Spaced fabric metamaterial terahertz wave absorber and application thereof

Abstract

The invention relates to a spacer fabric metamaterial terahertz wave absorber and application thereof, and the product is of a three-layer structure which sequentially comprises a conductive pattern layer, a polymer medium spacer wire layer and a metal conductor layer which are periodically arranged from top to bottom; the spacer fabric metamaterial terahertz wave absorber is obtained through a knitting integrated forming method, and a conductive pattern layer and a metal conductor layer which are arranged periodically are connected through polymer medium spacer wires. The absorptivity gt of the interval fabric metamaterial terahertz wave absorber in the frequency band of 0.6-1.56 THz is obtained; the absorption rate is 90%, and the effective absorption bandwidth is 0.96-4.20 THz; the method is applied to the fields of anti-terahertz radar and electronic equipment, radar communication and individual protection. The product provided by the invention has good structural integrity and excellent layering resistance, and can maintain good structural stability in extreme environments such as external force impact and temperature shock; the product provided by the invention has a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the field of electronic information technology and relates to a spacer fabric metamaterial terahertz absorber and application thereof. Background Art

[0002] Terahertz waves refer to electromagnetic waves with a frequency range of 0.1 to 10 THz, which is between microwaves and infrared. Terahertz radar is one of the hot spots in the application research of terahertz technology. Compared with conventional microwave radar, terahertz radar has a stronger detection capability for stealth targets, which will have a subversive impact on existing stealth technology in the military. Because terahertz waves have a narrower beam, wider bandwidth, and shorter wavelength, they have good transmittance to microwave absorbing materials, which means that traditional microwave absorbing materials will find it difficult to resist terahertz radar. Therefore, the development of high-performance terahertz absorbing materials is of great significance to the strategy of strengthening the military through science and technology and safeguarding national security.

[0003] Metamaterial absorbers are composed of a periodically arranged conductive pattern layer (to regulate incident electromagnetic waves), a polymer dielectric spacer layer (to lose electromagnetic waves), and a metal conductor layer (to prevent electromagnetic wave transmission). They can achieve zero reflection and strong absorption of incident electromagnetic waves through structural optimization, and are one of the emerging technologies for high-end stealth equipment. However, current research on electromagnetic metamaterial absorbers focuses on improving absorbing performance (absorption rate, bandwidth range, etc.), and rarely pays attention to their structural stability.

[0004] Literature (Materials & Design 2022, 222, 111079; Materials & Design 2023, 225, 111586; Advanced Optical Materials 2022, 10(1), 2101008) records that the preparation of conventional metamaterial absorbers generally adopts lamination, printing or chemical bonding techniques to composite periodic conductive pattern layers, dielectric spacer layers and metal conductor layers. Due to the large differences in modulus and thermal expansion coefficients between metals and polymers, the bonding force between interfaces is insufficient, and interlayer delamination is very likely to occur under the influence of complex environmental factors such as external force deformation, high and low temperature shock, etc.

[0005] The metamaterial absorber in the prior art changes the position of the absorption frequency by adjusting the geometric dimensions of different metal patterns (such as crosses, square rings, circular rings, etc.), the thickness of the dielectric layer and other parameters, but based on this typical three-layer structure, the metamaterial absorber can only achieve near-perfect absorption at a certain frequency, so it has the problem of narrow bandwidth. Researchers have successively adopted the method of horizontal integration of multiple conductive patterns or overlapping multi-layer structure design to superimpose absorption peaks at different positions to increase the absorption bandwidth, but the number of patterns integrated in each unit structure is limited, making it difficult to achieve full coverage in an ultra-wide frequency band. In addition, the multi-layer structure usually requires a multi-step photolithography process, which further increases the difficulty and cost of processing, and the increase in thickness limits its wide application.

