Terahertz metamaterial sensor based on metal microstructure

Abstract

The invention discloses a terahertz metamaterial sensor based on a metal microstructure, which comprises a substrate layer, a metal reflecting layer, a microfluidic channel layer and a cover layer, and further comprises the metal microstructure, the metal microstructure extends into the microfluidic channel layer, and the top of the metal microstructure is fixed on the cover layer through etching; the metal microstructure comprises resonance units which are arranged periodically, and each resonance unit comprises an inverted-L-shaped structure and a circular ring-shaped structure. According to the invention, the resonance units of the metal microstructures are arranged to be two circular ring structures and one inverted L-shaped structure, absorption peaks with high absorptivity are generated in different wavelength ranges, and high-sensitivity sensing detection of liquid-phase biological analytes with different refractive indexes is realized; the synergistic effect of dipole resonance and lattice surface resonance initiates high-order response, an absorption peak with higher sensitivity is generated, and the detection sensing sensitivity is improved; the liquid-phase biological analyte is in contact with the terahertz waves in the microfluidic channel layer, so that the absorption of water to the terahertz waves is effectively reduced, and the detection sensitivity of the sensor is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz metamaterial sensors, and in particular to a terahertz metamaterial sensor based on a metal microstructure. Background Art

[0002] Terahertz waves (THz), with a frequency range of approximately 0.1-10THz, are between microwaves and infrared light and have a series of unique properties. Terahertz waves have good penetration into non-polar substances and high sensitivity to polar molecules, and their non-ionizing radiation properties make them extremely promising for non-destructive testing. In the biomedical field, terahertz waves can be used to detect lesions in biological tissues. For example, tumor tissues and normal tissues exhibit different absorption and scattering characteristics in the terahertz frequency band, which is expected to achieve non-invasive diagnosis of early cancer. In terms of security inspections, terahertz waves can penetrate materials such as clothing and plastics, and effectively detect hidden dangerous items such as drugs and explosives. The polar molecules in these items will produce characteristic responses under the action of terahertz waves.

[0003] However, traditional terahertz sensing technology faces many challenges. Due to the relatively long wavelength of terahertz waves, the scattering and diffraction effects when interacting with matter are more obvious, which limits the spatial resolution of traditional terahertz sensors and makes it difficult to accurately detect tiny samples or tiny features in samples. At the same time, the interaction between terahertz waves and matter is relatively weak, and conventional terahertz sensing structures often find it difficult to achieve high-sensitivity detection, and their ability to detect low-concentration substances or weak physical and chemical changes is insufficient.

[0004] In addition, when testing liquid samples, the strong absorption of terahertz waves by water will seriously interfere with the detection signal, greatly affecting the accuracy and reliability of the detection. Microfluidics, as a technical means to accurately manipulate trace fluids, has been widely used in the fields of biochips, chemical analysis microsystems, etc. It can integrate multiple functional units such as sample processing, reaction, and separation on a tiny chip to achieve automated, high-throughput analysis and detection. Through the microfluidic channel, the flow rate, flow rate, and residence time of the liquid sample can be accurately controlled, thereby providing precise condition control for sample pretreatment and reaction.

[0005] Metamaterials are artificially designed material structures with special electromagnetic properties. Their electromagnetic properties are not derived from the natural properties of the material itself, but are determined by the periodically arranged subwavelength unit structure. In the terahertz frequency band, metamaterials show powerful electromagnetic regulation capabilities. For example, by designing different metamaterial structures, flexible control of the resonance, focusing, absorption and other functions of terahertz waves can be achieved. The resonant structure of metamaterials can enhance the interaction between terahertz waves and matter, improve the sensitivity of sensors, and their unique electromagnetic response can be designed as a detection feature for specific substances or physical and chemical changes.

