Microfluidic sensing chip based on terahertz topology photonic crystal waveguide and preparation method thereof

Abstract

The invention relates to the technical field of micro-fluidic sensing chips, in particular to a micro-fluidic sensing chip based on terahertz topological photonic crystal waveguides and a preparation method thereof.A micro-fluidic channel structure is applied, absorption of terahertz wave band electromagnetic waves by polar substances in a sample can be reduced, and therefore the detection sensitivity is high, and the sample consumption amount is small; the yield and the signal-to-noise ratio of sensor production can be improved by applying the characteristics of immune manufacturing defects and back scattering of the topological photonic crystal waveguide, and the sensitivity of the sensor can be improved by accurately constraining electromagnetic wave energy in a microfluidic channel range by utilizing the characteristics of a topological transmission edge state; besides, the piezoelectric ceramic micropump can realize high-precision feeding of samples, simplify the use steps and reduce the integrated volume, and the bubble separation device solves the problem that the sample introduction pressure is increased due to bubble suspension in a microgravity environment, so that the working stability of the chip is ensured; in addition, the micro-fluidic sensing chip is suitable for a microgravity environment.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidic sensor chips, and in particular to a microfluidic sensor chip based on a terahertz topological photonic crystal waveguide and a preparation method thereof. Background Art

[0002] Terahertz sensing is a technology that uses electromagnetic radiation in the terahertz band for detection and imaging. This band is between microwaves and infrared rays, with a frequency range of 0.1 to 10 THz. Terahertz waves have low energy, do not produce ionizing radiation, and are safe for biological tissues. Many organic molecules and biomacromolecules have unique absorption characteristics in the terahertz band. Taking advantage of this, terahertz sensors can identify different substances by analyzing the spectral characteristics of samples, which is very useful for chemical composition analysis. However, terahertz is sensitive to polar molecules, which greatly attenuate the energy of terahertz electromagnetic waves.

[0003] At present, the detection sensitivity is mainly improved by designing sub-wavelength metasurface structures, utilizing the effect of locally enhancing the electric field of the metasurface structure, and placing the detection channel in the electric field enhancement area. The metasurface structure chip can be miniaturized and integrated, but its manufacturing process is complex and the yield rate is low. This technology requires a device to focus the terahertz electromagnetic wave to the sensor, such as a mechanical structure that combines the TPX lens and the optical slide. It is necessary to debug the signal coupling before the experiment, which increases the workload of astronaut training. At the same time, the volume of the system is difficult to reduce, and it is not suitable for use in volume-sensitive detection tasks such as space stations.

[0004] Based on microfluidic chip technology, the position of the sample in the microfluidic channel can be precisely controlled, thereby achieving precise coupling between the sample and the terahertz electromagnetic wave in time and space, improving the response of the terahertz electromagnetic wave to the sample, and thus improving the sensitivity of the sensor. However, in a microgravity environment, due to the lack of convection, buoyancy and static pressure, the liquid is mainly affected by surface tension, which causes density-driven convection to no longer occur, and the gas and liquid will not separate spontaneously, which brings challenges to bubble management. In addition, the accumulation of bubbles in the microfluidic channel will cause the injection pressure to rise suddenly, resulting in blank gaps between channel samples, affecting the detection results, and even causing the microfluidic channel injection to fail and disable the sensor.

[0005] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a microfluidic sensor chip based on terahertz topological photonic crystal waveguide and a preparation method thereof, aiming to solve the problems that the existing microfluidic sensor chips are large in size, difficult to manufacture, and not suitable for microgravity environments.

