US20210140075A1

US20210140075A1 - Electrically conductive and elastic textile band capable of transmitting electrical signal without distortion

Info

Publication number: US20210140075A1
Application number: US16/676,742
Authority: US
Inventors: Sangwook JUNG; Hongjae Kim; Sanghoo JEON; Jinnyun HWANG
Original assignee: Kwangrim Textile Co Ltd
Current assignee: Kwangrim Textile Co Ltd
Priority date: 2019-11-07
Filing date: 2019-11-07
Publication date: 2021-05-13

Abstract

Disclosed is an electrically conductive and elastic textile band capable of transmitting an electrical signal by interconnecting wearable smart devices. The textile band can precisely transmit an electrical signal without distortion because there is almost no change in resistance according to extension although the textile band is extended in one direction.

Description

RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrically conductive textile band for transmitting an electrical signal by interconnecting wearable smart devices and, more particularly, to an electrically conductive and elastic textile band capable of precisely transmitting an electrical signal without distortion because a change in resistance according to extension is rarely present although the textile band is extended in one direction.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98

With the development of the information communication technology, a study on a wearable smart device worn by a user is actively carried out.
The wearable smart device is an electronic device which is attached to the human body or a thing and can collect or analyze information while operating in conjunction with an external computer. A patch type attachable device attached to a portable device, such as clothes, a watch, a bracelet or glasses, or the skin and configured to detect a heartbeat or a body heat and an implantable device which may be implemented into the human body are developed.
The wearable smart device is connected to a conductive line in order to transmit an electrical signal between devices or to an external computer in order to collect or analyze information. Conventionally, a cable type conductive line is used. The cable type conductive line has a poor wearing sensation and is very inconvenient to use because it has to be removed upon washing. In order to solve such problems, a technology for a conductive yarn and fiber which can be conveniently worn, can be washed and has electrical conduction is developed.
As such an example, Korean Patent Application Publication No. 10-2010-0012593 discloses fabric in which conductive yarns are formed in non-conductive fabric in an embroidery form. However, such an embroidery method has a problem in that productivity is low because a separate design and pattern are formed for each product.
Furthermore, Korean Patent Application Publication No. 10-2018-0069287 discloses conductive fabric in which conductive yarns are weaved as wefts or warps, and has advantages in that conductive fabric has excellent productivity compared to the embroidery method and can be freely extended in response to a motion of a user because a crimp is formed in the conductive yarn.
If such conductive fabric is used in a wearable smart device, however, the conductive fabric can provide a wearer's convenience because it can be freely extended in response to a motion of the human body of a wearer, but may experience a change in resistance because the cross section or length of the conductive yarn is changed upon extension.
Accordingly, there is a problem in that a fine electrical signal, such as a bio signal, cannot be precisely transmitted because noise occurs in the electrical signal due to a change in resistance occurring in response to a motion of the human body of a wearer.

PRIOR ART

(Patent Document 1) Korean Patent Application Publication No. 10-2010-0012593 entitled “Electrically conductive metal composite embroidery yarn and embroidered circuit using thereof”
(Patent Document 2) Korean Patent Application Publication No. 10-2018-0069287 entitled “Stretchable conductive fabric”

