Liquid particle detection device and method

Abstract

The invention provides a liquid particle detection device and method. The liquid particle detection device comprises an optical module, a microfluidic transportation module, an optical detection module, a signal acquisition module and a signal analysis module. The optical detection module comprises a bearing frame. A cavity penetrates through the bearing frame, and a plurality of nanometer strips which are parallel to one another and are not in contact with one another are arranged on the two parallel cavity walls of the cavity. The microfluidic transport module controls the liquid sample to flow through the cavity to pass through the optical detection module. The optical module emits laser to the optical detection module. The signal acquisition module is used for acquiring a first optical signal and a second optical signal. The first optical signal and the second optical signal are optical signals corresponding to laser before and after passing through the optical detection module respectively. The signal analysis module is used for determining particle information of particles included in the liquid sample based on the first optical signal and the second optical signal, so that the detection precision of particle detection is improved, and efficient detection of weak scattering particles is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of particle detection, and particularly to a liquid particle detection device and method. Background Art

[0002] With the rapid development of modern science and technology, the requirements for the cleanliness of materials, quality control, and the purity of the production environment are becoming increasingly strict. In the fields of semiconductor manufacturing, pharmaceuticals, biotechnology, precision optics, and aerospace, the presence of minute particles may have a serious impact on the performance, reliability, and safety of the final products. Therefore, the detection of particles in samples has become a crucial link in quality control in these industries.

[0003] Currently, methods such as dynamic light scattering, light obscuration, and nanoparticle tracking analysis can be used to achieve particle detection. However, when detecting nanoparticles, especially particles with a size of 20 nanometers or less, the detected particle signals are easily overwhelmed by background noise, reducing the detection accuracy of particle detection. Summary of the Invention

[0004] The present invention provides a liquid particle detection device and method, which can improve the detection accuracy of particle detection and achieve efficient detection of weakly scattering particles.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] In a first aspect, the present invention provides a liquid particle detection device, including: an optical module, a microfluidic transport module, an optical detection module, a signal acquisition module, and a signal analysis module. The optical detection module includes a carrier frame; the carrier frame is a cuboid structure, and a cavity runs through the carrier frame along the side length direction of any side of the carrier frame, and the cavity wall is cuboid-shaped; the cavity wall includes a first cavity wall and a second cavity wall that are parallel to each other; for any one of the first cavity wall and the second cavity wall, a plurality of nanorods that are parallel to each other and are not in contact are arranged on any one of the cavity walls; the nanorod is a cuboid structure.

[0007] Among them, the microfluidic transport module is used to control the liquid sample to flow through the cavity to pass through the optical detection module. The optical module is used to emit laser light to the optical detection module; the beam direction of the laser light received by the optical detection module is perpendicular to the plane where any one of the cavity walls is located; the signal acquisition module is used to acquire a first optical signal and a second optical signal; wherein, the first optical signal is the optical signal corresponding to the laser light before passing through the optical detection module; the second optical signal is the optical signal corresponding to the laser light after passing through the optical detection module; the signal analysis module is used to determine the particle information of the particles included in the liquid sample based on the first optical signal and the second optical signal.

[0008] Based on the above technical solutions, the present invention can also be improved as follows.

[0009] Further, the optical module includes a light source and a beam splitter. The signal acquisition module includes a first signal collector and a second signal collector. The light source is used to emit laser light to the beam splitter. The beam splitter is used to split the received laser light so that a part of the received laser light is reflected to the first signal collector and another part of the received laser light is transmitted to the optical detection module. The first signal collector is used to collect a first optical signal, and the first optical signal is the optical signal corresponding to the laser light reflected by the beam splitter. The second signal collector is used to collect a second optical signal.

[0010] Further, the optical module further includes a chopper. The chopper is disposed between the light source and the beam splitter. The chopper is used to chop the laser light emitted by the light source so that the chopped laser light is incident on the beam splitter. The chopper is an optical chopper or a laser chopper.

[0011] Further, the optical module further includes a first lens and a second lens disposed between the chopper and the beam splitter. The first lens is disposed between the chopper and the second lens. Among them, the first lens is a focusing lens and the second lens is a beam expander lens. The first lens is used to converge the laser light passing through the chopper and refract the converged laser light to the second lens. The second lens is used to receive the laser light passing through the first lens and refract the received laser light to the beam splitter. The beam directions of the laser light passing through the second lens are parallel to each other.

[0012] Further, the optical module further includes a third lens disposed between the beam splitter and the microfluidic transport module. The third lens is used to collect the laser light transmitted by the beam splitter and converge the collected laser light to the optical detection module.

[0013] Further, the optical module further includes a fourth lens disposed between the optical detection module and the second signal collector. The fourth lens is used to collect the laser light passing through the optical detection module and converge the collected laser light to the second signal collector.

