Windmill-based terahertz metamaterial microfluidic sensor

Abstract

The application discloses a windmill type based terahertz metamaterial micro-fluidic sensor, which comprises a buffer layer, a metal reflection layer, a metal microstructure and a cover layer from bottom to top, and a micro flow channel is formed between the metal reflection layer and the metal microstructure; the metal microstructure is in a windmill type structure. The application provides a reference for enriching the diversification of terahertz sensor devices, and developing the terahertz wave band biomedical field, the nondestructive testing field of agricultural product quality safety and the like.

Description

Technical Field

[0001] This invention relates to the field of terahertz functional device technology. More specifically, this invention relates to a terahertz metamaterial microfluidic sensor based on a windmill model. Background Technology

[0002] Terahertz waves refer to electromagnetic waves with frequencies between 0.1 and 10 THz, falling between microwaves and infrared radiation. THz photons have energy a million times lower than X-rays, and do not cause radiation damage when penetrating matter. Furthermore, the vibrational and rotational energy levels of many semiconductors, plasmas, and biomolecules fall within the THz band. In recent years, terahertz time-domain spectroscopy (THz-TDS) has become an effective means of detecting information about matter in the THz band, and can be used for qualitative / quantitative analysis of medical diagnostics, agricultural products, cultural relics, and drugs. However, due to the lack of efficient terahertz generation devices and sensitive detectors, the interaction between THz waves propagating in free space and matter is weak, becoming a bottleneck restricting the detection of trace or micro-samples.

[0003] Metamaterials are composite structures or materials with unique properties composed of periodic or aperiodic artificial atomic arrangements. Terahertz biosensors based on metamaterials can enhance local electromagnetic fields and the interaction between terahertz waves and matter. They are also label-free, affinity sensors, providing new insights for the detection of trace samples. Currently, research focuses on filtering and absorbing sensors, primarily on improving sensor performance and designing multi-band sensors to study the detection mechanisms of substances. However, the strong absorption of terahertz waves by polar solutions such as water remains unresolved. Even with drying treatment during pretreatment to eliminate the influence of liquids on detection results, sample properties may change, and the phenomenon of the sample in a real-world environment cannot be detected. Microfluidic chips confine microfluidics with volumes ranging from nanoliters to microliters within a cavity through microfluidic channels, significantly reducing sample volume and improving reaction efficiency, as well as enhancing the extraction of target biomolecules in an "aquatic environment." Therefore, addressing or reducing the interference of polar solutions such as water in sample detection is particularly important in biomedical and other fields. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0005] Another objective of this invention is to provide a terahertz metamaterial microfluidic sensor based on a windmill model, which provides a reference for enriching the diversity of terahertz sensor devices and expanding the field of non-destructive testing in terahertz band biomedicine, agricultural product quality and safety, and other fields.

[0006] To achieve these objectives and other advantages according to the present invention, a terahertz metamaterial microfluidic sensor based on a windmill model is provided, which is a cubic structure formed by splicing multiple unit cells; each unit cell includes, from bottom to top, a buffer layer, a metal reflective layer, a metal microstructure and a capping layer, wherein a microfluidic channel is formed between the metal reflective layer and the metal microstructure; the metal microstructure is a windmill model structure.

[0007] Preferably, the terahertz metamaterial microfluidic sensor based on a windmill model is described above, wherein the metal microstructure is a windmill model structure formed by arranging four semi-circular frame-like unit components at intervals along the circumference, and each unit component includes a first part of an arc-shaped structure and a second part of a straight line connecting the two ends of the arc-shaped structure.

[0008] Preferably, in the aforementioned terahertz metamaterial microfluidic sensor based on a windmill model, the capping layer is made of PTFE material with a dielectric constant of 2.1+i0.0002.

[0009] Preferably, in the terahertz metamaterial microfluidic sensor based on a windmill model, both the metal microstructure and the metal reflective layer are made of gold; and both have an electrical conductivity of 4.561e+007S / m.

[0010] Preferably, the terahertz metamaterial microfluidic sensor based on a windmill model has a buffer layer made of high-resistivity silicon material with a dielectric constant of 11.9+i0.00025.

