KR102185565B1 - Conductive composite yarn capable of sensing the force in vertical and horizontal direction and textile sensor having the same - Google Patents

Abstract

The present invention relates to conductive composite yarn and a fabric sensor including the same. As electrical resistance varies when the conductive composite yarn is stretched in a horizontal direction or is compressed in a vertical direction, the fabric sensor woven with a warp or a weft can measure the whole external force acting in horizontal and vertical directions while being stretched and compressed without being damaged by applied external force.

Description

Conductive composite yarn capable of sensing the force in vertical and horizontal direction and textile sensor having the same}

The present invention relates to a conductive composite yarn capable of measuring an external force acting in the horizontal and vertical directions and a fabric sensor including the same, and more particularly, a plurality of fibers having different electrical conductivity on the outer surface of the elastic core yarn are multiplexed. The present invention relates to a conductive composite yarn made of covered fibers and capable of measuring both a tensile force in a horizontal direction and a pressure in a vertical direction, and a fabric sensor including the same.

With the development of IT technology, the development of light, compact and portable electronic products is actively progressing, and accordingly, various materials or parts are being developed together. Among these, electronic fibers, which are coated with a metal powder or a conductive polymer to impart electrical conductivity to the fibers, are in the spotlight recently.

Electronic fibers are used as flexible displays, wearable smart devices, and various sensors as they exhibit electrical conductivity while retaining the characteristics of light and easily bent fibers.

As a sensor using an electronic fiber, “a strain sensor for sensing the tensile force in the horizontal direction and a method for manufacturing the same” in Korean Patent Laid-Open Publication No. 10-2019-0032987, and “a fabric capable of measuring pressure and using the same” in Korean Patent Publication No. 10-2019-0032987 A pressure measuring device" is disclosed.

The sensor of Korean Patent Application Laid-Open No. 10-2019-0032987 measures a tensile force by detecting a change in resistance when tensile in a horizontal direction by placing fibers having different tensile modulus or conductive particle density per unit area in contact with each other in the left and right directions. And, the fabric of Korean Patent Application Publication No. 10-2018-0083220 consists of weft yarn and warp, which is a conductive composite yarn having an elastic polymer coating layer, and when pressure is applied in the vertical direction, the thickness of the polymer coating layer changes at the intersection of the weft yarn and warp. It detects the pressure according to the variable capacitance or resistance.

However, since the external force applied to the object to be sensed can be generated in various directions in the horizontal and vertical directions, there is a burden to separately install the above-described strain sensor and the pressure sensor in order to measure the external force on the object.

Korean Patent Laid-Open Publication No. 10-2019-0032987 (Name of the invention: Strain sensor for sensing a tensile force in the horizontal direction and a manufacturing method thereof) Republic of Korea Patent Publication No. 10-2018-0083220 (Name of invention: fabric capable of measuring pressure and pressure measuring device using the same)

An object of the present invention is to provide a conductive composite yarn capable of measuring both a tensile force acting in a horizontal direction and a pressure acting in a vertical direction, and a fabric sensor including the same.

In order to solve the above technical problem, the conductive composite yarn according to an embodiment of the present invention includes a core yarn made of an elastic material, a conductive layer formed to conduct electricity to surround the core yarn, and a first covering yarn. A conductive layer is formed so as to have a greater electrical resistance of the yarn, and the conductive yarn having a second covering yarn surrounding the first covering yarn is formed by combining them.

In addition, the conductive composite yarn according to another embodiment of the present invention includes a core yarn made of an elastic material, a conductive layer formed to conduct electricity, and surrounds the core yarn, and conducts the first covering yarn to have a greater electrical resistance. A second covering yarn is formed with a layer to surround the first covering yarn, and a third covering yarn is formed with a conductive layer formed to have an electric resistance smaller than that of the second covering yarn to surround the second covering yarn.

In addition, the present invention provides a fabric sensor including the above-described conductive composite yarn as warp or weft yarn to measure external forces acting in horizontal and vertical directions.

In addition, the fabric sensor according to another embodiment of the present invention has a center yarn made of an elastic material, a conductive layer formed to conduct electricity, and surrounds the core yarn, and has an electrical resistance greater than that of the conductive layer of the first covering yarn. A first fabric layer and a second fabric layer including a conductive composite yarn having a second covering yarn surrounding the first covering yarn as a weft yarn or a warp yarn are partially or entirely laminated to form a conductive layer.