[0014] Further, the microfluidic transport module further includes a liquid sample injection unit, and the microfluidic transport module further includes at least one guiding channel. For any one of the at least one guiding channels, one end of any one guiding channel is connected to the liquid injection unit, and the other end of any one guiding channel faces the cavity. The liquid sample injection unit is used to inject a liquid sample into at least one guiding channel. Any one guiding channel is used to guide the injected liquid sample into the cavity.

[0015] Further, the particle information includes at least one of the number and concentration of particles included in the corresponding liquid sample.

[0016] Second aspect, the present invention provides a method for detecting liquid particles, which is applied to an optical detection module. The optical detection module includes a carrier frame; the carrier frame is in a cuboid structure, and there is a cavity penetrating along the side length direction of any side of the carrier frame inside the carrier frame, and the cavity wall of the cavity is in a cuboid shape; the cavity wall includes a first cavity wall and a second cavity wall that are parallel to each other; for any one of the first cavity wall and the second cavity wall, a plurality of nanorods that are parallel to each other and are not in contact are arranged on any one of the cavity walls; the nanorods are in a cuboid structure. Wherein, the method includes:

[0017] Control the liquid sample to flow through the cavity so as to pass through the optical detection module. Emit a laser to the optical detection module; the beam direction of the laser received by the optical detection module is perpendicular to the plane where any one of the cavity walls is located. Collect a first optical signal and a second optical signal. Wherein, the first optical signal is the optical signal corresponding to the laser before passing through the optical detection module; the second optical signal is the optical signal corresponding to the laser after passing through the optical detection module. Based on the first optical signal and the second optical signal, determine the particle information of the particles included in the liquid sample.

[0018] Based on the above technical solutions, the present invention can also be improved as follows.

[0019] Further, the particle information includes at least one of the number and concentration of the particles included in the corresponding liquid sample.

[0020] The beneficial effects of the present invention are:

[0021] (1) Improve the detection sensitivity and achieve efficient detection of weakly scattering particles

[0022] By adopting the corresponding structure of the optical detection module, the present invention utilizes the optical field local resonance cavity enhancement effect to improve the scattering-enhanced interaction between light and particles, thereby enhancing the detection ability of weakly scattering particles with a size of 20 nanometers or less, and overcoming the defect of insufficient particle detection sensitivity in the prior art.

[0023] (2) Improve the signal-to-noise ratio and enhance the particle feature recognition ability

[0024] Through the corresponding structure of the optical detection module and the light beam path formed by the optical module, the present invention can reduce the interference of ambient light and system noise. At the same time, through the precise analysis of the particle response characteristic mode signals (the first optical signal and the second optical signal), the signal-to-noise ratio of the particles to be collected can be effectively improved, the stable extraction of weak signals can be realized, and the problem of difficult feature recognition caused by low signal-to-noise ratio in particle detection in the prior art can be solved.

[0025] (3) Improve the resolution and achieve precise distinction of particles in a polydisperse system

[0026] The present invention adopts a structure corresponding to an optical detection module, which can provide an optical enhancement effect with a high Q factor, enabling the system to distinguish particles of different sizes by using the uniform change effect of the mode response at the sub-hundred-nanometer scale, and solving the problem of limited resolution in particle detection in the prior art for a polydisperse system.

[0027] (4) Simplify the sample preparation process and improve the operation convenience

[0028] By integrating microfluidic technology, the present invention realizes the automatic processing of liquid samples, avoids particle aggregation and sample loss, reduces cumbersome pre-treatment steps, improves the operability of particle detection and the accuracy of result data, and overcomes the problems of complex liquid sample preparation and cumbersome operation in the prior art.

[0029] (5) Improve the accuracy of particle concentration measurement and provide absolute concentration information

[0030] By combining the particle response characteristic signals (the first optical signal and the second optical signal), the present invention can directly extract the particle number information of particles from the optical response without relying on a reference standard sample, can provide more reliable absolute concentration data, and solves the problem of difficult accurate measurement of particle concentration in a liquid sample in the prior art. Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the frame structure of a liquid particle detection device provided by the present invention;

[0032] Figure 2 It is a schematic diagram of the structure of an optical detection module provided by the present invention;

[0033] Figure 3 It is a schematic diagram of the detailed structure of a liquid particle detection device provided by the present invention;

[0034] Figure 4 It is a schematic diagram of the process of a liquid particle detection method provided by the present invention. Detailed Embodiments

[0035] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Among them, in the description of the present application, unless otherwise specified, " / " means that the objects associated before and after are in an "or" relationship. For example, A / B may represent A or B; "and / or" in the present application is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. These three situations, where A and B can be singular or plural. And, in the description of the present application, unless otherwise specified, "a plurality" means two or more than two. "At least one (item)" or its similar expression below refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b, or c may represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, c can be single or multiple. In addition, in order to clearly describe the technical solutions in the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that the words such as "first" and "second" do not limit the quantity and execution order, and the words such as "first" and "second" do not necessarily limit to be different. At the same time, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions.

