WO2021017841A1

WO2021017841A1 - Capacitive elastic strain sensor, and preparation method and use therefor

Info

Publication number: WO2021017841A1
Application number: PCT/CN2020/102250
Authority: WO
Inventors: 周酉林; 刘宜伟
Original assignee: 宁波韧和科技有限公司
Priority date: 2019-07-18
Filing date: 2020-07-16
Publication date: 2021-02-04
Also published as: CN110657741A

Abstract

A capacitive elastic strain sensor, having an elastic textile material (1) as a base, comprising an elastic bonding layer (2), a first conductive layer (3), an elastic dielectric layer (4), a second conductive layer (5), and an elastic encapsulation layer (6). The capacitive elastic strain sensor can be used in a wearable product to detect stress and strain from a body part, such as the bending of a joint, the contraction or bending of muscle, the contraction or bending of vertebrae, or a person's breathing. The sensor is comfortable and does not cause a foreign body sensation, and because the thickness of the conductive layers is lower, performance stability of the sensor can be maintained when subjected to the effects of external forces during actual use such as folding, rubbing, or pressing.

Description

A capacitive elastic strain sensor, and its preparation method and application

Technical field

The invention relates to the technical field of capacitive strain sensors, in particular to a capacitive elastic strain sensor, and its preparation method and application.

Background technique

With the development of wearable technology, especially the rise of smart clothing and smart wear, flexible and even elastic devices are the mainstream trend of smart clothing and smart wear in the future. At the same time, the size of the device is also very important. In the field of wearable technology, the ultra-thin device fits well with the human body and can increase the wearing comfort.

Flexible and even elastic ultra-thin devices are used in smart clothing and smart wear, which can not only increase the wearing comfort, but also detect the motion of various joints of the human body, breathing frequency, spine or cervical spine bending, etc., and have received extensive attention in recent years.

There are mainly two structures of capacitive elastic strain sensors reported in the past. One is a capacitive structure composed of a polymer elastomer and a certain shape of metal or conductive fiber. This structure has poor elastic strain and has a limited measurement range of tensile strain. The other is the combination of a polymer elastomer and a ductile conductor such as liquid metal to form a capacitor structure. This structure generally uses a method of constructing a channel on the elastomer and then injecting liquid metal into the channel. More complicated. In addition, the thickness of these two types of elastic strain sensors is relatively large, generally reaching more than 1,000 microns, and they are poorly fitted to the human body and have a foreign body sensation. This is one of the reasons why there are few reports about combining elastic strain sensors with textile materials. In addition, the binding force between the elastic strain sensor and the textile material is another reason.

Summary of the invention

In view of the above technical status, the present invention provides a capacitive elastic strain sensor, which uses textile materials as a matrix and can be used as a wearable device to detect stress and strain of the body such as stretching and bending.

The technical solution of the present invention is: a capacitive elastic strain sensor, which is characterized in that: an elastic textile material is used as a matrix, and includes an elastic bonding layer, a first conductive layer, a second conductive layer, an elastic dielectric layer and an elastic packaging layer;

The elastic bonding layer has conductive and insulating properties and is located on the surface of the substrate;

The first conductive layer is located on the surface of the elastomer bonding layer, is composed of conductive liquid, conductive paste or conductive gel, and is connected to the external first electrode;

The elastic dielectric layer has conductive and insulating properties and is located on the surface of the first conductive layer;

The second conductive layer is located on the surface of the elastic dielectric layer, is composed of conductive liquid, conductive paste or conductive gel, and is connected to the external second electrode;

The elastic packaging layer is used for packaging the first conductive layer and the second conductive layer.

In the present invention, elasticity refers to the ability to bend, stretch and deform under the action of external force, and have a certain shape recovery ability when the external force is removed.

The textile material layer is a fabric formed of one or more of materials such as cotton, linen, wool, silk, woolen cloth, and fiber.