[0007] The technical solution of the present invention is as follows:

[0008] A microfluidic sensor chip based on terahertz topological photonic crystal waveguide, comprising:

[0009] A housing, comprising a first accommodating cavity, a second accommodating cavity and a base fixing platform arranged between the first accommodating cavity and the second accommodating cavity;

[0010] A bubble separation device and a piezoelectric ceramic micropump, wherein the bubble separation device and the piezoelectric ceramic micropump are connected via a pipeline, and the bubble separation device and the piezoelectric ceramic micropump are arranged in the first accommodating cavity;

[0011] A waste liquid bin is disposed in the second containing chamber;

[0012] A substrate is arranged on the substrate fixing platform; the substrate is provided with a type A topological photonic crystal, a type B topological photonic crystal and a microfluidic channel; a topological transmission path is provided at the junction of the type A topological photonic crystal and the type B topological photonic crystal; the microfluidic channel partially overlaps with the topological transmission path; a film is provided on the side of the microfluidic channel away from the shell, and a channel liquid inlet is provided at one end of the microfluidic channel close to the bubble separation device, and a channel liquid discharge port is provided at one end close to the waste liquid bin;

[0013] A liquid inlet seat and a liquid discharge seat, wherein the liquid inlet seat is arranged at the liquid inlet of the channel, and the liquid discharge seat is arranged at the liquid discharge port of the channel.

[0014] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the refractive index of the material used for the substrate is greater than 1.2 and the absorption coefficient is less than 50 / mm at an operating frequency between 0.1THz and 10THz.

[0015] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the A-type topological photonic crystal is composed of a plurality of periodic topological photonic crystal unit cells, and the B-type topological photonic crystal is composed of a plurality of topological photonic crystal unit cells periodically rotated 180° around a geometric center; the topological photonic crystal unit cell is provided with a first air hole and a second air hole.

[0016] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the lattice constant of the topological photonic crystal unit cell is 1 μm to 1 mm.

[0017] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the topological transmission path is formed by the junction of the A-type topological photonic crystal and the B-type topological photonic crystal.

[0018] In the microfluidic sensor chip based on terahertz topological photonic crystal waveguide, the microfluidic channel and the topological transmission path overlap in at least one lattice period.

[0019] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the starting end and the ending end of the topological transmission path are both provided with signal coupling ports.

[0020] In the microfluidic sensor chip based on terahertz topological photonic crystal waveguide, the piezoelectric ceramic micropump is provided with a micropump electrical interface and a micropump liquid inlet.

[0021] The microfluidic sensor chip based on terahertz topological photonic crystal waveguide, wherein the waste liquid bin is provided with a waste liquid bin liquid inlet and a waste liquid bin liquid discharge port; the waste liquid bin liquid inlet is connected to the liquid discharge seat; and the liquid inlet seat is connected to the bubble separation device.

[0022] A method for preparing a microfluidic sensor chip based on terahertz topological photonic crystal waveguide comprises the following steps:

[0023] A topological transmission path is set on the substrate to divide the substrate into an A-type topological photonic crystal region and a B-type topological photonic crystal region;

[0024] A-type topological photonic crystals and B-type topological photonic crystals are respectively arranged in the A-type topological photonic crystal region and the B-type topological photonic crystal region;

[0025] Disposing a microfluidic channel on the substrate, wherein the microfluidic channel partially overlaps with the topological transmission path;

[0026] A thin film is prepared on a side of the microfluidic channel away from the substrate, wherein the thin film covers the substrate except the A-type topological photonic crystal region and the B-type topological photonic crystal region, and covers the microfluidic channel;

[0027] A liquid inlet seat and a liquid discharge seat are respectively arranged at two ends of the microfluidic channel;

[0028] A bubble separation device, a piezoelectric ceramic micropump, a waste liquid bin and the substrate are arranged on a shell, the bubble separation device and the piezoelectric ceramic micropump are connected through a pipeline, the bubble separation device is connected to the liquid inlet seat, and the waste liquid bin is connected to the liquid discharge seat to obtain a microfluidic sensor chip.