[0006] Although many sensing structures that achieve multi-band absorption have emerged based on metamaterial integrated microfluidic technology, they still have many flaws. For example, in pursuit of higher sensing sensitivity, metamaterial structures have advanced from two-dimensional to three-dimensional. Although three-dimensional structures can expand the electromagnetic field to three-dimensional space and strengthen the interaction between analytes and electromagnetic waves, they also make the manufacturing difficulty rise sharply. In addition, the Q value (quality factor) of these structures is generally not high, which has a negative impact on the energy storage capacity of the device and directly restricts the sensing performance. It should be noted that a larger Q value is often closely related to the high sensitivity and stability of the sensor, and is a key indicator that must be considered in sensor design. Moreover, their half-width (FWHM) is relatively large. In fact, the smaller the FWHM, the higher the sensing sensitivity. Narrow FWHM and high Q value can be said to be the two core elements that affect sensing performance. Unfortunately, there is no microfluidic sensor with both high Q value and narrow FWHM.

[0007] Based on the above technical status, it is of great significance to integrate metamaterials and microfluidics into the design of terahertz resonant structure sensing. This integration method is expected to overcome many defects of traditional terahertz sensing technology, use microfluidics to accurately control liquid samples, reduce the adverse effects of water on terahertz waves, design metamaterials with specific structures, and use their electromagnetic control capabilities to enhance the interaction between terahertz waves and samples, improve the sensitivity and detection accuracy of sensors, and thus open up a wider application prospect of terahertz sensing technology in many fields such as biomedicine, chemical analysis, and environmental monitoring. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a terahertz metamaterial sensor based on a metal microstructure. By designing a metal microstructure with specific structural characteristics and organically combining the metal microstructure with microfluidic technology and a terahertz resonant structure, the present invention is committed to solving the problems of low sensitivity, limited detection accuracy, inconvenient sample processing and poor adaptability to complex sample detection in traditional terahertz sensing technology; a highly efficient, highly sensitive, multifunctional and integrable terahertz resonant structure sensing system is constructed, which provides strong technical support for the wide application of terahertz sensing technology in various fields and promotes the process of terahertz sensing technology from laboratory research to actual industrial application.

[0009] In order to solve the above technical problems, the present invention provides a terahertz metamaterial sensor based on a metal microstructure, comprising a substrate layer, a metal reflection layer, a microfluidic channel layer and a cover layer stacked sequentially from bottom to top, and also comprising a metal microstructure, wherein the metal microstructure extends into the microfluidic channel layer and the top is fixed on the cover layer by etching;

[0010] The metal microstructure includes a plurality of periodically two-dimensionally arranged resonance units, and the resonance units include a "|"-shaped structure and annular structures symmetrically arranged on both sides of the "|"-shaped structure.

[0011] The present invention sets a microfluidic channel layer between the metal reflective layer and the metal microstructure. During sensing and detection, the liquid-phase biological analyte is injected into the microfluidic channel layer, the terahertz wave is incident from the cover layer, the metal microstructure generates resonance, the liquid-phase biological analyte is fully in contact with the terahertz wave in the microfluidic channel layer, the metal reflective layer reflects the terahertz wave after the liquid-phase biological analyte acts, and the external device receives the terahertz wave reflected by the metal reflective layer to achieve sensing and detection of the liquid-phase biological analyte. The present invention utilizes the microfluidic channel to effectively reduce the thickness of the liquid-phase biological analyte, thereby effectively reducing the absorption of the terahertz wave by water and improving the detection sensitivity of the sensor; the resonance unit of the metal microstructure is set as two annular structures and a "|"-shaped structure, and absorption peaks with high absorption rates are generated in different wavelength ranges, achieving high-sensitivity sensing and detection of liquid-phase biological analytes with different refractive indices.

[0012] The multi-band terahertz sensor of the present invention combines high-order response with microfluidics. Its resonant unit structure is composed of a ring and a strip structure. It can generate three resonance peaks in the frequency range of 0.8-1.5THz, with absorption rates as high as 0.976, 0.864 and 0.977, respectively, and the corresponding quality factors are 21, 19 and 123. Compared with the previous high-sensitivity microfluidic multi-band sensors, this design has a simple structure and is easy to manufacture. It promotes the coordination of surface lattice resonance and dipole resonance in the microfluidic channel to generate high-order response, achieving a refractive index sensitivity of up to 400GHz / RIU for multi-band absorption sensors.

