like can be mentioned. Among these rubbers, natural rubber is preferable from the viewpoint of strength and the like.

This CNT film is formed of a resin composition containing a large number of CNT fibers. Specifically, the CNT film has a plurality of CNT fiber bundles composed of a plurality of CNT fibers oriented in one direction, and a resin layer that covers the peripheral surface of the plurality of CNT fiber bundles. When the strain that stretches the CNT film is applied, the contact condition between the CNT fibers changes, and the resistance change can be obtained as a strain sensor. In order to detect strain more efficiently, it is preferable that the CNT fibers in the CNT film are oriented in the expansion and contraction direction.

As the lower limit of the average thickness of the CNT film in the unloaded state, 1 μm is preferable, and 10 μm is more preferable. On the other hand, the upper limit of the average thickness of the CNT film is preferably 1 mm, more preferably 0.5 mm. If the average thickness of the CNT film is less than the lower limit, it may be difficult to form such a thin film, or the resistance may increase too much during elongation. On the contrary, when the average thickness of the CNT film exceeds the upper limit, the elasticity may be insufficient, the resistance to expansion / contraction may be changed, that is, the detection sensitivity may be insufficient, or the subject may feel uncomfortable. There is.

The CNT film may have a single-walled structure in which CNT fibers are arranged substantially in parallel in a plane, or may have a multi-walled structure. However, in order to secure a certain degree of conductivity, it is preferable to have a multi-layer structure.

As the CNT fiber, either a single-walled nanotube (SWNT) or a multi-walled nanotube (MWNT) can be used, but MWNT is preferable from the viewpoint of conductivity and heat capacity, and the diameter is 1.5 nm. MWNT of 100 nm or more is more preferable.

The resin layer of the CNT film is a layer containing resin as a main component and covering the peripheral surfaces of a plurality of CNT fiber bundles. Examples of the main component of the resin layer include synthetic resins and rubber exemplified as the material of the support film, and among these, rubber is preferable. By using rubber, it is possible to exert a sufficient protective function of the CNT fiber even against a large strain. Further, the resin layer of the CNT film may be formed integrally with the support film or the protective film. In other words, the support film or the protective film may be omitted by increasing the thickness of the resin layer that does not impregnate the CNT fiber layer.

In the laminated structure of these resin layers and the CNT film, a material for forming another layer (or film) may be formed on any layer (or film) by coating or the like, and each layer (or film) may be formed. It may be formed by welding or welding, or it may be formed by bonding each layer (or film) using a thermoplastic adhesive. Further, the resin layer may be formed at least partially integrally with the insulating elastomer that impregnates the surface layer and the back layer of the CNT film. That is, in the step of forming the CNT film, the insulating elastomer may be applied so as not to impregnate the plurality of CNT fibers but to stay on the front and back surfaces of the plurality of CNT fibers to form a resin layer. Further, the resin layer may have a multilayer structure composed of a plurality of different layers. In that case, it is advisable to combine it with a material having high springiness. Specifically, it is preferable to use polyurethane as a material having high springiness.

The lower limit of the average thickness of the resin layer is preferably 10 μm, more preferably 15 μm. On the other hand, the upper limit of the average thickness of the resin layer is preferably 1 mm, more preferably 0.5 mm. If the average thickness of the resin layer is less than the lower limit, the CNT film may not be sufficiently protected. On the contrary, when the average thickness of the resin layer exceeds the upper limit, the elastic modulus of the CNT film may increase and the deformation of the measurement target may be hindered. The average thickness of the resin layer may differ between the front and back sides of the CNT film.

The lower limit of the average width of the strain sensor element 2 formed by such a CNT strain sensor in a no-load state is preferably 0.1 mm, more preferably 0.5 mm. On the other hand, the upper limit of the average width of the strain sensor element 2 is preferably 10 mm, more preferably 5 mm. If the average width of the strain sensor element 2 is less than the lower limit, the detection sensitivity may be insufficient, or the strain sensor element 2 may be torn due to the movement of the measurement target portion. On the contrary, when the average width of the strain sensor element 2 exceeds the upper limit, the subject may feel uncomfortable.