[0029] Beneficial effects: The present invention provides a microfluidic sensor chip based on terahertz topological photonic crystal waveguide and a preparation method thereof, wherein the microfluidic sensor chip comprises: a housing, provided with a first accommodating cavity, a second accommodating cavity and a substrate fixing platform arranged between the first accommodating cavity and the second accommodating cavity; a bubble separation device and a piezoelectric ceramic micropump, wherein the bubble separation device and the piezoelectric ceramic micropump are connected through a pipeline and are arranged in the first accommodating cavity; a waste liquid tank, arranged in the second accommodating cavity; a substrate, arranged on the substrate fixing platform; and an A A type topological photonic crystal, a B type topological photonic crystal and a microfluidic channel; a topological transmission path is provided at the junction of the A type topological photonic crystal and the B type topological photonic crystal; the microfluidic channel partially overlaps with the topological transmission path; a thin film is provided on the side of the microfluidic channel away from the shell, and a channel liquid inlet is provided at one end of the microfluidic channel close to the bubble separation device, and a channel liquid discharge is provided at one end close to the waste liquid bin; a liquid inlet seat and a liquid discharge seat, the liquid inlet seat is arranged at the channel liquid inlet, and the liquid discharge seat is arranged at the channel liquid discharge. The present invention applies a microfluidic channel structure to reduce the absorption of terahertz-band electromagnetic waves by polar substances in the sample, thereby having high detection sensitivity and consuming less sample; applying the characteristics of topological photonic crystal waveguides immune to manufacturing defects and backscattering, the yield rate and signal-to-noise ratio of sensor production can be improved, and the characteristics of topological transmission edge states can be used to accurately constrain the electromagnetic wave energy within the range of the microfluidic channel, thereby improving the sensitivity of the sensor; in addition, a piezoelectric ceramic micropump can achieve high-precision sample feeding, simplify the use steps and reduce the integrated volume, and a bubble separation device can solve the problem of increased injection pressure caused by bubble suspension in a microgravity environment, thereby ensuring the stability of the chip operation; the microfluidic sensor chip provided by the present invention is a highly integrated sensor, which reduces the difficulty of experimental operation and reduces the learning cost of astronauts, so the microfluidic sensor chip is suitable for experimental research in the restricted environment of a space station. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the front view of a microfluidic sensor chip based on a terahertz topological photonic crystal waveguide according to the present invention;

[0031] Figure 2 A schematic diagram of the structural assembly of a microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to the present invention;

[0032] Figure 3 This is the electric field distribution diagram of the terahertz electromagnetic wave of the microfluidic sensor chip based on the terahertz topological photonic crystal waveguide of the present invention at 0.27THz;

[0033] Figure 4 It is a schematic diagram of the structure of a topological photonic crystal unit cell;

[0034] Figure 5 The S21 parameter diagram of the microfluidic sensor chip based on terahertz topological photonic crystal waveguide;

[0035] Figure 6 Schematic diagram of the substrate structure of a microfluidic sensor chip based on terahertz topological photonic crystal waveguide;

[0036] Figure 7 Schematic diagram of the local structure of the substrate of a microfluidic sensor chip based on terahertz topological photonic crystal waveguide;

[0037] Explanation of the reference numerals: shell 10, first accommodating cavity 11, second accommodating cavity 12, substrate fixing platform 13, bubble separation device 20, pipeline 21, piezoelectric ceramic micropump 30, micropump electrical interface 31, micropump liquid inlet 32, waste liquid bin 40, waste liquid bin liquid inlet 41, waste liquid bin liquid discharge port 42, substrate 50, A-type topological photonic crystal 51, topological photonic crystal unit cell 511, first air hole 512, second air hole 513, B-type topological photonic crystal 52, topological photonic crystal unit cell 521, microfluidic channel 53, channel liquid inlet 531, channel liquid discharge port 532, topological transmission path 54, signal coupling port 541, film 60, through hole 61, liquid inlet seat 70, liquid discharge seat 80. DETAILED DESCRIPTION

[0038] The present invention provides a microfluidic sensor chip based on terahertz topological photonic crystal waveguide and a preparation method thereof. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0040] With the advancement of human science and technology, there are many unknown experimental phenomena waiting to be explored under microgravity experimental conditions. Under gravity environment, the application of microfluidics and terahertz sensing technology to manufacture sensors has many advantages. Microfluidics chip technology is a technology that accurately controls and operates fluids at the micrometer scale. It integrates basic operating units such as sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes into a micrometer-scale chip. This technology can automatically complete the entire analysis process and has the advantages of controllable liquid flow, minimal consumption of samples and reagents, and fast analysis speed.