The elastic textile material is an elastic textile material, and the textile material can be made elastic through structural design, for example, the textile material can be made elastic through a rib structure, or the textile material itself has elasticity.

The elastic bonding layer material is not limited, and includes elastic polymer materials and the like. As a further preference, the elastic bonding layer adopts an elastic material with good bonding ability with textile materials, such as thermoplastic elastomer (TPE), thermoplastic polyurethane elastomer rubber poly (TPU), dimethyl siloxane (PDMS) , Aliphatic aromatic random copolyester (Ecoflex), high molecular polymer resin, silica gel, rubber, hydrogel, polyurethane, polyvinyl octene co-elastomer (POE) one or more.

The material of the elastic dielectric layer is not limited, and includes elastic polymer materials and the like. As a further preference, the elastic bonding layer adopts an elastic material with good bonding ability with textile materials, such as thermoplastic elastomer (TPE), thermoplastic polyurethane elastomer rubber poly (TPU), dimethyl siloxane (PDMS) , Aliphatic aromatic random copolyester (Ecoflex), high molecular polymer resin, silica gel, rubber, hydrogel, polyurethane, polyvinyl octene co-elastomer (POE) one or more.

The material of the elastic encapsulation layer is not limited, and includes elastic polymer materials and the like. As a further preference, the elastic bonding layer adopts an elastic material with good bonding ability with textile materials, such as thermoplastic elastomer (TPE), thermoplastic polyurethane elastomer rubber poly (TPU), dimethyl siloxane (PDMS) , Aliphatic aromatic random copolyester (Ecoflex), high molecular polymer resin, silica gel, rubber, hydrogel, polyurethane, polyvinyl octene co-elastomer (POE) one or more.

The conductive liquid is not limited, such as liquid metal, conductive ink and the like.

The conductive gel is not limited, such as graphite conductive gel, silver gel and the like.

The conductive paste is not limited, and includes graphene paste, a mixed paste of conductive material and elastomer, and the like. The mixed slurry of conductive material and elastomer includes, but is not limited to, a mixed slurry of liquid metal and elastomer, a mixed slurry of carbon powder and elastomer, a mixed slurry of carbon fiber and elastomer, and a mixed slurry of graphene and elastomer. Materials, metal powder and elastomer mixed slurry, etc. Preferably, the liquid metal and the elastomer are mixed according to the mass ratio of 100: (1-100) to form a slurry; the carbon powder and the elastomer are mixed according to the mass ratio (1-100): 100 to form the slurry; the carbon fiber and the elastomer are mixed according to the mass ratio (1～100): 100 is mixed into slurry; graphene and elastomer are mixed according to mass ratio (1-100): 100 to form slurry; metal powder and elastomer are mixed according to mass ratio (1-100): 100 to form slurry material.

The liquid metal refers to a metal conductive material that is liquid at room temperature, including but not limited to mercury, gallium indium alloy, gallium indium tin alloy, and one or more doped gallium indium of transition metals and solid non-metal elements Alloy, gallium indium tin alloy, etc.

The first electrode is used to electrically connect external devices, and its material is not limited, including metal materials, conductive cloth, graphene, graphite conductive glue, silver glue, liquid metal, circuit boards, and the like.

The second electrode is used to electrically connect external devices, and its material is not limited, including metal materials, conductive cloth, graphene, graphite conductive glue, silver glue, liquid metal, circuit boards, etc.

Preferably, the thickness of the first conductive layer is less than 500um, preferably less than 100um, or even less than 10um.

Preferably, the thickness of the second conductive layer is less than 500um, preferably less than 100um, or even less than 10um.

Preferably, the first conductive layer has a certain pattern structure on the surface of the elastic bonding layer. The pattern is not limited, and includes one or more patterns composed of straight lines, sine lines, wavy lines, sawtooth waves, triangular waves, ellipses, loops, coils, heart shapes, etc., and two or more parallel, intersecting, and stacked patterns.