[0036] With the rapid development of modern science and technology, the requirements for the cleanliness of materials, quality control, and the purity of the production environment are becoming increasingly strict. In the fields of semiconductor manufacturing, pharmaceuticals, biotechnology, precision optics, and aerospace, the presence of microscopic particles may have a serious impact on the performance, reliability, and safety of the final product. Therefore, particle detection in samples has become a key link in quality control in these industries.

[0037] In an existing technology, particle detection of particles in a sample can be based on the light blocking method. However, the sensitivity of particle detection based on the light blocking method is limited to micron-sized particles (>1 μm), and it is easily interfered by bubbles and refractive index changes, and cannot meet the detection requirements for nanoparticles.

[0038] In an existing technology, particle detection of particles in a sample can be based on dynamic light scattering technology. However, particle detection based on dynamic light scattering technology is difficult to distinguish a polydisperse system and cannot provide the absolute concentration information of particles in a liquid because it depends on the refractive index of particles and low-concentration samples (multiple scattering needs to be avoided).

[0039] In an existing technology, particle detection of particles in a sample can be performed based on nanoparticle tracking analysis technology. However, due to the limitation of the field of view, particle detection based on nanoparticle tracking analysis technology is difficult to detect high-concentration particle liquid samples, and requires manual parameter optimization, making it difficult to achieve automated on-line detection.

[0040] In an existing technology, particle detection of particles in a sample can be performed based on electron microscopy technology. However, particle detection based on electron microscopy technology requires a vacuum environment, complex sample preparation, and off-line analysis, and cannot meet the requirements of real-time detection in industrial fields.

[0041] In an existing technology, particle detection of particles in a sample can be performed based on atomic force microscopy technology. However, particle detection based on atomic force microscopy technology has a slow scanning speed (minute / micron-level area), is easily interfered by surface effects, and is not suitable for high-throughput analysis.

[0042] Therefore, in view of the problems such as low sensitivity of particle detection in the above-mentioned existing technologies, the present invention provides a liquid particle detection device and method. Through the unique structure included in the optical detection module, the detection limit for particles below 20 nm can be broken through, and at the same time, it has characteristics such as high sensitivity, strong anti-interference ability, integratability, and multi-parameter analysis to meet the stringent requirements of high-end manufacturing for particle pollution control.

[0043] Figure 1 A liquid particle detection device provided by the present invention. Refer to Figure 1 The liquid particle detection device provided by the present invention includes: an optical module, a microfluidic transportation module, an optical detection module, a signal acquisition module, and a signal analysis module.

[0044] Refer to Figure 2 In (a) of, the optical detection module includes a carrier frame 200. The carrier frame 200 is a cuboid structure, and there is a cavity 201 penetrating along any side length direction of the carrier frame 200 inside the carrier frame 200. The cavity wall of the cavity 201 is in the shape of a cuboid. The cavity wall includes a first cavity wall and a second cavity wall that are parallel to each other. For any one of the first cavity wall and the second cavity wall, a plurality of parallel and non-touching nano strips (for example, nano strip 202) are provided on the any one of the cavity walls, and the nano strip is a cuboid structure.

[0045] It should be noted that both the carrier frame and the nano strips provided on the carrier frame are made of transparent materials (for example, sapphire wafers). And those skilled in the art can adjust the specific values of the setting period of each nano strip, the interval between each nano strip, and the inner diameter of the cavity included in the carrier frame based on actual needs, and the embodiments of the present application do not limit them.

[0046] In some embodiments, referring still to Figure 2 (a) in Figure 2 , the straight-line direction L1 perpendicular to the two cavity surfaces passing through the cavity can be determined as the target direction. The nanobars (e.g., nanobar 202) can be arranged parallel to each other along the direction L1 on the above-mentioned cavity wall. Or, referring to Figure 2 (b) in

[0047] , the nanobars (e.g., nanobar 203) can also be arranged parallel to each other along the direction perpendicular to the direction L1 (the direction perpendicular to the direction L1 is the Figure 2 direction of direction L2 in (b) in

[0048] ) on any of the above-mentioned cavity walls.

[0049] The microfluidic transport module is used to control the flow direction of the liquid sample so that the liquid sample flows through the cavity and thus passes through the optical detection module. The flow direction of the liquid sample can be Figure 2 the direction of direction L1 shown in (a) in

[0048] .

