A device and method for measuring and sorting the size and refractive index of micro- and nano-particles

Abstract

The application relates to the technical field of micro-nanoparticle sorting, in particular to a device and method for measuring and sorting the particle size and refractive index of micro-nanoparticles. The device comprises a plurality of liquid storage containers, a measuring and sorting module, a magnifying lens, a reflecting mirror, a liquid receiving container, a control module, and a pump body, a laser module and a camera module which are electrically connected to the control module. The measuring and sorting module comprises a substrate assembly and a carrier chip, the carrier chip is arranged on the substrate assembly, and the carrier chip is provided with an inlet channel, a measuring and sorting channel and a plurality of outlet channels. The inlet channel is communicated with the measuring and sorting channel, and the measuring and sorting channel is communicated with the outlet channels. The pump body is connected with the liquid storage container and is also connected with a micro-particle inlet. The laser module is used for emitting laser. The camera module, the reflecting mirror and the magnifying lens form a preset angle. The device is used for realizing the quantitative characterization and synchronous sorting and collection of micro-nanoparticles with high stability.

Description

Technical Field

[0001] This invention relates to the field of micro-nano particle sorting technology, and more specifically, to a device and method for measuring and sorting the particle size and refractive index of micro-nano particles. Background Technology

[0002] The particle size and refractive index of micro and nanoparticles are key parameters for characterizing their physical properties, composition, and bioactivity, and are crucial in fields such as cancer diagnosis, microplastic detection, and drug screening. Currently, flow cytometry is commonly used to detect the particle size and refractive index of micro and nanoparticles. However, while flow cytometry is the industry standard, it relies on exogenous fluorescent labeling, which not only increases costs but may also interfere with the intrinsic properties of micro and nanoparticles. Existing technologies also rely on optical tweezers for measurement. This technology has attracted much attention due to its non-contact and non-destructive nature. However, this technology mostly focuses on binary sorting of particles larger than / smaller than a threshold, and some high-precision characterization methods rely on complex optical paths such as spatial light modulators or off-axis holography, resulting in heavy computational burdens and difficulties in miniaturization. At the same time, the high-power lasers used in optical tweezers-based optical manipulation techniques cause thermal convection and low processing throughput, which also limit the actual effectiveness of micro and nanoparticles. Summary of the Invention

[0003] This invention provides a device and method for measuring and sorting the particle size and refractive index of micro- and nano-particles, which can be used to achieve highly stable quantitative characterization and simultaneous sorting and collection of micro- and nano-particles.

[0004] According to a first aspect of this application, a device for measuring and sorting the particle size and refractive index of micro-nano particles is provided. The device includes several liquid storage containers, a measurement and sorting module, a magnifying glass, a reflector, several liquid receiving containers, a control module, and a pump body, a laser module, and a camera module, all of which are electrically connected to the control module. The measurement and sorting module includes a substrate assembly and a carrier chip. The carrier chip is disposed on the substrate assembly and has an inlet channel, a measurement and sorting channel, and several outlet channels. The measurement and sorting channel is provided with a scale. One end of the carrier chip is provided with a particle inlet communicating with the inlet channel, and the other end is provided with several particle outlets respectively communicating with the several outlet channels. The particle outlets are communicated with the corresponding liquid receiving containers. The inlet channel is also communicated with the measurement and sorting channel, and the measurement and sorting channel is communicated with the several outlet channels. The pump body is connected to several of the liquid storage containers, and the pump body is also connected to the particle inlet; The laser module is used to emit laser light, so that the laser light is incident on the measurement and sorting channel within the carrier chip; The camera module, the reflector, and the magnifying glass form a preset angle, enabling the camera module to capture images of particles on the measurement and sorting channel within the carrier chip.

[0005] Understandably, a pump pushes the solution of micro / nano particles to be tested into the measurement and sorting channel of the carrier chip. A laser emitted by a laser module applies photodynamic force to the micro / nano particles, and a camera module acquires real-time images of the particles within the measurement and sorting channel. The control module then quantitatively obtains the particle size or refractive index based on the results from the measurement and sorting process, achieving label-free, non-contact measurement of the physical parameters of individual micro / nano particles. Simultaneously, the measurement and sorting channel is equipped with graduations, providing a spatial reference for the control module to identify the physical location of the particles in the image, effectively improving the accuracy and efficiency of quantitative characterization.

[0006] Optionally, the laser emitted by the laser module is an elliptical spot or a linear spot; the major axis of the elliptical spot or the linear spot is distributed along the length of the measurement and sorting channel.

[0007] Understandably, by shaping the laser into an elliptical or linear spot, the high intensity gradient along its short axis binds micro / nanoparticles to the center line of the spot, while the long axis provides a lateral displacement path for the micro / nanoparticles. With the long axis distributed along the length of the measurement and sorting channel, micro / nanoparticles of different sizes or refractive indices can move to different equilibrium positions under the influence of the lateral light force along the long axis. This transforms the differences in the physical properties of the micro / nanoparticles into differences in spatial displacement, laying the physical foundation for subsequent quantitative analysis and sorting collection.

