KR102299529B1 - Transparent stretchable structure with one direction orientes structure and its manufacturing method - Google Patents

Abstract

A transparent stretchable structure according to various embodiments of the present disclosure for realizing the above-described problems is disclosed. The transparent stretchable structure can include: a transparent base material made of an elastic material; and a reinforcing material provided inside the base material and made of a transparent material. The present invention can improve the productivity of the stretchable structure.

Description

Transparent stretchable structure of one-way orientation structure and manufacturing method thereof

The present disclosure relates to a substrate material having elasticity, and more specifically, by creating an elastic substrate having a Poisson's ratio close to zero, when the substrate is stretched based on one axis, the strain rate related to the other axis can be controlled. It relates to a possible stretchable substrate and a method for manufacturing the same.

Recently, research and development on stretchable electronic devices in which electrodes are formed on flexible substrates, away from conductive devices in which electrodes are formed on a rigid substrate, are being actively researched and developed. A stretchable electronic device is an electronic device manufactured on a substrate that can be freely stretched against external stress, and is a next-generation electronic device that maintains electrical/physical properties of the device even when mechanical deformation or external force is applied. Such a stretchable electronic device may be applied to a flexible device, a wearable device, and the like, and further may be utilized as a display or a sensor, an electrode, etc. attached to the human body.

The fields in which stretchable electronic devices can be most widely used include stretchable displays, stretchable solar cells, and stretchable energy storage/generation devices, which show the potential as a next-generation technology that follows flexible displays. In addition, stretchable electronic devices not only increase design freedom due to their excellent mechanical variability, but also secure mechanical stability due to external forces, such as wearable devices, electronic skin, smartphones, medical devices, healthcare monitoring systems, national defense, and aviation. The market is expanding to the space industry.

For a specific example, in relation to the display field, from a fixed flat/curved display to a flexible, foldable, or rollable form such as folding or rolling in a single direction, it develops in the direction of increasing the degree of freedom of deformation are doing Recently, as electronic devices become smarter and space mobility is emphasized, development of a flexible display that can be freely used and deformed in a multi-dimensional axial direction under various conditions is required, away from a fixed display.

As described above, it is expected that the realization of a new digital interface that exceeds the existing method is possible due to the development of technologies related to the field of stretchable displays. However, since the stretchable display does not have a fixed deformation axis or direction unlike the conventional flexible, foldable, and roller bull displays, a distortion phenomenon during deformation is emerging as an issue.

Accordingly, it may be necessary to develop a substrate that can be freely deformed without distortion of the display even under low stress, low resistance, high flexibility, and high stability stretchable electrode technology. That is, there may be a demand in the art for a stretchable substrate having a stable mechanical strain as well as a reduction in distortion and high transmittance.

Registered Patent Publication No. 10-1749861 (2017.06.15)

The problem to be solved by the present disclosure is to solve the above problems, and by creating an elastic structure having a Poisson's ratio close to zero, when the structure is stretched with respect to one axis, the strain with respect to the other axis An object of the present invention is to provide a controllable stretchable structure and a method for manufacturing the same.

The problems to be solved by the present disclosure are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A transparent stretchable structure according to various embodiments of the present disclosure for solving the above-described problems is disclosed. The transparent stretchable structure may include a transparent base material made of a material having elastic force, and a reinforcing material provided inside the base material and made of a transparent material.

In an alternative embodiment, it may include one or more sub-reinforcements, each of the one or more sub-reinforcements being provided through a fiber shape and oriented in one direction.

In an alternative embodiment, the transparent stretchable structure may be characterized in that the modulus in the first direction has an anisotropy of at least 10 times the modulus in the second direction, and the Poisson's ratio is 0.05 or less.

In an alternative embodiment, the modulus in the first direction is a composite modulus in an orientation direction of the reinforcement material, and is calculated through an arithmetic mean of modulus according to a volume ratio between the reinforcement material and the base material, and the modulus in the second direction is, As the composite modulus in a direction perpendicular to the orientation of the reinforcing material, it may be calculated through a harmonic average of modulus according to a volume ratio between the reinforcing material and the base material.

In an alternative embodiment, the base material has a volume fraction in the range of 0.1 to 0.9, it may be characterized in that it is provided through a modulus (modulus) in the range of 0.01 MPa to 100 MPa.

In an alternative embodiment, the reinforcing material has a volume fraction in the range of 0.1 to 0.9, and is a fiber-shaped aggregate having a diameter in the range of 200 nm to 100 μm, and may be characterized in that it is provided through a modulus in the range of 1 MPa to 1000 GPa. .

In an alternative embodiment, the base material includes a transparent additive matching the refractive index with the reinforcing material, and the transparent additive is composed of nanoparticles having a size of 3 nm to 100 nm, zirconium oxide (ZrO2), titanium dioxide It may include at least one of (TiO2) and aluminum oxide (Al2O3), and may be characterized in that it is added to the base material during the manufacturing process of the base material.

In an alternative embodiment, the reinforcement may include a plurality of glass fibers.

A method of manufacturing a transparent stretchable structure according to various embodiments of the present disclosure is disclosed. The method includes the steps of: creating a first base material of an elastic material; generating a reinforcement including one or more sub-reinforcements; placing the reinforcement on one surface of the first base material; and a second on the upper side of the reinforcement. It may include the step of impregnating the reinforcing material by supplying a base material.

In an alternative embodiment, the method for manufacturing the transparent stretchable structure further includes the step of generating the first base material, wherein the generating of the first base material includes adding a transparent additive to the first base material in a liquid state. , supplying the first base material in the liquid state to a fixed plate, performing curing on the first base material in the liquid state, and separating the fixed plate.

In an alternative embodiment, the transparent additive is composed of nanoparticles having a size of 3 nm to 100 nm, and may include at least one of zirconium oxide (ZrO2), titanium dioxide (TiO2), and aluminum oxide (Al2O3).