[0011] Preferably, the terahertz metamaterial microfluidic sensor based on the windmill model has the following parameters: the length and width of the metal microstructure are P = 80 μm, the radius of the first part of the unit is r = 15 μm, half the length of the second part of the unit is d = 15 μm, the thickness of the unit is w = 4 μm, the thickness of the capping layer is h1 = 50 μm, the thickness of both the metal microstructure and the metal reflective layer is t = 0.2 μm, the height of the microfluidic channel is h2 = 3 μm, and the thickness of the buffer layer is h3 = 500 μm.

[0012] Preferably, the terahertz metamaterial microfluidic sensor based on a windmill model has three distinct resonant absorption peaks in the 1.5-3 THz frequency range, namely M1 = 1.971 THz, M2 = 2.836 THz, and M3 = 2.981 THz, with corresponding quality factor Q values ​​of 23, 472, and 596 under the three absorption peak modes.

[0013] The present invention has at least the following beneficial effects:

[0014] This invention combines microfluidic technology to design a terahertz metamaterial microfluidic sensor for liquid sample detection, reducing the strong absorption of terahertz waves by polar solutions. Based on a windmill structure, the sensor exhibits three resonant absorption peaks in the 1.5-3 THz range, with absorption rates exceeding 90% for each peak. This achieves perfect matching with free space, demonstrating wide-angle insensitivity and excellent detection performance, and also enabling the identification of cancer cells.

[0015] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the terahertz metamaterial microfluidic sensor structure based on a windmill model as described in this invention. Figure 1 (a) is a schematic diagram of the overall structure of the terahertz metamaterial microfluidic chip. Figure 1 (b) is an enlarged view of the metal microstructure;

[0017] Figure 2 (a) is the absorption characteristic curve of the sensor described in Embodiment 1 of the present invention when there is no sample covering in the microfluidic channel; Figure 2 (b) is the relative impedance curve of the sensor described in Embodiment 1 of the present invention in M1 mode;

[0018] Figure 3 The diagram shows the electric field (Re(Ez)) and current distribution of the sensor at the resonant frequency in Embodiment 2 of the present invention. Figure 3 (a) and (d) are in M1 mode; Figure 3 (b) and (e) are under M2 mode; Figure 3 (c) and (f) are in M3 mode;

[0019] Figure 4 (a) is the absorption characteristic curve of the sensor described in Embodiment 3 of the present invention when TE and TM polarized THz waves are incident; Figure 4 (b) is the electric field distribution diagram of the sensor described in Embodiment 3 of the present invention under TM polarization; the vertical propagation direction of the electric field of the TE wave (transverse electric wave); the vertical propagation direction of the magnetic field of the TM wave (transverse magnetic wave);

[0020] Figure 5 The absorption characteristic curves under TE polarization mode with varying polarization angle and incident angle in Embodiment 3 of the present invention are shown. Figure 5 (a) shows the absorption characteristic curve as a function of polarization angle phi when the incident angle theta = 0°. Figure 5 (b) shows the change of the absorption characteristic curve with the incident angle theta when the polarization angle phi = 0°.

[0021] Figure 6 (a) shows the absorption spectra of the sensor with different h2 values ​​in Embodiment 4 of the present invention; Figure 6 (b) shows the changes in Q value and absorption intensity of the sensor in M1 mode as a function of h2 in Embodiment 4 of the present invention;

[0022] Figure 7 (a) is a graph showing the characteristics of evaluating the sensing and detection capabilities of a terahertz metamaterial microfluidic chip by adding analytes with different refractive indices to the microfluidic channel of the sensor in Embodiment 5 of the present invention. Figure 7 (b) shows the absorption intensity and Q factor variation curves of the sensor described in Embodiment 5 of the present invention in modes M1 and M2.

[0023] Explanation of reference numerals in the attached diagram: Buffer layer 1, Metal reflective layer 2, Metal microstructure 3, Cover layer 4. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0025] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0026] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0027] In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] This invention provides a terahertz metamaterial microfluidic sensor based on a windmill model, which is a cubic structure formed by assembling multiple unit cells. Each unit cell, from bottom to top, includes a buffer layer 1, a metal reflective layer 2, a metal microstructure 3, and a capping layer 4. A microfluidic channel is formed between the metal reflective layer 2 and the metal microstructure 3. The metal microstructure 3 has a windmill model structure. The overall structure of the terahertz metamaterial microfluidic sensor provided by this invention is as follows: Figure 1 As shown in (a), the magnified view of the metal microstructure is as follows: Figure 1 As shown in (b).

