A terahertz topological photonic crystal waveguide sensor and a preparation method thereof

Abstract

The application discloses a terahertz topological photonic crystal waveguide sensor and a preparation method thereof, which comprises a substrate, a topological photonic crystal waveguide and a microfluidic channel structure arranged on the substrate, a film arranged on the surface of the microfluidic channel structure, and liquid inlet and outlet holes arranged at the two ends of the surface of the film respectively; the liquid inlet and outlet holes are respectively communicated with the two ends of the microfluidic channel structure, and the detection liquid flowing from the liquid inlet hole flows out from the liquid outlet hole after flowing through the microfluidic channel structure. The terahertz topological photonic crystal waveguide sensor disclosed in the embodiment has simple structure and is easy to prepare, and the microfluidic channel structure is arranged on the surface of the waveguide, so that the detection speed is high, and the sensor can be applied to the detection of different liquids, and therefore better detection effect can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of topological photonics sensing, in particular to a terahertz topological photonic crystal waveguide sensor and a preparation method thereof. BACKGROUND

[0002] Microfluidic chip technology is a technology that integrates multiple steps of sample detection into a chip, and realizes the miniaturization and automation of the chip device through the combination design of flow channels, microvalves, cavities and other functional units.

[0003] Based on the advantages of miniaturization and automation of microfluidic chip technology, using microfluidic chip technology to solve the problem of sensitivity of terahertz waves to polar substances has become a new research topic. This research mainly includes two directions of terahertz time-domain spectroscopy technology and super surface structure. Among them, the terahertz microfluidic sensor based on the super surface structure has the advantage of high sensitivity, but it is difficult to manufacture and easy to be damaged. The microfluidic sensing device based on the terahertz time-domain spectroscopy technology has the advantages of simple operation and durability, but its sensitivity is low, so the microfluidic sensor in the prior art cannot meet the demand of high sensitivity, simple manufacturing and convenient operation.

[0004] Therefore, the prior art needs to be improved. SUMMARY

[0005] In view of the deficiencies in the prior art described above, the purpose of the present application is to provide a terahertz topological photonic crystal waveguide sensor and a preparation method thereof, which overcomes the defects that the microfluidic sensor in the prior art cannot simultaneously meet the requirements of high sensitivity, simple manufacturing and convenient operation.

[0006] The technical scheme adopted by the present application to solve the technical problems is as follows:

[0007] In a first aspect, the present embodiment discloses a terahertz topological photonic crystal waveguide sensor, which comprises:

[0008] a substrate;

[0009] a topological photonic crystal waveguide and a microfluidic channel structure arranged on the substrate;

[0010] a thin film arranged on the surface of the microfluidic channel structure;

[0011] and a liquid inlet hole and a liquid outlet hole arranged at the two ends of the surface of the thin film, respectively;

[0012] The liquid inlet hole and the liquid outlet hole are respectively communicated with the two ends of the microfluidic channel structure, and the detection liquid flowing from the liquid inlet hole flows out from the liquid outlet hole after flowing through the microfluidic channel structure.

[0013] Optionally, the microfluidic channel structure comprises a liquid channel and an inlet-outlet buffer structure arranged on both sides of the liquid channel.

[0014] The liquid channel is etched on the surface of the substrate, and is used for detecting the flow of the detection liquid from one end of the microfluidic channel structure to the other end.

[0015] The inlet-outlet buffer structure is arranged at both ends of the liquid channel, and is used for buffering the speed of the detection liquid flowing into the liquid channel and the speed of the detection liquid flowing out of the liquid channel.

[0016] Optionally, the inlet-outlet buffer structure is recessed on the surface of the substrate, and the inner surface of the inlet-outlet buffer structure is in a cylindrical structure.

[0017] Optionally, the microfluidic channel structure comprises a plurality of microfluidic channel structure units; one microfluidic channel structure unit comprises at least one liquid channel and at least one inlet-outlet buffer structure.

[0018] Optionally, the film covers the surface of the liquid channel and the inlet-outlet buffer structure, and forms a closed channel with the liquid channel and the inlet-outlet buffer structure.