[0008] Optionally, the major axis of the elliptical light spot ranges from 1 mm to 10 mm, and the minor axis of the elliptical light spot ranges from 50 μm to 100 μm.

[0009] Understandably, setting the major axis of the elliptical light spot within the range of 1 mm to 10 mm provides a sufficiently long optical interaction distance for micro / nano particles, allowing them ample time and space to move to distinguishable equilibrium positions. Setting the minor axis within the range of 50 μm to 100 μm ensures a sufficiently strong minor axis gradient force to overcome fluid disturbances and stably confine the micro / nano particles within the optical field's range. This coordinated setting of the major and minor axes balances measurement range and capture stability, providing optical assurance for high-precision quantitative characterization.

[0010] Optionally, the ratio of the major axis to the minor axis of the linear light spot is greater than 10:1.

[0011] Understandably, when using a linear spot size, a design with an aspect ratio greater than 10:1 further extends the detection range of lateral displacement, allowing micro / nano particles with small differences in size or refractive index to be fully separated over a longer distance, thereby improving the ability to resolve minute differences in the physical properties of micro / nano particles. Simultaneously, the extremely short minor axis ensures that the gradient trapping force is not significantly weakened, maintaining a stable micro / nano particle confinement effect while extending the measurement range.

[0012] Optionally, the width of the measurement and sorting channel is 200μm-500μm, the length of the measurement and sorting channel is 500μm-1000μm, and the depth of the measurement and sorting channel is 150μm-500μm.

[0013] Understandably, setting the width of the measurement and sorting channel to 200 μm to 500 μm geometrically matches the major and minor axes of the elliptical laser spot, ensuring that the spot completely covers the effective area along the width of the measurement and sorting channel, keeping the micro / nanoparticles within the optical field's influence range during lateral displacement. Setting the channel length to 500 μm to 1000 μm provides ample physical space for micro / nanoparticle loading, capture, lateral displacement, and sorting outlet diversion. Setting the channel depth to 150 μm to 500 μm ensures both free flow of micro / nanoparticles within the channel without excessive constraint from the walls and consistent optical field distribution within the laser penetration depth, thereby improving the repeatability and reliability of the measurement results.

[0014] Optionally, the laser is obliquely incident on the measurement and sorting channel at a preset incident angle and polarization angle, wherein the incident angle is the angle between the incident direction of the laser and the normal direction perpendicular to the plane of the carrier chip; and the polarization angle is the angle between the electric field vector direction of the laser and the length direction of the measurement and sorting channel.

[0015] Understandably, the laser is incident at a preset angle into the measurement and sorting channel. A highly reflective substrate reflects the laser back into the channel, creating a superimposed light field to enhance the interaction between the light and the micro / nano particles. The coordinated setting of the incident and polarization angles effectively adjusts the magnitude and direction of the lateral light force along the long axis, optimizing the distribution of the light force acting on the micro / nano particles. Precise control of the polarization angle allows the lateral light force along the channel width to directionally drive the micro / nano particles, transforming differences in their physical properties into distinguishable lateral displacements—the mechanical basis for achieving high-precision quantitative characterization.

[0016] Optionally, the incident angle ranges from 10 degrees to 80 degrees, and the polarization angle ranges from 10 degrees to 80 degrees.

[0017] Understandably, setting the incident angle within the range of 10 to 80 degrees ensures efficient reflection of the laser on the substrate and effective construction of the superimposed light field. Simultaneously, it moderates the component of the scattering force along the depth direction of the measurement and sorting channel, preventing micro / nano particles from being excessively pressed against the channel walls. Setting the polarization angle within the range of 10 to 80 degrees allows the long-axis lateral light force to achieve optimal amplitude output within a wide adjustment range. This provides flexible force control space for micro / nano particle systems with different refractive index contrasts, enhancing the device's applicability to different types of micro / nano particles.

[0018] Optionally, the laser is a linearly polarized laser with a wavelength of 400nm-1200nm, and / or the output power of the laser is 1W-4W.

[0019] Understandably, using linearly polarized lasers in the 400nm-1200nm band, which falls within the low-loss absorption window of water, effectively suppresses fluid thermal convection caused by photothermal effects under high power density irradiation. This ensures the stability of the laminar flow field within the measurement area and the repeatability of the micro / nano particle trajectories. The output power is set to 1W to 4W, ensuring sufficient long-axis lateral light force to overcome residual fluid resistance and Brownian motion under oblique incidence conditions. This allows micro / nano particles to be effectively driven and stabilized in their equilibrium positions, while avoiding excessive power that could cause photodamage to biological samples, thus balancing measurement efficiency and sample safety.

