KR20210133560A - Triboelectric energy harvester comprsing stretchable electrode - Google Patents

Abstract

According to the present invention, a friction power generating element comprises a stretchable electrode to generate electrical energy by stretching in a plane direction in addition to a contact or sliding method, thereby obtaining a drastically high energy conversion rate and having high flexibility and maintaining durability for a long time compared to the prior art.

Description

Triboelectric energy harvester comprsing stretchable electrode including a stretchable electrode

The present invention relates to a friction power generator.

Recently, research on wearable devices that can be attached to the body to perform a computing action is being actively conducted. Wearable devices attached to the body are important for flexibility, adhesion, and fit, and in order to realize this, the development of flexible electrodes that are free from deformation is required.

A device such as a wearable device requires a power source to drive it, and an energy harvesting technology that converts mechanical energy into electrical energy is in the spotlight due to the nature of the device requiring frequent mechanical movement and lightness.

Energy harvesting technology capable of converting mechanical energy into electrical energy can realize self-generation as a power source for such wearable devices. Triboelectricity, one of the energy harvesting technologies, can be applied to the body to obtain electrical energy through frictional motion generated in the human body. However, conventional triboelectric nanogenerator research has been on generators using friction motion of a contact method or a friction motion of a sliding method. Therefore, in the prior art, since energy can be obtained by one operation mode such as a contact or sliding method, electricity can be generated only by a specific movement, and there is a limitation in that the energy conversion rate is significantly lowered.

As an energy harvesting technology, there is a friction generator including an elongated electrode, and the friction generator generates electrical energy through friction caused by mechanical movement. In order to generate electrical energy through friction caused by mechanical movement, conventionally, a stretchable electrode that is stretchable by distributing conductive particles or conductive wires on a flexible substrate is used. However, in the conventional stretched electrode, although the resistance change during bending is not large, when stretching in the planar direction, the distance between the conductive particles increases and the electrical conductivity decreases. thus reducing reliability. In addition, when the electrode is stretched over a certain distance, the resistance increases rapidly and the function of the electrode is lost, so there is a limit to stretching.

Therefore, it has excellent durability and weather resistance, and even if the electrode is stretched or stretched in various directions, it should be possible to minimize the increase in resistance and decrease in electrical conductivity. It is necessary to study a tribological generator with significantly high conversion efficiency.

Korean Patent Publication No. 10-2018-0098777 (2018.09.05)

An object of the present invention is to provide a tribological generator having a remarkably high energy conversion rate by generating electrical energy through stretching or contraction in a plane direction in addition to a contact or sliding method.

Another object of the present invention is to provide a friction power generator that has higher flexibility than the prior art and can maintain high durability for a long period of time.

A friction power generator according to the present invention is a friction power generator in which a first electrode and a second electrode are stacked and includes a non-adhesive stacked surface, wherein at least one electrode selected from the first electrode and the second electrode is a flexible electrode. Including, wherein the flexible electrode, a plurality of electrode units are spaced apart; and a bridge connecting any one of the electrode units to an adjacent electrode unit, wherein, when the stretched electrode is stretched or contracted in a planar direction, electrical energy is generated by friction between the stretched electrode and the second electrode. have

In one embodiment of the present invention, the first electrode may include the stretching electrode; and a positively charged layer or a negatively charged layer laminated on the stretching electrode, wherein the second electrode includes: a conductive layer; and a charge layer laminated on the conductive layer opposite to the positive charge layer or the negative charge layer of the first electrode, wherein the positive charge layer or the negative charge layer of the first electrode and the charge layer of the second electrode face each other It may be laminated toward.

In an example of the present invention, the positive charge layer may include any one or two or more selected from a urethane-based resin, silver metal, and aluminum metal.

In one embodiment of the present invention, the negative charge layer may include any one or two or more selected from perfluoroalkoxy-based resins, tetrafluoroethylene-based resins, fluorinated ethylenepropylene-based resins, and ethylene terephthalate-based resins.

In an example of the present invention, the positively charged layer may include a urethane-based resin, and the negatively charged layer may include a perfluoroalkoxy-based resin.

In one embodiment of the present invention, the stretched electrode may include a conductive polymer layer containing conductive particles.

In one embodiment of the present invention, the conductive polymer layer may contain the conductive particles in an amount of 10 to 80% by weight.

In one example of the present invention, the stretched electrode may further include a stretched layer laminated on one surface of the conductive polymer layer, and the conductive polymer layer of the first electrode and the second electrode are laminated to face each other. have.

In one embodiment of the present invention, the average thickness of the conductive polymer layer may be 100 to 500 ㎛, the average thickness of the stretched layer may be 1 to 5 mm.