[0049] Exemplarily, the microfluidic transport module can be made of polydimethylsiloxane material. The microfluidic transport module can control the flow rate of the liquid sample to be between 10 microliters per minute and 100 microliters per minute. The microfluidic transport module can adopt constant pressure control to avoid particle aggregation and improve fluid stability. The microfluidic transport module can be integrally arranged with the optical detection module to reduce optical signal loss and reduce noise interference.

[0049] The optical module is used to emit a laser to the optical detection module. The beam direction of the laser received by the optical detection module is perpendicular to the plane where any of the above-mentioned cavity walls (the first cavity wall or the second cavity wall) is located (for example, the beam direction of the laser can be Figure 2 the direction shown by direction L3 in (a) in

[0050] ).

[0051] The signal acquisition module is used to acquire the first optical signal and the second optical signal. Among them, the first optical signal is the optical signal corresponding to the laser before passing through the optical detection module, and the second optical signal is the optical signal corresponding to the laser after passing through the optical detection module.

[0051] The signal analysis module is used to determine the particle information of the particles included in the liquid sample based on the first optical signal and the second optical signal.

[0052] Specifically, the signal acquisition module can synchronously calibrate the first optical signal and the second optical signal to remove noise interference and improve the signal-to-noise ratio of the optical signal to be detected. Based on the calibrated and denoised optical signal, the particle information of the particles included in the liquid sample can be determined.

[0053] In some embodiments, the particle information includes at least one of the number and concentration of the particles included in the corresponding liquid sample. The concentration of the particles is the concentration of the particles in the liquid sample.

[0054] In some embodiments, referring to Figure 3 , the optical module includes a light source 301 and a beam splitter 302. The signal acquisition module includes a first signal collector 303 and a second signal collector 304. The light source 301 is configured to emit a laser to the beam splitter 302 (for example, the light source can emit a laser with a wavelength of 860 nanometers and a power of 10 milliwatts to the beam splitter 302). The beam splitter 302 is configured to split the received laser, reflecting a part of the received laser to the first signal collector 303 and transmitting the other part of the received laser to the optical detection module 300. The first signal collector 303 is configured to collect a first optical signal, which is the optical signal corresponding to the laser reflected by the beam splitter 302. The second signal collector 304 is configured to collect a second optical signal.

[0055] It should be noted that when the laser is incident on the optical detection module, an optical enhancement effect will occur in the optical detection module. When the particles in the liquid sample pass through the optical detection module, the light intensity in the optical detection module will change significantly, enabling the device to capture weak signals and further analyze the particle information of the particles in the liquid sample.

[0056] In some embodiments, both the first signal collector and the second signal collector can employ avalanche photodiodes. Their detection ranges can cover the photoelectric detection unit.

[0057] In some embodiments, the sampling frequencies of the first signal collector and the second signal collector are the same. For example, the sampling frequencies of both the first signal collector and the second signal collector can be set to 1 MHz.

[0058] In some embodiments, continuing to refer to Figure 3 , the optical module further includes a chopper 305. The chopper 305 is disposed between the light source 301 and the beam splitter 302. The chopper 305 is configured to chop the laser emitted by the light source 301 so that the chopped laser is incident on the beam splitter 302. The chopper 305 is an optical chopper or a laser chopper.

[0059] In some embodiments, continuing to refer to Figure 3 , the optical module further includes a first lens 306 and a second lens 307 disposed between the chopper 305 and the beam splitter 302. The first lens 306 is disposed between the chopper 305 and the second lens 307. Among them, the first lens 306 is a focusing lens, and the second lens 307 is a beam expander lens. The first lens 306 is configured to converge the laser passing through the chopper 305 and refract the converged laser to the second lens 307. The second lens 307 is configured to receive the laser passing through the first lens 306 and refract the received laser to the beam splitter 302. The beam directions of the lasers passing through the second lens 307 are parallel to each other.

[0060] In some embodiments, continuing to refer to Figure 3 , the optical module further includes a third lens 308 disposed between the beam splitter 302 and the optical detection module 300. The third lens 308 is used to collect the laser transmitted by the beam splitter 302 and converge the collected laser to the optical detection module 300.

[0061] In some embodiments, continuing to refer to Figure 3 , the optical module further includes a fourth lens 309 disposed between the optical detection module 300 and the second signal collector 304. The fourth lens 309 is used to collect the laser passing through the optical detection module 300 and converge the collected laser to the second signal collector 304.

[0062] In some embodiments, continuing to refer to Figure 3 , the microfluidic transportation module 310 further includes a liquid sample injection unit 311, and the microfluidic transportation module 310 further includes at least one guiding channel. For any one of the at least one guiding channels, one end of any one guiding channel is connected to the liquid injection unit, and the other end of any one guiding channel faces the cavity. The liquid sample injection unit 311 is used to inject a liquid sample into the at least one guiding channel. Any one guiding channel is used to guide the injected liquid sample into the cavity.