Further, the average length of the strain sensor element 2 in a no-load state is selected according to the measurement target portion. As a general rule, the lower limit of the average length of the strain sensor element 2 in a no-load state is preferably 3 mm, more preferably 15 mm. On the other hand, as the upper limit of the average length of the strain sensor element 2 in the no-load state, 70 mm is preferable, and 50 mm is more preferable. If the average length of the strain sensor element 2 is less than the lower limit, the detection value may change significantly due to a slight deviation from the measurement target portion of the strain sensor element 2, and the detection error may increase. On the contrary, when the average length of the strain sensor element 2 exceeds the upper limit, a region in which the length does not change due to the detected movement is included, and the rate of change in the length of the strain sensor element 2 with respect to the movement becomes small. There is a risk that the detection sensitivity will be insufficient.

The lower limit of the 10% elongation load of the strain sensor element 2 is preferably 0.01 N, more preferably 0.03 N, and even more preferably 0.05 N. On the other hand, the upper limit of the 10% elongation load of the strain sensor element 2 is preferably 0.5N, more preferably 0.3N, and even more preferably 0.2N. If the 10% elongation load of the strain sensor element 2 is less than the lower limit, the detection accuracy may be insufficient due to expansion and contraction due to factors other than the operation of the measurement target portion. On the contrary, when the 10% extension load of the strain sensor element 2 exceeds the upper limit, the reaction force at the time of extension becomes large, which may give the subject a sense of discomfort or restraint.

As the lower limit of the resistance value of the strain sensor element 2 in the no-load state, for example, 10Ω is preferable, and 100Ω is more preferable. On the other hand, as the upper limit of the resistance value of the strain sensor element 2 in the no-load state, 100 kΩ is preferable, and 10 kΩ is more preferable. If the resistance value of the strain sensor element 2 in the no-load state is less than the lower limit, the current for detecting elongation strain may increase and the power consumption may increase. On the contrary, when the resistance value of the strain sensor element 2 in the no-load state exceeds the upper limit, the voltage of the detection circuit becomes high, which may make it difficult to reduce the size and power consumption.

The rate of change of the resistance value due to the elongation of the strain sensor element 2 is appropriately selected so that sufficient detection accuracy can be obtained, but the strain sensor element 2 is stretched by 10% with respect to the resistance value in the unloaded state. The ratio of the resistance values of is, for example, 1.5 times or more and 20 times or less.

<Adhesive sheet>
The pair of adhesive sheets 3 are adhered to both ends of the strain sensor element 2 and are attached to the front surface of the detection target portion due to the adhesiveness of the back surface. As a result, the pair of adhesive sheets 3 expands and contracts the strain sensor element 2 according to the movement of the detection target portion.

The pressure-sensitive adhesive sheet 3 may be formed from a single resin composition having sufficient tackiness, but typically, the base material layer 4 adhered to the back surface of the strain sensor element 2 and the base material layer. It is possible to have an adhesive layer 5 laminated on the back surface side of 4.

The planar shape of the adhesive sheet 3 is not particularly limited, and may be any shape such as a circle, a square, or a polygon. Among them, a circle without corners is preferable in consideration of sticking to the human body. Will be adopted.

The plane dimensions of the adhesive sheet 3 differ depending on the material, the size of the strain sensor element 2, and the like, but the average width of the adhesive sheet 3 (the average length in the width direction of the strain sensor element 2) is the average of the strain sensor elements 2. As the lower limit of the ratio to the width, 1.5 is preferable, and 2 is more preferable. On the other hand, as the upper limit of the ratio of the average width of the adhesive sheet 3 to the average width of the strain sensor element 2, 30 is preferable, and 20 is more preferable. If the ratio of the average width of the adhesive sheet 3 to the average width of the strain sensor element 2 is less than the lower limit, the adhesive force to the measurement target may be insufficient. On the contrary, when the ratio of the average width of the adhesive sheet 3 to the average width of the strain sensor element 2 exceeds the upper limit, the strain sensor unit 1 may become unnecessarily large. The "mean width" of the adhesive sheet 3 means a value obtained by dividing the area of the adhesive sheet 3 by the maximum length in the direction perpendicular to the width direction.