In an example of the present invention, the width of the bridge may be formed to be smaller than the width of the electrode unit.

In one embodiment of the present invention, the electrode unit may be formed in a polygonal shape, and the bridge may be formed adjacent to or at a corner of the electrode unit.

In an example of the present invention, the electrode unit may rotate in a direction perpendicular to a plane direction as a rotation axis during stretching.

In an example of the present invention, the bridge may be disposed on one or more of each side of the electrode unit and may be disposed singly on each side.

In one embodiment of the present invention, the bridge may have a negative Poisson's ratio by reducing a change in cross-sectional area when the stretched electrode is stretched.

In an example of the present invention, the ratio of the separation width between the electrode unit and the adjacent electrode unit to the width of the electrode unit may be 1:4 to 9.

The friction power generator according to the present invention can generate friction by stretching in the plane direction in addition to the contact or sliding method, as well as maximize the frictional force to significantly improve the amount of electrical energy generated, and almost seamlessly It has the effect of continuously generating electrical energy.

In addition, the friction power generator according to the present invention has a higher flexibility compared to the prior art, and has the effect of maintaining high durability for a long period of time.

1 is an image showing measuring the power generation efficiency by the contraction (contact mode) of a friction power generator according to an embodiment of the present invention.
2 is an image illustrating measuring power generation efficiency by stretching mode of a friction power generator according to an embodiment of the present invention.
3 is a view showing a stacked structure of a friction power generator according to the present invention.
4 is a plan view of a stretched electrode according to an embodiment of the present invention.
5 is a partially enlarged plan view of a stretched electrode according to an embodiment of the present invention.
6 and 7 are partially enlarged plan views illustrating the stretching of the stretching electrode according to an embodiment of the present invention.
8 shows an image of a friction power generator according to an embodiment of the present invention.
9 is a plan view of a stretched electrode according to another embodiment of the present invention.
10 is a graph showing a planar photograph and a rate of change in resistance according to stretching of a general flexible electrode during stretching.
11 is a graph illustrating a planar photograph during stretching of a stretched electrode according to an embodiment of the present invention and a rate of change in resistance according to stretching.
12 is a flowchart of a method for manufacturing a stretched electrode according to an embodiment of the present invention.
13 is a schematic cross-sectional view of a main process of a method for manufacturing a stretched electrode according to an embodiment of the present invention.

Hereinafter, a friction power generator including an elongated electrode according to the present invention will be described in detail with reference to the accompanying drawings.

The drawings described in this specification are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the drawings presented and may be embodied in other forms, and the drawings may be exaggerated to clarify the spirit of the present invention.

Unless otherwise defined in technical terms and scientific terms used in this specification, those of ordinary skill in the art to which this invention belongs have the meanings commonly understood, and in the following description and accompanying drawings, the subject matter of the present invention Descriptions of known functions and configurations that may unnecessarily obscure will be omitted.

A singular form of a term used herein may be construed to include a plural form unless otherwise indicated.

s1, s2, s3, ... as referred to herein; a1, a2, a3, ...; b1, b2, b3, ...; a, b, c, ...; The term itself referring to each step, such as etc., is only used to refer to a certain step, means, etc., and should not be construed as meaning an order relationship of the respective objects referred to by the terms.

In the present specification, the unit of % used without special mention means % by weight unless otherwise specified.

As used herein, the term “layer” or “film” means that each material forms a continuum and has a dimension with a relatively small thickness compared to width and length. Accordingly, the terms “layer” or “film” in this specification should not be interpreted as a two-dimensional flat plane.

A friction power generating device according to the present invention is a friction power generating device in which a first electrode (1) and a second electrode (2) are stacked and includes a non-adhesive stacked surface, and the first electrode (1) and the second electrode (2) ) any one or more electrodes selected from the group consisting of a flexible electrode, the flexible electrode, a plurality of electrode units arranged spaced apart (110); and a bridge 150 for connecting any one of the electrode units 110 to the neighboring electrode units 110, wherein the stretched electrode 11 is stretched or contracted in the plane direction when the stretched electrode 11 is stretched or contracted in the plane direction. It has a structure in which electrical energy is generated by friction between and the second electrode 2 .

The triboelectrode device according to the present invention has a structure in which the first electrode 1 and the second electrode 2 are stacked, wherein the stacking surface is a non-adhesive stacked surface or includes an area of the non-adhesive stacked surface. Through this, the first electrode 1 or the second electrode 2 can have mechanical energy such as mechanical movement, and the mechanical energy causes the first electrode 1 and the second electrode 2 to rub against each other to generate electricity. make it happen

In particular, in the tribological electrode device according to the present invention, when the first electrode 1 including the stretched electrode 11 is stretched in the planar direction, electricity is generated by a change in the friction area between the stretched electrode 11 and the second electrode 2 . It has a structure in which energy is generated. Therefore, even when the stretched electrode 11 of the first electrode 1 is not only contracted but also stretched, the friction of the second electrode 2 is effectively implemented, so that the amount of electrical energy generated is significantly higher even in a state with less mechanical movement compared to the prior art.