[0006] Therefore, it is of great significance to study a spacer fabric metamaterial terahertz absorber and its application to solve the above problems. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a spacer fabric metamaterial terahertz absorber and application thereof.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A spacer fabric metamaterial terahertz absorber has a three-layer structure, which includes a periodically arranged conductive pattern layer, a spacer silk layer and a metal conductor layer from top to bottom;

[0010] The spacer fabric metamaterial terahertz absorber is obtained by a knitting one-piece forming method. The periodically arranged conductive pattern layer and the metal conductor layer are connected by spacer wires. The preparation of metamaterial absorbers in the prior art generally adopts lamination, printing, chemical bonding and 3D printing and other technologies, and the above technologies cannot achieve one-piece forming; although the woven spacer fabric can achieve one-piece forming, it is difficult to control the surface conductive pattern; the spacer wire is a polymer dielectric spacer wire;

[0011] The conductive pattern layer includes conductive fibers;

[0012] The conductive pattern layer may include conductive fibers and dielectric fibers, or only conductive fibers. For example, if a square ring is designed, the conductive fibers may be woven into the shape of a square ring using an intarsia weave, and the dielectric fibers may be woven into the remaining portion. When the conductive fibers are exposed on the surface, the dielectric fibers exist in the form of floating lines on the back. For example, if the hexagonal mesh structure is used, the conductive fibers may be directly used for weaving.

[0013] The outer side length of the square ring is 1.35-1.5 mm, the inner side length of the square ring is 0.60-0.80 mm, and the side length of the conductive pattern unit is 2-2.2 mm;

[0014] The absorption rate of the spacer fabric metamaterial terahertz absorber in the frequency band of 0.6 to 1.56 THz is >90%, and the effective absorption bandwidth (RL<-10dB) is 0.96 to 4.20 THz;

[0015] Compared with traditional metamaterial absorbers, the spacer fabric metamaterial terahertz absorber of the present invention does not have the phenomenon of easy delamination between layers under temperature changes or force changes, has excellent structural stability, and can be characterized by impact testing.

[0016] As the preferred technical solution:

[0017] In the above-mentioned spacer fabric metamaterial terahertz absorber, the conductive pattern layer further comprises dielectric fibers, and the dielectric fibers are one or more of polyester fibers, acrylic fibers and nylon fibers.

[0018] In the above-mentioned spacer fabric metamaterial terahertz absorber, the spacer fabric is a warp knitted spacer fabric or a weft knitted spacer fabric.

[0019] In the spacer fabric metamaterial terahertz absorber as described above, the periodically arranged conductive pattern layer is one or more of a warp knitted basic structure, a weft knitted basic structure, a variable structure and a pattern structure; in the present invention, different conductive periodic units are obtained by changing the structure of the upper surface, the incident electromagnetic wave can be regulated, the position of the absorption frequency can be determined, and further different structure structures can be combined to superimpose the absorption frequencies, thereby broadening the working bandwidth.

[0020] In the above-mentioned spacer fabric metamaterial terahertz absorber, the material of the periodically arranged conductive fibers is one or more of carbon-coated modified fibers, MXene-coated fibers, metal-coated fibers and conductive polymer-coated modified fibers, and the dielectric fibers are one or more of polyester fibers, acrylic fibers and nylon fibers. Different conductive fibers are used in the present invention to adjust the fiber conductivity, thereby achieving impedance matching to improve the absorption of electromagnetic waves and reduce reflection.

[0021] In the above-mentioned spacer fabric metamaterial terahertz absorber, the spacer wire layers are arranged in at least one of an I-shape, a V-shape and an X-shape.

[0022] In the above-mentioned spacer fabric metamaterial terahertz absorber, the material of the spacer silk layer is one or more of polypropylene, nylon, polyester and polyurethane.

[0023] In the above-mentioned spacer fabric metamaterial terahertz absorber, the metal conductor layer is one or more of a warp knitting basic structure, a weft knitting basic structure, a variable structure and a pattern structure.