[0029] Furthermore, the metal microstructure is a windmill structure formed by arranging four semi-circular frame-like unit components at intervals along the circumference. Each unit component includes a first part of an arc-shaped structure and a second part of a straight line connecting the two ends of the arc-shaped structure.

[0030] Furthermore, the capping layer is made of PTFE material with a dielectric constant of 2.1+i0.0002.

[0031] Furthermore, both the metal microstructure and the metal reflective layer are made of gold; their electrical conductivity is 4.561e+007S / m.

[0032] Furthermore, the buffer layer is made of high-resistivity silicon material with a dielectric constant of 11.9+i0.00025.

[0033] Furthermore, the sensor parameters are as follows: the length and width of the metal microstructure are P = 80 μm, the radius of the first part of the unit is r = 15 μm, half the length of the second part of the unit is d = 15 μm, the thickness of the unit is w = 4 μm, the thickness of the capping layer is h1 = 50 μm, the thickness of both the metal microstructure and the metal reflective layer is t = 0.2 μm, the height of the microfluidic channel is h2 = 3 μm, and the thickness of the buffer layer is h3 = 500 μm.

[0034] Furthermore, the sensor exhibits three distinct resonant absorption peaks in the 1.5-3THz frequency range, namely M1 = 1.971THz, M2 = 2.836THz, and M3 = 2.981THz, with corresponding quality factor Q values ​​of 23, 472, and 596 under the three absorption peak modes, respectively.

[0035] Based on the principle that multiple resonances can be generated by the superposition of multiple metal microstructures, this invention proposes a windmill-shaped structure. The sensor of this invention uses a microfluidic channel to confine a trace amount of fluid with a volume ranging from nanoliters to microliters in a cavity, which not only significantly reduces the amount of sample used, but also reduces the strong absorption of terahertz waves by polar solutions, improves reaction efficiency, and enhances the information extraction efficiency and accuracy of target biomolecules in the "aquatic environment".

[0036] The sensor of this invention is based on a windmill structure and has three resonant absorption peaks in the range of 1.5-3 THz. The three absorption peaks are formed by dipole resonance, interaction between metal and dielectric materials, destructive interference between structural units, or internal friction between materials, respectively. The absorption rate of each peak is over 90%, achieving perfect matching with free space. It has wide-angle insensitivity and excellent detection performance, and can also identify cancer cells.

[0037] <Example 1>

[0038] Structural Design and Simulation

[0039] This invention utilizes the CST MWS2020 (CST Microwave Studio) to perform numerical simulation calculations on the terahertz metamaterial microfluidic sensor provided by this invention. In the simulation settings, a frequency domain solver based on the finite element method is used to solve Maxwell's differential equations. A tetrahedral mesh is used for mesh generation. In the boundary settings, the xy-plane is set as a periodic boundary, and the z-direction is set as an open boundary, simulating an infinitely large periodic array. A THz wave is incident perpendicularly onto the surface of the terahertz metamaterial microfluidic chip. The electromagnetic response caused by geometric parameters is analyzed using CST's built-in parametric scanning to obtain perfect absorption. The optimized parameters are shown in Table 1.

[0040] Table 1 Structural parameters of the terahertz metamaterial microfluidic chip

[0041]

[0042] Notes: P represents the length and width of the metal microstructure; r represents the radius of the first part of the unit; w represents the thickness of the unit; h1 represents the thickness of the capping layer (50 μm); d represents half the length of the second part of the unit (15 μm); t represents the thickness of the metal microstructure / metal reflective layer; h2 represents the height of the microfluidic channel; h3 represents the thickness of the buffer layer.