In an alternative embodiment, the step of positioning the reinforcing member on one surface of the first base material may include positioning each of the one or more sub-reinforcing materials on one surface of the first base material in one direction.

In an alternative embodiment, the step of supplying a second base material to the upper side of the reinforcing material and impregnating the reinforcing material includes positioning the second base material on the upper side of the reinforcing material and performing a high-temperature pressing process to each base material. It may include impregnating the reinforcing material therebetween.

In an alternative embodiment, the step of supplying a second base material to the upper side of the reinforcing material and impregnating the reinforcing material may include supplying a liquid second preform to the upper side of the reinforcing material and the liquid second preform It may include the step of performing curing for the.

In an alternative embodiment, each of the first base material, the second base material, and the reinforcing material is characterized in that it is provided to satisfy the following equation conditions,

은 제 1 모재와 제 2 모재의 모듈러스이며,

은 상기 제 1 모재와 상기 제 2 모재의 부피 분율이며,

는 상기 보강재의 모듈러스이며,

는 상기 보강재의 부피 분율일 수 있다.

is the modulus of the first base material and the second base material,

is the volume fraction of the first base material and the second base material,

is the modulus of the reinforcement,

may be a volume fraction of the reinforcing material.

Other specific details of the present disclosure are included in the detailed description and drawings.

According to various embodiments of the present disclosure, the present disclosure may provide a transparent stretchable structure that can be freely used by being deformed in a multidimensional axial direction under various conditions. In addition, it is possible to provide a stretchable structure having high transmittance as well as a stable mechanical strain. Additionally, by optimizing the manufacturing process, it is possible to improve the mass productivity of the stretchable structure by inducing an improvement in manufacturing speed and a large area.

Effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

Various aspects are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements collectively. In the following examples, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It will be evident, however, that such aspect(s) may be practiced without these specific details.
1 is a schematic view showing a transparent stretchable structure related to an embodiment of the present disclosure.
FIG. 2 is an exemplary view of an ogetic structure having a Poisson ratio close to zero as provided through various shapes related to an embodiment of the present disclosure.
3 shows a flowchart exemplarily illustrating a method of manufacturing a transparent stretchable structure related to an embodiment of the present disclosure.
4 shows an exemplary view from the side of the transparent stretchable structure related to an embodiment of the present disclosure.
5 is a view showing experimental values related to an orientation direction composite modulus and a vertical direction composite modulus of orientation according to a volume ratio between a base material and a reinforcing material related to an embodiment of the present disclosure;
6 is a view showing experimental values related to the Poisson ratio according to the volume ratio between the base material and the reinforcing material related to an embodiment of the present disclosure.
7 is a view showing experimental values related to the volume fraction of the base material related to an embodiment of the present disclosure.

Various embodiments and/or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of one or more aspects. However, it will also be appreciated by one of ordinary skill in the art that such aspect(s) may be practiced without these specific details. The following description and accompanying drawings set forth in detail certain illustrative aspects of one or more aspects. These aspects are illustrative, however, and some of the various methods in principles of various aspects may be employed, and the descriptions set forth are intended to include all such aspects and their equivalents. Specifically, as used herein, “embodiment”, “example”, “aspect”, “exemplary”, etc. is not to be construed as an advantage or advantage of any aspect or design described over other aspects or designs. It may not be.

Hereinafter, the same or similar components are assigned the same reference numerals regardless of reference numerals, and overlapping descriptions thereof will be omitted. In addition, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the accompanying drawings.

Although first, second, etc. are used to describe various elements or elements, these elements or elements are not limited by these terms, of course. These terms are only used to distinguish one element or component from another. Accordingly, it goes without saying that the first element or component mentioned below may be the second element or component within the spirit of the present invention.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or clear from context, "X employs A or B" is intended to mean one of the natural implicit substitutions. That is, X employs A; X employs B; or when X employs both A and B, "X employs A or B" may apply to either of these cases. It should also be understood that the term “and/or” as used herein refers to and includes all possible combinations of one or more of the listed related items.

Also, the terms "comprises" and/or "comprising" mean that the feature and/or element is present, but excludes the presence or addition of one or more other features, elements, and/or groups thereof. should be understood as not Also, unless otherwise specified or otherwise clear from context to refer to a singular form, the singular in the specification and claims should generally be construed to mean "one or more."

When a component is referred to as being “connected” or “connected” to another component, it is understood that it is directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that there is no other element in the middle.

The suffixes “module” and “part” for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves.

References to an element or layer “on” or “on” another component or layer mean that another layer or other component is directly on, as well as intervening, another component or layer. Including all intervening cases. On the other hand, when a component is referred to as "directly on" or "immediately on", it indicates that another component or layer is not interposed therebetween.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe a component or a correlation with other components. Spatially relative terms should be understood as terms including different orientations of the device during use or operation in addition to the orientation shown in the drawings.

For example, when a component shown in the drawing is turned over, a component described as “beneath” or “beneath” of another component may be placed “above” of the other component. can Accordingly, the exemplary term “below” may include both directions below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

Objects and effects of the present disclosure, and technical configurations for achieving them will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. In describing the present disclosure, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in the present disclosure, which may vary according to intentions or customs of users and operators.

However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. Only the present embodiments are provided so that the present disclosure is complete, and to fully inform those of ordinary skill in the art to which the present disclosure belongs, the scope of the disclosure, and the present disclosure is only defined by the scope of the claims . Therefore, the definition should be made based on the content throughout this specification.

1 is a schematic view showing a transparent stretchable structure related to an embodiment of the present disclosure. As shown in FIG. 1 , the transparent stretchable structure 100 of the present disclosure is provided with a transparent base material 120 made of a material having elastic force, and a fiber-shaped reinforcing material oriented in one direction inside the base material and made of a transparent material. (110) may be included. The transparent stretchable structure 100 may have a Poisson's ratio close to zero. Specifically, the transparent stretchable structure 100 may be created by providing the reinforcing material 110 including one or more sub-reinforcing materials in an inner region of the base material 120 to be oriented in one direction. In this case, the one or more sub-reinforcements may be oriented in one direction. For example, each sub-reinforcement member may be oriented in one direction to be parallel to each other. That is, the transparent stretchable structure 100 can maximize the mechanical anisotropy of the composite through one or more fiber-shaped sub-reinforcements oriented in one direction inside the base material 120, and can be provided to have a Poisson's ratio close to zero. have.