The conductive composite yarn according to the present invention is composed of fibers in which a plurality of fibers having different electrical conductivity are covered in multiple layers on the outer surface of the elastic core yarn, and when it is stretched in the horizontal direction or compressed in the vertical direction, the electrical resistance is changed, The fabric sensor woven with warp or weft can be used as a strain sensor and a pressure sensor because it can measure both the external force acting in the horizontal and vertical directions while being stretched and compressed without being damaged by an applied external force.

1 is a plan view of a fabric sensor according to an embodiment of the present invention.
2 is a view showing a conductive composite yarn used in the fabric sensor of FIG.
3 is a cross-sectional view of a first covering yarn and a second covering yarn of the conductive composite yarn used in FIG. 1.
FIG. 4 is a view showing states before and after stretching the conductive composite yarn used in the fabric sensor of FIG. 1 in the horizontal direction.
5 is a view showing the state before and after the vertical compression of the fabric sensor of Figure 1;
6 is a plan view of a fabric sensor according to another embodiment of the present invention.
7 is a view showing a conductive composite yarn used in the fabric sensor of FIG. 6.
8 is a view showing the state before and after the vertical compression of the fabric sensor of Figure 6;
9 is a view showing a fabric sensor according to another embodiment of the present invention.
10 is a view showing a state before and after the vertical compression of the fabric sensor of Figure 9;

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

This embodiment is provided to more completely describe the present invention to those with average knowledge in the art, and the shape of the element, the size of the element, the spacing between the elements, etc. in the drawings emphasize a more clear description. For this reason, it can be exaggerated or reduced.

In addition, when it is determined that the technical features of the present invention may be unnecessarily obscure as matters already obvious to those skilled in the art, such as known functions or known configurations related in principle in describing the embodiments, the detailed The explanation will be omitted.

The term'fiber' in the present invention refers to a natural or artificial linear polymer object that can be bent long, thin, and soft, and the term'conductive composite yarn' is used as a weft or warp in the fabric sensor of the present invention to It is a fiber whose electrical resistance varies depending on the external force acting in the direction.

1 is a plan view of a fabric sensor 10 according to the present invention. Referring to FIG. 1, the fabric sensor 10 according to the present invention is woven with a weft yarn 11 and a warp 12, and the fabric structure may be variously formed of a plain weave as well as a twill weave, a runner weave, or a change structure thereof. have. Fabric sensor 10, one or more weft yarn 11 is formed of a conductive composite yarn 110, and the warp yarn 12 intersecting with the weft yarn 11 is a vision of polyester yarn, nylon yarn, etc. that do not cause an electrical short It is formed as a sword.

The weft yarn 11 formed of the conductive composite yarn 110 changes the electrical resistance according to the external force applied horizontally or vertically as described later to detect the external force, and a part of the fabric sensor 10 depending on the sensor sensitivity or use. The conductive composite yarn 110 may be used only for the weft yarn 11, or the conductive composite yarn 110 may be used for all of the weft yarn 11.

As shown in FIG. 1, the weft yarn 11 having electrical conductivity is formed of a conductive composite yarn 110 in which two conductive yarns 110a and 110b are bonded together, and such a conductive composite yarn 110 is shown in FIG. 2 Is shown in. As shown in FIG. 2, the conductive yarns 110a and 110b cover the elastic core yarn 111, the first covering yarn 112 and the first covering yarn 112 through which electricity is conducted. It has a large electrical resistance and includes a second covering yarn 113 surrounding the first covering yarn 112.

The core yarn 111 is formed of a single fiber or a composite fiber made of an elastic material such as polyurethane, styrene-butadiene-styrene (SBS), styrene butadiene rubber (SBR), polydimethylsiloxane (PDMS), or silicone. It can be stretched and contracted by an external force applied to (10) in the weft direction.

The first covering yarn 112 is a fiber having electrical conductivity, and the conductive layer 115 made of metal nanoparticles or a conductive polymer is formed on the entire outer circumferential surface as shown in FIG. 3(a). It is formed with a larger surface area. Here, the metal nanoparticles may be gold (Au), silver (Ag), copper (Cu), nickel (Ni), and the like, and the conductive polymers are carbon black, carbon nanotubes (CNT), silver nanowires, polyurethane Etc. can be used. In this way, the first covering yarn 112 having a large surface area of the conductive layer 115 has a low line resistance of 1 to 100 Ω/cm, preferably 100 Ω/cm or less, so that electricity can be smoothly energized. have. The first covering yarn 112 formed as described above is wound in a spring structure along the central axis of the central yarn 111, and the distance between the first covering yarn 112 is increased by the central yarn 111 that is stretched and contracted in the central axis direction. As it becomes variable, resistance change occurs.