[0041] Microfluidic chips require precise liquid drive control to achieve precise control of fluid pressure, fluid flow rate and fluid position. Traditional liquid drive methods mainly use peristaltic pumps and mechanical syringe pumps as power sources. Both of these are dozens of times larger than sensor chips in volume and are not suitable for use in volume-sensitive detection tasks such as space stations. Peristaltic pumps have the characteristics of continuous large flow and can pump liquid quickly in a short time, but their accuracy is not as good as mechanical syringe pumps. Mechanical syringe pumps can achieve high-precision liquid drive, but the liquid needs to be transferred to a syringe before use. The upper limit of the liquid volume pumped at a single time is limited by the volume of the syringe. Continuous pumping of liquid requires multiple mechanical syringe pumps to work alternately.

[0042] In addition, in a microgravity environment, due to the lack of convection, buoyancy and static pressure, the liquid in the existing microfluidic chip is mainly affected by surface tension, which results in density-driven convection no longer occurring, and the gas and liquid will not separate spontaneously, thus posing a challenge to bubble management. The accumulation of bubbles in the microfluidic channel will cause a sudden increase in the injection pressure, resulting in blank gaps between channel samples, affecting the test results, and even causing the microfluidic channel injection to fail.

[0043] Therefore, due to the limitations of current technology, there is a need for a terahertz microfluidic sensor chip that is small in size, easy to operate and suitable for use in microgravity environments.

[0044] Based on this, Figure 1 and Figure 2 As shown, the present invention provides a microfluidic sensor chip based on terahertz topological photonic crystal waveguide, comprising:

[0045] The housing 10 is provided with a first accommodating cavity 11, a second accommodating cavity 12, and a substrate fixing platform 13 disposed between the first accommodating cavity 11 and the second accommodating cavity 12;

[0046] A bubble separation device 20 and a piezoelectric ceramic micro pump 30, wherein the bubble separation device 20 and the piezoelectric ceramic micro pump 30 are connected via a pipeline 21, and the bubble separation device 20 and the piezoelectric ceramic micro pump 30 are disposed in the first accommodating chamber 11;

[0047] A waste liquid tank 40 is disposed in the second receiving chamber 12;

[0048] A substrate 50 is arranged on the substrate fixing platform 13; an A-type topological photonic crystal 51, a B-type topological photonic crystal 52 and a microfluidic channel 53 are arranged on the substrate 50; a topological transmission path 54 is arranged at the junction of the A-type topological photonic crystal 51 and the B-type topological photonic crystal 52; the microfluidic channel 53 partially overlaps with the topological transmission path 54; a film 60 is arranged on the side of the microfluidic channel 53 away from the shell 10, and a channel liquid inlet 531 is arranged at one end of the microfluidic channel 53 close to the bubble separation device 20, and a channel liquid discharge port 532 is arranged at one end close to the waste liquid bin 40;

[0049] The liquid inlet seat 70 and the liquid discharge seat 80 are arranged at the liquid inlet port 531 of the channel, and the liquid discharge seat 80 is arranged at the liquid discharge port 532 of the channel.

[0050] In this embodiment, the application of a microfluidic channel structure can reduce the absorption of terahertz-band electromagnetic waves by polar substances in the sample, thereby achieving high detection sensitivity and low sample consumption; the application of the characteristics of topological photonic crystal waveguides that are immune to manufacturing defects and backscattering can improve the yield rate and signal-to-noise ratio of sensor production, and the use of the characteristics of topological transmission edge states can accurately constrain the electromagnetic wave energy within the range of the microfluidic channel, thereby improving the sensitivity of the sensor; in addition, a piezoelectric ceramic micropump can achieve high-precision sample feeding, simplify the use steps and reduce the integrated volume, and a bubble separation device can solve the problem of increased injection pressure caused by bubble suspension in a microgravity environment, thereby ensuring the stability of the chip operation; the microfluidic sensor chip provided by the present invention is a highly integrated sensor, which reduces the difficulty of experimental operation and reduces the learning cost of astronauts, and therefore the microfluidic sensor chip is suitable for experimental research in the confined environment of a space station.