As for the stacked structure of the first electrode 1 and the second electrode 2, various means can be used as long as the stacked structure is such that the stretched electrode 11 of the first electrode 1 can be contracted or stretched as described above. There is, for example, a device used as a wearable device in which both ends of the first electrode 1 are connected to and fixed to a support member that can be stretched and contracted. Accordingly, the stretchable and contractible support member can also perform a function by stretching or contracting the stretchable electrode 11 of the first electrode 1 by mechanical movement. However, this is only described as a specific example, and if the stretched electrode 11 of the first electrode 1 is contracted or stretched to generate electrical energy, the present invention is not limited thereto.

Although the stretched electrode 11 may be used as the first electrode 1 as it is, in terms of further increasing energy conversion efficiency, as shown in FIG. 3 , the first electrode 1 is the stretched electrode (11); and a positive charge layer 12 or a negative charge layer 22 stacked on the stretching electrode 11 , wherein the second electrode 2 includes a conductive layer 21 ; and a charge layer stacked on the conductive layer 21 and opposite to the positive charge layer 12 or the negative charge layer 22 of the first electrode 1 . In this case, the positive charge layer 12 or the negative charge layer 22 of the first electrode 1 and the charge layer of the second electrode 2 may be stacked to face each other. As a specific example, the first electrode 1 may include the stretching electrode 11; and a positive charge layer 12 laminated on the stretching electrode 11 , wherein the second electrode 2 includes a conductive layer 21 ; and a negative charge layer 22 of the first electrode 1 laminated on the conductive layer 21 . As a specific example, the first electrode 1 may include the stretching electrode 11; and a negative charge layer 22 laminated on the stretching electrode 11 , wherein the second electrode 2 includes a conductive layer 21 ; and a positive charge layer 12 of the first electrode 1 stacked on the conductive layer 21 .

In a preferred embodiment, the positively charged layer 12 is not particularly limited as long as a positively charged material is applied. When the urethane-based resin is included, it may be preferable in terms of remarkably excellent power generation efficiency when contracted, particularly when stretched. The weight average molecular weight of the resin may be any degree capable of maintaining its structure while functioning as a positive charge layer, for example, 10,000 to 1000,000 g/mol. However, this is only described as a specific example, and the present invention is not limited thereto.

In a preferred embodiment, the negatively charged layer 22 is not particularly limited as long as a negatively charged material is applied, for example, perfluoroalkoxy-based resins, tetrafluoroethylene-based resins, fluorinated ethylenepropylene-based resins, and ethylene terephthalate-based resins. It may include any one or two or more selected from the like, and among them, when a perfluoroalkoxy-based resin is included, it may be preferable in terms of remarkably excellent power generation efficiency when contracted, particularly when stretched. The weight average molecular weight of the resin may be any degree capable of maintaining its structure while functioning as a negative charge layer, for example, 10,000 to 1000,000 g/mol. However, this is only described as a specific example, and the present invention is not limited thereto.

In a more preferred embodiment, when the positively charged layer 12 includes a urethane-based resin and the negatively charged layer 22 includes a perfluoroalkoxy-based resin, the power generation efficiency is further improved when contracted, particularly when stretched. may be more preferable.

The average thickness of the first electrode 1 and the second electrode 2 may be appropriately adjusted according to the required power generation capacity and use scale of the triboelectric generator, for example, 0.1 to 10 mm independently of each other, specifically 0.5 to 7 mm. However, this is only described as a preferred example, and the present invention is not limited thereto. Here, “average thickness” means in a flat state, not in a stretched or contracted state.

The average thickness of the elongated electrode 11 may be appropriately adjusted according to the required power generation capacity of the tribological generator and the scale of use, for example, 0.5 to 7 mm, specifically 1 to 5 mm. However, this is only described as a preferred example, and the present invention is not limited thereto. Here, “average thickness” means in a flat state, not in a stretched or contracted state.

The average thickness of the positively charged layer 12 and the negatively charged layer 22 may be appropriately adjusted according to the required power generation capacity and use scale of the triboelectric generator, for example, independently of each other 0.1 μm to 1,000 μm, preferably 1 μm to 500 μm, more preferably 5 to 300 μm. However, this is only described as a preferred example, and the present invention is not limited thereto. Here, “average thickness” means in a flat state, not in a stretched or contracted state.