BRIEF SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve the above problems occurring in the prior art, and the present invention provides an electrically conductive and elastic textile band capable of transmitting an electrical signal to an electronic device connected thereto without distortion because a change in resistance according to extension is minimized although the textile band is connected to a wearable smart device and extended in one direction.
In an embodiment, there is provided an electrically conductive and elastic textile band in which a first direction fiber and the second direction fiber are orthogonal to each other, wherein the first direction fiber includes an extensible yarn and a conductive yarn having electrical conduction, the extensible yarn and conductive yarn are orthogonal to the second direction fibers, respectively, the extensible yarn has a greater size of fiber than the conductive yarn, and the conductive yarn is positioned within a marginal space orthogonally formed by the second direction fiber.
Furthermore, in an embodiment of the present invention, the marginal space is formed between the extensible yarn arranged in the first direction.
Furthermore, in an embodiment of the present invention, the marginal space is formed by the extensible yarn protruded to a top and bottom of the second direction fiber.
Furthermore, in an embodiment of the present invention, the conductive yarn is extended in the first direction within the marginal space by a height difference formed by the conductive yarn before and after the extensible yarn.
Furthermore, in an embodiment of the present invention, a single or a plurality of the conductive yarns is alternately arranged along with one or more extensible yarns in the first direction.
Furthermore, in an embodiment of the present invention, a ratio of sizes of fiber of the conductive yarn and the extensible yarn is 1:4 to 1:8.
Furthermore, in an embodiment of the present invention, the electrically conductive textile band has a rate of change in resistance of 3% or less according to extension in the first direction.
Furthermore, in an embodiment of the present invention, the electrically conductive textile band has a rate of change in resistance of 3% or less if the electrically conductive textile band is extended 80% or less in the first direction.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a plan view of an electrically conductive textile band according to an embodiment of the present invention.

FIG. 2 is a cross section of the electrically conductive textile band in a first direction before and after the textile band is extended according to an embodiment of the present invention.

FIG. 3 is a diagram showing a change in the form of a conductive yarn before and after the electrically conductive textile band is extended according to an embodiment of the present invention.

FIG. 4 illustrates an electrically conductive textile band according to an embodiment of the present invention.

FIG. 5 illustrates an experiment for measuring a change in resistance according to extension in an embodiment of the present invention and a comparison example.

FIG. 6 is a graph showing a comparison between changes in resistance according to extension in an embodiment and comparison example, which were measured in the experiment of FIG. 5.

DESCRIPTION OF REFERENCE NUMERALS

10: electrically conductive textile band
20: first direction fiber
21: extensible yarn
22: conductive yarn
30: second direction fiber
40: clamp
S: marginal space
D₁: extensible yarn thickness before extension
D₂: extensible yarn thickness after extension
H₁: conductive yarn height before extension
H₂: conductive yarn height after extension
C: conductive yarn path length

