WO2012152022A1

WO2012152022A1 - High strength meta-material and preparation process thereof

Info

Publication number: WO2012152022A1
Application number: PCT/CN2011/084581
Authority: WO
Inventors: 刘若鹏; 赵治亚; 盖佐•法布里齐亚
Original assignee: 深圳光启高等理工研究院; 深圳光启创新技术有限公司
Priority date: 2011-05-10
Filing date: 2011-12-23
Publication date: 2012-11-15
Also published as: CN102891368B; CN102891368A

Abstract

Disclosed is a high strength meta-material, comprising a base material, and an artificial microstructure (2) attached to the base material, the base material having a grid cross section. Also provided is a process for preparing the high strength meta-material, comprising the steps of: S1, forming a flat base material sheet (1); S2, attaching the artificial microstructure (2) to the base material sheet (1), so as to obtain a meta-material sheet (3); S3, bending the meta-material sheet (3) into a zigzag shape; and S4, laminating a plurality of zigzag-shaped meta-material sheets (3) and incorporating the same into a whole body, so that the plurality of base material sheets (1) form a base material having a grid cross section. The high strength meta-material has a high strength, great deformation resistance and a light weight, and can be used in various situations where the material may be subject to impact.

Description

Description High-strength metamaterial and preparation method thereof

This invention relates to the field of metamaterials and, more particularly, to a high strength metamaterial and a method of making same. Background technique

Metamaterial is a new type of synthetic material with special electromagnetic response characteristics, so it can be widely used in electromagnetic communication and other fields.

The metamaterial includes a substrate and an artificial microstructure attached to the substrate. Usually, the artificial microstructure is a wire having a certain geometric pattern such as a "work" shape, an open resonant ring, or the like, and the substrate is in the shape of a flat plate, usually using ceramics or the like. The dielectric constant and magnetic permeability are close to the material of the air, that is, the influence of the substrate on the electromagnetic response is relatively small.

Metamaterials typically include a plurality of substrate plates, which are typically stacked together in parallel with each other and then assembled into a unit by a packaging process. The flat-panel structure has the advantages of simple positioning and simple packaging, but the disadvantages are that the strength is not large enough, the thickness is heavy, and the substrate material is expensive. Summary of the invention

The technical problem to be solved by the present invention is to provide a high-strength metamaterial and a preparation method thereof in view of the above-mentioned drawbacks of the prior art.

The technical solution adopted by the present invention to solve the technical problem is to construct a high-strength metamaterial comprising a substrate and an artificial microstructure attached to the substrate, the substrate having a cross-section in a grid shape.

In the high strength metamaterial of the present invention, the individual cells of the grid are rectangular or diamond or circular.

The invention also provides a preparation method of high-strength metamaterial, comprising the following steps:

Sl, forming a flat sheet substrate layer; 52, attaching an artificial microstructure to the substrate sheet layer to obtain a super material sheet layer;

53. The super material sheet is bent into a zigzag shape;

54. Stack a plurality of zigzag metamaterial sheets and combine them into one.

In the preparation method of the present invention, the step S2 attaches the artificial microstructure by an etching or printing process.

In the preparation method of the present invention, the step S3 is produced by a hot press forming process.

In the preparation method of the present invention, each of the teeth of the serration is rectangular or triangular or semi-circular.

In the preparation method of the present invention, the step S4 includes the following steps:

541. Stacking a plurality of zigzag metamaterial sheets from bottom to top;

542. Heating the plurality of zigzag metamaterial sheets, and heating temperature is lower than a melting point of the substrate sheet;

543. Squeeze the plurality of zigzag metamaterial sheets to fuse the contacts of the adjacent two zigzag metamaterial sheets to join the two.

In the preparation method of the present invention, the step S4 is carried out by joining any adjacent two zigzag metamaterial sheets by a spot welding process.

In the preparation method of the present invention, the step S4 is achieved by the screw holes on the metamaterial sheet layer and the bolts, thereby achieving the connection and bonding of the respective zigzag-shaped metamaterial sheets.

In the preparation method of the present invention, the material of the substrate is polytetrafluoroethylene or epoxy resin. The high-strength metamaterial of the invention and the preparation method thereof have the following beneficial effects: by adopting the method of the invention, a plurality of super-material sheets can be directly bonded at one time to directly produce a high-strength metamaterial, which is simple in operation and requires no special equipment. The super-material which is low in manufacturing cost and obtained has a grid-shaped cross section, high impact strength and light weight. DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a flow chart of a method for preparing a high strength metamaterial of the present invention;

Figure 2 is a specific flow chart of step S4 shown in Figure 1; Figure 3 is a side view of the substrate sheet obtained through the step S1;

Figure 4 is a side view of the super-material sheet obtained in step S2 of the substrate sheet of Figure 3; Figure 5 is a plan view of the super-material sheet of Figure 4;

Figure 6 is a side view of the super material sheet shown in Figures 4 and 5 after step S3;

Figure 7 is a plan view of the zigzag metamaterial sheet of Figure 6;

Figure 8 is a side elevational view of a plurality of zigzag metamaterial sheet stacks of Figure 7;

Fig. 9 is a high-strength metamaterial composed of a plurality of zigzag-shaped metamaterial sheets shown in Fig. 8. Fig. 10 is a perspective structural view of the high-strength metamaterial shown in Fig. 9.