[0013] Furthermore, the period length of the periodic arrangement of the metal microstructure is 120-170 μm.

[0014] Furthermore, the length of the “|”-shaped structure is 85-95 μm;

[0015] And / or, the width of the “|”-shaped structure is 4-6 μm.

[0016] Further, the inner diameter of the circular ring structure is 20 - 26 μm, the outer diameter of the circular ring structure is 25 - 31 μm, and the outer diameter is 4 - 5 μm larger than the inner diameter.

[0017] Further, the distance between the center of the circular ring structure and the center point of the "|" - shaped structure is 38 - 48 μm.

[0018] Further, the "|" - shaped structure generates a first absorption peak in the range of 0.8 - 1 THz, and the two circular ring structures generate a second absorption peak and a third absorption peak in the range of 1 - 1.5 THz.

[0019] Further, the materials of the metal reflection layer and the metal microstructure are independently selected from one of gold, silver, aluminum, copper, nickel, and titanium;

[0020] and / or, the thicknesses of the metal reflection layer and the metal microstructure are independently selected from 0.15 - 0.2 μm.

[0021] Further, the thickness of the micro - fluidic channel layer is 6 - 14 μm.

[0022] Further, the material of the cover layer is selected from one of quartz, polyimide, gallium arsenide, glass, polyethylene, polytetrafluoroethylene, and polypropylene;

[0023] and / or, the thickness of the cover layer is 80 - 120 μm.

[0024] Further, the material of the substrate layer is selected from one of silicon, quartz, and glass;

[0025] and / or, the thickness of the substrate layer is 100 - 1000 μm.

[0026] Advantages of the present invention:

[0027] The present invention organically combines metal microstructures with micro - fluidic technology and terahertz resonance structures. The resonance units of the metal microstructures are set as two circular ring structures and a "|" - shaped structure, which generate absorption peaks with high absorption rates in different wavelength ranges, realizing highly sensitive sensing detection of liquid - phase biological analytes with different refractive indices; among them, the synergistic effect of dipole resonance and lattice surface resonance triggers a higher - order response, generating absorption peaks with higher sensitivity and further improving the sensitivity of detection and sensing.

[0028] The present invention provides a micro - fluidic channel layer between the metal reflection layer and the metal microstructure for injecting liquid - phase biological analytes. The liquid - phase biological analytes are in full contact with terahertz waves in the micro - fluidic channel layer. The use of the micro - fluidic channel can effectively reduce the thickness of the liquid - phase biological analytes, and thus can effectively reduce the absorption of terahertz waves by water, improving the detection sensitivity of the sensor. Description of the Drawings

[0029] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0030] Figure 1 is a three-dimensional structural schematic diagram of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0031] Figure 2 is a cross-sectional view of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0032] Figure 3 is a structural schematic diagram of a resonant unit of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0033] Figure 4 is an absorption spectrum diagram of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0034] Figure 5 is a refractive index characteristic diagram of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0035] Figure 6 is a sensitivity characteristic diagram of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0036] Figure 7 is a near-field distribution diagram of the resonant unit structure of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0037] Figure 8 is a magnetic field distribution diagram in the microfluidic channel of the terahertz metamaterial sensor based on a metal microstructure of the present invention;

[0038] Explanation of reference numerals in the figure: 1. Cover layer, 2. Metal microstructure, 21. "|" - shaped structure, 22. Circular ring structure, 3. Microfluidic channel layer, 4. Metal reflection layer, 5. Substrate layer. Detailed implementation manners