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention are described in detail with reference to the accompanying drawings.
The embodiments are provided to a person having ordinary knowledge in the art to which the present invention pertain to fully describe the present invention. In the drawings, the shape of an element, the size of an element and the distance between elements may have been exaggerated or reduced in order to emphasize a clearer description.
Furthermore, in describing the embodiments, a detailed description of a known art which is evident to an ordinary person in the art to which the present invention pertains, such as a known function or construction related to the present invention, will be omitted if it is deemed to make the gist of the present invention unnecessarily vague.
In the present invention, a term “fiber” means a natural or artificial line-shaped polymer object which can be bent lengthily, slimly and flexibly. A term “elongation rate” means a ratio of a drawn and extended length and the original length (unit: %).
Furthermore, in the present invention, a term “first direction fiber” means a fiber arranged in the direction in which the length of the fiber is extended, and means a warp or a weft. A “second direction fiber” means a fiber orthogonal to the “first direction fiber”, and means a weft or a warp.
An electrically conductive textile band according to an embodiment of the present invention is a conductive line used to electrically connect an electrical element, such as a sensor embedded in smart clothes, an electronic device, such as a display or a terminal, and a power source unit for driving a sensor or an electronic device.
FIG. 1 is a plan view of an electrically conductive textile band 10 according to an embodiment of the present invention. Referring to FIG. 1, the electrically conductive textile band 10 according to an embodiment of the present invention is formed in a band form having a given length, and is configured with a first direction fiber 20 and a second direction fiber 30 orthogonal to the first direction fiber 20 so that they have a comfortable wearing sensation and flexibility.
The first direction fiber 20 is configured with an extensible yarn 21 having elasticity and a conductive yarn 22 having electrical conduction, and is orthogonal to the second direction fiber 30.
In this case, the extensible yarn 21 and the conductive yarn 22 are arranged in the same first direction, and are freely extended by the extensible yarn 21 in the first direction in which an electrical signal is transmitted in response to a motion of a user.
Furthermore, the extensible yarn 21 extends the electrically conductive textile band 10 in the first direction and also forms a marginal space S in the first direction in which the conductive yarns 22 are arranged. To this end, as shown in FIG. 1, the extensible yarn 21 has a greater size of fiber than the conductive yarn 22. This is described later. The extensible yarn 21 may be made of a single fiber or complex fiber of polyurethane, styrene-butadiene-styrene (SBS), styrene butadiene rubber (SBR), polydimethylsiloxane (PDMS) or a silicon material.
The conductive yarn 22 is a fiber having electrical conduction. The conductive yarn 22 and the extensible yarn 21 and are alternately arranged in the first direction. FIG. 1 illustrates an example in which the conductive yarn 22 and the extensible yarn 21 have been alternately arranged in a 1-to-1 manner. However, the conductive yarns 22 may be arranged with various densities in the first direction depending on the size of a transmitted electrical signal or the environment of an electronic device. A single yarn or a plurality of conductive yarns 22 may be alternately arranged along with one or more extensible yarn 21 in the first direction.
As described above, the conductive yarn 22 that is alternately arranged along with the extensible yarn 21 can be freely extended by an adjacent extensible yarn 21. Furthermore, as shown in FIG. 1, the conductive yarn 22 cam be easily arranged in the marginal space S formed by the extensible yarn 21. A fiber having metal nanoparticles or a conductive polymer coated on a surface thereof may be used as the conductive yarn 22. The coated fiber may be used without limit. Gold (Au), silver (Ag), copper (Cu) or nickel (Ni) may be used as the metal nanoparticles. Carbon black, carbon nanotube (CNT), silver nanowire or polyurethane may be used as the conductive polymer.
A known synthetic fiber, such as a polyester yarn or a nylon yarn, may be used as the second direction fibers 30 orthogonal to the respective extensible yarn 21 and conductive yarn 22 configuring the first direction fiber 20. The electrically conductive textile band 10 illustrated in FIG. 1 shows an example in which the first direction fiber 20 and the second direction fiber 30 have been weaved by a plain weave, but the present invention is not limited thereto. The electrically conductive textile band 10 may be weaved by a twill weave, a satin weave or a changed weave thereof.
FIG. 2 is a cross section of the electrically conductive textile 10 band in the first direction before and after the textile band is extended according to an embodiment of the present invention. FIGS. 2(a) and 2(b) are cross sections before and after the textile band is extended. Referring to FIG. 2(a), the extensible yarn 21 having a great size of fiber is weaved along with the first direction fiber 20 and protruded and is arranged at the top and bottom of the first direction fiber 20. Accordingly, as shown in FIG. 1, the marginal space S is formed between the extensible yarns 21 arranged in the first direction. The conductive yarn 22 having a smaller size of fiber than the extensible yarn 21 is positioned within the marginal space S.