Here, the Poisson ratio may mean a ratio between the degree of strain in the transverse direction and the degree of strain in the longitudinal direction, which are stretched in a specific direction by applying a tensile force to the material. Most materials have a positive Poisson's ratio when a tensile force is applied uniaxially because the signs of the tensile direction and the lateral strain of the material are different from each other.

As a specific example, when a stress in the transverse direction is applied to a material having a general structure, it expands in that direction and shrinks in the longitudinal direction at the same time. That is, the Poisson ratio between the deformation in the longitudinal direction and the deformation in the transverse direction due to the normal stress generated inside the material may be positive. Although such a Poisson's ratio is a characteristic inherent in the original material, when the material is formed to have a specific shape or specific arrangement characteristics, it may be possible to control the strain rate in the vertical direction of the stretching direction.

The transparent stretchable structure 100 of the present disclosure, when stress is applied in the transverse direction (vertical direction of orientation), the modulus in the longitudinal direction (orientation direction of the filler (ie, one or more sub-reinforcements)) is very high compared to the transverse direction. high, so that little shrinkage in the longitudinal direction may occur. That is, the transparent stretchable structure 100 in the present disclosure may refer to a material designed to have a Poisson's ratio close to zero, unlike a general material. According to the embodiment, the transparent stretchable structure 100 may be provided so that deformation in the vertical direction, which is difficult to appear in normal natural stretching, does not occur.

In other words, the transparent stretchable structure 100 of the present disclosure is implemented through the base material 120 having an elastic force and the reinforcing material 110 oriented in one direction inside the base material 120 , thereby close to zero Poisson. ratio, or the strain with respect to the direction perpendicular to the stretching direction can be minimized.

Accordingly, the transparent stretchable structure 100 of the present disclosure may provide a high degree of design freedom, such as being deformed in various axial directions. For example, when a display is configured through the transparent stretchable structure 100 of the present disclosure, it is possible to support deformation in a multi-dimensional axial direction under various conditions outside of a fixed display such as folding or rolling in a single direction. This may have the effect of not only improving design freedom by providing higher variability, but also ensuring mechanical stability due to external force.

On the other hand, as a material having a structure that supports deformation in a multidimensional axial direction under various conditions (ie, a material having a Poisson ratio close to zero), a material having an auxetic structure typically exists. The orgetic structure may be configured to be impregnated to have a specific shape inside the structure (eg, a substrate), and may cause deformation in the direction of the other axis in response to an external force generated based on one axis. For example, as shown in FIG. 2 , when an orgetic including reentrant, chiral, and rotational rigid unit structures are impregnated in the substrate, the substrate may have a Poisson's ratio close to zero.

As a more specific example, as shown in (a) of FIG. 2 , when an external force based on a longitudinal direction is applied to an orgetic including a unit structure having a reentrant shape, the lateral direction of each unit structure is applied. As an internal stress acts in the direction, the orgetic can have a negative Poisson's ratio. That is, in response to an external force with respect to the longitudinal axis, the ogetic may be extended with respect to the transverse axis.

Also, for example, as shown in (b) of FIG. 2 , when an external force based on a longitudinal direction is applied to an orgetic including a unit structure having a chiral shape, each unit structure is rotated in a clockwise direction or As it is rotated counterclockwise, the orgetic may have a negative Poisson's ratio.

Also, for example, as shown in (c) of FIG. 2 , an orgetic including a unit structure having a rotational rigid body shape may share one node, and each unit body through the node is rotated, which can represent the properties of a material with a negative Poisson's ratio. That is, when an external force based on the longitudinal direction is applied to the orgetic, each unit structure is rotated clockwise or counterclockwise as the connecting line is released based on the shared node between each unit structure. A jettic may have a negative Poisson's ratio.

That is, as in the above-described example, there is a material having an orgetic structure having a negative Poisson's ratio as it is implemented through unit structures of various shapes. In the case of a substrate impregnated therein (that is, a material of an organic structure), when an external force based on a specific axial direction is applied through the shape of the unit structures included in the corresponding organic structure, the other can control the strain in the axial direction of

The material of such an organic structure may be generated, for example, through a printing process using an elastic material. Here, the printing process is a process of printing a target object through an inkjet printer or laminator, etc. on a designed circuit pattern. roll processing). Such a printing process may refer to, for example, a process using equipment such as inkjet, pneumatic dispenser, screw dispenser, screen printing, bar coater, and straight printing.

As described above, the material of the oregetic structure may implement material properties having a negative Poisson ratio through the shapes of various unit structures (eg, reentrant, chiral, and rotational rigid bodies). However, in order to have a negative Poisson's ratio, since it is necessary to form an oegetic corresponding to various shapes of tens to hundreds of micro-intervals and sizes, equipment related to a high-precision printing process is essential, and the Various additional processes may be required, such as a curing process and an additional curing process in the process of creating a stretchable substrate by impregnating the organic substrate therein. In other words, the material of the organic structure may require expensive and high-precision equipment in the manufacturing process, and a lot of effort and time may be required for various lattice structure designs, additive manufacturing processes, and curing processes.

On the other hand, the transparent stretchable structure 100 of the present disclosure may be implemented through a relatively simple process, such as a process of manufacturing each of the reinforcing material 110 and the base material 120 and a process of bonding or impregnating each material, and pultrustion. A continuous process such as this may be possible. Here, the pultrustion process may include a continuous process in which the fiber-shaped reinforcing material 110 is continuously supplied and the prepreg is manufactured by impregnating the molten stretchable base material 120 .