[0051] Specifically, the present invention utilizes the characteristics of topological photonic crystal waveguides that are immune to manufacturing defects and backscattering to improve the yield rate and signal-to-noise ratio of sensors. Figure 3As shown, by utilizing the characteristics of topological transmission edge states, the energy of electromagnetic waves can be precisely constrained within the range of the microfluidic channel, thereby improving the sensitivity of the sensor. Water molecules in the air absorb terahertz electromagnetic waves, causing the terahertz signal to oscillate and affect the results of the experiment. Traditional terahertz sensors need to be in an environment with a relative humidity below 5%, using TPX and an optical displacement stage for signal coupling. The microfluidic sensor chip based on the terahertz topological photonic crystal waveguide of the present invention only needs to couple the terahertz electromagnetic wave signal to the sensor through a metal waveguide or a terahertz near-field antenna in the terahertz band at the signal coupling port, which simplifies the steps of adjusting the optical path and the corresponding auxiliary equipment, and does not need to maintain an experimental environment with a relative humidity of less than 5%. Therefore, compared with traditional terahertz sensors, it has better environmental adaptability, and achieves a reduction in weight and volume, and can be more easily launched into the microgravity environment of the space station for experiments.

[0052] In some embodiments, the material used for the substrate 50 has a refractive index greater than 1.2 and an absorption coefficient less than 50 / mm at an operating frequency between 0.1 THz and 10 THz; the operating frequency range of the topological photonic crystal waveguide is 0.1 THz to 10 THz.

[0053] Terahertz radiation refers to electromagnetic waves with a frequency between 0.1 and 10 terahertz and a wavelength between 3 mm and 30 microns, which is between microwaves and infrared rays. Terahertz sensing technology has many advantages. Terahertz waves can interact with the molecular vibration modes in substances, thereby accurately detecting the composition and structure of the substances. This characteristic allows terahertz sensors to be used to detect trace chemicals or biological molecules. Terahertz radiation can penetrate a variety of non-polar materials, but is very sensitive to polar molecules. This characteristic can be used to detect polar molecules in samples. Since the energy level of terahertz radiation is lower than that of X-rays, it will not cause ionizing damage. This is particularly important for use conditions where there is no adequate protection against ionizing radiation, which can protect the safety of samples and experimenters. Based on the different responses of different substances to terahertz spectra, various substances can be distinguished by analyzing the absorption characteristics at specific frequencies, which is very beneficial for the qualitative and quantitative analysis of target components in complex mixtures.

[0054] In a preferred embodiment, the material of the substrate is high-resistance silicon.

[0055] In some embodiments, Figure 4 As shown, the A-type topological photonic crystal 51 is composed of a plurality of periodic topological photonic crystal unit cells 511, and the B-type topological photonic crystal 52 is composed of a plurality of topological photonic crystal unit cells 521 periodically rotated 180° around the geometric center; the topological photonic crystal unit cell is provided with a first air hole 512 and a second air hole 513.

[0056] In some embodiments, the lattice constant of the topological photonic crystal unit cell is 1 μm to 1 mm.

[0057] Specifically, the shapes of the first air hole 512 and the second air hole 513 are both equilateral triangles. Preferably, the lattice constant of the topological photonic crystal unit cell is 340 μm, the side length of the equilateral triangle of the first air hole is 244.75 μm, and the side length of the equilateral triangle of the second air hole is 140.80 μm. The operating frequency range of the sensor chip is determined by the lattice constant, the side length of the equilateral triangle of the first air hole, and the side length of the equilateral triangle of the second air hole. In this embodiment, Figure 5 The S21 parameters shown, the operating frequency of the sensor chip is 0.259THz ~ 0.284THz.

[0058] In some embodiments, Figure 6 and Figure 7 As shown, the topological transmission path is formed by the junction of the A-type topological photonic crystal and the B-type topological photonic crystal. By utilizing the characteristics of the topological transmission edge state, the electromagnetic wave energy can be precisely confined in the microfluidic channel, which can improve the sensitivity of the sensor.

[0059] In this embodiment, the bubble separation device 20, the piezoelectric ceramic micropump 30, the waste liquid tank 40 and the substrate 50 are all fixed on the housing 10, and the housing 10 can protect the internal components of the sensor chip under a high acceleration environment. Among them, the bubble separation device 20 can be used to filter out the bubbles suspended in the sample to ensure the stable operation of the sensor; the piezoelectric ceramic micropump 30 has the characteristics of small size, large flow, high precision, high pressure, and simple driving, which is conducive to reducing the volume of the microfluidic sensor chip provided by the present invention.