As long as the conductive layer 21 is a conductor through which current can flow, various materials may be used. As a specific example, not only metal plates such as copper and aluminum, but also particles such as activated carbon, graphite, and carbon nanotubes mixed with a binder may be used, but the present invention is not limited thereto.

The means for forming the positive charge layer 12 or the negative charge layer 22 on the stretched electrode 11 and the means for forming the positive charge layer 12 or the negative charge layer 22 on the conductive layer 21 include a positively charged material or a negatively charged material. It may be formed on the surface of the stretched electrode 11 or the conductive layer 21 so as to be well fixed. Examples of the conventionally known coating method include a dip coating method, a coating method, a spin coating method, a spraying method, and the like, and various other known methods may be used.

The stretched electrode 11 may be any one capable of being stretched and contracted and capable of generating electricity through friction of the second electrode 2, for example, a conductive polymer layer 101 containing conductive particles or the conductive polymer. It may be desirable to include layer 101 .

The conductive particles may have various shapes such as spheres, rods, and flakes, but preferably plate-shaped conductive flakes, and various conductive particles such as silver, carbon nanotubes, activated carbon, and the like may be used. When plate-shaped conductive flakes are used, the average length of the long axis of the flakes is not particularly limited, and an example may be 0.1 to 50 μm, specifically 0.5 to 30 μm. However, this is only described as a specific example, and the present invention is not limited thereto.

The polymer of the conductive polymer layer 101 may be any material capable of functioning as a polymer matrix in which conductive particles can exist in a dispersed state while having flexibility so as to be contracted or stretched, and an elastomer may be generally used. As a specific example, various types of the polymer such as polydimethylsiloxane, polyurethane, and silicone rubber may be used. At this time, the weight average molecular weight of the polymer may be sufficient as long as it has flexibility to enable shrinkage or stretching and allowing conductive particles to exist in a dispersed state, for example, 10,000 to 100,000 g/mol. However, this is only described as a specific example, and the present invention is not limited thereto.

The content of the conductive particles contained in the conductive polymer layer 101 may be within a range such that it is easy to shrink or stretch and has conductivity higher than required. For example, the conductive polymer layer 101 may contain the conductive particles. It may be contained in an amount of 10 to 80% by weight, preferably 20 to 70% by weight. However, this is only described as a preferred example, and the present invention is not limited thereto.

In a preferred embodiment, the stretched electrode 11 may further include a stretched layer 102 laminated on one surface of the conductive polymer layer 101 . In this case, the tribological generator may have a structure in which the stretching layer 102 is formed outward so that the conductive polymer layer 101 of the first electrode 1 and the second electrode 2 are stacked to face each other. When the stretched electrode 11 includes the conductive polymer layer 101 and the stretched layer 102, compared with the stretched electrode having a single-layer structure having a thickness of several mm, the conductivity required for frictional power generation with the second electrode is maximized. It may be preferable because it is possible to further improve the stretching performance while at the same time. Through this, electrical performance, structural rigidity, and elongation performance of the electrode can be further improved.

The average thickness of the conductive polymer layer 101 may be set to have sufficient conductivity and flexibility, and may be, for example, 100 to 500 μm. In addition, the average thickness of the stretched layer 102 may be set to such an extent that it has sufficient flexibility as well, and may be, for example, 1 to 5 mm. However, this is only described as a preferred example, and the present invention is not limited thereto.

The stretched electrode 11 may be or be included in the first electrode 1, but may be or be included in the second electrode 2, of course. As a specific example, a first electrode including or a first stretched electrode and a second electrode; a first electrode and a second electrode including or having a second stretched electrode; or a first electrode including or being a first stretched electrode, and a second electrode having or being a second stretched electrode.

The friction power generator according to the present invention may have a maximum voltage of 5 to 500 V, preferably 100 to 500 V, more preferably 200 to 500 V, even more preferably 300 to 500 V when friction occurs. have.

The friction power generator according to the present invention has a maximum current that can have when friction is generated from 2 to 100 μA, preferably from 10 to 100 μA, more preferably from 20 to 100 μA, even more preferably from 30 to 100 μA, very Preferably, it may be 40 to 100 μA.

As described above, the friction generating element according to the present invention includes a stretched electrode, specifically a stretched electrode having a structure to be described later, so that friction is generated even by stretching in the plane direction, and in particular, frictional force caused by stretching in the plane direction is reduced. It can be maximized so that frictional power generation can be continuously performed almost seamlessly even in various directions of mechanical movement.