The lower limit of the average length of the strain sensor element 2 of the adhesive sheet 3 in the width direction is preferably 1 mm, more preferably 2 mm. On the contrary, the upper limit of the average length of the strain sensor element 2 of the adhesive sheet 3 in the width direction is preferably 30 mm, more preferably 20 mm. If the average length of the strain sensor element 2 of the adhesive sheet 3 in the width direction is less than the lower limit, the adhesive force to the measurement target may be insufficient. On the contrary, when the average length of the strain sensor element 2 of the adhesive sheet 3 in the width direction exceeds the upper limit, the subject may feel uncomfortable.

As the lower limit of the ratio of the average length of the adhesive sheet 3 (the average length in the length direction of the strain sensor element 2) to the average width of the strain sensor element 2, 1.5 is preferable, and 2 is more preferable. On the other hand, as the upper limit of the ratio of the average length of the adhesive sheet 3 to the average width of the strain sensor element 2, 50 is preferable, and 30 is more preferable. If the ratio of the average length of the adhesive sheet 3 to the average width of the strain sensor element 2 is less than the lower limit, the adhesive force to the measurement target may be insufficient. On the contrary, when the ratio of the average length of the adhesive sheet 3 to the average width of the strain sensor element 2 exceeds the upper limit, the strain sensor unit 1 may become unnecessarily large. The "average length" of the adhesive sheet 3 is a value obtained by dividing the area of the adhesive sheet 3 by the maximum width.

As the lower limit of the average length of the strain sensor element 2 of the adhesive sheet 3 in the length direction, 2 mm is preferable, and 3 mm is more preferable. On the contrary, the upper limit of the average length of the strain sensor element 2 of the adhesive sheet 3 in the length direction is preferably 50 mm, more preferably 30 mm. If the average length of the strain sensor element 2 of the adhesive sheet 3 in the length direction is less than the lower limit, the adhesive force to the measurement target may be insufficient. On the contrary, when the average length of the strain sensor element 2 of the adhesive sheet 3 in the length direction exceeds the upper limit, the subject may feel uncomfortable.

The thickness of the pressure-sensitive adhesive sheet 3 varies depending on the material thereof, the size of the strain sensor element 2, and the like, but the lower limit of the average thickness of the pressure-sensitive adhesive sheet 3 is preferably 50 μm, more preferably 100 μm. On the other hand, the upper limit of the average thickness of the pressure-sensitive adhesive sheet 3 is preferably 5 mm, more preferably 3 mm. If the average thickness of the adhesive sheet 3 is less than the lower limit, the strength of the adhesive sheet 3 may be insufficient. On the contrary, when the average thickness of the adhesive sheet 3 exceeds the upper limit, the subject may feel uncomfortable.

(Base layer)
As the base material layer 4, for example, a resin sheet, a woven fabric, a non-woven fabric, a knitted fabric, a metal foil, or the like can be used. Used for. Since the adhesive sheet 3 contains the woven fabric, the strength of the adhesive sheet 3 is increased, so that both ends of the strain sensor element 2 can be reliably fixed to the surface of the measurement target.

As the woven fabric contained in the base material layer 4, for example, polyethylene cloth, aramid cloth, glass cloth and the like can be used.

The lower limit of the average thickness of the base material layer 4 is preferably 20 μm, more preferably 50 μm. On the other hand, as the upper limit of the average thickness of the base material layer 4, 1 mm is preferable, and 0.5 mm is more preferable. If the average thickness of the base material layer 4 is less than the lower limit, the strength of the base material layer 4 may be insufficient. On the contrary, when the average thickness of the base material layer 4 exceeds the upper limit, the thickness of the pressure-sensitive adhesive sheet 3 may be unnecessarily increased, which may give the subject a sense of discomfort.