The second covering yarn 113 is provided to substantially separate the conductive yarns 110a and 110b, which are bonded into two strands, so as to sense the pressure acting in the vertical direction on the fabric sensor 10 without electrically insulating them. to be. To this end, the second covering yarn 113 is formed with a conductive layer to have an electrical resistance greater than that of the first covering yarn 112. The conductive layer may be formed of a conductive material having a higher specific resistance value than the conductive layer 115 of the first covering yarn 112 and may have a small surface area. For example, the conductive layer of the second covering yarn 113 may be made of carbon having a higher specific resistance value than that of metal, and as shown in FIG. 3, the conductive layer 116 is inside the second covering yarn 113. The conductive layer 117 may be formed to have a predetermined thickness (FIG. 3(b)) or may be formed in the longitudinal direction in the form of a plurality of strips having a predetermined width, that is, a part of the surface of the second covering yarn 113 ( Fig. 3(c)).

Due to the conductive layers 116 and 117 formed as described above, the second covering yarn 113 has electrical conductivity, but the line resistance is formed as large as 10 ⁵ ~ 10 ⁸ Ω/cm. As such, as the line resistance of the second covering yarn 113 is formed to be greater than 10 ⁵ Ω/cm, each of the first covering yarns 112 of the two-stranded conductive yarns 110a and 110b to be braided is substantially electrically Since it can be isolated, it can be electrically connected only to the pressure in the vertical direction, as described later. And, when the line resistance of the second covering yarn 113 exceeds 10 ⁸ Ω/cm, the second covering yarn 113 acts as a switch according to the pressure in the vertical direction, resulting in a rapid electrical change according to On/Off. Therefore, there is a problem of impairing the sensor sensitivity. Therefore, the second covering yarn 113 has a lower electrical conductivity than a conductor, but is formed to be conductive so as not to insulate it. The second covering yarn 113 is wound around the first covering yarn 112 along the central axis of the center yarn 111, and is conductive when the first and second covering yarns 112 are twisted in the same direction. It is preferable that the composite yarn 110 is twisted in different directions as shown in FIG.

An external force acts on the conductive composite yarn 110 formed in this way in a horizontal direction, and the states before and after stretching are shown in FIG. 4. As shown, when the conductive composite yarn 110 is elongated in the horizontal direction, that is, in the weft direction in which the conductive composite yarn 110 is arranged, the center yarn 111, which is an elastic yarn, extends and a spring structure on the surface of the center yarn 111 As the distance between the first covering yarn 112 wound with a wider becomes a change in resistance, an external force in the horizontal direction can be detected.

And, the pressure acts on the fabric sensor 10 in the vertical direction, and the states before and after compression are shown in FIG. 5. As shown, before compression, the conductive composite yarn 110 is substantially separated from two strands of conductive yarns 110a and 110b by the second covering yarn 113 in the outermost layer of the conductive yarns 110a and 110b, Here, when pressure is applied in the vertical direction, the two conductive threads 110a and 110b are squeezed due to the central yarn 111 made of an elastic material, and the first covering yarn 112, which is a conductor, is electrically connected to change resistance. As is generated, the pressure in the vertical direction can also be detected.

Each of the first covering yarn 112 of the conductive yarns 110a and 110b in the textile sensor 10 to measure the external force in the horizontal and vertical directions is connected to electrodes of different polarities to measure tensile force and pressure (not shown). ) And is electrically connected. Here, the tension and pressure measuring device may include a battery, a memory, a memory controller, one or more processors (CPU), a display device, an input device, and a communication circuit, and these components communicate through one or more communication buses or signal lines. An external force measuring program is installed in the memory of the tensile force and pressure measuring device, and the one or more processors measure the resistance change of the fabric sensor 10 according to the external force measuring program stored in the memory, and then display this as external force information on the display device. Alternatively, it may be transmitted to a remote device through a communication circuit, and pressure information may be stored for each time period and statistical information may be displayed on a display device.

On the other hand, as an example, the fabric sensor 10 formed of the conductive composite yarn 110 by combining two strands of conductive yarns 110a and 110b has been described, but a conductive composite yarn obtained by combining three or more conductive yarns 110a and 110b It is also possible to implement the fabric sensor 10 as (110).