That is, the extensible yarn 21 orthogonal to the top and bottom of the first direction fiber 20 is protruded by a corresponding thickness, and the conductive yarn 22 having a smaller size of fiber than the extensible yarn 21 is orthogonal to the first direction fiber 20 in parallel to the extensible yarn 21. Accordingly, as shown in FIG. 2(a), the marginal space S corresponding to a difference in the size of fiber between the extensible yarn 21 and the conductive yarn 22 is formed at the crossing of the conductive yarn 22 and the first direction fiber 20.
In this case, in order for the marginal space S to be formed by the extensible yarn 21, a ratio of the sizes of fiber of the conductive yarn 22 and the extensible yarn 21 may be 1:4 to 1:8. If the ratio of the sizes of fiber of the conductive yarn 22 and the extensible yarn 21 is less than 1:4, a change in resistance occurs if the elongation rate of the extensible yarn 21 is high because the marginal space S is reduced. If the ratio of the sizes of fiber of the conductive yarn 22 and the extensible yarn 21 exceeds 1:8, it is difficult for the conductive yarn 22 and the first direction fiber 20 to be weaved because the marginal space S is too large. Furthermore, the ratio of the sizes of fiber of the conductive yarn 22 and the first direction fiber 20 may be 1:1˜1:4. If the ratio of the sizes of fiber of the conductive yarn 22 and the first direction fiber 20 is less than 1:1, it is difficult for the second direction fiber 30 to be weaved with the first direction fiber 20. If the ratio of the sizes of fiber of the conductive yarn 22 and the first direction fiber 20 exceeds 1:4, a change in resistance occurs because the second direction fiber 30 presses the conductive yarn 22 upon extension.
The state in which the electrically conductive textile band 10 has been extended is illustrated in FIG. 2(b). Referring to FIG. 2(b), if the extensible yarn 21 is extended in the first direction, the thickness of the extensible yarn 21 is reduced (D₁→D₂). Furthermore, the extensible yarn 21 is extended in the first direction because the vertical height of the conductive yarn 21 is reduced by the thickness reduction width (D₁-D₂).
Changes in the form of the conductive yarn 22 before and after the electrically conductive textile band 10 is extended as described above are illustrated in FIGS. 3(a) and 3(b). Referring to FIGS. 3(a) and 3(b), when the extensible yarn 21 is extended, the distance is extended (i.e., extended length: H₁-H₂) in the first direction within the marginal space S by the height difference (H₁→H₂) of the conductive yarn 22. As a result, the path lengths C of the conductive yarn 22 before and after the extension are the same. Furthermore, when the extensible yarn 22 is extended, the conductive yarn 22 positioned within the marginal space S rarely experiences a change in resistance before and after the extensible yarn 22 is extended because the conductive yarn 22 is not influenced by weight according to the extension of the extensible yarn 21 or an external force.
Such embodiment of the present invention and a comparison example are described below.
<Embodiment 1>
A conductive yarn having a size of fiber of 70 denier was prepared as a warp by covering an outer side of a polyurethane yarn, that is, corn yarn, with a nylon covered yarn and coating silver (Ag) nanopowder on an extensible yarn having a size of fiber of 420 deniers and the nylon yarn. Furthermore, a polyester yarn having a size of fiber of 150 deniers was prepared as a weft. One strand of an extensible yarn and one strand of a conductive yarn are alternately weaved along with the weft in the warp direction, thus forms side parts on both sides. Only the extensible yarn and the weft are weaved at the center. Accordingly, as shown in FIG. 4, an electrically conductive textile band having a length of 20 cm and a width of 5 cm was fabricated.
<Embodiment 2>
An electrically conductive textile band identical with that of the embodiment 1 was fabricated except that an extensible yarn having a size of fiber of 350 deniers was used.
<Comparison Example 1>
An electrically conductive textile band identical with that of the embodiment 1 was fabricated except that an extensible yarn having a size of fiber of 200 deniers was used.
<Comparison Example 2>
An electrically conductive textile band identical with that of the embodiment 1 was fabricated except that an extensible yarn and a conductive yarn both having a size of fiber of 70 deniers were used.
<Comparison Example 3>
An electrically conductive textile band identical with that of the embodiment 1 was fabricated except that a weft having a size of fiber of 350 deniers was used.
Changes in resistance according to the extension of the textile bands according to the embodiments 1 and 2 and the comparison examples 1 to 3 were measured as follows.
<Experiment 1: Measurement of Changes in Resistance According to Extension>
As shown in FIG. 5, after both sides of each of the textile bands according to the embodiments 1 and 2 and comparison examples 1 to 3 were fixed by a clamp 40, the textile bands were extended by 10%, 25%, 50%, 75%, and 80%, respectively, in the warp direction, and changes in resistance before and after the extension were measured. The results of the measurement are shown in Table 1 and FIG. 6.
A rate of change in resistance according to extension (%)=(resistance value after extension in the warp direction−resistance value prior to extension)/(resistance value prior to extension)×100.