Figure 11 is a cross-sectional view showing another embodiment of the high strength metamaterial of the present invention;

Figure 12 is a schematic cross-sectional view of yet another embodiment of the high strength metamaterial of the present invention. detailed description

The present invention relates to a high strength metamaterial comprising a substrate and an artificial microstructure attached to the substrate. Existing substrates generally use materials having a dielectric constant and magnetic permeability close to that of air, such as plastics, ceramics, and the like. The present invention is preferably a thermoplastic material and utilizes its ability to be deformed by heat to form a substrate having a particular cross-sectional structure.

As shown in Fig. 9, the substrate of the present invention has a cross section of a substrate cut surface which is perpendicular to the axis of the substrate with a straight line as an axis, and the substrate of the present invention has a grid shape in cross section. The grid shape is a graph composed of a closed curve in a regular array and adjacent two closed curves, each of which is a grid unit. As shown in Fig. 8 and Fig. 9, the high-strength metamaterial has a rectangular grid element, which can be regarded as a shape and a straight line "one". Further, as shown in Fig. 11, the cross section of the substrate has a lattice unit of a diamond shape, and can be regarded as two triangles having a rhombic diagonal as a symmetry axis. Also, as shown in Fig. 12, the cross section of the substrate, the grid unit is a ring, which can be regarded as being formed by two semicircles. Of course, the grid unit of the present invention is not necessarily a regular geometric figure, and may be any other closed curve, and the grid-shaped cross section formed is not necessarily identical to each grid unit, and a certain existence is allowed. The deformation, or a partial solid fill.

By adopting the substrate of the grid-shaped structure of the invention, the main body of the metamaterial is a hollow structure, which is greatly reduced The weight of the metamaterial, and the grid-like structure, similar to the honeycomb, supports each other between the grid cells, and once impacted or squeezed, they are mutually restrained to prevent deformation. Therefore, the use of such a structure can greatly Improve impact resistance and prevent deformation.

The artificial microstructure 2 is distributed on the surface of the substrate, usually a wire having a certain geometric shape, such as a "work" shape, a snowflake shape, an open resonance ring, and the like. Because of the existence of the artificial microstructure 2, the metamaterial composed of the substrate and the artificial microstructure 2 can respond to the electric field and the magnetic field, thereby changing the propagation direction of the electromagnetic wave, causing electromagnetic wave convergence, divergence, deflection, and the like.

Since the artificial microstructure 2 is attached to the substrate, if the grid-shaped substrate is formed by a conventional injection molding, casting process, etc., the artificial microstructure 2 is difficult to manufacture on the substrate one by one, because each The grids all have a certain depth along the axis, and it is difficult to ensure that the artificial microstructures are attached inside the depth without destroying the substrate adjacent to them. Moreover, the conventional process of attaching an artificial microstructure is electroplating, precipitation, etching, etc., and it is difficult to divide a region and a blank region to which an artificial microstructure is to be attached on an already formed grid-shaped substrate.

Therefore, for such a grid-shaped metamaterial of the present invention, it is necessary to design a new preparation method, as shown in Fig. 1. The preparation process of the high-strength metamaterial of the present invention sequentially comprises the following steps:

51, made of a flat substrate layer 1;

52, attaching an artificial microstructure to the substrate sheet layer 1 to obtain a super-material sheet layer 3;

53. The super-material sheet layer 3 is bent into a zigzag shape;

54. Stack a plurality of zigzag metamaterial sheets 3 and combine them into one body.

In step S1, the substrate layer is made of a thermoplastic material, including epoxy resin, polytetrafluoroethylene, and the like. This is accomplished by a conventional plastic molding process such as injection molding, and the resulting substrate sheet 1 is shown in FIG.

In step S2, the attachment of the artificial microstructure on the substrate sheet 1 can be achieved by processes such as electroplating, deposition, etching, printing, and the like. For example, step S2 is implemented using an etching process. The etching process here generally refers to photochemical etching, which is similar to the fabrication of a PCB, in which a metal foil layer is first deposited on the surface of the substrate sheet, and the protective film of the region to be etched is removed by exposure plate making and development. When the metal is in contact with the chemical solution in the region, it is dissolved and corroded, and the remaining metal wire having a certain geometric pattern is an artificial microstructure, and the obtained super-material layer is obtained. 3 as shown in Figure 4, Figure 5.

Step S2 can also be printed onto the substrate sheet using a printing process. Similar to a conventional printer, a metal particle size of a certain particle size range is placed in a printer, and in a region where an artificial microstructure is required, metal particles are pushed onto the region of the substrate sheet and heated to melt, so that the metal particles are Melting into a single metal wire forms the effect of "printing" the artificial microstructure 2.