6 is a plan view of a fabric sensor 20 according to another embodiment of the present invention, and FIG. 7 is a view showing a conductive composite yarn 210 used therein. The embodiment of FIG. 6 is the same in that at least one weft yarn 21 is formed of a conductive composite yarn 210 and the warp yarn 22 is formed of a non-conductive yarn, as in the embodiment of FIG. 1 described above. Unlike the embodiment of FIG. 1 in which, 110b) is laminated to form a conductive composite yarn 110, in the embodiment of FIG. 6, a conductive composite yarn 210, which is a single yarn, is formed.

As shown in Figs. 6 and 7, the conductive composite yarn 210 is a first covering yarn 212, a first covering yarn 212 that surrounds the elastic core yarn 211, the center yarn 211 and conducts electricity. 112) A third covering yarn 213 that surrounds the first covering yarn 212 and has a smaller electrical resistance than the second covering yarn 213 and surrounds the second covering yarn 213 It has a yarn (214). In the first covering yarn 212 of the conductive composite yarn 210 according to the present embodiment, a conductive layer 115 having the same structure as the conductive composite yarn 110 is formed, and the second covering yarn 213 is also described above. Conductive layers 116 and 117 having the same structure as the conductive composite yarn 110 are formed, respectively, and a third covering yarn 214 is further formed.

Here, the third covering yarn 214 is a conductive layer that is formed to have the same line resistance as the first covering yarn 212, that is, 1 to 100 Ω/cm, and preferably 100 Ω/cm or less so that electricity is smoothly energized. Is equipped. The conductive layer of the third covering yarn 214 is made of metal nanoparticles or a conductive polymer like the conductive layer 115 of the first covering yarn 212 to form a wider surface area over the entire outer circumferential surface, and the conductive composite yarn 210 Are twisted in different directions from the second covering yarn 213 on the inside so as not to be twisted.

When the conductive composite yarn 210 formed as described above is stretched, as in the above-described embodiment, a resistance change occurs according to a change in the distance of the first covering yarn 112 to detect an external force in the horizontal direction. And, in the embodiment of Figure 6, the state before and after compression of the fabric sensor 20 according to the pressure acting in the vertical direction is shown in Figure 8. As shown, prior to compression, the first covering yarn 212 and the third covering yarn 214 are substantially separated electrically by the second covering yarn 213 having a high resistance value, and here, in the vertical direction. When pressure is applied, the conductive composite yarn 210 is compressed due to the central yarn 211 made of an elastic material, and the first covering yarn 212 and the third covering yarn 214, which are conductors, are electrically connected, thereby reducing resistance change. As it occurs, the pressure in the vertical direction can also be detected. On the other hand, the first covering yarn 212 and the third covering yarn 214 are each connected to electrodes of different polarities to detect such external force in the vertical and horizontal directions, and are electrically connected to the aforementioned tensile force and pressure measuring device. do.

9 is a plan view of a fabric sensor 30 according to another embodiment of the present invention. The fabric sensor 30 of FIG. 9 is formed by laminating a first fabric layer 30a and a second fabric layer 30b, and at least one weft 31 in each fabric layer 30a, 30b is a conductive composite yarn With 310, the warp 32 is formed of non-conductive yarn. As the conductive composite yarn 310, the conductive yarns 110a and 110b of FIG. 1 made of the central yarn 111, the first covering yarn 112, and the second covering yarn 113 are used, but are used as single yarns that are not bonded. The fabric sensor 30 of FIG. 9 is formed by stacking a first fabric layer 30a and a second fabric layer 30b including the weft 31 made of such a conductive composite yarn 310. 9 illustrates that some regions of the first fabric layer 30a and the second fabric layer 30b are stacked, but the entire region may be stacked.

In the fabric sensor 30 of FIG. 9, the + electrode and the-electrode are connected to the first covering yarn 112 of the first fabric layer 30a and the second fabric layer 30b, respectively, and are electrically connected to the tensile force and pressure measuring device. Connected. As in the above-described embodiment, as in the above-described embodiment, when the fabric sensor 30 is stretched, a change in resistance occurs according to a change in the distance of the first covering yarn 112 to detect an external force in the horizontal direction, and likewise act in the vertical direction. Pressure can also be detected, and the state before and after compression of the fabric sensor 30 is shown in FIG. 10. As shown in Fig. 10, the first fabric layer 30a and the second fabric layer 30b are separated before compression of the fabric sensor 30. When pressure is applied in the vertical direction, the core yarn made of an elastic material Due to 111, the conductive composite yarn 110 of each of the first fabric layer 30a and the second fabric layer 30b is compressed and electrically connected, so that the pressure in the vertical direction can be detected as the resistance change occurs. .

