WO2017164523A1

WO2017164523A1 - Active metamaterial array and method for manufacturing same

Info

Publication number: WO2017164523A1
Application number: PCT/KR2017/001929
Authority: WO
Inventors: 이호진; 강문성; 정현승; 허은아; 조보은; 구재목
Original assignee: 숭실대학교산학협력단
Priority date: 2016-03-25
Filing date: 2017-02-22
Publication date: 2017-09-28

Abstract

An active metamaterial array of the present invention comprises: a substrate; a plurality of metamaterial structures disposed on the substrate and spaced apart from each other; a conductivity varying material layer formed between each of the plurality of the metamaterial structures so as to selectively connect the metamaterial structures; an electrolyte material layer formed on the metamaterial structures and the conductivity varying material layer; and a gate electrode disposed at one end of the substrate so as to be in contact with one region of the electrolyte material layer, wherein, when external voltage is applied to the gate electrode, the gate electrode changes the conductivity of the conductivity varying material layer by controlling the migration of ions contained in the electrolyte material layer.

Description

Active Metamaterial Arrays and Manufacturing Method Thereof

The present invention relates to an active metamaterial array and a method of manufacturing the same.

Active metamaterial technology uses visible light (VL), infrared (IR), infrared (IR), ultraviolet (UV) rays and terahertz waves through the structure, conductivity, and arrangement of metaatoms that make up metamaterials. (Terahertz Wave) is a technology that selectively tunes, particularly as an important research area for implementing terahertz systems. Metamaterial arrays for actively varying the terahertz wave adjustment have been implemented using electrical, optical, mechanical and thermal variables. A method for switching terahertz waves by changing the conductivity of the entire metamaterial array or a portion of the metaatoms through external stimuli has been studied. In addition, a method of adjusting the spectral characteristics by changing the spatial arrangement of metamaterials through a mechanical change using a MEMS (micro electro mechanical system) has been studied. However, active metamaterials reported to date have limitations in the variable range of frequency and phase or the variable level of resonance due to a limited design method, and thus have difficulty in commercialization for active terahertz systems.

1A and 1B schematically illustrate a conventional metamaterial array. In this regard, referring to FIG. 1A, a technique of controlling the change of the metamaterial structure 101 as a whole may be performed by coating a material capable of changing conductivity on the substrate 102 including the metamaterial structure 101. As shown in 1a, the conductivity is changed through the external magnetic pole 103, and thus the resonance of the metamaterial is switched. This method can switch the resonance of the metamaterial itself and does not require an additional pattern, but has the disadvantage that it is impossible to vary the resonance frequency to have a desired frequency or phase.

In addition, referring to FIG. 1B, the technique of controlling the change of the entire metamaterial structure 101 by adding the semiconductor layer 105 to the metamaterial structure 101 may vary the resonance frequency through an external stimulus. The variable range is limited because the range is defined within the structure of the metamaterial structure. In addition, there is a difficulty in the electrical wiring for the variable of the individual metamaterial structure, and thus there is a limit in the variable method.

In this regard, the prior art Korea Patent Publication No. 2016-0013423 (name of the invention: high-efficiency terahertz transceiver capable of frequency modulation) is capable of frequency modulation capable of modulating the frequency to increase the generation output and measurement sensitivity of the terahertz wave A high efficiency terahertz transceiver is disclosed.

The present invention to solve the above problems, to provide a meta-material array for changing the conductivity of the material layer that can vary the conductivity connecting between the meta-material structure to connect or separate a plurality of meta-material structure integrally. There is this.

However, the technical problem to be achieved by the present embodiment is not limited to the technical problems as described above, and further technical problems may exist.

As a technical means for achieving the above technical problem, an active metamaterial array according to an embodiment of the present invention is a substrate; A plurality of metamaterial structures disposed on the substrate and spaced apart from each other; A conductivity varying material layer formed between the plurality of metamaterial structures to selectively connect the metamaterial structures; An electrolyte material layer required for conductivity control of the conductivity varying material; And a gate electrode disposed at one end of the substrate and in contact with the electrolyte, wherein the gate electrode controls the movement of ions included in the electrolyte material layer when an external voltage is applied to the gate electrode to thereby control the conductivity of the layer of variable conductivity material. Variable.