Preferably, the second conductive layer has a certain pattern structure on the surface of the elastic dielectric layer. The pattern is not limited, and includes one or more patterns composed of straight lines, sine lines, wavy lines, sawtooth waves, triangular waves, ellipses, loops, coils, heart shapes, etc., and two or more parallel, intersecting, and stacked patterns.

The present invention also provides a method for preparing the capacitive elastic strain sensor, which includes the following steps:

(1) Prepare an elastic bonding layer on the surface of the elastic textile material;

(2) Prepare a first conductive layer on the surface of the elastic bonding layer;

(3) Prepare an elastic dielectric layer on the surface of the first conductive layer;

(4) Prepare a second conductive layer on the surface of the elastic dielectric layer;

(5) An elastic encapsulation layer is prepared on the surface of the second conductive layer.

In the step (1), the method for preparing the elastic bonding layer on the surface of the elastic textile material is not limited. Taking into account the material characteristics of the elastic textile material, as a preference, the elastic bonding layer is prepared on the surface of the textile material by a hot pressing method. Practice has proved that, The method can give full play to the material characteristics of the textile material, and obtain an elastic bonding layer with high bondability with the textile material, simple preparation and high yield.

In the step (2), the method for preparing the first conductive layer on the surface of the elastic bonding layer is not limited. The present invention preferably adopts a hollow template, placing the template on the surface of the elastic bonding layer, and then pouring, coating, printing or hot pressing conductive liquid, conductive paste or conductive gel in the hollow of the template to obtain the first conductive layer. Finally remove the template. Wherein, the template is used to form the first conductive layer, and plays a role in positioning the boundary of the conductive material during the preparation of the first conductive layer, and the mold can be directly and conveniently removed after the first conductive layer is formed. When the first conductive layer is in a certain pattern, the template is used to form a patterned first conductive layer, and plays a role in positioning the pattern boundary of the conductive material during the preparation of the first conductive layer. When the patterned first conductive layer The mold can be removed directly after the formation of the subordinate layer. Therefore, the role of the mold in the present invention is different from that of the mask in the prior art. On the one hand, a first conductive layer mold with a smaller three-dimensional size can be obtained, and on the other hand, the mold can be easily and simply removed after filling the mold with conductive paste. Material, so that the first conductive layer with small three-dimensional size can be easily obtained, especially the first conductive layer with small thickness and width can be easily obtained. Its thickness is ultra-thin, reaching the order of hundreds of microns, preferably less than 500um, It is more preferably less than 100um, even less than 10um.

In the step (3), the method for preparing the elastic dielectric layer on the surface of the first conductive layer is not limited, including printing, baking, hot pressing and the like.

In the step (4), the method for preparing the second conductive layer on the surface of the elastic dielectric layer is not limited. The present invention preferably adopts a hollow template, placing the template on the surface of the elastic bonding layer, and then pouring, coating, printing or hot pressing conductive liquid, conductive paste or conductive gel in the hollow of the template to obtain the second conductive layer. Finally remove the template. Wherein, the template is used to form the second conductive layer, and plays a role in positioning the boundary of the conductive material during the preparation of the second conductive layer, and the mold can be directly and conveniently removed after the second conductive layer is formed. When the second conductive layer is in a certain pattern, the template is used to form a patterned second conductive layer, which plays a role in positioning the pattern boundary of the conductive material during the preparation of the second conductive layer. When the patterned second conductive layer The mold can be removed directly after the formation of the subordinate layer. Therefore, the role of the mold in the present invention is different from that of the mask in the prior art. On the one hand, a second conductive layer mold with a smaller three-dimensional size can be obtained, and on the other hand, the mold can be easily and simply removed after filling the conductive paste in the mold. Material, so that the second conductive layer with small three-dimensional size can be easily obtained, especially the second conductive layer with small thickness and width can be easily obtained. Its thickness is ultra-thin, reaching the order of hundreds of microns, preferably less than 500um, It is more preferably less than 100um, even less than 10um.