[0019] Optionally, the inlet hole and the outlet hole are arranged above the inlet-outlet buffer structure, and the inlet hole and the outlet hole are hollow cylindrical structures corresponding to the inlet-outlet buffer structure and penetrating through the inlet-outlet buffer structure, so that the detection liquid flows into the inlet-outlet buffer structure through the inlet hole and the detection liquid flowing out of the inlet-outlet buffer structure flows out through the outlet hole.

[0020] Optionally, the topological photonic crystal waveguide is composed of a plurality of periodic topological photonic crystal unit cells, and each topological photonic crystal unit cell is composed of an independently arranged first air hole and a second air hole.

[0021] Optionally, the working frequency range of the topological photonic crystal waveguide is 100GHz-1000GHz.

[0022] In a second aspect, the embodiment discloses a preparation method of a terahertz topological photonic crystal waveguide sensor, and has the characteristics that the preparation method comprises the following steps:

[0023] Preparation of a film; the material of the film is one or more of polydimethylsiloxane or monocrystalline silicon, glass, quartz, ceramic, polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, photoresist, polyimide, perfluoroalkoxy and fluorinated ethylene propylene; the thickness of the film ranges from 1um to 5mm;

[0024] Preparation of a substrate with a microfluidic channel structure;

[0025] covering the thin film on the substrate;

[0026] preparing an inlet hole and an outlet hole and bonding the inlet hole and the outlet hole to the thin film.

[0027] Optionally, the step of preparing the substrate with the microfluidic channel structure comprises:

[0028] etching a topological photonic crystal waveguide on a substrate; the material of the substrate is one or more of high-resistance silicon or intrinsic germanium, intrinsic gallium arsenide, gallium nitride, silicon carbide, sapphire, fused quartz, indium phosphide, indium gallium nitride, silicon dioxide, and aluminum oxide; the topological photonic crystal waveguide is composed of a plurality of periodic topological photonic crystal unit cells, each topological photonic crystal unit cell is composed of a first air hole and a second air hole arranged independently; wherein the lattice constant of the topological photonic crystal waveguide is 1 um-1 mm, and the side length of the first air hole or the second air hole ranges from 1 um to 1 mm.

[0029] etching a microfluidic channel structure on the structure of the topological photonic crystal waveguide.

[0030] The embodiment discloses a terahertz topological photonic crystal waveguide sensor and a preparation method thereof, comprising: a substrate; a topological photonic crystal waveguide and a microfluidic channel structure arranged on the substrate; a thin film arranged on the surface of the microfluidic channel structure; and an inlet hole and an outlet hole arranged at both ends of the surface of the thin film, respectively; the inlet hole and the outlet hole are respectively in communication with both ends of the microfluidic channel structure, and detection liquid flowing from the inlet hole flows out from the outlet hole after flowing through the microfluidic channel structure. The terahertz topological photonic crystal waveguide sensor disclosed in the embodiment has simple structure, fast detection speed, and can be applied to detection of different liquids, and therefore has better liquid sample detection effect. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 FIG. 1 is a structural schematic diagram of a terahertz topological photonic crystal waveguide sensor based on the embodiment of the present application;

[0032] Figure 2 FIG. 2 is a structural schematic diagram of a microfluidic channel structure in the embodiment of the present application;

[0033] Figure 3 FIG. 3 is a structural schematic diagram of a first air hole and a second air hole in a topological photonic crystal waveguide provided by the embodiment of the present application;

[0034] Figure 4 FIG. 4 is a specific application embodiment schematic diagram of a terahertz topological photonic crystal waveguide sensor provided by the embodiment of the present application;

[0035] Figure 5A preparation step flow chart of the terahertz topological photonic crystal waveguide sensor provided by the embodiment of the present application is provided.

[0036] Figure 6 A preparation step schematic diagram of the terahertz topological photonic crystal waveguide sensor provided by the embodiment of the present application is provided.

[0037] Figures 7a to 7c A different response effect diagram of the terahertz topological photonic crystal waveguide sensor provided by the embodiment of the present application on a sample is provided.