[0063] In some embodiments, after the signal analysis module obtains the particle information, it can also prompt the particle information. For example, display the text, picture, etc. corresponding to the particle information for online monitoring in industrial applications.

[0064] It should be noted that the carrier frame provided with the nanorods in the optical detection module of the present invention constitutes a nano-slit array resonator. The preparation method of the nano-slit array resonator will be described in detail below.

[0065] First, substrate preparation. A sapphire wafer can be selected as the substrate material of the nano-slit array resonator. Sapphire has excellent optical transparency, corrosion resistance and mechanical stability, and is suitable for high-precision optical applications. The wafer size is generally 20 mm × 20 mm according to application requirements. The surface of the wafer is cleaned by ultrasonic waves to remove surface organic and particle contamination and ensure processing accuracy.

[0066] Subsequently, the preparation of the nano-slit array is carried out. An electron beam lithography technique is used to write a 10 mm × 20 mm nano-slit array pattern in the central region of the sapphire wafer. The key parameter control includes a slit width of 100 nm, an array period of 500 nm, and a slit depth of 80 nm. In the lithography process, a high-resolution electron beam resist is uniformly coated on the sapphire surface with a thickness controlled between 100 and 200 nm, and high-precision exposure is performed under an electron beam microscope to form a nano-slit pattern (a nano-slit array formed by multiple nano-strips). After exposure, a suitable developer is used for treatment to reveal the nano-slit structure. Subsequently, a coating process is carried out to directly deposit a metal layer in the nano-slit pattern area to form a nano-slit array structure. Among them, the thickness of the gold layer is controlled at 80 nm to ensure that the height of the nano-slits meets the design requirements. The coating process uses electron beam evaporation or magnetron sputtering to ensure the uniformity and adhesion of the thin film. Subsequently, the lift-off process is used to remove the uncoated area, making the final nano-slit structure fully revealed.

[0067] After the processing of the nano-slit array is completed, a physical vapor deposition technique is used to deposit aluminum films on both sides of the un-lithographed area of the sapphire substrate, with the thickness between 5 μm and 10 μm according to the design requirements. The role of the aluminum film is to enhance the optical resonance effect, improve the coupling efficiency of the incident light, and increase the mechanical stability of the structure. The deposition process uses electron beam evaporation or magnetron sputtering to ensure the uniformity and adhesion of the thin film. A gold film with a thickness of about 200 nm is further deposited on the surface of the aluminum film. The gold film has a high reflectivity and good biocompatibility, which helps to improve the optical performance of the resonant cavity. A magnetron sputtering or electron beam evaporation process is used to ensure the uniform coverage of the gold film and optimize the optical loss characteristics.

[0068] After depositing the gold film, a photoresist or mask material is used to temporarily cover the nano-slit area to prevent the influence of subsequent processes. Annealing treatment is carried out to improve the crystallization quality of the gold film, reduce the surface roughness, and enhance the optical performance. Plasma treatment is used to remove the residual photoresist to ensure the optical cleanliness of the nano-slits.

[0069] After the surface treatment is completed, two sapphire wafers prepared by the same process are aligned and packaged through a gold-gold bonding process to form a complete resonant cavity structure. The alignment system uses a high-precision mechanical or optical alignment system to accurately overlap the nano-slit areas on the two sapphire wafers. Under the conditions of a high temperature of 150 to 300 °C and a pressure of 10 to 50 MPa, a strong bond is formed between the gold films to ensure the sealing and mechanical stability of the cavity. The thickness after bonding is controlled within a reasonable range to ensure the precise size of the optical resonant cavity. This process ensures the sealing performance of the cavity and optimizes the optical coupling efficiency of the resonant cavity.

[0070] Finally, multiple detection methods are used to evaluate the quality of the finished product, including scanning electron microscopy to examine the morphology and dimensional accuracy of the nano-gaps, atomic force microscopy to measure the surface roughness to ensure the optical surface quality, and spectroscopic testing to test the transmission and reflection characteristics of the resonant cavity using a spectrometer and confirm the position of the resonant peak and the Q factor. After passing the quality inspection, the qualified resonant cavity structures are assembled and put into application.

[0071] The assembly method of the above-mentioned nano-slit array resonant cavity and microfluidic transport module will be described in detail below.

[0072] First, prepare the aforementioned nano-slit array resonant cavity, and ensure that the surface of the nano-slit array resonant cavity is clean, free of particle contamination and fingerprints, so as not to affect the optical detection performance. The microfluidic transport module can be made of PDMS material, which has been pre-designed with fluid channels to ensure that the inlet and outlet positions are precisely matched with the nano-slit array resonant cavity. The microfluidic transport module needs to be treated with oxygen plasma surface activation before assembly to enhance the adhesion force. In addition, biocompatible adhesives need to be prepared or methods such as plasma bonding and UV-curing adhesives are used for assembly, and at the same time, a microscopic alignment tool is used to ensure high-precision alignment.