Accordingly, since a separate printing process is not required to generate a specific lattice shape, it is possible to provide the effect of simplifying equipment used in the manufacturing process. In addition, a fine process for a structure having a size of several tens to several hundred micrometers (eg, an organic) may be omitted. That is, a manufacturing process for a material having a Poisson's ratio close to zero may be simplified. This leads to an improvement in manufacturing speed and a large area through optimization of the manufacturing process, and since continuous process development is possible, mass productivity of the transparent stretchable structure can be easily secured.

A more specific manufacturing method, structural features, and effects thereof for the transparent stretchable structure 100 of the present disclosure will be described below with reference to FIGS. 3 to 6 .

3 shows a flowchart exemplarily illustrating a method of manufacturing a transparent stretchable structure related to an embodiment of the present disclosure. According to an embodiment, the method of manufacturing the transparent stretchable structure may include the following steps. The order of the steps shown in FIG. 3 may be changed if necessary, and at least one or more steps may be omitted or added. That is, the above-described steps are merely an embodiment of the present disclosure, and the scope of the present disclosure is not limited thereto.

According to an embodiment of the present disclosure, the transparent stretchable structure 100 may include a base material 120 made of a material having an elastic force and a reinforcing material 110 oriented in one direction inside the base material 120 . In this case, the reinforcing material 110 may include one or more sub-reinforcing materials 110 having a fiber shape. That is, the transparent stretchable structure 100 may be implemented in the shape of a base material 120 in which one or more sub-reinforcement materials 110 are impregnated therein in one direction. To this end, the transparent stretchable structure 100 may be created through a process of creating two layers of the base material 120 , and locating one or more sub-reinforcing materials 110 between each of the generated base materials. In this case, each of the two base material 120 layers may be located on the upper surface and the lower surface with respect to the reinforcing material 110 . Specifically, the base material 120 positioned on the lower surface with respect to the reinforcing material 110 may be the first base material, and the base material positioned on the upper surface with respect to the reinforcing material 110 may be the second base material. That is, in the present disclosure, the base material 120 may include a first base material and a second base material positioned on the lower surface and the upper surface, respectively, with respect to the reinforcing material 110 . In one embodiment, during the manufacturing process of the base material 120, a process (ie, a process of impregnating the inside of the base material) so that the reinforcing material 110 is oriented in one direction may be performed at the same time. That is, the transparent stretchable structure 100 of the present disclosure having the structure of the base material 120 for orienting the reinforcing material 110 therein in one direction through one process may be implemented.

According to an embodiment of the present disclosure, the method of manufacturing the transparent stretchable structure may include generating a base material ( 210 ). The first base material and the second base material in the present disclosure may be produced through the same material and the same process process. That is, the step of generating the base material may comprehensively mean generating each of the first base material and the second base material.

The base material 120 of the present disclosure is composed of a material having elasticity, for example, polydimethylsiloxane (PDMS, Polydimethylsiloxane), Ecoflex, silicone, polyurethane, stretchable epoxy, thermoplastic elastomer (TPE, thermoplastic elastomer, typically Styrene-ethylene) -butylene-styrene (SEBS)), polyisobutylene, and butyl rubber may be provided through at least one. In a specific embodiment, the base material related to PDMS can be produced by mixing Dow Corning Sylgard 184 material in the ratio of A 10 and B 1, and then curing the material at a high temperature of 80 degrees for 4 hours or more. As another example, after mixing the Clearflex 30 material in the ratio of the first agent A and the first agent B, the base material related to the cross-linked transparent PU can be produced through a process of curing at a high temperature of 80 degrees for 16 hours or more. As another example, a base material related to thermoplastic PU (TPU) or SEBS can be produced through a process of compressing a granular thermoplastic elastomer in a hot press of 120 to 150 degrees. The detailed description of the above-described base material production process method and base material is only an example, and the present disclosure is not limited thereto.

According to one embodiment, the step of generating the base material includes the steps of adding a transparent additive to the base material in a liquid state, supplying the base material in a liquid state to the fixed plate, performing curing on the base material in the liquid state, and the fixed plate Separation may be included.

In more detail, a transparent additive may be added in the process of forming the base material. The transparent additive has the shape of nanoparticles having a size of 3 nm to 100 nm, and may include, for example, at least one of zirconium oxide (ZrO2), titanium dioxide (TiO2), and aluminum oxide (Al2O3). Such a transparent additive may be for matching the refractive index between the base material 120 and the reinforcing material 110 . For example, when each of the base material 120 and the reinforcing material 110 is provided through different materials, a difference in refractive index between each material occurs and the transparent stretchable structure 100 is substrateized for use in the display field. As the interface between each material becomes visible, it may be difficult to secure visibility.

Accordingly, a transparent additive formed of nanoparticles may be added to the base material to match the refractive index between the base material 120 and the reinforcing material 110 . That is, the transparent additive is added to the base material 120 to match the refractive index of the base material to the same as the reinforcing material, thereby securing transparency and providing the transparent stretchable structure 100 having improved visibility in the field of display application. Therefore, since the transparent stretchable structure 100 configured through the base material 120 including the transparent additive of the present disclosure is generated in consideration of the refractive index between each material (ie, the base material and the reinforcing material), improved transparency can be provided. .

The transparent additive as described above may be characterized in that it is added to the base material 120 during the manufacturing (eg, hardening or melting) process of the base material 120 . Specifically, the transparent additive may be added to the base material in a liquid state, and the base material in the liquid state to which the transparent additive is added may be supplied to the fixed plate. Here, the fixing plate is provided to temporarily support the corresponding base material 120 in the process of generating the base material 120 , and may be separated from the base material 120 after the base material generating process. That is, the base material 120 may be generated through the use of a separate fixing plate different from the components constituting the transparent stretchable structure 100 .