Hereinafter, the structure of the stretched electrode 11 according to the present invention will be described in detail, and since the stretched electrode 11 has a specific structure to be described later, the characteristics and effects according to the present invention, such as durability, weather resistance, power generation efficiency, etc. more improved

4 is a plan view of a stretchable electrode 100 (hereinafter, 'stretched electrode') capable of being stretched in a plane direction according to an embodiment of the present invention, and FIG. 5 is a stretched electrode 100 according to an embodiment of the present invention. ) is a partially enlarged plan view of the figure.

As shown, the stretched electrode 100 may be formed in a form in which a plurality of electrode units 110 are spaced apart from each other by a predetermined distance, and each electrode unit 110 spaced apart is connected through a bridge 150 . Accordingly, when the stretched electrode 100 is stretched, the space between the electrode units 110 is widened to minimize deformation of the electrode unit 110 , thereby minimizing an increase in resistance of the electrode unit 110 .

More specifically, the electrode units 110 are formed in a substantially rectangular shape, and a plurality of electrode units 110 may be disposed to be spaced apart from each other by a predetermined distance. The bridge 150 may be configured to extend from one side of the electrode unit 110 to be connected to any one side of the neighboring electrode unit 110 . The width of the bridge 150 may be formed to be smaller than the width of the electrode unit 110, which is to prevent an increase in resistance by reducing deformation of the electrode unit 110 that may occur when the stretching electrode 100 is stretched. .

The bridge 150 may have the following configuration to rotate about a rotation axis orthogonal to the stretching direction of the electrode unit 110 when the stretching electrode 100 is stretched. This is because, when the electrode unit 110 does not rotate during stretching, resistance may increase as the electrode unit 110 is stretched. To this end, the bridge 150 may be connected singly between any one side of the electrode unit 110 and any one side of the neighboring electrode unit. Also, the bridge 150 may be disposed adjacent to a corner portion of the electrode unit 110 . In addition, when the bridge 150 is disposed at one end of one side of the electrode unit 110 , the other bridge 150 may be disposed at the other end of the side opposite to the one side. That is, the bridge 150 may be disposed on a diagonal line with respect to opposite sides of the electrode unit 110 facing each other. Therefore, the electrode unit 110 connected through the arrangement of the bridge 150 as described above may be configured to rotate when stretching in a planar direction to minimize deformation.

In particular, the stretched electrode 100 of the present invention can be stretched in both directions through the structure of the bridge 150 while the bridge 150 has a negative Poisson's ratio. Although general stretchable electrodes have a characteristic that the cross-sectional area decreases and the thickness becomes thin when stretching, the stretched electrode 100 according to the present invention is stretched through rotation of the electrode unit 110, so the cross-sectional area of the bridge 150 during stretching. little change Therefore, the stretched electrode 100 according to the present invention has the advantage of absorbing energy well and having strong characteristics against external impact.

Although it is shown in the drawing that the bridge 150 is formed separately from the electrode unit 110 and coupled thereto, it may be formed integrally. That is, the stretching electrode 100 is provided with a protrusion to form stretching spaces 121 and 122 as shown in the mold for forming a square plate so that the electrode unit 110 and the bridge 150 are integrally formed. (100) may be molded by a molding method.

In another embodiment, a thin film or plate-shaped electrode having a predetermined thickness is first formed, and then the stretching spaces 121 and 122 are cut to form a stretching electrode in which the plurality of electrode units 110 and the bridge 150 are integrally connected ( 100) can be molded.

On the other hand, a ratio between the distance W2 between the plurality of electrode units 110 and the electrode units and the width W1 of the electrode unit 110 may be configured within the range of 1:4 to 9. As a non-limiting example, if it exceeds 1:9, the stretching distance may be shortened, and if it is less than 1:4, the area of the electrode unit 110 may be reduced and electrical characteristics may be deteriorated.

6 is a partially enlarged plan view before stretching of the stretched electrode 100 according to an embodiment of the present invention, and FIG. 7 is a partially enlarged plan view after stretching of the stretched electrode 100 according to an embodiment of the present invention. is shown.

As illustrated, when the first to fourth units 111 , 112 , 113 , and 114 are spaced apart from each other and stretched in the planar direction while connected through the bridge 150 , the rotation direction is changed according to the arrangement state of the bridge 150 . it is decided

The first unit 111 disposed on the upper left side of the drawing, and the fourth unit 114 disposed on the lower right side of the drawing rotate clockwise during stretching, and the second unit 112 disposed on the upper right side of the drawing and , the third unit 113 disposed on the lower left side rotates counterclockwise during stretching. That is, the electrode unit and the adjacent electrode unit rotate in opposite directions to allow stretching without deformation of the electrode unit as the space between the electrode unit and the electrode unit expands.