[0060] In some embodiments, the microfluidic channel overlaps with the topological transmission path in at least one lattice period, and the overlapping area is the area where the sample interacts with the terahertz electromagnetic wave. The more overlapping lattice periods there are, the higher the sensor sensitivity is, but the topological edge state will be destroyed to a greater extent, thereby increasing the insertion loss of the sensor.

[0061] In a preferred embodiment, the microfluidic channel and the topological transmission path overlap by 15 lattice periods.

[0062] In some embodiments, the starting end and the ending end of the topological transmission path 54 are both provided with a signal coupling port 541. The microfluidic sensor chip can couple the terahertz electromagnetic wave signal to the sensor through a metal waveguide or a terahertz near-field antenna in the terahertz band at the signal coupling port, which simplifies the steps of adjusting the optical path and the corresponding auxiliary equipment, and does not need to maintain an experimental environment with a relative humidity of less than 5%. Therefore, compared with traditional terahertz sensors, it has better environmental adaptability, achieves weight and volume reduction, and can be more easily launched into the microgravity environment of the space station for experiments.

[0063] In some embodiments, the piezoelectric ceramic micropump 30 is provided with a micropump electrical interface 31 and a micropump liquid inlet 32 ​​.

[0064] In some embodiments, the waste liquid bin 40 is provided with a waste liquid bin liquid inlet 41 and a waste liquid bin liquid discharge port 42; the waste liquid bin liquid inlet 41 is connected to the liquid discharge seat 80; and the liquid inlet seat 70 is connected to the bubble separation device 20.

[0065] Specifically, before starting the detection, the sample catheter is inserted into the micropump inlet 32, the piezoelectric ceramic micropump driver cable is connected to the micropump electrical interface 31, the terahertz electromagnetic wave signal is coupled to the signal coupling port 541, and the piezoelectric ceramic micropump 30 is started. The sample to be detected is extracted from the micropump inlet 32 ​​by the piezoelectric ceramic micropump 30, flows through the pipeline 21 and enters the bubble separation device 20. The bubble separation device 20 removes bubbles suspended in the liquid sample. The bubble-free sample enters the microfluidic channel 53 from the liquid inlet seat 70 and then flows from the liquid discharge seat 80 to the waste liquid bin inlet 41 and is stored in the waste liquid bin 40. After the detection is completed, the waste liquid is discharged from the waste liquid bin discharge port 42.

[0066] In some embodiments, the film 60 is provided with through holes 61 corresponding to the channel liquid inlet 531 and the channel liquid outlet 532, and the liquid inlet seat 70 and the liquid outlet seat 80 are arranged on the side of the film 60 away from the substrate and correspond to the through holes.

[0067] In some embodiments, the material of the film is selected from but not limited to one or more of polydimethylsiloxane, polyethylene, polypropylene, polybutene, polytetrafluoroethylene, polyester, silicone rubber, cycloolefin copolymer, polyvinylidene fluoride-hexafluoropropylene copolymer, polyphenylene sulfide, polyvinylidene fluoride-hexafluoropropylene copolymer, polyurethane, and polyester; the thickness of the film ranges from 1 μm to 5 mm.

[0068] In addition, the present invention also provides a method for preparing a microfluidic sensor chip based on a terahertz topological photonic crystal waveguide, comprising the steps of:

[0069] Step S10: setting a topological transmission path on the substrate to divide the substrate into an A-type topological photonic crystal region and a B-type topological photonic crystal region;

[0070] Step S20: arranging type A topological photonic crystals and type B topological photonic crystals in the type A topological photonic crystal region and the type B topological photonic crystal region, respectively;

[0071] Step S30: providing a microfluidic channel on the substrate, wherein the microfluidic channel partially overlaps with the topological transmission path;

[0072] Step S40: preparing a thin film on the side of the microfluidic channel away from the substrate, the thin film covering the area of ​​the substrate except the A-type topological photonic crystal area and the B-type topological photonic crystal area, and covering the microfluidic channel;

[0073] Step S50: respectively setting a liquid inlet seat and a liquid discharge seat at two ends of the microfluidic channel;

[0074] Step S60: Arrange a bubble separation device, a piezoelectric ceramic micropump, a waste liquid bin and the substrate on the shell, connect the bubble separation device and the piezoelectric ceramic micropump through a pipeline, connect the bubble separation device to the liquid inlet seat, connect the waste liquid bin to the liquid discharge seat, and obtain a microfluidic sensor chip.