In other words, the base material 120 in a liquid state is supplied to one surface of the fixed plate, and after curing is performed on the base material 120, by separating the fixed plate, the base material 120 can be generated. For example, the hardening performed may be hardening to secure the mechanical strength or rigidity of the base material 120 .

The base material of the present disclosure may have a volume fraction in the range of 0.1 to 0.9 and may be characterized in that it is provided through a modulus in the range of 0.01 MPa to 100 MPa. Here, the volume fraction means a ratio of the volume of one component to the total volume, and the volume fraction of the base material may represent a ratio of the volume occupied by the base material to the total volume of the transparent stretchable structure 100 .

According to an embodiment of the present disclosure, the method of manufacturing the transparent stretchable structure may include generating a reinforcing material including one or more fiber-shaped sub-reinforcing materials ( 220 ). In the present disclosure, the reinforcing material 110 may be provided with a transparent material, for example, may be provided with a transparent material related to at least one of glass fibers or polymer fibers. Specific description of the aforementioned reinforcing material is only an example, and the present disclosure is not limited thereto.

As a specific example, the step of generating the reinforcing material may be a process of continuously generating and extracting thin glass fibers through a continuous process. In an embodiment, the reinforcing material 110 may be extracted through a relatively simple continuous extraction process and provided in a roving form.

As described above, the reinforcing material 110 may be implemented through a plurality of transparent glass fibers having a fiber shape. The plurality of glass fibers may be oriented inside the reinforcing material through various angles, but the reinforcing material is oriented in one direction and the compounding process is performed. That is, the reinforcing material 110 can implement the anisotropy of the mechanical modulus in the composite substrate through a plurality of glass fibers oriented in one direction therein, and the strain in the vertical direction is controlled in response to an external tensile force and can be tensioned.

The reinforcing material 110 of the present disclosure has a volume fraction in the range of 0.1 to 0.9, is formed in the form of a bundle of fibers having a diameter in the range of 200 nm to 100 μm, and is provided with a modulus in the range of 1 MPa to 1000 GPa. . Here, the volume fraction of the reinforcing material may represent a ratio of the volume occupied by the reinforcing material to the total volume of the transparent stretchable structure 100 .

According to an embodiment of the present disclosure, the method of manufacturing the transparent stretchable structure may include a step 230 of positioning a reinforcing material on one surface of the first base material. The positioning of the reinforcing material may include positioning each of the one or more sub-reinforcing materials on one surface of the first base material in one direction.

Specifically, each of one or more sub-reinforcing materials may be aligned and positioned on one surface of the first base material in one direction. For example, referring to FIG. 4 , the plurality of sub-reinforcing materials having a fiber shape include a first sub-reinforcing material 111 , a second sub-reinforcing material 112 , a third sub-reinforcing material 113 , and a fourth sub-reinforcing material 114 . It may include more than one fiber shape, such as In this case, each sub-reinforcement member may be aligned (or disposed) in the same direction with respect to an axis in one direction. In other words, each sub-reinforcement member may be aligned in one direction to be parallel to each other.

According to one embodiment, each of the one or more fiber-shaped sub-reinforcing materials is impregnated without voids in the interface between the reinforcing material and the base material when the interface is subjected to a sizing process in which the interface is coated with silane or the complexing process is performed through various interface control methods to achieve a uniform composite to be able to form

According to an embodiment of the present disclosure, the method of manufacturing the transparent stretchable structure may include the step of impregnating the reinforcing material by supplying a second base material to the upper side of the reinforcing material ( 240 ).

Specifically, according to one embodiment, the step of supplying the second base material to the upper side of the reinforcing material 110 and impregnating the reinforcing material includes positioning the second base material on the upper side of the reinforcing material 110 and a high-temperature pressing process. It may include impregnating the reinforcing material between each base material by performing a. As a specific example, one or more fiber-shaped reinforcing materials 110 are oriented in one direction between each base material (ie, the first base material and the second base material) composed of thermoplastic polyurethane (TPU, Thermoplastic Polyurethane), and 120 By performing a pressing process for 30 seconds through a temperature of to 150 degrees, it is possible to impregnate the reinforcing material in the interior of the base material. In other words, by arranging and providing a fiber reinforcement on the upper surface of the first base material in one direction, and positioning the second base material on the upper side of the fiber reinforcement arranged in one direction to perform a high-temperature pressing process, the first base material and the second base material One or more sub-reinforcing materials may be oriented in one direction within the base material formed of the two base materials.

According to another embodiment of the present disclosure, the step of supplying the second base material to the upper side of the reinforcing material 110 and impregnating the reinforcing material includes the steps of supplying the second base material in a liquid state to the upper side of the reinforcing material 110 and It may include performing curing on the second base material in a liquid state. For a specific example, when the base material is composed of a cross-linked polymer or a polymer matrix in a molten form, one or more glass fibers are placed on the upper surface of the first base material in one direction, and the base material in liquid form is supplied to the upper side of the base material. By hardening, the reinforcing material can be impregnated inside the base material. In other words, by disposing one or more fiber reinforcing materials on the upper surface of the first base material in one direction and supplying a second base material in a liquid state to the upper side of the one or more reinforcing materials arranged in one direction to harden, the first base material and One or more sub-reinforcing materials may be oriented in one direction inside the base material formed of the second base material.

As described above, the reinforcing material 110 including one or more sub-reinforcing materials 110 may be oriented in one direction inside the base material 120 , thereby configuring the transparent stretchable structure 100 of the present disclosure. In this case, the transparent stretchable structure 100 may be provided to have a Poisson's ratio of 0.05 or less by providing the reinforcing material 110 and the base material 120 having specific conditions. In other words, the reinforcing material 110 and the base material 120 are provided under specific conditions, thereby forming the transparent stretchable structure 100 having a Poisson's ratio close to zero.