In the step (5), the method for preparing the elastic encapsulation layer on the surface of the second conductive layer is not limited, including printing, baking, hot pressing and other methods.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention combines a capacitive elastic strain sensor with textile materials, so the capacitive elastic strain sensor can be used in wearable devices, such as stitching or hot pressing with smart clothing or smart wear, for detecting the body The stress and strain of the part, such as joint bending, muscle stretching or bending, vertebral body stretching or bending, etc., are elastic and comfortable;

(2) The capacitive elastic strain sensor of the present invention has a low thickness and no foreign body sensation. In particular, the thickness of the first conductive layer and the second conductive layer can reach the order of hundreds of microns, preferably less than 500um, more preferably less than 100um, or even less than 10um, which can improve the wearability and comfort of the sensor, and in practical applications, when subjected to external forces such as folding, kneading, squeezing, etc., the impact of the liquid metal layer is extremely thin, which is beneficial to improve the sensor’s performance. Performance stability.

Description of the drawings

Fig. 1 is a schematic cross-sectional structure diagram of a capacitive elastic strain sensor of the present invention.

Figure 2 is a tensile strain test diagram of the capacitive elastic strain sensor in Example 1 of the present invention.

The reference signs in Figure 1 are: 1-Elastic textile material, 2-Elastic adhesive layer, 3-First conductive layer, 4-Elastic dielectric layer, 5-Second conductive layer, 6-Elastic encapsulation layer, 7 -Externally connect the first electrode, 8-Externally connect the second electrode

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be pointed out that the following embodiments are intended to facilitate the understanding of the present invention and do not have any limiting effect on it.

Example 1:

In this embodiment, the structure of the capacitive elastic strain sensor is shown in FIG. 1, which uses elastic textile material as a matrix and consists of an elastic bonding layer, a first conductive layer, a second conductive layer, an elastic dielectric layer and an elastic encapsulation layer. The elastic bonding layer is conductive and insulating and is located on the surface of the substrate; the first conductive layer is located on the surface of the elastomer bonding layer and is composed of liquid metal and is connected to the external first electrode; the elastic dielectric layer is conductive and insulating and is located on the surface of the first conductive layer The second conductive layer is located on the surface of the elastic dielectric layer and is composed of liquid metal, connected to the external second electrode; the elastic packaging layer is used to encapsulate the first conductive layer and the second conductive layer.

In this embodiment, the elastic textile material is spandex cloth, the elastomer adhesive layer, the elastomer dielectric layer, and the elastomer encapsulation layer are all selected from thermoplastic polyurethane elastomer rubber poly (TPU). The first conductive layer and the second conductive layer are The liquid metal GaInSn, the outer first electrode and the outer second electrode are copper sheets.

In this embodiment, the thickness of the first conductive layer and the second conductive layer are both 100 μm.

In this embodiment, the preparation of the aforementioned capacitive elastic strain sensor includes the following steps:

(1) Using a hot pressing process to form an elastic adhesive layer on the elastic textile material;

(2) Place a hollow template on the surface of the elastic adhesive layer; then, fill the template with liquid metal GaInSn by printing; then, remove the template material to obtain the first conductive layer;

(3) At both ends of the first conductive layer prepared in step (2), thin copper sheets are attached as external first electrodes;

(4) Using a hot pressing process to form an elastic dielectric layer on the surface of the first conductive layer;

(5) Place a hollow template on the surface of the elastic dielectric layer; then, fill the template with liquid metal GaInSn by printing; then, remove the template material to obtain a second conductive layer;

(6) Stick thin copper sheets on both ends of the second conductive layer as the external second electrode;

(7) A hot pressing process is used to form an elastic packaging layer on the surface of the second conductive layer.

The capacitive elastic strain sensor prepared above can be stitched or hot pressed and attached to smart clothing or smart wear, such as knee and elbow pads, breathing belts, body correction belts, cervical vertebrae belts, etc. It is convenient and comfortable to wear, and is similar to ordinary fabrics. The same experience, which can be used to detect the stress and strain of body parts, such as joint bending, muscle stretching or bending, vertebral stretching or bending, etc., especially when stretching, bending, kneading, squeezing and other operations are compared with ordinary fabrics The experience is the same.