[0038] Figure 8 A response effect diagram of the terahertz topological photonic crystal waveguide sensor provided by the embodiment of the present application on different samples is provided. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0040] Terahertz waves refer to electromagnetic waves with a wavelength of 0.03-3mm and a frequency of 0.1-10THz. Terahertz has the following characteristics: wider bandwidth in the frequency spectrum region, which can realize high-speed wireless data transmission; non-invasive, non-contact and non-ionizing radiation characteristics, which will not cause damage to cells and biological tissues; extremely sensitive to polar substances, which can be used to identify differences in water content in the environment or biological samples. However, due to the extreme sensitivity of terahertz to polar substances, the absorption coefficient of water to terahertz waves at room temperature is about 200cm-1, which makes the target signal of the sample be submerged in the noise of water when detecting some biological samples such as living biological tissues, living cells, etc. The water content of such biological samples is large, and dehydration treatment is required before detection when using terahertz waves for detection, which will cause the death of biological tissues and cells, the denaturation of some biological molecules (such as proteins), and affect the detection results.

[0041] The on-chip valley Hall photonic crystal based on high-resistance silicon has the advantages of extremely low loss, one-way conduction, immunity to defects, no back and side loss, etc. The terahertz topological waveguide composed of it has shown excellent signal transmission capability and adjustable characteristics. By adjusting the structure design, material selection, control conditions, etc. in all aspects, optical devices based on silicon-based topological photonic crystals are expected to be applied in signal conduction, sample detection, military communication and other fields. At present, high-sensitivity sensing devices based on topological photonic devices in the terahertz wave band have been realized, but they cannot detect liquid samples.

[0042] Microfluidic chip technology is a typical new cross-frontier technology, which can concentrate multiple steps of sample detection on a chip with very small volume, and finally realize miniaturization and automation of the chip device through the combination design of flow channel, micro-valve, cavity and other functional units, and the microfluidic technology requires less reagent and sample amount, which can save detection cost.

[0043] Many researchers have thought of using microfluidic technology to solve the problem that terahertz waves are sensitive to polar substances. Commonly used technologies include terahertz time-domain spectroscopy technology and super surface structure. The terahertz microfluidic sensor based on the super surface structure has the advantage of high sensitivity, but it is difficult to manufacture and easy to be damaged. The microfluidic sensing device based on the terahertz time-domain spectroscopy technology has the advantages of simple operation and durability, but its sensitivity is not high.

[0044] In order to overcome the defects that the microfluidic sensing device in the prior art cannot simultaneously have simple manufacturing, high detection efficiency and fast detection speed, the present application discloses a terahertz topological photonic crystal waveguide sensor. The terahertz topological photonic crystal waveguide sensor disclosed by the present application comprises: a substrate, a topological photonic crystal waveguide arranged on the substrate, a microfluidic channel structure etched on the topological photonic crystal waveguide, a thin film covering the microfluidic channel structure, and an inlet hole and an outlet hole arranged at both ends of the microfluidic channel structure. When the detection liquid flows into the microfluidic channel structure from the inlet hole, it has an influence on the terahertz waves transmitted in the topological photonic crystal waveguide, and different detection liquids have different influences on the terahertz waves transmitted in the topological photonic crystal waveguide, thereby realizing the detection of different detection liquids. The sensor structure disclosed in this embodiment is simple, fast in detection speed, and high in detection reaction sensitivity.

[0045] The terahertz topological photonic crystal waveguide sensor and the preparation method thereof disclosed by the present application will be further described in more detail in combination with the drawings of the specification.

[0046] This embodiment discloses a terahertz topological photonic crystal waveguide sensor, as shown in Figure 1 , comprising:

[0047] The substrate 1, the topological photonic crystal waveguide and the microfluidic channel structure 2 arranged on the substrate; the thin film 3 arranged on the surface of the microfluidic channel structure 2; and the inlet and outlet holes 4 (the inlet and outlet holes include: an inlet hole and an outlet hole) arranged at both ends of the surface of the thin film 3 respectively; the inlet hole and the outlet hole are respectively communicated with both ends of the microfluidic channel structure, and the detection liquid flowing from the inlet hole flows through the microfluidic channel structure and then flows out from the outlet hole.