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0040] Refer to Figure 1-2As shown in the figure, this embodiment relates to a terahertz metamaterial sensor based on metal microstructures, which includes a substrate layer 5, a metal reflection layer 4, a microfluidic channel layer 3, and a cover layer 1 stacked in sequence from bottom to top. It also includes metal microstructures 2. The metal microstructures 2 extend into the microfluidic channel layer 3 and are fixed to the cover layer 1 at the top by etching. The metal microstructures 2 include a number of periodically two-dimensionally arranged resonant units, such as Figure 3 As shown, the resonant unit includes a "|" shaped structure 21 and circular ring structures 22 symmetrically arranged on both sides of the "|" shaped structure 21. In this embodiment, terahertz waves are incident from the cover layer 1, and the metal microstructures 2 generate a resonant response. The liquid-phase biological analyte is injected into the microfluidic channel layer 3, that is, the liquid-phase biological analyte fills the pores between the metal microstructures 2 and the metal reflection layer 4. In the microfluidic channel layer 3, the liquid-phase biological analyte fully contacts and responds to the resonant terahertz waves. The terahertz waves after interacting with the liquid-phase biological analyte are reflected by the metal reflection layer 4 to an external receiving device, realizing the sensing detection of the liquid-phase biological analyte.

[0041] This embodiment uses the microfluidic channel to effectively reduce the thickness of the liquid-phase biological analyte, and thus can effectively reduce the absorption of terahertz waves by water and improve the detection sensitivity of the sensor. The resonant units of the metal microstructures 2 are set as two circular ring structures 22 and a "|" shaped structure 21, generating absorption peaks with high absorption rates in different wavelength ranges, realizing high-sensitivity sensing detection of liquid-phase biological analytes with different refractive indices. Different metal microstructures 2 (metamaterial structures) can generate different resonant responses. In the resonant unit of this embodiment, the "|" shaped structure 21 generates a first absorption peak in the range of 0.8 - 1 THz, and the two circular ring structures 22 generate a second absorption peak and a third absorption peak in the range of 1 - 1.5 THz. The three absorption peaks have high absorption rates and sensitivities, improving the detection and sensing sensitivity.

[0042] As an implementation manner of this embodiment, the material of the cover layer 1 is selected from one of quartz, polyimide, gallium arsenide, glass, polyethylene, polytetrafluoroethylene, and polypropylene, preferably quartz; referring to Figure 2 , the thickness t1 of the cover layer 1 is 80 - 120 μm, preferably 100 μm.

[0043] As an implementation manner of this embodiment, the thickness t2 of the metal microstructures 2 is selected from 0.15 - 0.2 μm, preferably 0.2 μm; the thickness of the metal reflection layer 4 is selected from 0.15 - 0.2 μm, preferably 0.2 μm; the thickness h of the microfluidic channel layer 3 is 6 - 14 μm, preferably 9 μm.

[0044] As an implementation manner of this embodiment, the material of the substrate layer 5 is selected from one of silicon, quartz, and glass; preferably silicon. The thickness t3 of the substrate layer 5 is 100 - 1000 μm, preferably 500 μm.

[0045] As an implementation manner of this embodiment, the materials of the metal reflection layer 4 and the metal microstructure 2 are independently selected from one of gold, silver, aluminum, copper, nickel, and titanium, preferably gold;

[0046] As an implementation manner of this embodiment, referring to Figure 3 , the periodic two-dimensional arrangement of the metal microstructure 2 has a periodic length Px and Py in two directions independently of 120 - 170 μm. Preferably, Px = 138 μm and Py = 155 μm.

[0047] As an implementation manner of this embodiment, the width W of the "|" - shaped structure is 4 - 6 μm, preferably 5 μm; the length n of the "|" - shaped structure is 85 - 95 μm, preferably 90 μm; the inner diameter r - w of the circular - ring structure 22 is 20 - 26 μm, preferably 23 μm; the outer diameter r of the circular - ring structure 22 is 25 - 31 μm, preferably 28 μm; the distance y from the center of the circular - ring structure 22 to the center point of the "|" - shaped structure is 38 - 48 μm, preferably 45 μm.

[0048] To determine the absorption - peak sensitivity of the sensor in the above - mentioned embodiment, the following detections are carried out on a specific example of the preferred implementation manner.