(Adhesive layer)
As the adhesive forming the pressure-sensitive adhesive layer 5, it is preferable to use a material such as an acrylic pressure-sensitive adhesive that does not easily cause skin inflammation even when directly attached to human skin.

The adhesive forming the pressure-sensitive adhesive layer 5 may be impregnated in the base material layer 4.

The lower limit of the average thickness of the pressure-sensitive adhesive layer 5 is preferably 30 μm, more preferably 50 μm. On the other hand, the upper limit of the average thickness of the pressure-sensitive adhesive layer 5 is preferably 3 mm, more preferably 1 mm. If the average thickness of the pressure-sensitive adhesive layer 5 is less than the lower limit, sufficient adhesive strength may not be obtained. On the contrary, when the average thickness of the pressure-sensitive adhesive layer 5 exceeds the upper limit, the thickness of the pressure-sensitive adhesive sheet 3 may be unnecessarily increased, which may give the subject a sense of discomfort.

The adhesive sheet 3 can be adhered to the strain sensor element 2 by thermocompression bonding or the like, but it is preferable to use an adhesive. By adhering the pressure-sensitive adhesive sheet 3 to the strain sensor element 2 with an adhesive, the strain sensor unit 1 can be manufactured relatively easily.

The adhesive for adhering the pressure-sensitive adhesive sheet 3 to the strain sensor element 2 is not particularly limited, but the use of the pressure-sensitive adhesive which has tackiness and does not solidify further facilitates the manufacture of the strain sensor unit 1. be able to. Examples of the pressure-sensitive adhesive for adhering the pressure-sensitive adhesive sheet 3 to the strain sensor element 2 include a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, and an acrylic-based pressure-sensitive adhesive.

When the adhesive sheet 3 is adhered to the strain sensor element 2 with an adhesive, a commercially available adhesive tape is used as a laminate with the base material layer 4 and the adhesive for adhering the base material layer 4 to the strain sensor element 2. be able to. As described above, by using the commercially available adhesive tape, the strain sensor unit 1 can be manufactured more easily, and the strain sensor unit 1 can be manufactured at a lower cost.

<Advantage>
The strain sensor unit 1 includes a pair of adhesive sheets 3 laminated on both ends of one surface of the strain sensor element 2, and the pair of adhesive sheets 3 measures both ends of the strain sensor element 2. It can be fixed to the surface of the object. Therefore, in the strain sensor unit 1, even if the surface of the measurement target portion in contact with the strain sensor element 2 expands and contracts unevenly or forms wrinkles, the strain sensor element 2 can expand and contract relatively evenly. The movement of the measurement target part can be measured relatively accurately.

[Strain measurement kit]
FIG. 3 shows a strain measurement kit according to another embodiment of the present invention.

The strain measurement kit is laminated on the strain sensor unit 1 of FIG. 1, the release sheet 6, and the release sheet 6, and is transferred to the back surface side of the base material layer 4 of the strain sensor unit 1 to form an adhesive layer. A plurality of pressure-sensitive adhesive patches 7 capable of forming the 5 are provided. That is, in the strain measurement kit, the pressure-sensitive adhesive layer 5 of the strain sensor unit 1 is replaced with the pressure-sensitive adhesive patch 7, or the pressure-sensitive adhesive patch 7 is laminated on the pressure-sensitive adhesive layer 5 of the strain sensor unit 1. The adhesive strength of the adhesive sheet 3 of 1 can be restored as if it were new.

<Advantage>
Since the strain measurement kit includes a plurality of adhesive patches 7, the used adhesive layer 5 is replaced with a new adhesive patch 7, or the new adhesive patch 7 is replaced with a new adhesive patch 7 on the back surface side (one side) of the used adhesive layer 5. The strain sensor unit 1 can be reused relatively easily by stacking it on the surface side of the surface. Therefore, the strain measuring kit can be used to measure the movement of various parts of the human body, or to repeatedly measure the movement of the same part at intervals such as once a day.