In addition, the method of manufacturing an active metamaterial array according to an embodiment of the present invention comprises the steps of forming a plurality of metamaterial structures to be spaced apart from each other on a substrate; Forming a layer of semiconductor or conductivity varying material to selectively connect metamaterial structures between the plurality of metamaterial structures; Forming an electrolyte material layer on the metamaterial structure and the conductivity varying material layer; And forming a gate electrode disposed at one end of the substrate to contact a region of the electrolyte material layer.

According to the above-described problem solving means of the present invention, it is possible to provide a metamaterial array having a wide variable width and a high resolution frequency and phase selectivity compared to the conventional metamaterial array, and at the same time shorten the process and reduce the cost .

In addition, the overall control range of terahertz waves is limited, and it overcomes the existing metamaterial design technology, which is fundamentally difficult to precisely modulate the phase and frequency, and secures not only wider terahertz frequency variable width but also higher phase shift width. There is an effect that can be arbitrarily adjusted to the traveling direction of the terahertz wave. In addition to the terahertz band as well as visible light, infrared and ultraviolet bands can be extended to apply.

1A and 1B schematically illustrate a conventional metamaterial array.

2 is a cross-sectional view illustrating a configuration of a metaatom array according to an embodiment of the present invention.

3A is a view for explaining a method of controlling a metamaterial structure through an electrolyte material layer integrally formed with a size corresponding to the size of the entire metamaterial structure according to one embodiment of the present invention.

3B is a view illustrating a frequency varying result according to a change in conductivity of a layer of a conductive variable material including a semiconductor and graphene according to an exemplary embodiment of the present invention.

3C is a view illustrating a phase shift result according to a change in conductivity of a layer of a conductive variable material including graphene and a semiconductor according to an embodiment of the present invention;

4A is a diagram for describing a method of controlling a metamaterial structure through a plurality of units of electrolyte material layers arranged in a matrix structure according to an embodiment of the present invention.

4B is a diagram illustrating multiple frequencies according to modulation of an external voltage connected to the plurality of units of the electrolyte material layer of FIG. 4A.

4C is a diagram illustrating a phase change in phase according to modulation of an external voltage connected to a plurality of units of an electrolyte material layer of FIG. 4A.

5 is a conceptual diagram illustrating that the metamaterial structure is connected to one metamaterial molecular structure according to an embodiment of the present invention.

6 is a flowchart illustrating a method of manufacturing an active metamaterial array according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components, unless specifically stated otherwise, one or more other features It is to be understood that the present disclosure does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof.

Referring to FIG. 2, the active metamaterial array of the present invention includes a substrate 200, a metamaterial structure 201, a layer of variable conductivity material 202, an electrolyte material layer 203, and a gate electrode 204. Here, the metamaterial structures 201 are spaced apart from each other, and the conductivity variable material layer 202 may be formed between the metamaterial structures 201 to selectively connect the metamaterial structures 201. An electrolyte material layer 203 is formed on the metamaterial structure 201 and the variable conductivity material layer 202, and the gate electrode 204 is disposed at one end of the substrate 200 to form a region of the electrolyte material layer 203. Contact with In this case, when an external voltage is applied to the gate electrode 204, the gate electrode 204 may change the conductivity of the conductivity-variable material layer 202 by controlling the movement of ions included in the electrolyte material layer 203. . According to the conductivity change of the conductivity-variable material layer 202, the plurality of metamaterial structures 201 may be integrally connected or separated, thereby changing the resonant frequency and phase. The active metamaterial array of the present invention can reduce the manufacturing cost while having a wide variable width and high resolution frequency and phase selectivity compared to the conventional metamaterial array.