A tensile strain test was performed on the elastic textile material-based capacitive elastic strain sensor prepared above. The test result is shown in Figure 2. It can be seen that the tensile-capacitance change of the elastic strain sensor is linear, and the tensile is 30%. , The capacitance changes about 500pF, the rate of change is large. In addition, because the liquid metal layer is ultra-thin, the influence of the liquid metal layer is greatly reduced when subjected to external forces in practical applications, so its performance has high stability.

Example 2:

In this embodiment, the structure of the capacitive elastic strain sensor is the same as that in embodiment 1, except that the first conductive layer is in a parallel sine pattern on the surface of the elastic adhesive layer, and the second conductive layer is in the surface of the elastic dielectric layer. Parallel sine graph.

(2) Place a hollow template on the surface of the elastic adhesive layer; then, fill the template with liquid metal GaInSn by printing; then, remove the template material to obtain the first conductive layer in a parallel sinusoidal pattern;

(3) The two ends of each liquid metal with a sinusoidal pattern prepared in step (2) are pasted with thin copper sheets as the external first electrode;

(5) Place a hollow template on the surface of the elastic dielectric layer; then, fill the template with liquid metal GaInSn by printing; then, remove the template material to obtain a second conductive layer in a parallel sinusoidal pattern;

Same as Example 1, the capacitive elastic strain sensor prepared above can be stitched or hot pressed and attached to smart clothing or smart wear, such as knee and elbow pads, breathing belts, body correction belts, cervical spine belts, etc., which are convenient to wear Comfortable, the same as ordinary fabric experience, can be used to detect the stress and strain of body parts, such as joint bending, muscle stretching or bending, vertebral body stretching or bending, etc. Especially when stretching, bending, kneading, squeezing and other operations, the experience is the same as ordinary fabrics. A tensile strain test is performed on the elastic textile material-based capacitive elastic strain sensor prepared above, and the test result shows that the tensile-capacitance change of the elastic strain sensor is linear, and the rate of change is large. In addition, because the liquid metal layer is ultra-thin, the influence of the liquid metal layer is greatly reduced when subjected to external forces in practical applications, so its performance has high stability.

Example 3:

In this embodiment, spandex cloth is selected as the elastic textile material, dimethylsiloxane (PDMS) is selected for the elastomer adhesive layer, elastomer dielectric layer, and elastomer encapsulation layer. The first conductive layer and the second conductive layer are Liquid metal GaInSn, the outer first electrode and the outer second electrode are conductive cloth.

In this embodiment, the thickness of the first conductive layer and the second conductive layer are both 50 μm.

(3) The two ends of the first conductive layer prepared in step (2) are thermally pressed and bonded to conductive cloth as the external first electrode;

(6) Hot-press bonding conductive cloth on both ends of the second conductive layer as the external second electrode;

Example 4:

In this embodiment, the structure of the capacitive elastic strain sensor is the same as that of the third embodiment, except that the outer first electrode and the outer second electrode are polyimide circuit boards.

(3) Fixing the polyimide circuit board as the external first electrode at both ends of the first conductive layer prepared in step (2);

(6) Fixing a polyimide circuit board as an external second electrode on both ends of the second conductive layer;

As in Example 3, the capacitive elastic strain sensor prepared above can be stitched or hot pressed and attached to smart clothing or smart wear, such as knee and elbow pads, breathing belts, body correction belts, cervical spine belts, etc., which are convenient to wear Comfortable, the same as ordinary fabric experience, can be used to detect the stress and strain of body parts, such as joint bending, muscle stretching or bending, vertebral body stretching or bending, etc. Especially when stretching, bending, kneading, squeezing and other operations, the experience is the same as ordinary fabrics. A tensile strain test is performed on the elastic textile material-based capacitive elastic strain sensor prepared above, and the test result shows that the tensile-capacitance change of the elastic strain sensor is linear, and the rate of change is large. In addition, because the liquid metal layer is ultra-thin, the influence of the liquid metal layer is greatly reduced when subjected to external forces in practical applications, so its performance has high stability.