TABLE 1

Classification/	10%	25%	50%	75%	80%
Elongation rate
Embodiment
1	0.1%	0.4%	1.1%	1.8%	2.3%
Embodiment
2	0.2%	0.8%	1.8%	2.4%	3.0%
Comparison example 1	1.8%	4.5%	11%	24%	32%
Comparison example 2	5%	22%	45%	66%	73%
Comparison example 3	1.5%	3.9%	10%	22%	29%

As shown in Table 1 and FIG. 6, in the textile bands according to the embodiments 1 and 2, the rate of change in resistance is very low, that is, 0.1%˜3.0%, until the elongation rate increases from 10% to 80%. In contrast, in the textile bands according to the comparison examples 1 and 2 in which the size of fiber of the extensible yarn is different from that of the embodiment, the rate of change in resistance is suddenly changed 10 times or more compared to the embodiment. In particular, in the textile band according to the comparison example 2 in which the extensible yarn and the conductive yarn have the same size of fiber, the rate of change in resistance is changed up to a maximum of 73%. Furthermore, in the textile band according to the comparison example 3 in which the size of fiber of the weft is different from that of the embodiments 1 and 2, it could be seen that the rate of change in resistance is slightly smaller than that of the comparison examples 1 and 2, but is very different from that of the embodiments 1 and 2.
From such an experiment, it could be seen that a difference in the size of fiber between the extensible yarn and weft arranged in the same direction as the conductive yarn 22 greatly influences a rate of change in resistance. The reason for this is that upon extension, the conductive yarn 22 positioned within the marginal space S formed by the extensible yarn 21 having a large size of fiber is extended in the warp direction without being influenced by weight or an external force according to the extension of the extensible yarn 21. Accordingly, the cross section and path length C of the conductive yarn 22 before and after extension is almost the same, and there is almost no change in resistance in the conductive yarn 22.
As described above, the electrically conductive textile band 10 according to an embodiment of the present invention can transfer an electrical signal in the direction in which the extensible yarn 21 and the conductive yarn 22 are extended because the extensible yarn 21 and the conductive yarn 22 are arranged in the same direction. Accordingly, a fine electrical signal can be accurately transmitted to an electronic device connected to the textile band without noise because a change in resistance can be minimized upon extension.
The electrically conductive and elastic textile band according to an embodiment of the present invention can transfer an electrical signal in the direction in which the extensible yarn and the conductive yarn, that is, the first direction fiber, are extended because the first direction fiber is orthogonal to the second direction fiber. Furthermore, when the extensible yarn is extended, a change in resistance can be minimized because the conductive yarn within the marginal space formed by the extensible yarn having a large size of fiber is not influenced by weight according to extension or an external force and is extended without a change in the path length. Accordingly, when the textile band is used in a wearable smart device, a fine electrical signal, such as a bio signal, can be precisely transmitted to an electronic device connected to the textile band without noise.
The present invention is not limited to the embodiments and it is evident to those skilled in the art that the present invention may be modified and changed in various ways without departing from the spirit and range of the present invention. Accordingly such modifications or changes may fall within the claims of the present invention.

Claims

We claim:

1. An electrically conductive and elastic textile band in which a first direction fiber and the second direction fiber are orthogonal to each other, wherein the first direction fiber comprises an extensible yarn and a conductive yarn having electrical conduction, the extensible yarn and conductive yarn are orthogonal to the second direction fibers, respectively, the extensible yarn has a greater size of fiber than the conductive yarn, and the conductive yarn is positioned within a marginal space orthogonally formed by the second direction fiber.

2. The textile band of claim 1, wherein the marginal space is formed between the extensible yarn arranged in the first direction.

3. The textile band of claim 2, wherein the marginal space is formed by the extensible yarn protruded to a top and bottom of the second direction fiber.

4. The textile band of claim 2, wherein the conductive yarn is extended in the first direction within the marginal space by a height difference formed by the conductive yarn before and after the extensible yarn.

5. The textile band of claim 1, wherein a single or a plurality of the conductive yarns is alternately arranged along with one or more extensible yarns in the first direction.

6. The textile band of claim 1, wherein a ratio of sizes of fiber of the conductive yarn and the extensible yarn is 1:4 to 1:8.

7. The textile band of claim 1, wherein the electrically conductive textile band has a rate of change in resistance of 3% or less according to extension in the first direction.

8. The textile band of claim 6, wherein the electrically conductive textile band has a rate of change in resistance of 3% or less if the electrically conductive textile band is extended 80% or less in the first direction.