Meanwhile, in the above embodiments, an example of using the conductive composite yarn as the weft has been described, but it is of course possible to implement a fabric sensor by using the warp as the conductive composite yarn.

The conductive composite yarn according to the present invention is composed of fibers in which a plurality of fibers having different electrical conductivity are covered in multiple layers on the outer surface of the elastic core yarn, and the electrical resistance is variable when it is stretched in a horizontal direction or compressed in a vertical direction. Therefore, the fabric sensor woven with such a conductive composite yarn can be used as a strain sensor and a pressure sensor because it is not damaged by an applied external force and can measure both external forces acting in the horizontal and vertical directions while being stretched and compressed.

The present invention described above is not limited to the described embodiments, and it is apparent to those of ordinary skill in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such variations or modifications will have to belong to the claims of the present invention.

10, 20, 30: fabric sensor 11: weft
12: warp 30a: first fabric layer
30b: second fabric layer 110, 210: conductive composite yarn
110a,110b: evangelist 115, 215, 217: conductive layer
111, 211: central yarn 112, 212: first covering yarn
113, 213: second covering yarn 214: third covering yarn

Claims (12)

In the conductive composite yarn whose electrical resistance is variable according to an external force acting in horizontal and vertical directions,
A core yarn made of an elastic material;
A first covering yarn formed with a conductive layer to conduct electricity to surround the center yarn; And,
Conductive composite yarn, characterized in that formed by combining the conductive yarns having a; a second covering yarn to surround the first covering yarn by forming a conductive layer to have a greater electrical resistance than the first covering yarn. In the conductive composite yarn whose electrical resistance is variable according to an external force acting in horizontal and vertical directions,
A core yarn made of an elastic material;
A first covering yarn formed with a conductive layer to conduct electricity to surround the center yarn;
A second covering yarn having a conductive layer formed to have a greater electrical resistance than the first covering yarn to surround the first covering yarn; And,
And a third covering yarn having a conductive layer formed to have an electrical resistance smaller than that of the second covering yarn to surround the second covering yarn. The method according to claim 1 or 2,
The conductive layer of the first covering yarn and the third covering yarn is formed of metal nanoparticles or a conductive polymer on the entire outer peripheral surface of the covering yarn. The method of claim 3,
The conductive composite yarn, characterized in that the line resistance of the first covering yarn and the third covering yarn is 100 Ω/cm or less. The method according to claim 1 or 2,
The conductive layer of the second covering yarn is a conductive composite yarn, characterized in that formed of a conductive material having a higher specific resistance value than the first covering yarn and the third covering yarn. The method of claim 3,
A conductive composite yarn, characterized in that the conductive layer of the second covering yarn is made of carbon, and has a smaller surface area than that of the conductive layers of the first and third covering yarns. The method of claim 5,
Conductive composite yarn, characterized in that the line resistance of the second covering yarn is 10 ⁵ ~ 10 ⁸ Ω / cm. The method according to claim 1 or 2,
The second covering yarn is twisted in different directions from the first covering yarn, and the third covering yarn is twisted in different directions from the second covering yarn. A fabric sensor, characterized in that it comprises a conductive composite yarn to which electrodes of different polarities are connected to each of the first covering yarns of the different conductive yarns to be laminated of claim 1 as warp or weft. A fabric sensor comprising a conductive composite yarn in which electrodes of different polarities are connected to the first covering yarn and the third covering yarn of claim 2 as warp or weft yarns. In a textile sensor that measures external forces acting in horizontal and vertical directions,
A core yarn made of an elastic material;
A first covering yarn formed with a conductive layer to conduct electricity to surround the center yarn; And,
A first fabric layer and a second fabric including a conductive composite yarn having a weft or a warp; a second covering yarn formed with a conductive layer having an electrical resistance greater than that of the conductive layer of the first covering yarn to surround the first covering yarn Fabric sensor, characterized in that the layer is formed by laminating some or all areas. The method of claim 11,
Fabric sensor, characterized in that connected to electrodes of different polarities to the first covering yarn of the first fabric layer and the second fabric layer.

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