[0048] First, a substrate of a predetermined size is cut out, the substrate being made of one or more of high-resistance silicon or intrinsic germanium, intrinsic gallium arsenide, gallium nitride, silicon carbide, sapphire, fused quartz, indium phosphide, indium gallium nitride, silicon dioxide, and aluminum oxide, and having a thickness of 1 um to 1 mm. The predetermined size can range from 10 mm to 30 mm in length and from 10 mm to 30 mm in width.

[0049] A topological photonic crystal waveguide is etched on the substrate, the topological photonic crystal waveguide being composed of a plurality of periodically arranged photonic crystal cell units, each photonic crystal cell unit being composed of two independent first air holes and second air holes arranged inside the substrate, and capable of achieving rapid transmission of terahertz waves.

[0050] A microfluidic channel structure is etched on the upper surface of the topological photonic crystal waveguide, the structure being located on the upper surface of the substrate and recessed downward by a certain depth to allow liquid to flow in the channel. Figure 2 As shown, the microfluidic channel structure includes: a liquid channel and an inlet and outlet buffer structure arranged on both sides of the liquid channel; the liquid channel is etched on the surface of the substrate and used for detecting the flow of a detection liquid from one end of the microfluidic channel structure to the other end; the inlet and outlet buffer structure is arranged at both ends of the liquid channel and used for buffering the speed of the detection liquid flowing into the liquid channel and the speed of the detection liquid flowing out of the liquid channel. The inlet and outlet buffer structure is recessed on the surface of the substrate, and the inner surface of the inlet and outlet buffer structure is in a cylindrical structure.

[0051] The liquid channel is a liquid flow channel etched on the upper surface of the substrate, which is recessed downward by a predetermined depth compared with the upper surface of the substrate, the depth ranging from 1 um to 1 mm, the minimum width being 1 um, and the maximum width being the distance between adjacent sides of an air hole in a photonic crystal cell, for example, if the shape of the air hole is a triangle or a polygon, the maximum depth is the distance between adjacent sides of the triangle or polygon air hole.

[0052] The inlet and outlet buffer structure is located at both ends of the liquid channel and is also etched on the upper surface of the substrate and recessed downward by a predetermined depth compared with the upper surface of the substrate, the recessed inner surface being in a cylindrical structure, and the diameter of the circular cross section ranging from 1 um to 3 mm, the depth being the same as that of the microfluidic channel structure.

[0053] In a specific implementation, the microfluidic channel structure includes: a plurality of microfluidic channel structure units; one microfluidic channel structure unit includes: at least one liquid channel and at least one inlet and outlet buffer structure. In this embodiment, one microfluidic channel structure is provided with three groups of microfluidic channel structure units.

[0054] A thin film is arranged on the surface of the microfluidic channel structure and the periphery of the liquid inlet and outlet buffer structure, the thin film and the liquid channel structure form a cuboid-shaped liquid channel, preferably, the material of the thin film is cured PDMS (polydimethylsiloxane), and the thickness of the thin film is 30-50 um. The thin film covers the surface of the liquid channel and the liquid inlet and outlet buffer structure, and forms a closed channel with the liquid channel and the liquid inlet and outlet buffer structure.

[0055] The liquid inlet hole and the liquid outlet hole are arranged above the liquid inlet and outlet buffer structure, and the liquid inlet hole and the liquid outlet hole are hollow cylindrical structures penetrating through the liquid inlet and outlet buffer structure corresponding to the liquid inlet and outlet buffer structure, so that the detection liquid flows into the liquid inlet and outlet buffer structure through the liquid inlet hole and the detection liquid in the liquid inlet and outlet buffer structure flows out through the liquid outlet hole.

[0056] The material of the thin film, the liquid inlet hole and the liquid outlet hole is one or more of polydimethylsiloxane (PDMS) or monocrystalline silicon, glass, quartz, ceramic, polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), SU-8 photoresist, polyimide, Teflon PFA and Teflon FEP, the thickness of the thin film is 1 um-5 mm, the thickness of the liquid inlet hole and the liquid outlet hole is 100 um-5 mm, and the diameter is 1 um-5 mm.