[0043] The S-parameters are obtained using the finite element integration method. 11 S represents the reflection coefficient. 21 This represents the transmission coefficient. Due to the total reflection of THz waves by the metal reflective layer, the transmittance of the terahertz metamaterial microfluidic chip is T(w) = |S 21 | 2 =0. Absorption characteristic curve A(w) = 1 - R(w) - T(w) = 1 - |S 11 | 2 The absorption characteristic curves when there is no sample covering in the microfluidic channel are as follows: Figure 2 As shown in (a), within the 1.5-3 THz frequency range, the terahertz metamaterial microfluidic chip exhibits three distinct resonant absorption peaks: M1 = 1.971 THz, M2 = 2.836 THz, and M3 = 2.981 THz. The absorption rate of the terahertz metamaterial microfluidic chip is above 90% for all three peaks, with the absorption rate corresponding to M1 reaching over 99.99%.

[0044] According to the equivalent model theory, the relative impedance of a terahertz metamaterial microfluidic chip can be calculated using S-parameters, i.e., relative impedance. because This can be simplified to Z = (1 + S) 11 ) / (1-S 11 The relative impedance of the terahertz metamaterial microfluidic chip in M1 mode is as follows: Figure 2As shown in (b), the real part Re(Z) approaches 1, and the imaginary part Im(Z) approaches 0, achieving impedance matching with free space. When the terahertz metamaterial microfluidic chip is used as a sensing signal in mode M1, the absorption peak position of water molecules is avoided, which is beneficial for obtaining a stronger signal. In addition, the Q factor calculated from the absorption characteristic curves shows that the Q values ​​of the terahertz metamaterial microfluidic chip in the three modes are 23, 472, and 596, respectively, indicating that the terahertz metamaterial microfluidic chip has high spectral resolution.

[0045] <Example 2>

[0046] physical mechanism

[0047] To further explain the formation mechanism of the three resonances in the terahertz metamaterial microfluidic chip in the 1.5-3 THz range, Figure 3 The electric field (Re(Ez)) and current distribution at the resonant frequency are shown using the terahertz microfluidic sensor provided by this invention. Figure 3 As can be seen from (a) and (d), at 1.971 THz, the electric field is mainly distributed on the microstructure. Since the direction of the applied electric field is parallel to the y-axis, the surface current has a higher intensity along the vertical arm of the windmill structure. In addition, the electric field intensity is displayed in the form of "+" and "-", which suggests that M1 is a typical dipole resonance. Figure 3 (b) indicates that the electric field is mainly distributed in the microstructure and the capping material PTFE. The figure within the box shows the electric field distribution in the yz plane, and... Figure 3 (e) The displayed current is very small. Therefore, the formation of the M2 resonance is likely due to internal losses within the dielectric material. Figure 3 As can be seen in (c), the electric field is mainly distributed in the vertical semicircular ring of the microstructure, with a partial electric field existing in the capping material, and is caused by... Figure 3 (f) It can be seen that the current intensity is relatively small. Therefore, the destructive interference between unit structures or the internal loss of materials are the main reasons for the formation of M3.

[0048] <Example 3>

[0049] stability

[0050] The polarization sensitivity and incident angle sensitivity of a sensor are important indicators for evaluating its stability. The electromagnetic response curves of a transversely electric and magnetically polarized THz wave perpendicularly incident on the surface of a terahertz microfluidic sensor are shown below. Figure 4 As shown in (a), due to the centrally symmetric shape of the unit cell designed in this invention, the terahertz microfluidic sensor exhibits good consistency under both polarization wave incident conditions. Furthermore, the electric field distribution of the terahertz microfluidic sensor under the transverse magnetic field mode was analyzed, as shown in... Figure 4As shown in (b), it can be seen from the figure that, compared with the electric field distribution of THz waves perpendicularly incident on the sensor surface under transverse electric field polarization, the electric field distribution changes with the polarization direction.