Example 5:

In this embodiment, the structure of the capacitive elastic strain sensor is the same as that in Embodiment 1, except that the material of the first conductive layer is graphene, and the material of the second conductive layer is graphene.

(2) Place a hollow template on the surface of the elastic adhesive layer; then, fill the template with graphene slurry by printing; then, remove the template material to obtain the first conductive layer;

(5) Place a hollow template on the surface of the elastic dielectric layer; then, fill the template with graphene paste by printing; then, remove the template material to obtain a second conductive layer;

Example 6:

In this embodiment, the structure of the capacitive elastic strain sensor is the same as that in Embodiment 1, except that the material of the first conductive layer is conductive ink, and the material of the second conductive layer is conductive ink.

(2) Place a hollow template on the surface of the elastic adhesive layer; then, fill the template with conductive ink by printing; then, remove the template material to obtain the first conductive layer;

(5) Place a hollow template on the surface of the elastic dielectric layer; then, fill the template with conductive ink by printing; then, remove the template material to obtain a second conductive layer;

Example 7:

In this embodiment, the structure of the capacitive elastic strain sensor is the same as that in Embodiment 1, except that the material of the first conductive layer is graphite conductive glue, and the material of the second conductive layer is graphite conductive glue.

(2) Place a hollow template on the surface of the elastic adhesive layer; then, fill the template with graphite conductive glue by printing; then, remove the template material to obtain the first conductive layer;

(5) Place a hollow template on the surface of the elastic dielectric layer; then, fill the template with graphite conductive glue by printing; then, remove the template material to obtain a second conductive layer;

The above-mentioned embodiments describe in detail the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Anything within the principle scope of the present invention Any modifications and improvements made should be included in the protection scope of the present invention.

Claims

A capacitive elastic strain sensor, which is characterized in that: an elastic textile material is used as a matrix, and includes an elastic bonding layer, a first conductive layer, a second conductive layer, an elastic dielectric layer and an elastic encapsulation layer;

The elastic bonding layer has conductive and insulating properties and is located on the surface of the substrate;

The first conductive layer is located on the surface of the elastomer bonding layer, is composed of conductive liquid, conductive paste or conductive gel, and is connected to the external first electrode;

The elastic dielectric layer has conductive and insulating properties and is located on the surface of the first conductive layer;

The second conductive layer is located on the surface of the elastic dielectric layer, is composed of conductive liquid, conductive paste or conductive gel, and is connected to the external second electrode;