More specifically, in the anisotropic transparent stretchable structure 100 , the modulus of the first direction, which is the direction in which the reinforcing material 110 is oriented, may be at least 10 times greater than the modulus of the second direction, which is the direction perpendicular to the orientation. In this case, when the transparent stretchable structure 100 is manufactured in an oriented form of the fiber-type reinforcing material, the modulus in the first direction with respect to the alignment direction may be calculated through the arithmetic average of the modulus according to the volume ratio between the reinforcing material and the base material. . In addition, the modulus in the second direction in relation to the direction perpendicular to the orientation may be calculated through a harmonic average of modulus according to a volume ratio between the reinforcing material and the base material.

)이 10배 이상의 모듈러스를 가지는 배향 방향으로 걸리므로, 그 수축되는 변형률이 10배 이하로 줄어들 수 있게 된다. 다시 말해, 본 개시의 보강재(예컨대, 파이버 형태의 투명 필러)가 일 방향으로 배향된 투명 신축 구조체(100)를 구성하는 보강재(110)와 모재(120)는 하기와 같은 수식 조건을 충족하도록 구비되는 것을 특징으로할 수 있다.That is, in the transparent stretchable structure 100 of the present disclosure, the orientation direction composite modulus (that is, the first direction modulus) calculated through the arithmetic average of the modulus according to the volume ratio between the reinforcing material and the base material is the modulus according to the volume ratio between the reinforcing material and the base material An anisotropy condition of at least 10 times or more of the composite modulus in the orientation vertical direction (ie, the second direction modulus) calculated through the harmonic average of may be satisfied. In this case, when the transparent stretchable structure 100 is stretched in the vertical direction of orientation, the force to be vertically compressed (

) is applied in the orientation direction having a modulus of 10 times or more, so that the shrinkage strain can be reduced to 10 times or less. In other words, the reinforcing material 110 and the base material 120 constituting the transparent stretchable structure 100 in which the reinforcing material of the present disclosure (eg, a transparent filler in the form of a fiber) is oriented in one direction is provided to satisfy the following formula conditions It can be characterized as being.

은 모재의 모듈러스(예컨대, 제 1 모재와 제 2 모재의 모듈러스)이며,

은 모재의 부피 분율(예컨대, 제 1 모재와 제 2 모재의 부피 분율)이며,

는 보강재의 모듈러스이며,

는 보강재의 부피 분율일 수 있다.in this case,

is the modulus of the base material (eg, the modulus of the first base material and the second base material),

is the volume fraction of the base material (eg, the volume fraction of the first base material and the second base material),

is the modulus of the reinforcement,

may be a volume fraction of the reinforcement.

That is, the present disclosure may include the base material 120 and the reinforcing material 110 to satisfy the above-mentioned formula conditions. In addition, by aligning one or more sub-reinforcing materials included in the reinforcing material 110 in one direction inside the base material 120 , the transparent stretchable structure 100 of the present disclosure may be implemented. As can be seen through the above-mentioned formula conditions, in order to maximize the difference between the arithmetic mean and the harmonic mean, the difference in modulus between the base material 120 and the reinforcing material 110 is large, and the content (ie, volume fraction) of the reinforcing material 110 is large. ) may need to be increased. Accordingly, when the transparent stretchable structure 100 of the present disclosure is configured such that the difference in modulus between the base material 120 and the reinforcing material 110 is large and the content of the reinforcing material 110 is maximized, the anisotropy of the modulus is maximized. and a Poisson's ratio closer to zero can be implemented. That is, the transparent stretchable structure 100 of the present disclosure has a different modulus (i.e., the orientation direction and the vertical direction of the orientation) different from each other through the structure in which the fiber-shaped reinforcing material 110 is oriented in one direction inside the base material 120 . , where the modulus with respect to the orientation direction is 10 times the modulus with respect to the perpendicular direction of the orientation). This makes it possible to have mechanical anisotropy with respect to the direction of tension and the direction perpendicular to the direction of tension. The transparent stretchable structure having mechanical anisotropy may implement a Poisson's ratio closer to zero as mechanical properties are different from each other according to directionality.

(즉, 모재의 모듈러스)을 4.998MPa로,

를 69GPa로 하였으며, 모재(120)와 보강재(110)를 포함하는 투명 신축 구조체(100)의 두께는 1mm로 하여 실험을 진행하였다. 5 is a view showing experimental values related to an orientation direction composite modulus and a vertical direction composite modulus of orientation according to a volume ratio between a base material and a reinforcing material related to an embodiment of the present disclosure; As shown in Figure 5,

(that is, the modulus of the base material) to 4.998 MPa,

was 69 GPa, and the thickness of the transparent stretchable structure 100 including the base material 120 and the reinforcing material 110 was 1 mm, and the experiment was conducted.

Specifically, the modulus and thickness of each of the base material 120 and the reinforcing material 110 are set as fixed values, and the volume fractions of the base material 120 and the reinforcing material 110 are varied differently, so that the arithmetic mean according to each volume fraction (i.e., E _cl ) and harmonic mean (ie, E _ct ) values were calculated.

)에, 산술 평균 및 조화 평균 각각이 최대(즉, 62,100,499,800 및 499,474,386)임을 확인할 수 있었다. 다시 말해, 모재와 보강재의 비율이 1:9인 경우에 산술 평균과 조화 평균의 차이가 극대화됨을 확인할 수 있었다. As shown in Fig. 5, when the volume fraction of the base material is the smallest and the volume fraction of the reinforcement material is the largest (that is,

), it can be confirmed that the arithmetic mean and the harmonic mean are maximum (ie, 62,100,499,800 and 499,474,386), respectively. In other words, it was confirmed that the difference between the arithmetic mean and the harmonic mean was maximized when the ratio of the base material to the reinforcing material was 1:9.

6 is a view showing experimental values related to the Poisson ratio according to the volume ratio between the base material and the reinforcing material related to an embodiment of the present disclosure. In this experiment, tensile force is applied to both ends of each material, and when each material is tensioned, the strain and longitudinal direction (e.g., filler The ratio between the degree of strain in the orientation direction and the y-axis) and the ratio between the degree of strain in the longitudinal direction and the degree of strain in the three-dimensional axial direction (eg, z-axis) in the vertical direction were measured.