[0075] In some embodiments, the A-type topological photonic crystal and the B-type topological photonic crystal are disposed on the substrate by etching, the microfluidic channel is disposed on the substrate by etching, and the film is disposed by bonding.

[0076] In some embodiments, the step S10 specifically includes: the topological transmission path divides the substrate into two parts, the upper part is etched with a type A topological photonic crystal, and the lower part is etched with a type B topological photonic crystal, the type A topological photonic crystal is composed of a plurality of periodic topological photonic crystal unit cells, and the type B topological photonic crystal is composed of a plurality of topological photonic crystal unit cells periodically rotated 180° around the geometric center.

[0077] In some embodiments, the step S40 specifically includes: opening holes in the film at corresponding positions above the channel inlet and the channel outlet etched on the substrate, and cutting the outer contour to be consistent with the outer contour of the substrate, and further removing the parts above the A-type topological photonic crystal and the B-type topological photonic crystal except for the three lattice periods away from the microfluidic channel.

[0078] In some embodiments, the combined substrate, film, liquid inlet seat, and liquid discharge seat can be combined into different components by one or more of electrostatic adsorption, chemical bonding, and physical fixation; preferably, chemical bonding is used to combine the components.

[0079] In this embodiment, the film is covered on the substrate by chemical bonding and closes the channel with the microfluidic channel. The liquid inlet seat and the liquid outlet seat are respectively aligned with the channel liquid inlet and the channel liquid outlet and are chemically bonded to the film.

[0080] In some embodiments, the housing is manufactured using photocuring 3D printing or CNC machining of non-magnetic materials. In this embodiment, the housing is preferably manufactured using 3D photocuring printing technology and photosensitive resin materials.

[0081] In some embodiments, the microfluidic sensor chip based on terahertz topological photonic crystal waveguide is used in a microgravity environment.

[0082] In summary, the present invention provides a microfluidic sensor chip based on terahertz topological photonic crystal waveguide and a preparation method thereof, wherein the microfluidic sensor chip comprises: a housing, provided with a first accommodating cavity, a second accommodating cavity and a substrate fixing platform arranged between the first accommodating cavity and the second accommodating cavity; a bubble separation device and a piezoelectric ceramic micropump, wherein the bubble separation device and the piezoelectric ceramic micropump are connected through a pipeline and are arranged in the first accommodating cavity; a waste liquid tank, arranged in the second accommodating cavity; a substrate, arranged on the substrate fixing platform; and an A A type topological photonic crystal, a B type topological photonic crystal and a microfluidic channel; a topological transmission path is provided at the junction of the A type topological photonic crystal and the B type topological photonic crystal; the microfluidic channel partially overlaps with the topological transmission path; a thin film is provided on the side of the microfluidic channel away from the shell, and a channel liquid inlet is provided at one end of the microfluidic channel close to the bubble separation device, and a channel liquid discharge is provided at one end close to the waste liquid bin; a liquid inlet seat and a liquid discharge seat, the liquid inlet seat is arranged at the channel liquid inlet, and the liquid discharge seat is arranged at the channel liquid discharge. The present invention applies a microfluidic channel structure to reduce the absorption of terahertz-band electromagnetic waves by polar substances in the sample, thereby having high detection sensitivity and consuming less sample; applying the characteristics of topological photonic crystal waveguides immune to manufacturing defects and backscattering, the yield rate and signal-to-noise ratio of sensor production can be improved, and the characteristics of topological transmission edge states can be used to accurately constrain the electromagnetic wave energy within the range of the microfluidic channel, thereby improving the sensitivity of the sensor; in addition, the piezoelectric ceramic micropump housing realizes high-precision sample feeding, simplifies the use steps and reduces the integrated volume, and the bubble separation device solves the problem of increased injection pressure caused by bubble suspension in a microgravity environment, thereby ensuring the stability of the chip operation; the microfluidic sensor chip provided by the present invention is a highly integrated sensor, which reduces the difficulty of experimental operation and reduces the learning cost of astronauts, so the microfluidic sensor chip is suitable for experimental research in the restricted environment of a space station.