[0051] Figure 5 The absorption characteristic curves are shown under the transverse electric field polarization mode with varying polarization angles and incident angles. Figure 5 (a) It is evident that within a 30° polarization range, the change in the absorption characteristic curve is negligible, indicating that the terahertz microfluidic sensor possesses polarization-insensitive characteristics. This indirectly demonstrates that even if the sensor is deflected due to improper operation during detection, its performance remains consistent. When the polarization angle phi = 0°, the incident angle theta varies from 0° to 30°, meaning the incident THz wave changes from perpendicular to oblique incidence on the terahertz microfluidic sensor surface. The absorption characteristic curve is as follows: Figure 5 As shown in (b), the oblique incident angle has a significant impact on the terahertz microfluidic sensor. Mode M1 exhibits more stable absorption at wide incident angles than the other two modes. Mode M2 ​​shows greater variation, with its resonant frequency shifting to lower frequencies and its absorption rate changing irregularly with increasing incident angle. Mode M3 shows relatively stable absorption intensity, with its resonant frequency shifting within a certain range. Based on the electromagnetic responses of the three modes under varying polarization and incident angles, mode M1 combines polarization insensitivity and incident angle insensitivity, making it the optimal mode for sensing signal detection.

[0052] <Example 4>

[0053] The effect of microfluidic channel height on the sensor

[0054] The height of the microfluidic channel is a crucial parameter that cannot be ignored in sensor design. Once the lateral dimensions of the sensor are determined, the height of the microfluidic channel not only determines the sensor's performance but also the sample injection volume. This embodiment will discuss the impact of the microfluidic channel height on the sensor's electromagnetic response to determine the optimal channel height.

[0055] When h2 increases from 1 μm to 10 μm, the absorption spectrum of the sensor is as follows: Figure 6 As shown in (a), it can be seen from the figure that with the increase of h2, mode M1 changes significantly, mainly reflected in the resonant frequency shifting to lower frequencies and the absorption intensity showing a trend of first increasing and then decreasing. Mode M2 ​​shifts to higher frequencies, but the range of shift is small, and the absorption intensity also shows a trend of first increasing and then decreasing. Mode M3 has a smaller change in resonant frequency and a larger change in absorption intensity. Figure 6(b) shows the variation of Q-value and absorbance of mode M1 with h2. When h2 = 3 μm, M1 exhibits the highest Q-value and absorbance. Since the Q-value largely determines the sensor's sensitivity, the sensor achieves optimal detection capability when the microfluidic channel height is 3 μm. For a terahertz metamaterial microfluidic sensor with dimensions of 1 cm × 1 cm, the injection volume only needs to be 3e... -7 L enables the detection of trace / ultra-scale samples, solving problems such as the need for large sample volumes.

[0056] <Example 5>

[0057] Sensing performance

[0058] The equivalent capacitance (C) of the sensor eff ) depends on the capacitance of the device itself and the capacitance generated by the analyte (C) sensor Once the sensor's structural dimensions are determined, the capacitance of the device itself remains unchanged. Therefore, changes in the refractive index of the analyte will cause changes in the surrounding dielectric environment, thereby altering the capacitance (C). sensor This affects the electromagnetic response characteristics of the sensor, such as resonant frequency and absorption intensity. When analyzing the sensor's sensing performance, analytes with different thicknesses and dielectric constants are coated on the sensor surface. By monitoring changes in parameters such as the sensor's resonant frequency shift and absorption rate, the analyte can be detected.

[0059] The sensing and detection capabilities of a sensor (terahertz metamaterial microfluidic chip) were evaluated by adding analytes with different refractive indices into the microfluidic channel. Specifically, for example... Figure 7 As shown, when the refractive index of the analyte changes from 1.1 to 1.5, the maximum sensitivity and FOM value of the sensor (terahertz metamaterial microfluidic chip) are 859 GHz / RIU and 10 RIU, respectively. -1 The absorption characteristic curves of the sensor (terahertz metamaterial microfluidic chip) were plotted on... Figure 7 (a) As can be seen from the figure, the absorption curve of M1 shows the largest change. With the increase of the refractive index of the analyte, the degree of resonance redshift increases, which indirectly reflects that M1 is the most sensitive to the analyte and has better detection performance. Since the change of M3 is negligible, the absorption intensities and Q factors of M1 and M2 are as follows: Figure 7 As shown in (b), compared with the M2 mode, the absorption and Q factor of the M1 mode are stable, and the absorption rate remains above 99% even when the refractive index of the material changes. Therefore, the absorption intensity cannot be used as a sensing signal for detection. Although the M2 mode has a high Q factor, its absorption stability is weak, which will put it at a disadvantage in complex detection environments. This confirms that the M1 mode has higher detection stability.