[0024] In the above-mentioned spacer fabric metamaterial terahertz absorber, the material of the metal conductor layer is one or more of gold-plated molybdenum wire, copper-plated fiber and stainless steel fiber.

[0025] The present invention also provides the use of the spacer fabric metamaterial terahertz absorber as described in any of the above items in the field of electromagnetic protection related to countering terahertz radar and electronic equipment, radar communication and personal protection.

[0026] Principle of the invention:

[0027] Spacer fabric is a three-dimensional fabric formed by interweaving two layers of surface fabric and internal spacer yarns, which has a similar three-layer structure to metamaterial absorbers. A large number of studies have shown that spacer fabrics have good dimensional stability, extremely high fracture strength at the seams, and no structural defects that are prone to delamination and cracking. By using knitting technology to feed conductive fibers and dielectric fibers in a specific proportion and arrangement, a fiber assembly containing different conductive periodic units can be made in one step.

[0028] The spacer fabric metamaterial terahertz absorber in the present invention breaks through the preparation technology of traditional multi-layer composite assembly, and simultaneously weaves a periodic array pattern and a metal reflective layer and connects them with spacer yarn. Since a pattern design can correspond to an absorption frequency point, each pattern will be centered on the absorption frequency point, and the absorption performance will gradually decrease on both sides. The frequency band with absorption performance <-10dB is the effective bandwidth, and different tissue structure designs can obtain different patterns. Through reasonable tissue design, the effective bandwidth of each pattern can be superimposed, thereby ensuring that the absorption performance is below -10dB in a wider frequency band, thereby effectively avoiding the complexity of multiple processing, and realizing a high-efficiency and low-cost one-piece formed all-fabric metamaterial absorber.

[0029] The structurally stable spacer fabric metamaterial terahertz absorber of the present application can be directly used to counter terahertz radar. The absorption frequency can be regulated by changing the upper surface tissue structure, and the absorption frequency can be further regulated by adjusting parameters such as the density and height of the middle spacer wire. By rationally combining different tissue structures, different absorption frequencies can be superimposed to expand the working bandwidth. Based on the impedance matching theory, the square resistance of the surface conductive pattern unit is adjusted; the type of spacer wire is changed to adjust the dielectric loss of the dielectric layer; the appropriate lower surface tissue structure is selected to achieve a zero-transmission metal conductor layer, thereby improving the terahertz wave absorption performance of the spacer fabric metamaterial terahertz absorber.

[0030] In the prior art, the research on metamaterials is mainly focused on improving the absorbing performance, including absorptivity and effective bandwidth. Generally, the higher the absorptivity and the wider the effective bandwidth, the better the absorbing performance. In the present invention, the absorbing performance is mainly related to the structure and electrical parameters such as the pattern, size, impedance of the surface conductive periodic unit, and the density, height and dielectric constant of the intermediate spacer wire, while the bottom acts as a perfect metal reflection layer (the perfect metal reflection layer is a metal conductor layer, and its function is to reflect the incident electromagnetic wave back to the inside of the absorber to prevent electromagnetic wave transmission), so a relatively tight fabric structure is required. The combination of different parameters can obtain different absorbing performances. For example, when other parameters are reasonably unchanged, the pattern of the conductive pattern is changed by the design of the organizational structure, so as to design different conductive periodic unit patterns (i.e., the structure of the conductive fibers on the surface of the spacer fabric), which can achieve strong absorption at different frequencies. One pattern corresponds to one frequency, which means that the absorption bandwidth of the metamaterial absorber with a single pattern is relatively narrow, so a combination of multiple patterns is required to broaden the effective bandwidth.