[0083] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A microfluidic sensor chip based on terahertz topological photonic crystal waveguide, characterized in that: include: A housing, comprising a first accommodating cavity, a second accommodating cavity and a base fixing platform arranged between the first accommodating cavity and the second accommodating cavity; A bubble separation device and a piezoelectric ceramic micropump, wherein the bubble separation device and the piezoelectric ceramic micropump are connected via a pipeline, and the bubble separation device and the piezoelectric ceramic micropump are arranged in the first accommodating cavity; A waste liquid bin is disposed in the second containing chamber; A substrate is arranged on the substrate fixing platform; the substrate is provided with a type A topological photonic crystal, a type B topological photonic crystal and a microfluidic channel; a topological transmission path is provided at the junction of the type A topological photonic crystal and the type B topological photonic crystal; the microfluidic channel partially overlaps with the topological transmission path; a film is provided on the side of the microfluidic channel away from the shell, and a channel liquid inlet is provided at one end of the microfluidic channel close to the bubble separation device, and a channel liquid discharge port is provided at one end close to the waste liquid bin; A liquid inlet seat and a liquid discharge seat, wherein the liquid inlet seat is arranged at the liquid inlet of the channel, and the liquid discharge seat is arranged at the liquid discharge port of the channel.

2. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1 is characterized in that: The material used for the substrate has a refractive index greater than 1.2 and an absorption coefficient less than 50 / mm at an operating frequency between 0.1 THz and 10 THz.

3. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The A-type topological photonic crystal is composed of a plurality of periodic topological photonic crystal unit cells, and the B-type topological photonic crystal is composed of a plurality of topological photonic crystal unit cells periodically rotated 180° around a geometric center; the topological photonic crystal unit cell is provided with a first air hole and a second air hole.

4. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 3 is characterized in that: The lattice constant of the topological photonic crystal unit cell is 1 μm to 1 mm.

5. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The topological transmission path is formed by the junction of the A-type topological photonic crystal and the B-type topological photonic crystal.

6. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The microfluidic channel and the topological transmission path overlap in at least one lattice period.

7. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The starting end and the ending end of the topological transmission path are both provided with signal coupling ports.

8. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The piezoelectric ceramic micropump is provided with a micropump electrical interface and a micropump liquid inlet.

9. The microfluidic sensor chip based on terahertz topological photonic crystal waveguide according to claim 1, characterized in that: The waste liquid bin is provided with a waste liquid bin liquid inlet and a waste liquid bin liquid discharge port; the waste liquid bin liquid inlet is communicated with the liquid discharge seat; and the liquid inlet seat is communicated with the bubble separation device.

10. A method for preparing a microfluidic sensor chip based on a terahertz topological photonic crystal waveguide according to any one of claims 1 to 9, characterized in that: Includes steps: A topological transmission path is set on the substrate to divide the substrate into an A-type topological photonic crystal region and a B-type topological photonic crystal region; A-type topological photonic crystals and B-type topological photonic crystals are respectively arranged in the A-type topological photonic crystal region and the B-type topological photonic crystal region; Disposing a microfluidic channel on the substrate, wherein the microfluidic channel partially overlaps with the topological transmission path; A thin film is prepared on a side of the microfluidic channel away from the substrate, wherein the thin film covers the substrate except the A-type topological photonic crystal region and the B-type topological photonic crystal region, and covers the microfluidic channel; A liquid inlet seat and a liquid discharge seat are respectively arranged at two ends of the microfluidic channel; A bubble separation device, a piezoelectric ceramic micropump, a waste liquid bin and the substrate are arranged on a shell, the bubble separation device and the piezoelectric ceramic micropump are connected through a pipeline, the bubble separation device is connected to the liquid inlet seat, and the waste liquid bin is connected to the liquid discharge seat to obtain a microfluidic sensor chip.

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