3A is a view for explaining a method of controlling a metamaterial structure through an electrolyte material layer integrally formed with a size corresponding to the size of the entire metamaterial structure according to an embodiment of the present invention, and FIG. 3B is a view illustrating the present invention. FIG. 3C is a view illustrating a result of varying frequency according to a change in conductivity of a conductive material layer according to an embodiment of the present disclosure, and FIG. 3C illustrates a change in conductivity of a conductive material layer including graphene and a semiconductor according to an embodiment of the present invention; 4A is a diagram illustrating a phase shifting result, and FIG. 4A is a diagram for describing a method of controlling a metamaterial structure through a plurality of units of electrolyte material layers arranged in a matrix structure according to an embodiment of the present invention. 4A is a diagram illustrating multiple frequencies in response to modulation of an external voltage connected to a plurality of units of an electrolyte material layer of FIG. FIG. 5 is a diagram illustrating a phase change in phase according to modulation of an external voltage connected to an electrolyte material layer of a unit, and FIG. 5 illustrates that a metamaterial structure is connected to one metamaterial molecular structure according to an embodiment of the present invention. The conceptual diagram shown.

2 and 3A, the metamaterial structure 201 is disposed on the substrate 200 and spaced apart from each other and formed in a plurality of units. The plurality of metamaterial structures 201 may be arranged in a matrix structure.

The meta-material structure 201 is composed of a middle portion formed in a rectangular shape and both ends formed on both sides of the middle portion, the horizontal length of the middle portion is longer than the horizontal length of each end portion, the longitudinal length of the intermediate portion is longitudinal It can be formed smaller than the length. For example, it may be formed in an H shape or an I shape. The metamaterial structure 201 and the gate electrode 204 described later may be formed using the same mask.

The conductivity variable material layer 202 may be formed between the plurality of metamaterial structures 201 to selectively connect the metamaterial structures 201. As a further embodiment, the layer of variable conductivity material 202 may be formed under the metamaterial structure 201 to connect the metamaterial structures 201.

The conductivity-variable material layer 202 is formed to have a length that can connect the plurality of metamaterial structures 201, and may be formed in a plurality of units in one direction. In this case, the plurality of units of the variable conductivity material 202 may be spaced apart from each other.

The material of the conductive variable material layer 202 may be, but is not limited to, graphene, silicon, an oxide semiconductor, a dielectric-metal transition material, and may be a material having a variable conductivity including other semiconductor materials.

In detail, the conductive variable material layer 202 may be conductively connected between the metamaterial structures 201, and the plurality of metamaterial structures 201 may be integrally formed through the variable conductivity of the conductive variable material layer 202. By being connected or disconnected, it is possible to change the resonant frequency of the active metamaterial array. In this case, the conductivity of the conductivity-variable material layer 202 may be varied by the movement of ions in the electrolyte material layer 203 which will be described later.

Referring to FIG. 5, when the conductivity of the variable conductivity material layer 202 exceeds a preset reference, the plurality of metamaterial structures 201 may be controlled by one metamaterial molecular structure 300.

The metamaterial molecular structure 300 may be connected to a plurality of metamaterial structures 201 arranged in any one of a horizontal, vertical, and matrix manner.

For example, as illustrated in FIG. 5A, the conductivity of the conductivity-variable material layer 202 formed between the metamaterial structures 201 arranged horizontally or vertically exceeds the predetermined reference. In this case, the plurality of metamaterial structures 201 may be controlled as one metamaterial molecular structure 300. In addition, as shown in FIG. 5 (b), even when the conductivity of the conductivity-variable material layer 202 formed between the metamaterial structures 201 arranged in a matrix structure exceeds a predetermined reference or more, The metamaterial structure 201 may be controlled as one metamaterial molecular structure 300. Accordingly, the present invention actively controls the phase of the metamaterial structure 201 with the metamaterial molecule structure 300, thereby actively adjusting the propagation direction of the terahertz wave or the focusing point of the active metamaterial flat lens. Can be enabled.

Referring again to FIG. 2, an electrolyte material layer 203 is formed on the metamaterial structure 201 and the conductivity varying material layer 202.