[0049] An analyte with a refractive index n in the range of 1.3 - 1.4 is added into the microfluidic channel. The incident terahertz wave is incident from the cover layer 1, and the metal microstructure 2 generates resonance. When the refractive index of the analyte is 1.3, the corresponding absorption spectrum is as shown in Figure 4 . Three absorption peaks with high absorption rates are generated (marked as Mode A, Mode B, and Mode C), and the corresponding quality factors are 21, 19, and 123 in sequence, and the FWHM are 42.9 GHz, 61.2 GHz, and 11.5 GHz in sequence. The liquid - phase biological analyte is in full contact with the incident terahertz wave in the microfluidic channel. The metal reflection layer 4 reflects the terahertz wave after interacting with the liquid - phase analyte. The external device realizes the sensing detection of the liquid - phase biological analyte by receiving the terahertz wave reflected by the metal reflection layer 4. For the results, see Figure 5 and Figure 6 . Figure 5 is the linear fitting graph of the resonance - frequency offset of the absorption peaks in the low - frequency band and the high - frequency band with the change of the refractive index. It can be seen that the sensitivities of this sensor at the three absorption peaks are 250 GHz / RIU, 275 GHz / RIU, and 400 GHz / RIU respectively. Figure 6 is the absorption spectrum corresponding to different refractive indices of the sensor. FromFigure 6 It can be seen that in the change of the refractive index n from 1.3 to 1.4, the absorption rates of the three absorption peaks of this terahertz metamaterial sensor all decrease relatively, and their absorption peaks all shift significantly. In the change of the refractive index n from 1.3 to 1.4, the resonance peak of the third absorption peak moves to the low frequency, and compared with the absorption peaks of the other two frequency bands, its frequency shift is larger. At the same time, compared with the absorption rates of the absorption peaks in the first two low-frequency bands, the change of the absorption rate of the resonance peak in the third frequency band is more obvious, indicating that the absorption peak in the third frequency band is more sensitive in amplitude to the detection of samples with different refractive indices, which is consistent with Figure 5 the detection results.

[0050] The research on the sensing performance of the metamaterial sensor has important reference significance for improving its sensing ability. Similarly, the electric field and the channel magnetic field are the keys to interpreting the formation mechanism of the absorption peaks. The results of the electric field and magnetic field distribution maps of the three absorption peaks are shown in Figure 7 and Figure 8 . In Figure 7 (a) showing the Mode A of the sensor, the electric field presents obvious distribution characteristics, that is, it is mainly concentrated at both ends of the metal strip ("|" shaped structure 21), and in the area outside the metal strip, the phenomenon of electric field aggregation is almost non-existent. This phenomenon indicates that dipole resonance occurs between the incident terahertz (THz) wave and the sensor. Similarly, for Mode B, as Figure 7 (b) shows, the electric field of the sensor is mainly distributed on the metal arms on both sides of the two metal rings (ring-shaped structure 22), and in the remaining areas of the metal rings, the degree of electric field aggregation is extremely weak. It can be seen that the electric field component of the incident THz wave and the resonant ring in the sensor also trigger dipole resonance. During this process, a large amount of the energy of the incident electromagnetic wave is absorbed due to the resonant characteristics of the metal structure, and then two absorption peaks with high absorption rates, Mode A and Mode B, appear in the spectrum.

[0051] However, the resonance mode of Mode C is significantly different from that of Mode A and Mode B. From Figure 7 (c), the distribution of its resonant electric field can be clearly observed. The electric field exists not only at both ends of the ring structure and the metal strip, but also in the non-metal area inside the unit, and the electric field coverage area in the non-metal area far exceeds the metal area on the metal arm. Therefore, Mode C does not rely solely on the dipole resonance generated by the metal structure, but results from the higher-order response caused by the synergistic effect of dipole resonance and lattice surface resonance. Since Mode C has a strong ability to store electromagnetic energy, its Q value is large, so its sensitivity is greater than that of the other two absorption peaks, which is consistent with Figure 5 and Figure 6 the detection results.