[0031] Beneficial effects:

[0032] (1) The spacer fabric metamaterial terahertz absorber of the present invention can adjust the absorption performance (including absorption rate and absorption frequency, etc.) by changing the structural parameters of the upper conductive pattern unit, the type, density and height of the spacer wire, etc.; at the same time, through the reasonable design of the upper periodically arranged conductive pattern, adjacent frequency bands can be superimposed, thereby achieving broadband absorption, strong adjustability, and the adjustment strategy is simple and easy to operate;

[0033] (2) The spacer fabric metamaterial terahertz absorber of the present invention can be used to counter terahertz radar, which has a disruptive impact on existing stealth technology and is expected to provide support for the development of the next generation of lightweight flexible stealth equipment and the strategy of strengthening the military through science and technology;

[0034] (3) The spacer fabric metamaterial terahertz absorber of the present invention is integrally formed. Compared with the three-layer structure metamaterial absorber commonly prepared by lamination, printing or chemical bonding technology, it cleverly utilizes the change of organizational structure to achieve absorption and broadening of different frequencies, has good structural integrity and excellent anti-delamination performance, and can maintain good structural stability in extreme environments such as external force impact and temperature sudden change. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of spacer fabric metamaterial terahertz absorber;

[0036] Figure 2 Schematic diagram of the conductive pattern unit of Examples 1 and 2;

[0037] Among them, 1-metal conductor layer, 2-spacer wire layer, 3-conductive pattern layer, 4-conductive fiber, 5-dielectric fiber. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0039] The test / calculation method involved in the present invention is as follows:

[0040] Absorption rate: The high average power terahertz free electron laser device (CTFEL device) system uses a femtosecond fiber laser with a central wavelength of 1550nm and a pulse width of 40fs as the excitation source; under the conditions of room temperature of 22℃ and humidity of 5%, the electro-optical effect of gallium arsenide crystal is used to generate and receive terahertz signals respectively; the power of the incident terahertz wave is 50μW, and the test time step of the entire experiment is 0.067ps.

[0041] Effective absorption bandwidth: The frequency band where the absorption rate is <-10dB is the effective absorption bandwidth.

[0042] Maximum load: The fabric was subjected to a low-speed impact test using an Instron Dynatup 9250HV impact tester. The test conditions were: temperature (25±2)°C, relative humidity (65±2)%; the impact head was hemispherical and had a diameter of 12.5 mm; each sample was tested 5 times, a load-time curve was drawn, and the test results were averaged.

[0043] Preparation of graphene-coated fibers of the present invention Reference: Bo Wu, Yu Liu, Hong Yu. High-performance electric heating yarns based on graphene-coated cotton fibers [J]. Applied Polymer. 2022.07(12).1-11;

[0044] References for the preparation of MXene-coated fibers: Simge Uzun, Shanyan Seyedin, Amy L. Stoltzfus. Et al. Knittable and Washable Multifunctional MXene-Coated Cellulose Yarns[J]. Advanced Functional Materials. 2019, 05(15): 1-13.

[0045] Example 1

[0046] A spacer fabric metamaterial terahertz absorber, such as Figure 1 As shown, it is a three-layer structure, which includes a periodically arranged conductive pattern layer 3, a polymer dielectric spacer layer 2 and a metal conductor layer 1 from top to bottom;

[0047] The spacer fabric metamaterial terahertz absorber is obtained by a knitting one-piece forming method, and the specific steps are as follows:

[0048] (1) Figure 2 As shown, the upper layer uses an intarsia structure to weave the graphene coated fiber (i.e., the conductive fiber 4) into a square ring, and polyester fiber (Zhejiang Jinxia New Material Technology Co., Ltd., 75D) is used as the dielectric fiber 5 to weave the remaining part to form a square ring conductive pattern layer; the conductive pattern layer is formed by infinitely extending the conductive pattern unit in the X and Y axis planes;

[0049] The outer side length of the square ring is 1.35 mm, the inner side length of the square ring is 0.60 mm, and the side length of the conductive pattern unit is 2.10 mm; the conductivity of the conductive pattern layer is 1.20×10 5 S / m;