The elastic packaging layer is used for packaging the first conductive layer and the second conductive layer.
The capacitive elastic strain sensor according to claim 1, wherein the elastic textile material layer is a fabric formed of one or more of cotton, linen, wool, silk, wool, and fiber materials.
The capacitive elastic strain sensor according to claim 1, wherein the material of the elastic bonding layer comprises an elastic polymer material.
The capacitive elastic strain sensor according to claim 3, characterized in that: the elastic bonding layer material is TPE, TPU, PDMS, Ecoflex, high molecular polymer resin, silica gel, rubber, hydrogel, polyurethane, POE One or more.
The capacitive elastic strain sensor according to claim 1, wherein the material of the elastic dielectric layer comprises an elastic polymer material.
The capacitive elastic strain sensor according to claim 5, wherein the material of the elastic dielectric layer is TPE, TPU, PDMS, Ecoflex, polymer resin, silica gel, rubber, hydrogel, polyurethane, POE One or more of them.
The capacitive elastic strain sensor according to claim 1, wherein the material of the elastic packaging layer comprises an elastic polymer material.
The capacitive elastic strain sensor according to claim 7, characterized in that: the elastic encapsulation layer material is TPE, TPU, PDMS, Ecoflex, high molecular polymer resin, silica gel, rubber, hydrogel, polyurethane, POE One or more.
The capacitive elastic strain sensor according to claim 1, wherein the conductive liquid includes one of liquid metal and conductive ink.
The capacitive elastic strain sensor according to claim 1, wherein the conductive gel includes one of graphite conductive glue and silver glue.
The capacitive elastic strain sensor according to claim 1, wherein the conductive paste comprises graphene paste, and a mixed paste of conductive material and elastomer.
The capacitive elastic strain sensor according to claim 11, wherein the mixed slurry of conductive material and elastomer includes a mixed slurry of liquid metal and elastomer, a mixed slurry of carbon powder and elastomer, carbon fiber and elastic Body mixed slurry, graphene and elastomer mixed slurry, metal powder and elastomer mixed slurry.
The capacitive elastic strain sensor according to claim 1, wherein the material of the first electrode includes one of metal materials, conductive cloth, graphene, graphite conductive glue, silver glue, liquid metal, and circuit board .
The capacitive elastic strain sensor according to claim 1, wherein the material of the second electrode includes one of metal material, conductive cloth, graphene, graphite conductive glue, silver glue, liquid metal, and circuit board .
The capacitive elastic strain sensor according to claim 1, wherein the thickness of the first conductive layer is less than 500 μm.
The capacitive elastic strain sensor according to claim 15, wherein the thickness of the first conductive layer is less than 100 μm.
The capacitive elastic strain sensor according to claim 16, wherein the thickness of the first conductive layer is less than 10 μm.
The capacitive elastic strain sensor according to claim 1, wherein the thickness of the second conductive layer is less than 500 μm.
The capacitive elastic strain sensor of claim 18, wherein the thickness of the second conductive layer is less than 100 μm.
The capacitive elastic strain sensor of claim 19, wherein the thickness of the second conductive layer is less than 10 μm.
The method for manufacturing a capacitive elastic strain sensor according to any one of claims 1 to 20, characterized in that it comprises the following steps:

(1) Prepare an elastic bonding layer on the surface of the elastic textile material;

(2) Prepare a first conductive layer on the surface of the elastic bonding layer;

(3) Prepare an elastic dielectric layer on the surface of the first conductive layer;

(4) Prepare a second conductive layer on the surface of the elastic dielectric layer;

(5) An elastic encapsulation layer is prepared on the surface of the second conductive layer.
The method for preparing a capacitive elastic strain sensor according to claim 21, characterized in that: in the step (1), the elastic bonding layer is prepared on the surface of the textile material by hot pressing, coating or baking.
The method for preparing a capacitive elastic strain sensor according to claim 21, characterized in that: in the step (2), a hollow template is used, the template is placed on the surface of the elastic bonding layer, and then the conductive liquid and conductive paste Or the conductive gel is poured, coated or printed on the hollow space of the template to obtain the first conductive layer, and finally the template is removed.
The method for preparing a capacitive elastic strain sensor according to claim 21, characterized in that: in the step (4), a hollow template is used, the template is placed on the surface of the elastic bonding layer, and then the conductive liquid and conductive paste Or the conductive gel is poured, coated or printed on the hollow of the template to obtain the second conductive layer, and finally the template is removed.
The method for manufacturing a capacitive elastic strain sensor according to claim 21, characterized in that: in the step (5), an elastic encapsulation layer is prepared on the surface of the second conductive layer by a method of hot pressing, coating or baking.
A wearable product, characterized in that it comprises the capacitive elastic strain sensor according to any one of claims 1 to 20.
The wearable product according to claim 26, characterized in that: the capacitive elastic strain sensor according to any one of claims 1 to 20 is integrated on the wearable product by stitching or hot pressing. .
The wearable product according to claim 26, wherein the capacitive elastic strain sensor is used for detecting joint bending, muscle stretching or bending, vertebral body stretching or bending, and human breathing.