8 is a plan view of the stretched electrode 200 according to another embodiment of the present invention. The stretched electrode 200 shown in FIG. 8 is characterized in that the number of electrode units is increased and the area of the electrode unit is reduced compared to the stretched electrode 100 according to the above-described embodiment of the present invention. That is, one electrode unit was divided into four electrode units again. As described above, when the number of electrode units is increased and the stretching space is increased, the stretching distance during stretching is increased, as well as deformation of the electrode unit can be further minimized, so that the increase in resistance can be reduced even when the stretching distance is increased.

10 is a graph showing the resistance change rate according to the stretching strength of a conventional conventional flexible electrode having no configuration of a stretched electrode according to the present invention, and FIG. 11 is a graph showing stretching according to one embodiment and another embodiment of the present invention. A graph showing the resistance change rate according to the stretching strength of the electrodes 100 and 200 is shown.

As shown in FIG. 10 , it can be seen that a general flexible electrode is deformed in a planar direction during stretching, and resistance increases as the distance between conductive particles increases. In particular, it can be seen that when the elongation strength is increased by 0.2 or more, the function of the electrode is lost as the resistance change rate increases exponentially. (The resistance change rate increases from 0.2 to 1100% at the elongation strength)

However, as shown in FIG. 11 , in the stretched electrodes 100 and 200 of the present invention, the resistance change rate is 54% even when the stretching strength is increased to 0.4 because only the stretching space increases and almost no deformation of the electrode unit occurs during stretching. It can be seen that within the range, in particular, in the case of the stretched electrode 200 according to another embodiment of the present invention, even when the stretching strength is increased to 0.5, it can be seen that the resistance change rate is within 26%.

Hereinafter, a method for manufacturing a stretched electrode according to an embodiment of the present invention configured as described above will be described in detail with reference to the drawings. 12 is a flowchart of a method for manufacturing a stretched electrode according to an embodiment of the present invention, and FIG. 13 is a schematic cross-sectional view of a main process related to a method for manufacturing a stretched electrode according to an embodiment of the present invention.

The method for manufacturing a stretched electrode according to the present invention may include a conductive polymer layer forming step (S10, S20) of filling a mold with a metal paste (S10) containing conductive particles, a polymer, and an organic solvent and drying (S20). In addition, the method may further include a stretching layer forming step (S30, S40) of stacking the stretched layer on the conductive polymer layer by filling (S30) and drying (S40) a polymer in the mold on which the conductive polymer layer is formed. In this case, the mold is a mold in which an electrode having a structure as shown in FIGS. 1 to 9 can be molded.

The composition ratio of the metal paste is not particularly limited as it may be appropriately adjusted according to the degree of flexibility and conductivity. For example, 100 to 500 parts by weight of conductive particles may be used based on 100 parts by weight of the polymer, and 10 to 500 parts by weight of the organic solvent. 80 parts by weight may be used. The organic solvent used at this time is not particularly limited as long as the conductive particles can be well dispersed and the polymer can be well dissolved, and an example of the organic solvent is methylisobutylketone (MIBK). However, this is only described as a specific example, and the present invention is not limited thereto.

Next, as shown in the uppermost part of FIG. 13, the prepared metal paste 101a is filled in the mold M for forming the stretched electrode, and the solvent on the metal paste 101a is evaporated and dried for curing. When the drying of the metal paste 101a is completed, the conductive polymer layer 101 having a reduced height (thickness) is formed as shown in the second figure from the top.

Next, a polymer 102a for stretching is filled in the mold M on which the conductive polymer layer 101 is formed.

Next, the polymer 102a protruding upward of the mold M is bladed using the blade B, and then dried at 80° C. for 1 hour for curing to form a stretched layer. When drying and curing of the polymer 102a is completed, the stretched layer 102 is formed on the conductive polymer layer 101 . Then, the prepared sample may be removed from the mold to manufacture the stretched electrode 100 structured as two layers of the conductive polymer layer 101 and the stretched layer 102 .

The friction power generator according to the present invention can be used in various fields as long as power is required in addition to the wearable device, and as long as the friction power generator such as a battery and a control module can be applied or applied, various related means may be further included.

That is, the technical idea should not be interpreted limited to the above-described embodiment of the present invention. Various modifications can be made at the level of those skilled in the art without departing from the gist of the present invention as claimed in the claims. Accordingly, such improvements and modifications fall within the protection scope of the present invention as long as it is apparent to those skilled in the art.

Hereinafter, the present invention will be described in detail by way of Examples, but these are for describing the present invention in more detail, and the scope of the present invention is not limited by the Examples below.

<Manufacture of stretched electrode>

As shown in the flowchart and process diagram of the manufacturing method of FIGS. 12 and 13 , the stretched electrode having the structure according to FIGS. 4 to 7 was manufactured.