The electrolyte material layer 203 may be manufactured by a spin coating process or a drop coating process without a pattern, or may be used by forming a pattern through a process such as photolithography or selective photocuring.

Referring to FIGS. 3A and 4A, the electrolyte material layer 203 may be formed in each column of the metamaterial structure 201 integrally formed in a size corresponding to the size of the entire metamaterial structure 201 or arranged in a matrix structure. It may be formed in a plurality of units to correspond to the length of each row.

For example, as illustrated in 4a, the electrolyte material layer 203 includes a plurality of units of the first electrolyte material layer 210 and the second electrolyte material layer 220, wherein the plurality of units of the first electrolyte are present. The material layer 210 and the second electrolyte material layer 220 may be formed in a bar shape and alternately disposed. In this case, the plurality of units of the first electrolyte material layer 210 may be connected to the first gate electrode 211 which will be described later, and the plurality of units of the second electrolyte material layer 220 may be connected to the second gate electrode 221 which will be described later. Can be.

The gate electrode 204 may be disposed at one end of the substrate 200 to contact a region of the electrolyte material layer 203. When an external voltage is applied to the gate electrode 204, the gate electrode 204 may vary the conductivity of the variable conductivity material layer 202 by controlling the movement of ions included in the electrolyte material layer 203.

For example, referring to FIG. 3A, the conductivity of the conductivity-variable material layer 202 upon voltage application can be varied through the movement of ions in the electrolyte material layer 203, thereby reducing the conductivity-variable material layer 202. The metamaterial structures 201 connected through the same may form resonance with one metamaterial molecular structure 300.

3B and 3C illustrate a process of changing the resonant frequency and phase of the metamaterial structure 201 according to the change in conductivity of the layer of variable conductivity material 202 according to an embodiment of the present invention. As the conductivity of the conductivity-variable material layer 202 increases, the plurality of metamaterial structures 201 may be molecularly formed into one metamaterial molecular structure 300 and move at a low resonance frequency. On the other hand, as the conductivity of the variable-conducting material layer 202 decreases, the molecular material structure 300 is not molecularized, and the plurality of meta-material structures 201 are formed, and the phases are also varied together while moving at a high resonance frequency. It can be seen that.

That is, by controlling the conductivity of the conductivity-variable material layer 202, the metamaterial structure 201 may be molecularized and may have a wide frequency and phase variable range. In addition, the number of metamaterial structures 201 connected to the metamaterial molecular structure 300 may be determined at the design stage, and by changing the number of conductive variable material layers 202 connected between the metamaterial structures 201. The designer can adjust the desired frequency or phase shift range.

Referring to FIG. 4A, the gate electrode 204 is composed of a plurality of units, and each gate electrode 204 is formed at one end and the other end of the substrate 200 and a different voltage is applied to each gate electrode 204. Can be.

For example, referring to FIGS. 4A to 4C, the gate electrode 204 includes a first gate electrode 211 and a second gate electrode 221 disposed at one end and the other end of the substrate 200, respectively. The first gate electrode 211 may be connected to the plurality of units of the first electrolyte material layer 210, and the second gate electrode 221 may be connected to the plurality of units of the second electrolyte material layer 220. In this case, the first electrolyte material layer 210 and the second electrolyte material layer 220 may operate independently by the first gate electrode 211 and the second gate electrode 221.

By applying different voltages V1 and V2 to the first gate electrode 211 and the second gate electrode 221 independently, various frequencies and phases may be varied. As shown in FIGS. 4B and 4C, for example, the voltages V1 and V2 are applied to all the

gate electrodes

211 and 221, or V1 or V2 is applied to one

gate electrode

211 or 221. Selection of frequency and phase may be possible.

Hereinafter, a method of manufacturing an active metamaterial array will be described.

In the case of the configuration performing the same function among the configuration shown in Figures 1 to 5 described above will be omitted.

2 and 6, first, a plurality of metamaterial structures 201 are formed on the substrate 200 to be spaced apart from each other (S110).