[0057] Further, the sizes of the two air holes in the photonic crystal unit cell are different. A plurality of photonic crystal unit cells formed based on the two air holes with different sizes constitute a topological photonic crystal waveguide. The air hole penetrates through the entire device, that is, it is a hollow air hole. The lattice constant is 1 um-1 mm, and the side length of the two air holes is 1 um-1 mm. In specific implementation, the shape of the air hole can be designed as a circle or a polygon, and in the example given in the embodiment, the shape of the air hole is designed as a triangle, but it is conceivable that in specific applications, the shape of the air hole can be arbitrarily set, and is not limited to a triangle and a polygon, as long as the two air holes are periodically arranged and the structure formed by the arrangement has topological properties, and it constitutes a topological photonic crystal waveguide.

[0058] In combination Figure 3As shown, taking the shape of the air hole as a triangle as an example, the triangular air hole and the silicon substrate form a photonic crystal unit cell 10, and the photonic crystal unit cell 10 includes: two air holes, which are a first air hole 11 and a second air hole 12, respectively, and the two air holes are arranged to form a waveguide part. The working frequency range of the topological photonic crystal waveguide is 100GHz-1000GHz. Preferably, the side length of the triangular air hole of the first air hole is designed to be 245um, and the actual processed product has a side length of 224um, the side length of the triangular air hole of the second air hole is designed to be 141um, and the actual processed product has a side length of 121um, resulting in that the design working frequency of the curved topological waveguide is 270GHz, and the actual working frequency is 260GHz.

[0059] As shown in Figure 4 , Figure 4 The test schematic diagram of the terahertz topological photonic crystal waveguide sensor provided by the present application is shown in the drawings, and the terahertz wave is coupled into the curved topological photonic crystal waveguide from one side of the substrate, transmitted to the other side, and the detection liquid enters the microfluidic channel from the liquid inlet hole at one end and is extracted from the liquid outlet hole. The vector network analyzer is used for detection, when different liquids exist in the microfluidic channel, the transmission of the terahertz wave will be affected, and because the refractive indexes are different, the transmission loss caused by the different refractive indexes will also be different.

[0060] The terahertz topological photonic crystal waveguide sensor provided by the present application has the advantages of small volume, easy integration, simple structure, fast detection speed, small sample amount required, and can save detection cost to a certain extent, and can realize the detection of different liquids.

[0061] On the basis of the above-mentioned terahertz topological photonic crystal waveguide sensor, the present application also discloses a preparation method of the terahertz topological photonic crystal waveguide sensor, which is shown in Figure 5 and Figure 6 The preparation method comprises the following steps:

[0062] Step S1, preparing a film.

[0063] In an implementation, a PDMS film can be prepared in this step, which can be generated by punching after spin coating. Specifically, a flat PDMS substrate is selected, the surface thereof is silanized, the surface thereof is cleaned using anhydrous ethanol, and then dried. Then, the prepared liquid PDMS is dropped on the surface thereof, the surface is covered with the liquid PDMS, and then a spin coater is used for spin coating, preferably at a speed of 1600 rpm for 60 s. Then, the sample after spin coating is placed in a 110°C oven for curing for 1 h, and the film is attached to the PDMS substrate. Then, a puncher is used to punch the liquid inlet and outlet buffer structures according to the drawing, and a PDMS film with holes matching the silicon substrate is generated. The film is made of one or more of polydimethylsiloxane, monocrystalline silicon, glass, quartz, ceramic, polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, photoresist, polyimide, perfluoroalkoxy, and fluorinated ethylene propylene; and the thickness of the film ranges from 1 um to 5 mm.

[0064] Step S2, preparing a substrate with a microfluidic channel structure.

[0065] This step includes etching a topological photonic crystal waveguide on the substrate; etching a microfluidic channel on the structure of the topological photonic crystal waveguide to obtain a substrate with a microfluidic channel structure and a topological photonic crystal waveguide structure.