Specifically, plate-shaped silver powder (Ag flake), methyl isobutyl ketone (MIBK) and polydimethylsiloxane (PDMS) (DC-184, Dow corning) (DC-184, Dow corning) having a major axis length of 1.5 μm were each 10: A metal paste was prepared by mixing in a weight ratio of 7:2. The prepared metal paste was filled in a mold capable of forming a stretched electrode having a fractal structure according to FIGS. 4 to 7 . Then, the mold was dried at 80° C. for 1 hour and cured by evaporating the solvent of the metal paste filled in the mold. PDMS is applied to the mold where the metal paste is hardened, and the pattern is filled through the doctor blading method, and then dried at 80°C for 1 hour for curing. And as in the 3rd image and 4th image of FIG. 13, polydimethylsiloxane (PDMS) was additionally applied on the cured metal paste in the mold, that is, on the conductive polymer layer, and filled in the pattern through the doctor blading method. Then, it was dried and cured at 80° C. for 1 hour. Then, it was separated from the mold, and after final curing at 100° C. for 2 hours, a stretched electrode having a two-layer structure in which a 3 mm thick stretched layer was formed on a 300 μm thick conductive polymer layer was manufactured. An image of the prepared stretched electrode is shown in FIG. 8 .

<Manufacture of friction power generator>

A first electrode is manufactured by laminating a positive charge layer on the stretched electrode in the following way, a second electrode is manufactured by laminating a negative charge layer on an aluminum metal plate, the second electrode is laminated on the second electrode, and the second electrode is laminated on the second electrode. A friction power generator was manufactured by fixing both ends of the first electrode and the second electrode. At this time, as shown in FIGS. 1 and 2 to measure the power generation efficiency, the fixing parts of both ends of the first electrode can be moved so that both ends of the first electrode can be stretched and contracted in the plane direction of the stretched electrode. made it possible

As a positive charge layer, a 50 μm thick polyurethane (Polyurethane, PU) layer was laminated on the stretched electrode to prepare a first electrode. The main agent (B) and the curing agent (A) (Flexfoam-iT X, SMOOTH-ON) were mixed within 1 minute in a weight ratio of 1:2 to prepare a flex polyurethane foam composition. The flex polyurethane foam composition was applied to the conductive polymer layer of the stretching electrode and spin-coated at 2,000 rpm for 60 seconds to laminate a positive charge layer on the stretching electrode. Subsequently, after curing at room temperature (25° C.) for 12 hours, additional curing was performed at 100° C. for 2 hours to prepare a first electrode in which a positive charge layer was laminated on the stretched electrode.

A second electrode was prepared by laminating a 50 μm thick polyperfluoroalkoxy (PFA) film layer on an aluminum metal plate as a negative charge layer.

Example 1 was performed in the same manner as in Example 1, except that a first electrode was manufactured by laminating a silver metal layer, which is a silver metal plate, on the stretched electrode instead of a polyurethane layer as a positive charge layer in Example 1.

Example 1 was carried out in the same manner as in Example 1, except that the first electrode was manufactured by laminating an aluminum metal layer, which is an aluminum metal plate, on the stretching electrode instead of a polyurethane layer as a positive charge layer in Example 1.

Example 1 was performed in the same manner as in Example 1, except that a second electrode was manufactured by laminating a polytetrafluoroethylene (PTFE) film layer on an aluminum metal plate instead of a polyperfluoroalkyl layer as a negatively charged layer.

In Example 1, in the same manner as in Example 1, except that the second electrode was manufactured by laminating a polyfluorinated ethylene propylene (FEP) film layer on an aluminum metal plate instead of a polyperfluoroalkyl layer as a negatively charged layer. carried out.

Example 1 was performed in the same manner as in Example 1, except that a second electrode was manufactured by laminating a polyimide (Pi) film layer on an aluminum metal plate instead of a polyperfluoroalkyl layer as a negatively charged layer in Example 1.

Example 1 was carried out in the same manner as in Example 1, except that a second electrode was manufactured by laminating a polyethyleneterephthalate (PET) film layer on an aluminum metal plate instead of a polyperfluoroalkyl layer as a negatively charged layer in Example 1.

[Experimental Example 1] Measurement of power generation efficiency according to the type of positive charge layer

The power generation efficiency according to the type of positively charged material of the positively charged layer was measured, and the results are shown in Table 1 below.

Example One 2 3 4 5 6 7 positive charge layer PU Silver aluminum PU PU PU PU negative charge layer PFA PFA PFA PTFE FEP PI PET Voltage(V) 320 245 265 177 132 125 8 Current (μA) 45 35 30 26 16 19 2.5

As shown in Table 1, a tribological generator using a polyurethane layer as a positively charged layer and a polyperfluoroalkyl layer as a negatively charged layer was compared to that of other types by contracting (Contact mode) or stretching (Stretching mode). It was confirmed that the power generation efficiency was more excellent.