[0073] Second, use plasma cleaning technology to clean the nano-slit array resonant cavity and the microfluidic transport module to remove surface organic contamination and improve adhesion. A low-power oxygen plasma treatment is applied to the surface of the microfluidic transport module to enhance the bonding force between the microfluidic transport module and the resonant cavity and ensure seamless docking of the flow channel and the resonant cavity. After the cleaning treatment, the microfluidic transport module is rinsed with deionized water, dried and placed in a clean environment for standby. Among them, the microfluidic transport module can be a microfluidic transport chip.

[0074] Then, adopt microscopic vision alignment technology to precisely align the inlet of the microfluidic channel with the cavity of the nano-slit array resonant cavity, with the error controlled within 5 microns, to ensure that the fluid can uniformly enter the cavity of the nano-slit array resonant cavity without forming bubbles or deposits. Gradually adjust the position of the flow channel to make it completely match the aperture of the cavity of the nano-slit array resonant cavity to avoid fluid bypass phenomenon.

[0075] After alignment, according to the experimental requirements, select oxygen plasma bonding to achieve glue-free bonding between the microfluidic transport module and the resonant cavity under the conditions of heating at 80 degrees Celsius and pressure of 10 to 20 kPa, or use UV-curing glue for bonding, apply uniform pressure to make the glue evenly distributed, and cure it with ultraviolet light to ensure the bonding strength and tightness. Bubbles need to be avoided during the bonding process to prevent affecting the stability of liquid flow.

[0076] After bonding is completed, the fluid pipeline needs to be connected. Install liquid connectors at the inlet and outlet of the microfluidic transportation module to ensure a tight connection with the external injection pump and liquid storage system. The connected pipeline needs to be subjected to a seal test to prevent liquid leakage from affecting the detection accuracy.

[0077] After that, use a microscope to check whether the microfluidic channel is accurately aligned with the nano-slit array resonator region, conduct a fluid test, and use deionized water or a standard solution to test the flow performance of the microfluidic system, observing the liquid flow rate, uniformity, and the absence of bubbles. Use the optical module to verify the optical performance of the nano-slit array resonator to ensure that the signal intensity is stable under liquid flow conditions and meets the expected detection sensitivity. By adjusting the fluid pressure, optimize the flow rate of the liquid sample through the nano-slit array resonator to ensure the best optical detection conditions.

[0078] The construction method of the optical module will be described in detail below.

[0079] First, prepare optical components (such as laser light sources, lenses, filters, etc.), ensure that their surfaces are clean, and assemble them using precision tools.

[0080] Then, install the light source and adjust the beam incident angle. Adjust the beam diameter through a collimating lens to ensure that the light source is aligned with the nano-slit array resonator and maximize the utilization of light power.

[0081] Next, adjust the positions of the nano-slit array resonator and the signal collector to ensure that the transmitted light signal is accurately received by the signal collector, and install a filter to improve the signal-to-noise ratio.

[0082] In the signal optimization stage, finely adjust the optical components, adjust the light source power and lens focal length to ensure that the system reaches the best working state. Use standard samples to verify the sensitivity and stability.

[0083] Finally, fix and seal the optical system to ensure stability. Conduct system calibration to verify the accuracy and repeatability of the optical system.

[0084] In some embodiments, the resonator material of the nano-slit array resonator can also be made of fused silica, silicon-based materials, polymer materials, etc., which are not limited in the embodiments of the present application.

[0085] In some embodiments, the process of fabricating the nano-slit array resonator can also adopt focused ion beam (FIB) processing, nanoimprint technology, and self-assembled nano technology, etc., which are not limited in the embodiments of the present application.

[0086] In some embodiments, the microfluidic transportation module can also adopt a glass microfluidic transportation chip, a silicon-based microfluidic transportation chip, a microfluidic structure manufactured by 3D printing, etc., which are not limited in the embodiments of the present application.

[0087] In some embodiments, the microfluidic transport module can control the flow of liquid samples based on techniques such as capillary action drive, electroosmotic pump, and pneumatic drive, which are not limited in the embodiments of this application.

[0088] In some embodiments, the light source can also adopt a broadband light source combined with a spectral filtering light source, a supercontinuum light source, an LED light source, etc., which are not limited in the embodiments of this application.

[0089] In some embodiments, the signal collector can adopt a CCD or CMOS image sensor, a fiber-coupled detector, Raman spectroscopy detection, etc., which are not limited in the embodiments of this application.

[0090] In some embodiments, the scheme of optically transmitting and detecting particle signals in this application can also be replaced by light scattering detection, resistive pulse detection, acoustic detection technology, etc., which are not limited in the embodiments of this application.