[0052] When the metal ring structure and the metal strip interact with THz waves, the generated dipole resonance will further interact with the metal reflection layer 4 below the channel analyte medium. During this process, a parallel current will be excited on the metal reflection layer 4. At the same time, a concentrated magnetic field will be correspondingly induced directly below the periodic array of the metal microstructures 2. As can be clearly observed from Figure 8 the magnetic field distributions in (a) and 8(b), that is, directly below the metal ring structure and the metal strip structure, there is an obvious strong magnetic field aggregation phenomenon. Different from the previous two magnetic field distribution patterns, as can be seen from Figure 8 (c), the magnetic field distribution of Mode C in the channel is not only limited to directly below the metal structure, but there is also a magnetic field distribution below other regions of the non-metal structure, which further strongly confirms that the third absorption peak is due to the high-order response mechanism triggered by the combination of the dipole resonance of the metal array and the lattice surface resonance.

[0053] In summary, in the present invention, the resonant units of the metal microstructures are set as two circular ring structures and a "|" shaped structure, which generate absorption peaks with high absorption rates in different wavelength ranges, and achieve high-sensitivity sensing detection of liquid-phase biological analytes with different refractive indexes; among them, the synergistic effect of dipole resonance and lattice surface resonance triggers a high-order response, generating absorption peaks with higher sensitivity, further improving the sensitivity of detection and sensing; a microfluidic channel layer is arranged between the metal reflection layer and the metal microstructures for injecting liquid-phase biological analytes. The liquid-phase biological analytes are in full contact with THz waves in the microfluidic channel layer. The use of the microfluidic channel can effectively reduce the thickness of the liquid-phase biological analytes, and thus can effectively reduce the absorption of THz waves by water, improving the detection sensitivity of the sensor.

[0054] The present invention has been described in detail above in combination with specific embodiments and exemplary examples, but these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present invention and their implementation manners, and these all fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims

1. A terahertz metamaterial sensor based on metal microstructure, characterized in that: It includes a substrate layer, a metal reflection layer, a microfluidic channel layer and a cover layer which are sequentially stacked from bottom to top, and also includes a metal microstructure, wherein the metal microstructure extends into the microfluidic channel layer and the top is fixed on the cover layer by etching; The metal microstructure includes a plurality of periodically two-dimensionally arranged resonance units, and the resonance units include a "|"-shaped structure and circular ring structures symmetrically arranged on both sides of the "|"-shaped structure.

2. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The period length of the periodic arrangement of the metal microstructure is 120-170 μm.

3. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The length of the "|"-shaped structure is 85-95 μm; And / or, the width of the "|"-shaped structure is 4-6 μm.

4. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The inner diameter of the circular ring structure is 20-26 μm, the outer diameter of the circular ring structure is 25-31 μm, and the outer diameter is 4-5 μm larger than the inner diameter.

5. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The distance between the center of the circular ring structure and the center point of the "|"-shaped structure is 38-48 μm.

6. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The "|"-shaped structure generates a first absorption peak in the range of 0.8-1 THz, and the two circular ring structures generate a second absorption peak and a third absorption peak in the range of 1-1.5 THz.

7. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The material of the metal reflective layer and the metal microstructure is independently selected from one of gold, silver, aluminum, copper, nickel and titanium; And / or, the thickness of the metal reflective layer and the metal microstructure are independently selected from 0.15-0.2 μm.

8. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The thickness of the microfluidic channel layer is 6-14 μm.

9. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The material of the cover layer is selected from one of quartz, polyimide, gallium arsenide, glass, polyethylene, polytetrafluoroethylene, and polypropylene; And / or, the cover layer has a thickness of 80-120 μm.

10. The terahertz metamaterial sensor based on metal microstructure according to claim 1, characterized in that: The material of the substrate layer is selected from one of silicon, quartz and glass; And / or, the thickness of the substrate layer is 100-1000 μm.

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