[0050] (2) The lower layer uses a plain stitch and a specific yarn feeding device (HBS-11OV, Jiangsu Saijia Co., Ltd.) is used to feed stainless steel wire (Laiwu Longzhi Metal Yarn Co., Ltd., with a diameter of 0.03 mm);

[0051] (3) The upper and lower layers are connected by polyester (Zhejiang Jinxia New Material Technology Co., Ltd., 150D) spacer wires. The height of the spacer wires is controlled to 3 mm by adjusting the spacing between the two needle beds. The dielectric constant of the spacer wires is 2.3 F / m. The dielectric spacer wire layers are arranged in an I shape, and finally a weft-knitted spacer fabric metamaterial terahertz absorber is formed;

[0052] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.56THz is 98%, the effective absorption bandwidth is 2.4THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 3.36kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

[0053] Example 2

[0054] A spacer fabric metamaterial terahertz absorber, which is basically the same as that in Example 1, such as Figure 2 As shown, the difference is that the spacer wire height is 5 mm.

[0055] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.52THz is 99%, the effective absorption bandwidth is 2.5THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 3.76kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

[0056] Example 3

[0057] A spacer fabric metamaterial terahertz absorber is basically the same as Example 1, except that a spacer wire made of polyurethane fiber (Xuzhou Xinchang Textile Co., Ltd., with a diameter of 0.2 mm) is used, and the dielectric constant of the spacer wire is 2.46F / m.

[0058] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.56THz is 98%, the effective absorption bandwidth is 2.1THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 3.03kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

[0059] Example 4

[0060] A spacer fabric metamaterial terahertz absorber has a three-layer structure, which includes a periodically arranged conductive pattern layer, a dielectric spacer layer, and a stainless steel conductor layer from top to bottom;

[0061] The spacer fabric metamaterial terahertz absorber is obtained by a knitting one-piece forming method, and the specific steps are as follows:

[0062] (1) The upper layer uses warp plain weave and warp satin weave to use MXene coated fibers as conductive fibers and acrylic filaments (Nantong Xindike Monofilament Technology Co., Ltd., 75D) as dielectric fibers to weave into a square ring conductive pattern layer composed of a combination of a quadrangular mesh and a hexagonal mesh;

[0063] The outer side length of the square ring is 1.50 mm, the inner side length of the square ring is 0.80 mm, and the side length of the conductive pattern unit is 2.2 mm; the conductivity of the conductive pattern layer is 1.4×10 5 S / m;

[0064] (2) The lower layer uses a plain stitch and a specific yarn feeding device (HBS-11OV, Jiangsu Saijia Co., Ltd.) is used to feed stainless steel wire (Laiwu Longzhi Metal Yarn Co., Ltd., with a diameter of 0.03 mm);

[0065] (3) The upper and lower layers are connected by a polymer dielectric spacer wire made of polyester (Zhejiang Jinxia New Material Technology Co., Ltd., 150D). The height of the spacer wire is controlled to 3 mm by adjusting the spacing between the two needle beds. The dielectric constant of the spacer wire is 2.43 F / m. The dielectric spacer wire layer is arranged in an I shape, and finally a warp knitted spacer fabric metamaterial terahertz absorber is formed;

[0066] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.56THz is 99%, the absorption rate at 0.8THz is 97%, the effective absorption bandwidth is 3.8THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 2.54kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

[0067] Example 5

[0068] A spacer fabric metamaterial terahertz absorber is basically the same as Example 4, except that the height of the spacer wire is 7 mm.