[Experimental Example 2] Measurement of power generation efficiency according to shrinkage and elongation

In addition, as shown in FIGS. 1 and 2 , the power generation efficiency by contraction (Contact mode) or stretching mode (Stretching mode) of the manufactured friction power generator was measured, and the results are shown in FIG. 14 .

As shown in FIG. 14, it was confirmed that electrical energy is generated with high efficiency as a high voltage and a high current in both the contract mode and the stretching mode, and in particular, the voltage and current are generated and generated even during stretching. can be checked On the other hand, in the case of a triboelectric power generator manufactured using a stretching electrode different from that of the stretching electrode according to the present invention, no electrical energy is generated during stretching and power generation itself is impossible.

As described above, it can be confirmed that the friction power generator according to the present invention generates power even during stretching, and when used in a wearable device, power generation is possible even during stretching, thereby significantly improving power generation efficiency. In addition, the power generation efficiency is very excellent by being developed even in a mechanical movement in a different direction from the case of contraction, and there is an effect of minimizing the moment when power generation is interrupted due to the power generation during stretching.

1: first electrode
11, 100, 200: Stretched electrode
12: positively charged layer or negatively charged layer
2: second electrode
21: conductive layer
22: charge layer (negative charge layer or positive charge layer)
101: conductive polymer layer
102: stretched layer
110: electrode unit
111, 112, 113, 114: first to fourth units
121, 122: Stretching space
150: bridge
W1: Width of electrode unit
W2: Interval between electrode units
M: mold
B: blade

Claims (15)

A triboelectric power element in which a first electrode and a second electrode are stacked and the non-adhesive stacked surface is included,
Any one or more electrodes selected from the first electrode and the second electrode include a flexible electrode,
The flexible electrode, a plurality of electrode units spaced apart; and a bridge connecting any one of the electrode units to a neighboring electrode unit.
A friction power generator having a structure in which electric energy is generated by friction between the stretched electrode and the second electrode when the stretched electrode is stretched or contracted in a planar direction. According to claim 1,
The first electrode may include the stretching electrode; and a positive charge layer or a negative charge layer laminated on the stretching electrode;
The second electrode may include a conductive layer; and a charge layer stacked on the conductive layer and opposite to the positive charge layer or the negative charge layer of the first electrode;
The tribological generator of the positive charge layer or the negative charge layer of the first electrode and the charge layer of the second electrode are laminated to face each other. 3. The method of claim 2,
The positive charge layer is a friction power generator comprising any one or two or more selected from a urethane-based resin, silver metal, and aluminum metal. 4. The method of claim 3,
The negative charge layer is a friction power device comprising any one or two or more selected from perfluoroalkoxy-based resins, tetrafluoroethylene-based resins, fluorinated ethylenepropylene-based resins, and ethylene terephthalate-based resins. 4. The method of claim 3,
The positively charged layer includes a urethane-based resin, and the negatively charged layer includes a perfluoroalkoxy-based resin. According to claim 1,
The stretching electrode is a friction power device comprising a conductive polymer layer containing conductive particles. 7. The method of claim 6,
The conductive polymer layer is a friction power element containing the conductive particles in an amount of 10 to 80% by weight. 7. The method of claim 6,
The stretched electrode further comprises a stretched layer laminated on one surface of the conductive polymer layer,
The triboelectric power device of which the conductive polymer layer of the first electrode and the second electrode are laminated to face each other. 9. The method of claim 8,
The average thickness of the conductive polymer layer is 100 to 500 μm, and the average thickness of the stretched layer is 1 to 5 mm. According to claim 1,
The width of the bridge is a friction power generator that is formed to be smaller than the width of the electrode unit. 11. The method of claim 10,
The electrode unit is made of a polygon,
The bridge is a friction power generator that is formed adjacent to the edge or edge of the electrode unit. 12. The method of claim 11,
The electrode unit is a friction power generator that rotates as a rotation axis in a direction orthogonal to a plane direction when each of the electrode units are stretched. 11. The method of claim 10,
The bridge is disposed on one or more of each side of the electrode unit, and the friction power generator is arranged singly on each side. 11. The method of claim 10,
The bridge is a friction power generator that has a negative Poisson's ratio by reducing a change in cross-sectional area when the stretched electrode is stretched. 11. The method of claim 10,
The ratio of the separation width between the electrode unit and the neighboring electrode unit and the width of the electrode unit is 1:4-9.

Images