[0091] In some embodiments, the gold-gold bonding of the nano-slit array resonator in this application can also be replaced by bonding methods such as glue bonding, electrostatic bonding, and mechanical clamping, which are not limited in the embodiments of this application.

[0092] In some embodiments, the signal analysis module in the embodiments of this application can adopt an AI algorithm to achieve more advanced particle feature analysis and improve the recognition accuracy.

[0093] In some embodiments, the signal analysis module in the embodiments of this application can be combined with cloud computing to achieve remote data storage and analysis, facilitating large-scale monitoring.

[0094] In some embodiments, the signal analysis module in the embodiments of this application can adopt an FPGA or a dedicated chip to reduce the calculation delay and improve the real-time analysis ability.

[0095] It can be seen that based on the high-sensitivity particle detection technology of the nano-slit array resonator, through the optical resonance effect, the present invention can achieve high-precision detection of particles with a size of less than sub-100 nanometers or even 20 nanometers. The precise preparation process of the nano-slits in the present invention, including photolithography, coating, gold-gold bonding, etc., realizes precise control of the slit width and forms a periodic nanostructure. The integrated integration of the microfluidic transport module and the nano-slit array resonator in the present invention ensures that the liquid sample flows uniformly through the optical detection module, improving the stability and repeatability of detection. The present invention identifies and judges the particle characteristic information through the particle response characteristic signals (the first optical signal and the second optical signal). The present invention adopts a high-precision optical module, including a laser light source with a specific wavelength, a beam splitter, and various lenses, to achieve high signal-to-noise ratio detection. The gold-gold bonding and encapsulation process of the double-chip structure of the nano-slit array resonator in the present invention can ensure the airtightness of the cavity, avoid liquid leakage, and optimize the optical performance.

[0096] Moreover, the present invention can be applied to the real-time online monitoring of various liquid environments (such as industrial ultrapure water, pharmaceutical solutions, etc.) to meet the requirements of industrial production. Through modular design, the present invention reduces the manufacturing and maintenance costs and improves the portability and operability of the system.

[0097] In addition, there are various alternatives for the present invention, covering materials, manufacturing processes, optical systems, and fluid control methods, providing a wider range of application adaptability.

[0098] The present invention also provides a liquid particle detection method, which is applied to the optical detection module. For the description of the optical detection module, reference can be made to the foregoing embodiments and will not be elaborated here.

[0099] See Figure 4 , the liquid particle detection method provided by the present invention includes the following steps:

[0100] S401: Control the liquid sample to flow through the cavity to pass through the optical detection module.

[0101] S402: Emit a laser to the optical detection module.

[0102] Among them, the beam direction of the laser received by the optical detection module is perpendicular to the plane where any cavity wall is located.

[0103] S403: Collect the first optical signal and the second optical signal.

[0104] Among them, the first optical signal is the optical signal corresponding to the laser before passing through the optical detection module, and the second optical signal is the optical signal corresponding to the laser after passing through the optical detection module.

[0105] S404: Based on the first optical signal and the second optical signal, determine the particle information of the particles included in the liquid sample.

[0106] For the description of the particle information, reference can be made to the foregoing embodiments and will not be elaborated here.

[0107] In some solutions, multiple embodiments of the present application can be combined and the combined solution can be implemented. Optionally, some operations in the processes of the method embodiments are optionally combined, and / or the order of some operations is optionally changed. And, the execution order between the steps of each process is only exemplary and does not constitute a limitation on the execution order between the steps. The steps can also be in other execution orders. It is not intended to indicate that the described execution order is the only order in which these operations can be performed. Those of ordinary skill in the art will think of various ways to reorder the operations described herein. In addition, it should be noted that the process details involved in a certain embodiment herein are similarly applicable to other embodiments, or different embodiments can be combined and used.

[0108] In addition, some steps in the method embodiments can be equivalently replaced by other possible steps. Or, some steps in the method embodiments may be optional and can be deleted in some usage scenarios. Or, other possible steps can be added to the method embodiments. Moreover, the method embodiments can be implemented independently or in combination with each other.

[0109] From the description of the above embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0110] In several embodiments provided in this application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0111] In addition, each functional unit in the various embodiments of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0112] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on such an understanding, the technical solution of the embodiments of this application, in essence, or the part that makes a contribution, or all or part of this technical solution, can be embodied in the form of a software product. The software product is stored in a storage medium and includes several instructions for causing a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of this application. The foregoing storage medium includes: USB flash drive, mobile hard disk, read only memory (ROM), random access memory (RAM), magnetic disk or optical disc and other various media that can store program codes.