[Second Embodiment]
The strain sensor unit 1a according to the second embodiment of the present invention shown in FIGS. 4 and 5 has a thread-like or band-shaped strain sensor element 2 for detecting expansion and contraction in the longitudinal direction, and back surfaces of both ends of the strain sensor element 2. A pair of adhesive sheets 3 laminated on (one surface side), having an average width larger than that of the strain sensor element 2 and having at least adhesiveness on the back surface, and front surface sides (the other surface) of both ends of the strain sensor element 2. It includes a pair of covering sheets 8 laminated so as to cover the adhesive sheet 3 so as to cover the side), and a pair of leads 9 connected to both ends of the strain sensor element 2 and covered by the covering sheet 8.

The configurations of the strain sensor element 2 and the adhesive sheet 3 in the strain sensor units of FIGS. 4 and 5 can be the same as the configurations of the strain sensor element 2 and the adhesive sheet 3 in the strain sensor units of FIGS. 1 and 2. Therefore, with respect to the strain sensor units of FIGS. 4 and 5, the same components as those of the strain sensor units of FIGS. 1 and 2 are designated by the same reference numerals, and redundant description will be omitted.

<Coating sheet>
The covering sheet 8 is laminated on the surface side (the other surface side) of the end portion of the strain sensor element 2 and the end portion of the lead 9, and the outer region protruding in the width direction from the strain sensor element 2 and the lead 9 in a plan view is formed. It is adhered to the adhesive sheet 3. As a result, the strain sensor element 2 and the lead 9 can be sandwiched between the adhesive sheet 3 and the adhesive sheet 3 and can be sandwiched relatively firmly.

The shape, material, and the like of the covering sheet 8 can be the same as the shape, material, and the like of the base material layer 4 of the adhesive sheet 3. Further, the method of adhering the covering sheet 8 to the strain sensor element 2 can be the same as the method of adhering the adhesive sheet 3 to the strain sensor element 2.

<Lead>
The lead 9 is used as wiring for connecting both ends of the distortion sensor element 2 to an external detection circuit.

As the lead 9, for example, an insulated wire, a flexible circuit board, a flat cable, or the like can be used.

Further, the lead 9 has an adhesive portion 10 which is partially widened and has adhesiveness at least on the back surface.

(Adhesive part)
The adhesive portion 10 has a structure having adhesiveness at least on the back surface, and for example, the adhesive patch 7 of the strain measurement kit of FIG. 3 can be attached. As a result, the adhesive portion 10 can be adhered to the surface to be measured.

When the lead 9 is formed from the flexible printed circuit board, the adhesive portion 10 may be formed by partially cutting out the flexible printed circuit board, and the lead 9 may be formed by another member such as a sheet similar to the adhesive sheet 3. May be formed by adhering.

<Advantage>
By providing the strain sensor unit 1a with a pair of covering sheets 8 laminated so as to face the pair of adhesive sheets 3, it is relatively easy and reliable to fix the adhesive sheets 3 to both ends of the strain sensor element 2. Therefore, it is relatively easy to manufacture.

Further, the strain sensor unit 1a is relatively easy to connect to the detection circuit of the strain sensor element 2 by providing a pair of leads 9 connected to both ends of the strain sensor element 2 in advance.

Further, in the strain sensor unit 1a, since the lead 9 has the adhesive portion 10, the adhesive portion 10 is moved to the strain sensor element 2 side by the tension of the strain sensor element 2 via the lead 9. To prevent. Therefore, the strain sensor unit 1a is more reliably attached to the measurement target.

[Third Embodiment]
The strain sensor unit 1b according to the third embodiment of the present invention shown in FIGS. 6 and 7 includes a thread-like or band-shaped strain sensor element 2 for detecting expansion and contraction in the longitudinal direction, and both ends and a central portion of the strain sensor element 2. A plurality of adhesive sheets 3 laminated on the back surface side (one surface side), having an average width larger than that of the strain sensor element 2 and having at least adhesiveness on the back surface, and the front surfaces of both ends and the center portion of the strain sensor element 2. It is provided with a pair of covering sheets 8b laminated so as to cover the side (the other surface side) so as to face the adhesive sheet 3.