Subsequently, the conductivity variable material layer 202 is formed to selectively connect the metamaterial structures 201 between the plurality of metamaterial structures 201 (S120).

Next, an electrolyte material layer 203 is formed on the metamaterial structure 201 and the variable conductivity material layer 202 (S130).

Finally, the gate electrode 204 is formed to be disposed at one end of the substrate 200 to contact a region of the electrolyte material layer 203 (S140). When the external voltage is applied to the gate electrode 204, the electrolyte material layer 203 may control the movement of ions included in the electrolyte material layer 203 to vary the conductivity of the variable conductivity material layer 202.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Claims

In an active metamaterial array,

Board;

A plurality of metamaterial structures spaced apart from each other on the substrate;

A variable conductivity material layer formed between the plurality of metamaterial structures to selectively connect the metamaterial structures;

An electrolyte material layer formed on the metamaterial structure and the conductivity varying material layer; And

A gate electrode disposed at one end of the substrate and in contact with one region of the electrolyte material layer,

The gate electrode,

And an external voltage applied to the gate electrode to control movement of ions included in the electrolyte material layer to vary conductivity of the variable conductivity material layer.
The method of claim 1,

And the plurality of metamaterial structures are integrally connected or separated in response to a change in conductivity of the layer of varying conductivity material, thereby changing a resonant frequency and phase.
The method of claim 2,

If the conductivity exceeds a predetermined reference,

And said plurality of metamaterial structures is controlled by one metamaterial molecule structure.
The method of claim 3, wherein

The metamaterial molecule structure is a plurality of metamaterial structures are active metamaterial array that is arranged and connected by any one method of the horizontal, vertical and matrix.
The method of claim 1,

And the electrolyte material layer comprises an electrolyte liquid, a gel, or a solidified electrolyte.
The method of claim 1,

The gate electrode is composed of a plurality of units, each gate electrode is formed on one end and the other end of the substrate,

And a different voltage is applied to each of the gate electrodes.
The method of claim 6,

The electrolyte material layer includes a first electrolyte material layer and a second electrolyte material layer composed of a plurality of units,

The gate electrode includes a first gate electrode and a second gate electrode disposed at one end and the other end of the substrate, respectively

And wherein the first electrolyte material layer is connected with the first gate electrode and the second electrolyte material layer is connected with the second gate electrode.
The method of claim 7, wherein

And the first and second electrolyte material layers are formed in a bar shape of a plurality of units and are alternately arranged.
The method of claim 1,

And wherein said layer of conductivity varying material is formed below said metamaterial structure to selectively connect said metamaterial structures.
The method of claim 1,

The metamaterial structure is composed of both ends formed on both sides of the middle portion and the intermediate portion formed in a square,

And the horizontal length of the middle portion is longer than the horizontal length of both ends, and the vertical length of the middle portion is smaller than the vertical length of the both ends.
The method of claim 1,

The conductivity-variable material layer is formed to a length that can connect the plurality of metamaterial structures, is formed in a plurality of units in one direction,

And the plurality of units of variable conductivity material are spaced apart from each other.
The method of claim 1,

The electrolyte material layer is formed in a plurality of units so as to correspond to the length of each column or each row of the metamaterial structure formed integrally or in a matrix structure corresponding to the size of the entire metamaterial structure. Metamaterial Array.
In the method of manufacturing an active metamaterial array,

Forming a plurality of metamaterial structures to be spaced apart from each other on the substrate;

Forming a layer of conductivity varying material to selectively connect the metamaterial structures between the plurality of metamaterial structures;

Forming an electrolyte material layer on the metamaterial structure and the conductivity varying material layer; And

Forming a gate electrode at one end of the substrate to contact a region of the electrolyte material layer,

The electrolyte material layer is a method of manufacturing an active metamaterial array to vary the conductivity of the variable conductivity material layer by controlling the movement of ions contained in the electrolyte material layer, when an external voltage is applied to the gate electrode.