[0069] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.12THz is 99%, the absorption rate at 0.75THz is 98%, the effective absorption bandwidth is 4.2THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 3.58kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

[0070] Example 6

[0071] A spacer fabric metamaterial terahertz absorber has a three-layer structure, which includes a periodically arranged conductive pattern layer, a polymer dielectric spacer layer, and a metal conductor layer from top to bottom;

[0072] The spacer fabric metamaterial terahertz absorber is obtained by a knitting one-piece forming method, and the specific steps are as follows:

[0073] (1) The upper layer uses a plain stitch and a weft-inserted stitch, and the material is a metal-coated fiber and a conductive polymer-coated modified fiber, forming a square ring-shaped conductive pattern layer; the conductive pattern layer is formed by infinitely extending the conductive pattern unit in the X and Y axis planes;

[0074] The outer side length of the square ring is 1.40 mm, the inner side length of the square ring is 0.80 mm, and the side length of the conductive pattern unit is 2 mm; the conductivity of the conductive pattern layer is 1.6×10 5 S / m;

[0075] (2) The lower layer uses weft-insertion weave, and a specific yarn feeding device (HBS-11OV, Jiangsu Saijia Co., Ltd.) is used to feed gold-plated molybdenum wire (Sichuan Weiner Special Electronic Materials Co., Ltd.) and copper-plated fiber;

[0076] (3) The upper and lower layers are connected by polymer dielectric spacer wires made of polypropylene (Weifang Runfengda Textile Co., Ltd., 150D) and nylon (Weifang Haofang Textile Co., Ltd., 20s) in a mass ratio of 1:1. The height of the spacer wire is controlled to 3 mm by adjusting the spacing between the two needle beds. The dielectric constant of the spacer wire is 2.38 F / m. The polymer dielectric spacer wire layers are arranged in V and X shapes, and finally a warp knitted or weft knitted spacer fabric metamaterial terahertz absorber is formed;

[0077] The absorption rate of the spacer fabric metamaterial terahertz absorber at 1.56THz is 99%, the absorption rate at 0.9THz is 96%, the effective absorption bandwidth is 4.2THz, and the impact velocity is 1.0m·s -1 In the impact test with an impact energy of 3J, the maximum load was 3.58kN; the spacer fabric metamaterial terahertz absorber is used to counter terahertz radar and electronic equipment, radar communications and personal protection.

Claims

1. A spacer fabric metamaterial terahertz absorber, characterized in that: It is a three-layer structure, which includes a periodically arranged conductive pattern layer, a spacer wire layer and a metal conductor layer from top to bottom; The spacer fabric metamaterial terahertz absorber is obtained by a knitting integrated forming method, and the periodically arranged conductive pattern layer and the metal conductor layer are connected by spacer wires, and the spacer wires are polymer dielectric spacer wires; The conductive pattern layer includes conductive fibers; The absorption rate of the spacer fabric metamaterial terahertz absorber in the frequency band of 0.6 to 1.56 THz is greater than 90%, and the effective absorption bandwidth is 0.96 to 4.20 THz.

2. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The conductive pattern layer further comprises dielectric fibers, and the dielectric fibers are one or more of polyester fibers, acrylic fibers and nylon fibers.

3. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The spacer fabric is a warp knitted spacer fabric or a weft knitted spacer fabric.

4. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The periodically arranged conductive pattern layer is one or more of a warp knitting basic structure, a weft knitting basic structure, a variable structure and a fancy structure.

5. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The material of the periodically arranged conductive fibers is one or more of carbon-coated modified fibers, MXene-coated fibers, metal-coated fibers, and conductive polymer-coated modified fibers.

6. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The spacer wire layer is arranged in at least one of an I-shape, a V-shape and an X-shape.

7. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The material of the spacer yarn layer is one or more of polypropylene, nylon, polyester and polyurethane.

8. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The metal conductor layer is one or more of a warp knitting basic structure, a weft knitting basic structure, a variable structure and a fancy structure.

9. The spacer fabric metamaterial terahertz absorber according to claim 1, characterized in that: The material of the metal conductor layer is one or more of gold-plated molybdenum wire, copper-plated fiber and stainless steel fiber.

10. Application of the spacer fabric metamaterial terahertz absorber according to any one of claims 1 to 9 in the fields of countering terahertz radar and electronic equipment, radar communication and personal protection.

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