For the experiment, a polyurethane in a state that does not include a separate reinforcing material layer was prepared as a comparative group. In addition, for comparison with the corresponding comparative group, the transparent stretchable structure 100 of the present disclosure through a reinforcing material composed of a plurality of glass fibers (GF, Glass Fiber) having a diameter of 20 μm and a base material composed of polyurethane (PU) has been implemented. In this case, the overall size of the material (ie, the total length and thickness of the sample) was constructed identically.

In addition, in order to observe the change in the Poisson's ratio according to the change in the volume ratio of the reinforcing material 110, by providing the base material (ie, PU) and the reinforcing material (ie, GF) of each different volume ratio, the transparent stretchable structure of the present disclosure ( 100) was implemented.

For example, the reinforcing material 110 may be impregnated into the base material 120 to have an orientation structure in one direction through the above-described process step (eg, a process of impregnating the reinforcing material between each base material to be oriented in one direction). For a specific example, the reinforcing material 110 may include one or more sub-reinforcing materials, and depending on the degree (ie, amount) of the one or more sub-reinforcing materials in the base material 120 , the base material 120 and the reinforcing material 110 . ) can be determined. For example, as the number of sub-reinforcement materials 110 impregnated in the base material 120 increases, the volume fraction of the base material 120 may be reduced, and the volume fraction of the reinforcing material 110 may be increased.

In such an experimental environment, the Poisson ratio of each transparent stretchable structure configured to satisfy the specific formula condition of the present disclosure was measured, and the measured Poisson ratio is shown in graph form in FIG. 6(b) .

That is, as shown in (a) and (b) of Figure 6, in the case of a general material that is not provided with the reinforcing material 110, it can be seen that it has a Poisson's ratio of 0.312 with respect to the two-dimensional plane. In addition, in the case of sample 1 in which the volume fraction of the base material and the reinforcing material is 0.1 and 0.9, respectively, it has a Poisson ratio of 0.048, and in the case of sample 2 in which the volume fraction of the base material and the reinforcing material is 0.3 and 0.7, respectively, it has a Poisson ratio of 0.058, In the case of sample 3, where the volume fractions of the base material and the reinforcement are 0.5 and 0.5, respectively, it has a Poisson ratio of 0.060, and in the case of sample 4 where the volume fractions of the base material and the reinforcement are 0.7 and 0.3, respectively, it is confirmed that it has a Poisson's ratio of 0.067. could

That is, the transparent stretchable structure 100 of the present disclosure is provided so that each of the base material 120 and the reinforcing materials (ie, one or more sub-reinforcements) oriented in one direction inside the base material 120 satisfy a predetermined formula condition. , it was confirmed that it has a Poisson's ratio close to 0. For example, as the volume fraction of the reinforcing material increases and the volume fraction of the base material decreases, it was confirmed that the transparent stretchable structure 100 of the present disclosure implements a Poisson's ratio close to zero. In particular, it was confirmed that, when the volume fraction of the reinforcing material was 0.9 and the largest, the transparent stretchable structure 100 having a Poisson's ratio of 0.048 or less of 0.5 could be implemented.

In other words, the transparent stretchable structure 100 of the present disclosure is implemented to have a Poisson's ratio of 0.05 or less by aligning the reinforcing material 110 in one direction in the interior of the base material 120 to satisfy the above-described formula conditions. can be Accordingly, it is possible to provide a high degree of design freedom, such as deformation in various axial directions. For example, when a display is configured through the transparent stretchable structure 100 of the present disclosure, it is possible to support deformation in a multi-dimensional axial direction under various conditions outside of a fixed display such as folding or rolling in a single direction. This may have the effect of not only improving design freedom by providing higher variability, but also ensuring mechanical stability due to external force.

Additionally, the transparent stretchable structure 100 may be implemented through a relatively simple process, such as a process of manufacturing each of the reinforcing material 110 and the base material 120 and a process of bonding each material. That is, since a separate printing process is not required to generate a specific lattice shape, it is possible to provide the effect of simplifying the equipment used in the manufacturing process. In addition, a microprocess for a structure having a size of several tens to several hundred micrometers (eg, an organic) may be omitted. That is, a manufacturing process for a material having a Poisson's ratio close to zero may be simplified. Since this is a structure that can be easily applied to a pultrusion process, which is a large-area continuous process, in particular, it is possible to maximize the mass productivity of the transparent stretchable structure.

Meanwhile, FIG. 7 shows experimental values when the volume fraction of the base material is 0.9 to 0.99. The modulus of the base material was set to 100 MPa and the modulus of the reinforcement material was set to 69 GPa, and the arithmetic mean (E _cl ) and the harmonic mean (E _ct ) were measured. At this time, it can be seen that the arithmetic mean is greater than 10 times the harmonic mean from when the volume fraction of the reinforcement becomes 0.02. Accordingly, the magnitude of the XY Poisson's ratio compared to the YZ Poisson's ratio is significantly reduced. Therefore, it is preferable that the volume fraction of the reinforcing material be at least 0.02 or more.

However, it is preferable that the volume fraction of the reinforcing material be at least 0.05, in consideration of the error caused by the incomplete orientation of the reinforcing material experimentally and the error occurring due to the incomplete interface between the reinforcing material and the base material. The magnitude of the X-Y Poisson's ratio compared to the Y-Z Poisson's ratio is also reduced more than when the volume fraction of the reinforcement is 0.02.

On the other hand, considering the predictable error factors and the experimental data obtained through the cumulative number of actual structures, it is most desirable that the volume fraction of the reinforcement is formed to be 0.1 or more. When the volume fraction of the reinforcing material is 0.1 or more, the yield of producing a structure with a target minimum performance is increased. In addition, when the volume fraction of the reinforcing material is 0.1 or more, the X-Y Poisson's ratio also falls below the minimum standard of 0.07.