The configurations of the strain sensor element 2 and the adhesive sheet 3 in the strain sensor units of FIGS. 6 and 7 can be the same as the configurations of the strain sensor element 2 and the adhesive sheet 3 in the strain sensor units of FIGS. 1 and 2. Therefore, with respect to the strain sensor units of FIGS. 6 and 7, the same components as those of the strain sensor units of FIGS. 1 and 2 are designated by the same reference numerals, and redundant description will be omitted.

<Coating sheet>
The covering sheet 8b is laminated on the surface side of the strain sensor element 2 so as to overlap the adhesive sheet 3 in a plan view.

Further, the covering sheet 8b has conductivity and is electrically connected to the strain sensor element 2 to be used as a terminal for connecting the wiring to the measurement circuit to the strain sensor element 2. Therefore, for bonding the covering sheet 8b to the strain sensor element 2, for example, a conductive adhesive or the like is used.

As the covering sheet 8b, for example, a sheet-like member such as a metal foil, a metal mesh, or a carbon cloth, or a sheet having a sheet-shaped portion facing the covering sheet 8b and a structural portion for electrical connection may be used. it can. As shown in the figure, examples of the material having the sheet-like portion and the structural portion for electrical connection include, for example, a male member of a snap button. When a male member of the snap button is used as the covering sheet 8b, by disposing the female member of the snap button at the tip of the wiring of the detection circuit, the strain sensor element 2 can be easily wired to the measurement circuit.

<Advantage>
The strain sensor unit 1b also has an adhesive sheet 3 in the center of the strain sensor element 2, so that the adhesive sheets 3 function as independent strain sensors. That is, the strain sensor unit 1b can measure the movement of two continuous sections of the measurement target portion.

[Other Embodiments]
The embodiments do not limit the configuration of the present invention. Therefore, it is possible to omit, replace or add components of each part of the embodiment based on the description of the present specification and common general technical knowledge, and all of them are construed as belonging to the scope of the present invention. Should be.

In the strain sensor unit, the pressure-sensitive adhesive sheet may be formed only from the pressure-sensitive adhesive layer.

The strain sensor element may be formed so that the portion where the adhesive sheets are laminated is widened to a shape corresponding to the adhesive sheet.

An adhesive may be laminated between the adhesive sheets on the back surface of the strain sensor element.

The lead of the strain sensor unit may not have an adhesive portion.

The present invention can be widely used for detecting the movement of the human body or the like.

1,1a, 1b Strain sensor unit 2 Strain sensor element 3 Adhesive sheet 4 Base material layer 5 Adhesive layer 6 Release sheet 7 Adhesive patch 8, 8b Coating sheet 9 Lead 10 Adhesive part

Claims (4)

A thread-like or band-shaped strain sensor element that detects expansion and contraction in the longitudinal direction having elasticity, and
A pair of adhesive sheets that are laminated on both ends of one surface of the strain sensor element, have a larger average width than the strain sensor element, and have adhesiveness on at least one surface are provided.
The pressure-sensitive adhesive sheet have a pressure-sensitive adhesive layer laminated on one surface of the base layer and the substrate layer,
Further provided with a pair of leads connected to both ends of the strain sensor element.
A strain sensor unit in which the lead is partially widened and has an adhesive portion having an adhesive portion on at least one surface side of the widened portion . The strain sensor unit according to claim 1, wherein the average thickness of the base material layer is 20 μm or more and 1 mm or less. The strain sensor unit according to claim 1 or 2, wherein the base material layer is a woven fabric impregnated with a resin, a resin sheet, a woven fabric, a non-woven fabric, a knitted fabric, or a metal leaf. The strain sensor unit according to claim 1, claim 2 or claim 3, wherein the planar shape of the adhesive sheet is circular, square or polygonal.

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