The specific process for producing artificial microstructures by printing process can also be referred to the patent "Fabrication of electronic components in plastic" (Application No. EP20060752653, inventor David Victor Thiel and Neeli Madhusudanrao), whose rice is embossing machine A conductive artificial microstructure having a certain geometric pattern is printed on the plastic substrate sheet 1. This invention patent demonstrates that step S2 of the present invention is feasible.

The individual artificial microstructures are sequentially produced, and the substrate sheets and the artificial microstructures thereon constitute a metamaterial sheet 3 together.

In step S3, the zigzag shape is a curve formed by repeatedly extending the teeth of a certain shape in a straight line direction, and the teeth are not straight and are not closed. In the zigzag metamaterial sheet 3 shown in Fig. 5, each tooth has a shape of a "U" line at the end of the "U" line, which is an approximate rectangle of the opening, and the corresponding sawtooth. Shaped as a curve obtained by cyclically extending the teeth in a direction parallel to the "one" line.

The metamaterial shown in Fig. 10, the grid-shaped cross section can be seen as being formed by two zigzag curves alternately stacked in a direction perpendicular to the direction in which the teeth extend, and the two zigzag curves are symmetrically arranged, each The zigzag teeth are approximate triangles of the opening, ie """ shape. Each two symmetrical "Λ" shapes form a diamond of a grid element.

The metamaterial shown in FIG. 11 has a circular grid in cross section, and can also be regarded as being formed by alternately stacking two symmetrical semicircular zigzag curves, and the teeth of each zigzag curve are Semicircular.

The flat-shaped metamaterial sheet 3 is bent into the above-described zigzag shape, and for the thermoplastic substrate sheet, a hot press forming process is usually employed. For better molding, a negative pressure can be applied to the die side of the molding machine so that the corners are sufficiently formed, and the obtained zigzag-shaped metamaterial sheet 3 is as shown in Figs.

In step S4, a plurality of zigzag-shaped metamaterial sheets 3 are integrated into one body. There are various implementations, and mechanical connection or physical and chemical bonding may be employed. For example, the present invention can use a spot welding process to weld adjacent two supermaterial sheets 3 together, and then multiple weldings in sequence, which is complicated in operation, and can only spot weld the outermost position of the super material sheet 3, and is stable. Poor sex. In addition, it is also possible to use a threaded hole in the adjacent two metamaterial sheets 3 and then to be bolted, and there is also a problem that the operation is complicated.

Therefore, the present invention proposes a preferred connection method, as shown in FIG. 2, including the following steps:

541. Stacking a plurality of zigzag metamaterial sheets 3 from bottom to top, as shown in FIG. 8;

542. heating the plurality of zigzag-shaped metamaterial sheets 3, and heating temperature is lower than a melting point of the substrate sheet;

543. Extruding the plurality of zigzag-shaped metamaterial sheets 3 to fuse the contact points of the adjacent two zigzag-shaped metamaterial sheets 3, as shown in FIG. 9, thereby joining and joining the two.

In this way, a plurality of super-material sheets 3 can be bonded at one time, and the resulting high-strength meta-material is as shown in FIG. The metamaterial thus obtained has a substrate composed of a plurality of zigzag-shaped substrate sheets and has a lattice-shaped cross section, thereby having high impact strength and light weight. By designing the artificial microstructure on the flat substrate sheet 1, it is possible to design metamaterials having different electromagnetic response characteristics to realize various functions such as a lens, a beam compressor, a beam shifter, and the like.

The embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive, and those skilled in the art In the light of the present invention, many forms may be made without departing from the spirit and scope of the invention as claimed.

Claims

Claim

A high strength metamaterial comprising a substrate and an artificial microstructure attached to said substrate, characterized in that said substrate has a cross section in a grid shape.

2. The high strength metamaterial of claim 1 wherein the individual cells of the grid are rectangular or diamond or circular.

3. A method of producing a high strength metamaterial according to claim 1, comprising the steps of:

51, forming a flat sheet substrate layer;

52, attaching an artificial microstructure to the substrate sheet layer to obtain a super material sheet layer;

53. The super material sheet is bent into a zigzag shape;

54. Stacking a plurality of zigzag metamaterial sheets and combining them so that the substrate composed of the plurality of substrate sheets has a grid shape in cross section.

4. The preparation method according to claim 3, wherein the step S2 attaches the artificial microstructure by an etching or printing process.

The preparation method according to claim 3, wherein the step S3 is performed by a hot press forming process.

6. The method according to claim 3, wherein each of the teeth of the saw tooth is rectangular or triangular or semi-circular.

The preparation method according to claim 3, wherein the step S4 comprises the following steps:

541. Stacking a plurality of zigzag metamaterial sheets from bottom to top;

8. The method according to claim 3, wherein the step S4 is performed by joining any adjacent two zigzag metamaterial sheets by a spot welding process.

9. The preparation method according to claim 3, wherein the step S4 passes the super The threaded holes on the sheet of material cooperate with the bolts to achieve the joint bonding of each of the zigzag metamaterial sheets.

The method according to claim 3, wherein the material of the substrate is polytetrafluoroethylene or epoxy resin.