When the diameter of the reinforcing material is also 200 nm to 100 μm, it is easier to manufacture and satisfies the minimum standard for X-Y Poisson's ratio of the finally manufactured structure.

In the above, embodiments of the present disclosure have been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present disclosure pertains know that the present disclosure may be embodied in other specific forms without changing its technical spirit or essential features. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

The specific implementations described in the present disclosure are examples, and do not limit the scope of the present disclosure in any way. For brevity of the specification, descriptions of conventional electronic components, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connection or connection members of the lines between the components shown in the drawings exemplarily represent functional connections and/or physical or circuit connections, and in an actual device, various functional connections, physical connections that are replaceable or additional may be referred to as connections, or circuit connections. In addition, unless there is a specific reference such as "essential" or "importantly", it may not be a necessary component for the application of the present invention.

It is understood that the specific order or hierarchy of steps in the presented processes is an example of exemplary approaches. Based on design priorities, it is understood that the specific order or hierarchy of steps in the processes may be rearranged within the scope of the present disclosure. The appended method claims present elements of the various steps in a sample order, but are not meant to be limited to the specific order or hierarchy presented.

The description of the presented embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments presented herein, but is to be construed in the widest scope consistent with the principles and novel features presented herein.

Transparent stretchable structure: 100
Reinforcement: 110
1st sub stiffener: 111
Second sub stiffener: 112
3rd sub stiffener: 113
4th sub stiffener: 114
Base material: 120

Claims (15)

Transparent base material made of elastic material; and
a reinforcing material provided inside the base material and made of a transparent material;
includes,
Each of the base material and the reinforcing material is characterized in that it is provided to satisfy the following equation conditions,

is the modulus of the base material,

is the volume fraction of the base material,

is the modulus of the reinforcement,

is the volume fraction of the reinforcement,
Transparent stretchable structure.
The method of claim 1,
The reinforcement is
one or more sub-reinforcements;
Each of the one or more sub-reinforcements,
It is provided through a fiber shape, characterized in that it is oriented in one direction,
Transparent stretchable structure.
The method of claim 1,
The transparent stretchable structure,
characterized in that the modulus in the first direction has an anisotropy of at least 10 times the modulus in the second direction, and the Poisson's ratio is 0.05 or less,
Transparent stretchable structure.
4. The method of claim 3,
The first direction modulus is,
The composite modulus in the orientation direction of the reinforcing material is calculated through the arithmetic mean of the modulus according to the volume ratio between the reinforcing material and the base material,
The second direction modulus is,
The composite modulus in a direction perpendicular to the orientation of the reinforcement, calculated through a harmonic average of the modulus according to the volume ratio between the reinforcement and the base material,
Transparent stretchable structure.
The method of claim 1,
The base material is
It has a volume fraction in the range of 0.1 to 0.95, characterized in that it is provided through a modulus in the range of 0.01 MPa to 100 MPa,
Transparent stretchable structure.
The method of claim 1,
The reinforcement is
It has a volume fraction in the range of 0.05 to 0.9, and a fiber-type aggregate having a diameter in the range of 100 nm to 1 mm, characterized in that it is provided through a modulus in the range of 1 MPa to 1000 GPa,
Transparent stretchable structure.
The method of claim 1,
The base material is
It contains a transparent additive that matches the refractive index with the reinforcing material,
The transparent additive,
It is composed of nanoparticles of 3 nm to 100 nm in size, and contains at least one of zirconium oxide (ZrO2), titanium dioxide (TiO2) and aluminum oxide (Al2O3), characterized in that it is added to the base material during the manufacturing process of the base material to do,
Transparent stretchable structure.
The method of claim 1,
The reinforcement is
comprising a plurality of glass fibers;
Transparent stretchable structure.
generating a first base material of an elastic material;
creating a stiffener comprising one or more sub-reinforcements;
positioning the reinforcing material on one surface of the first base material; and
impregnating the reinforcing material by supplying a second base material to the upper side of the reinforcing material;
includes,
Each of the first base material, the second base material and the reinforcing material is characterized in that it is provided so as to satisfy the following equation conditions,

is the modulus of the first base material and the second base material,

is the volume fraction of the first base material and the second base material,

is the modulus of the reinforcement,

is the volume fraction of the reinforcement,
A method for manufacturing a transparent stretchable structure.
10. The method of claim 9,
A method for manufacturing a transparent stretchable structure,
generating the first base material;
further comprising,
The step of creating the first base material,
adding a transparent additive to the first base material in a liquid state;
supplying a first base material in the liquid state to a fixed plate;
performing curing on the first base material in the liquid state; and
separating the fixing plate;
containing,
A method for manufacturing a transparent stretchable structure.
11. The method of claim 10,
The transparent additive,
Constructed through a nanoparticle shape of 3 nm to 100 nm in size, including at least one of zirconium oxide (ZrO2), titanium dioxide (TiO2) and aluminum oxide (Al2O3),
A method for manufacturing a transparent stretchable structure.
10. The method of claim 9,
The step of positioning the reinforcing material on one surface of the first base material,
positioning each of the one or more sub-reinforcing materials on one surface of the first base material in one direction;
containing,
A method for manufacturing a transparent stretchable structure.
10. The method of claim 9,
The step of impregnating the reinforcing material by supplying a second base material to the upper side of the reinforcing material,
locating the second base material on the upper side of the reinforcing material; and
impregnating the reinforcing material between each base material by performing a high-temperature pressing process;
containing,
A method for manufacturing a transparent stretchable structure.
10. The method of claim 9,
The step of impregnating the reinforcing material by supplying a second base material to the upper side of the reinforcing material,
supplying a second base material in a liquid state to the upper side of the reinforcing material; and
performing curing on the second base material in the liquid state;
containing,
A method for manufacturing a transparent stretchable structure.
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