[0066] Taking a high-resistance silicon substrate as an example, a terahertz topological photonic crystal waveguide with triangular air holes is etched on the high-resistance silicon substrate using photolithography processing, and then a microfluidic channel structure and a liquid inlet and outlet buffer structure are etched on the topological photonic crystal waveguide by secondary photolithography.

[0067] Step S3, covering a film on the substrate.

[0068] The film prepared in step S1 is covered on the substrate prepared in step S2, and specifically, the bonding method is high-temperature bonding. Illustratively, the silicon substrate with the microfluidic channel structure and the PDMS film attached to the PDMS substrate are cleaned with anhydrous ethanol and dried, the surfaces thereof are kept clean, and then they are placed in a PLASMA instrument for oxygen plasma surface modification for 1 min. After the treatment, the PDMS film surface is immediately aligned and attached to the microfluidic channel structure surface, and after the attachment, the same is placed in a 110°C oven, the temperature of the oven is stabilized, and then the bonding is completed after waiting for 2 min.

[0069] Step S4, preparing an inlet hole and an outlet hole, and bonding the inlet hole and the outlet hole to the film.

[0070] Two pieces of PDMS with thickness of about 2-3mm, length and width can cover the liquid buffer structure, are punched by a puncher according to the relative position of the liquid buffer structure to obtain the liquid inlet and outlet holes.

[0071] In the embodiment, the terahertz topological photonic crystal waveguide sensor is provided with three groups of microfluidic channel structures, and the working effects of the channels are different due to different action lengths of the liquid channels and the topological waveguide parts, as shown in Figures 7a-7c Figure 7a , Figure 7b and Figure 7c are respectively response effect diagrams of measuring the same liquid by using different channels of the terahertz topological photonic crystal waveguide sensor.According to the response effect diagrams, it can be obtained that the longer the coupling distance of the liquid channel and the waveguide part, the greater the attenuation caused after the liquid passes, and the better the working effect of the sensor.

[0072] As shown in Figure 8 , Figure 8 is a response effect diagram of measuring different liquids by using the terahertz topological photonic crystal waveguide sensor, and the selected samples are water and alcohol. The water causes the transmission loss of the sensor to increase by 0.5-0.8dB, and the alcohol causes the transmission loss of the sensor to increase by 0.3-0.5dB. The terahertz topological photonic crystal waveguide sensor provided by the application can realize the detection of different liquid samples.

[0073] In summary, the application provides a terahertz topological photonic crystal waveguide sensor, which comprises a substrate, a microfluidic channel structure, a thin film and liquid inlet and outlet holes. The terahertz topological photonic crystal waveguide sensor is different from the sensor based on the terahertz time-domain spectroscopy system and the super surface structure. The terahertz topological photonic crystal waveguide sensor combines the terahertz wave detection technology, the microfluidic sensing technology and the topological photonic crystal waveguide, detects different samples by using the interaction between the trace liquid and the waveguide, can realize label-free and contactless detection, needs a small amount of sample, can save costs to a certain extent, and the detection process is fast.

[0074] The terahertz topological photonic crystal waveguide sensor solves the shortcomings and deficiencies of the prior art, has the advantages of easy integration, simple operation, rapid detection and the like, and is especially suitable for the detection of liquid samples.

[0075] The application discloses a terahertz topological photonic crystal waveguide sensor and a preparation method thereof, which comprises a substrate, a topological photonic crystal waveguide and a microfluidic channel structure arranged on the substrate, a film arranged on the surface of the microfluidic channel structure, and liquid inlet and outlet holes arranged at the two ends of the surface of the film respectively; the liquid inlet and outlet holes are respectively communicated with the two ends of the microfluidic channel structure, and the detection liquid flowing from the liquid inlet hole flows out from the liquid outlet hole after flowing through the microfluidic channel structure. The terahertz topological photonic crystal waveguide sensor disclosed in the embodiment has simple structure and is easy to prepare, and the microfluidic channel structure is arranged on the surface of the waveguide, so that the detection speed is high, and the sensor can be applied to the detection of different liquids, and therefore better detection effect can be achieved.