[0113] The above content is only a specific implementation mode of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application shall be covered by the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A liquid particle detection device, characterized in that, Comprising: An optical module, a microfluidic transportation module, an optical detection module, a signal acquisition module, and a signal analysis module; the optical detection module includes a carrier frame; the carrier frame is a cuboid structure, and there is a cavity running through along the side length direction of any side of the carrier frame inside the carrier frame, and the cavity wall of the cavity is cuboid-shaped; the cavity wall includes a first cavity wall and a second cavity wall that are parallel to each other; for any one of the first cavity wall and the second cavity wall, a plurality of nanorods that are parallel to each other and are arranged without contact are provided on the any one of the cavity walls; the nanorod is a cuboid structure. Wherein, the microfluidic transportation module is used to control the liquid sample to flow through the cavity to pass through the optical detection module. The optical module is used to emit laser to the optical detection module; the beam direction of the laser received by the optical detection module is perpendicular to the plane where any one of the cavity walls is located. The signal acquisition module is used to acquire a first optical signal and a second optical signal; wherein, the first optical signal is the optical signal corresponding to the laser before passing through the optical detection module; the second optical signal is the optical signal corresponding to the laser after passing through the optical detection module. The signal analysis module is used to determine the particle information of the particles included in the liquid sample based on the first optical signal and the second optical signal.

2. The device according to claim 1, characterized in that The optical module includes a light source and a beam splitter; the signal acquisition module includes a first signal acquirer and a second signal acquirer. The light source is used to emit laser to the beam splitter. The beam splitter is used to perform beam splitting processing on the received laser, so as to reflect a part of the received laser to the first signal acquirer and transmit the other part of the received laser to the optical detection module. The first signal acquirer is used to acquire the first optical signal, and the first optical signal is the optical signal corresponding to the laser reflected by the beam splitter. The second signal acquirer is used to acquire the second optical signal.

3. The device according to claim 2, characterized in that, The optical module further includes a chopper; the chopper is arranged between the light source and the beam splitter; the chopper is used to perform chopping processing on the laser emitted by the light source so that the laser after chopping processing is incident on the beam splitter; the chopper is an optical chopper or a laser chopper.

4. The device according to claim 3, characterized in that, The optical module further includes a first lens and a second lens arranged between the chopper and the beam splitter; the first lens is arranged between the chopper and the second lens; the first lens is a focusing lens; the second lens is a beam expander lens; the first lens is used to converge the laser passing through the chopper and refract the converged laser to the second lens; the second lens is used to receive the laser passing through the first lens and refract the received laser to the beam splitter; the beam directions of the lasers passing through the second lens are parallel to each other.

5. The device according to claim 4, characterized in that, The optical module further includes a third lens arranged between the beam splitter and the optical detection module; the third lens is used to collect the laser transmitted by the beam splitter and converge the collected laser to the optical detection module.

6. The device according to claim 5, characterized in that, The optical module further includes a fourth lens disposed between the optical detection module and the second signal collector; the fourth lens is configured to collect the laser passing through the optical detection module and converge the collected laser to the second signal collector.

7. The device according to claim 6, wherein The microfluidic transportation module further includes a liquid sample injection unit; the microfluidic transportation module further includes at least one guiding channel; for any one of the at least one guiding channels, one end of the any one guiding channel is connected to the liquid injection unit, and the other end of the any one guiding channel faces the cavity. The liquid sample injection unit is configured to inject the liquid sample into the at least one guiding channel. The any one guiding channel is configured to guide the injected liquid sample into the cavity.

8. The device according to claim 7, characterized in that, The particle information includes at least one of the number and concentration of particles included in the corresponding liquid sample.

9. A method for detecting liquid particles, characterized in that, Applied to an optical detection module, the optical detection module includes a carrier frame; the carrier frame is in a cuboid structure, and a cavity runs through the carrier frame along the side length direction of any one side of the carrier frame, and the cavity wall of the cavity is in a cuboid shape; the cavity wall includes a first cavity wall and a second cavity wall that are parallel to each other; for any one of the first cavity wall and the second cavity wall, a plurality of nanorods that are parallel to each other and are not in contact with each other are disposed on the any one cavity wall. The nanorod is in a cuboid structure; the method includes: Controlling the liquid sample to flow through the cavity to pass through the optical detection module. Emitting a laser to the optical detection module; the beam direction of the laser received by the optical detection module is perpendicular to the plane where the any one cavity wall is located. Collecting a first optical signal and a second optical signal; wherein, the first optical signal is the optical signal corresponding to the laser before passing through the optical detection module; the second optical signal is the optical signal corresponding to the laser after passing through the optical detection module. Based on the first optical signal and the second optical signal, determining the particle information of the particles included in the liquid sample.

10. The method according to claim 9, wherein The particle information includes at least one of the number and concentration of particles included in the corresponding liquid sample.

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