[0060] This invention introduces a metamaterial-based microfluidic sensor for ultrasensitive detection of biomacromolecules in the terahertz band. The unit structure includes a PTFE (polyimide) capping layer, a windmill-shaped microstructure, microfluidic channels, a metal reflective layer, and a Si buffer layer. Finite element method calculations revealed three resonances in the 1.5-3 THz range, all with absorption rates exceeding 90%. Further investigation into the physical mechanism, microfluidic channel height, and sensing performance showed that M1 is the optimal choice for sensing the signal, achieving Q-factor, sensitivity, and FOM value of 23, 859 GHz / RIU, and 10 RIU, respectively. -1 This invention provides a reference for enriching the diversity of terahertz sensor devices and expanding the field of non-destructive testing in terahertz band biomedicine and agricultural product quality and safety.

[0061] This invention employs a five-layer structure of a capping layer, a metal microstructure, a microfluidic channel, a metal reflective layer, and a buffer layer to fabricate a microfluidic sensor. Based on the principle that multiple resonances can be generated by the superposition of multiple metal microstructures, a windmill-shaped structure is proposed.

[0062] The sensor provided by this invention generates three high absorption peaks by interacting with terahertz waves. The three absorption peaks are formed by dipole resonance, interaction between metal and dielectric materials, destructive interference between structural units, or internal friction between materials, respectively.

[0063] By adding analytes with different refractive indices to the sensor of the present invention for detection and analysis, the maximum refractive index sensitivity of the sensor provided by the present invention is found to be 859 GHz / RIU, which greatly improves the refractive index sensitivity of the terahertz sensor.

[0064] This invention comprehensively considers the influence of experimental operations and analyzes the polarization sensitivity and incident angle sensitivity of the microfluidic sensor. It finds that low-frequency resonance, combining polarization insensitivity and incident angle characteristics, is the optimal choice for signal detection. Furthermore, this invention also investigates the impact of the microfluidic channel height on the microfluidic sensor, ensuring that the sensor is fabricated within the error range and guaranteeing the accuracy of experimental results.

[0065] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0066] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A terahertz metamaterial microfluidic sensor based on a windmill model, characterized in that, The sensor is a cubic structure formed by splicing together multiple unit cells; each unit cell includes, from bottom to top, a buffer layer, a metal reflective layer, a metal microstructure, and a capping layer, with a microfluidic channel formed between the metal reflective layer and the metal microstructure; the metal microstructure is a windmill-shaped structure. The metal microstructure is a windmill structure formed by arranging four semi-circular frame-like unit components at intervals along the circumference. Each unit component includes a first part of an arc-shaped structure and a second part of a straight line connecting the two ends of the arc-shaped structure. The sensor parameters are as follows: the length and width of the metal microstructure are P=80μm, the radius of the first part of the unit is r=15μm, half the length of the second part of the unit is d=15μm, the thickness of the unit is w=4μm, the thickness of the capping layer is h1=50μm, the thickness of the metal microstructure and the metal reflective layer is t=0.2μm, the height of the microfluidic channel is h2=3μm, and the thickness of the buffer layer is h3=500μm.

2. The terahertz metamaterial microfluidic sensor based on a windmill model as described in claim 1, characterized in that, The capping layer is made of PTFE material with a dielectric constant of 2.1 + i0.0002.

3. The terahertz metamaterial microfluidic sensor based on a windmill model as described in claim 1, characterized in that, Both the metal microstructure and the metal reflective layer are made of gold; their electrical conductivity is 4.561e+007 S / m.

4. The terahertz metamaterial microfluidic sensor based on a windmill model as described in claim 1, characterized in that, The buffer layer is made of high-resistivity silicon material with a dielectric constant of 11.9+i0.00025.

5. The terahertz metamaterial microfluidic sensor based on a windmill model as described in claim 1, characterized in that, The sensor exhibits three distinct resonant absorption peaks in the 1.5-3 THz frequency range, namely M1=1.971THz, M2=2.836THz, and M3=2.981THz, with corresponding quality factor Q values ​​of 23, 472, and 596 under the three absorption peak modes.

Images