[0076] The above embodiment only expresses several implementation manners of the application, and the description is relatively specific and detailed, but it cannot be understood as the limitation on the patent scope of the application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the application, and these all belong to the protection scope of the application.

Claims

1. A terahertz topological photonic crystal waveguide sensor, characterized in that, include: Base; Topological photonic crystal waveguides and microfluidic channel structures disposed on the substrate; A thin film disposed on the surface of the microfluidic channel structure; And liquid inlet and liquid outlet holes respectively provided at both ends of the film surface; The inlet and outlet are respectively connected to both ends of the microfluidic channel structure. The detection liquid flowing in from the inlet flows out from the outlet after passing through the microfluidic channel structure. The topological photonic crystal waveguide is composed of multiple periodic topological photonic crystal unit cells, and each topological photonic crystal unit cell is composed of independently set first air holes and second air holes; The operating frequency range of the topological photonic crystal waveguide is 100GHz-1000GHz.

2. The terahertz topological photonic crystal waveguide sensor according to claim 1, characterized in that, The microfluidic channel structure includes: a liquid channel and inlet / outlet buffer structures disposed on both sides of the liquid channel; The liquid channel is etched onto the substrate surface to detect the flow of liquid from one end of the microfluidic channel structure to the other. The inlet and outlet buffer structure is disposed at both ends of the liquid channel to buffer the speed at which the detection liquid flows into the liquid channel and the speed at which the detection liquid flows out of the liquid channel.

3. The terahertz topological photonic crystal waveguide sensor according to claim 2, characterized in that, The liquid inlet / outlet buffer structure is recessed on the surface of the base, and the inner surface of the liquid inlet / outlet buffer structure has a cylindrical structure.

4. The terahertz topological photonic crystal waveguide sensor according to claim 2, characterized in that, The microfluidic channel structure includes: multiple microfluidic channel structure units; each microfluidic channel structure unit includes: at least one liquid channel and at least one inlet / outlet buffer structure.

5. The terahertz topological photonic crystal waveguide sensor according to claim 2, characterized in that, The film covers the surface of the liquid channel and the inlet / outlet buffer structure, forming a closed channel with the liquid channel and the inlet / outlet buffer structure.

6. The terahertz topological photonic crystal waveguide sensor according to claim 5, characterized in that, The inlet and outlet are located above the inlet and outlet buffer structure. The inlet and outlet are hollow cylindrical structures that are connected to the inlet and outlet buffer structure, so that the detection liquid flows into the inlet and outlet buffer structure through the inlet and outlet buffer structure and the detection liquid that flows out of the inlet and outlet buffer structure flows out through the outlet.

7. A method for fabricating a terahertz topological photonic crystal waveguide sensor as described in any one of claims 1-6, characterized in that, include: Prepare a thin film; the material of the thin film is one or more of polydimethylsiloxane or monocrystalline silicon, glass, quartz, ceramic, polymethyl methacrylate, polycarbonate, polystyrene, polyethylene terephthalate, polyvinyl chloride, photoresist, polyimide, perfluoroalkoxy, and fluorinated ethylene propylene; the thickness of the thin film ranges from 1µm to 5mm. Fabrication of substrates with microfluidic channel structures; This includes etching a topological photonic crystal waveguide on a substrate; The film is applied to the substrate; An inlet and an outlet are prepared, and the inlet and outlet are bonded to the thin film.

8. The preparation method according to claim 7, characterized in that, The step of preparing the substrate with the microfluidic channel structure includes: The substrate is made of one or more of the following materials: high-resistivity silicon, intrinsic germanium, intrinsic gallium arsenide, gallium nitride, silicon carbide, sapphire, indium phosphide, indium gallium nitride, silicon dioxide, and aluminum oxide. The topological photonic crystal waveguide is composed of multiple periodic topological photonic crystal unit cells, each of which is composed of independently set first and second air holes. The lattice constant of the topological photonic crystal waveguide is 1µm-1mm, and the side length of the first or second air hole is in the range of 1µm-1mm. Microfluidic channel structures are etched on the structure of the topological photonic crystal waveguide.

9. The preparation method according to claim 8, characterized in that, The silica is fused silica.

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