[0020] According to a second aspect of this application, a method for measuring and sorting the particle size and refractive index of micro / nano particles is provided. The method is implemented using the micro / nano particle size and refractive index measurement and sorting device described in the first aspect, wherein the liquid storage container includes a first liquid storage container and a second liquid storage container; the method includes: The control module controls the camera module to continuously capture particle images of the measurement and sorting channel, and the control module monitors the particle images; The control module controls the pump to turn on, and the pump pushes the solution in the first liquid storage container into the particle inlet; wherein, the solution in the first liquid storage container is a solution of the micro-nano particles to be tested; When the control module detects that a single micro / nano particle to be tested has entered the preset area of ​​the measurement and sorting channel in the particle image, the control module shuts down the pump. The control module controls the laser module to turn on, and the laser emitted by the laser module is incident on the micro-nano particles to be tested in the measurement and sorting channel, and the micro-nano particles to be tested are captured by the short axis gradient force of the laser. The micro / nano particles to be tested are laterally displaced along the length direction of the measurement and sorting channel under the action of the lateral optical force of the laser along the long axis, and stop at the corresponding equilibrium position; The control module obtains the equilibrium position of the micro / nano particle under test based on the particle image, and obtains the lateral displacement distance between the equilibrium position of the micro / nano particle under test and the center of the laser spot. Based on the lateral displacement distance and a preset mapping table including the mapping relationship between the particle size, refractive index and lateral displacement distance of the micro / nano particle, the control module obtains the particle size or refractive index of the micro / nano particle under test. The control module controls the laser module to shut down and restarts the pump. The pump pushes the solution from the second storage container into the measurement and sorting channel, and pushes the micro-nano particles to be tested at the corresponding equilibrium position into the nearest outlet channel among all the outlet channels. The particles then reach the corresponding receiving container through the outlet channel and the corresponding particle outlet, thus completing the sorting of the micro-nano particles to be tested.

[0021] Understandably, by employing a standardized process of single-particle sample introduction, followed by optical field capture and displacement, and finally quantitative analysis and sorting collection, a fully automated chain of operations for individual micro / nano particles, from physical property measurement to precise physical collection, has been achieved. Lateral displacement driven by light force in a static fluid avoids interference from flow field disturbances on the equilibrium position of micro / nano particles, ensuring a one-to-one correspondence between displacement measurements and physical properties. By comparing the lateral displacement distance with a mapping table, the refractive index can be output based on the known particle size, or the particle size can be output based on the known refractive index, thus achieving quantitative analysis of single-particle physical parameters. This method requires no external labeling or complex feedback control, ensuring both measurement accuracy and ease of operation and high sorting throughput.

[0022] Optionally, obtaining the particle size or refractive index of the micro / nano particle under test based on the lateral displacement distance and a preset mapping table including the mapping relationship between the particle size, refractive index, and lateral displacement distance of the micro / nano particle includes: If the particle size of the micro / nano particle to be tested is known, the refractive index of the micro / nano particle to be tested can be obtained based on the particle size of the micro / nano particle to be tested and the mapping table. If the refractive index of the micro / nano particle to be tested is known, the particle size of the micro / nano particle to be tested can be obtained based on the refractive index of the micro / nano particle to be tested and the mapping table.

[0023] Understandably, by pre-setting a mapping table covering the relationship between particle size, refractive index, and lateral displacement distance, one unknown property can be deduced even when only one physical property is known, thus achieving flexible quantitative characterization of the physical parameters of micro- and nano-particles. This mapping mechanism allows the same device to be used for both scenarios where the particle size is known and the refractive index is known, significantly expanding the applicability of the device and providing a universal solution for the characterization of micro- and nano-particles under different application requirements.

[0024] Based on any of the above aspects, the device and method for measuring and sorting the particle size and refractive index of micro / nano particles provided in this application can achieve the following technical effects: Based on a spatial displacement mapping mechanism of optical-mechanical equilibrium, quantitative characterization of the physical parameters of single particles is achieved. Microparticles are bound to the center line of an elliptical or linear light spot by the short-axis gradient force, while the long-axis lateral optical force drives lateral displacement along the channel length. Microparticles of different sizes or refractive indices eventually stabilize at different equilibrium positions under the combined action of the long-axis lateral optical force and the short-axis gradient force. The physical properties of microparticles are converted into directly readable spatial displacement signals. Precise quantitative output of the physical parameters of a single microparticle can be achieved through a pre-established mapping table, without the need for external fluorescent labeling or complex optical inversion algorithms, filling the technological gap in existing optical manipulation techniques that emphasize sorting but lack quantitative analysis.

[0025] A progressive fluid control strategy balances measurement accuracy and sorting / recovery efficiency: This strategy employs a step-by-step approach, starting with single-particle sample introduction followed by pump shutdown, then light field capture and displacement measurement, and finally driving sorting and collection. During the measurement phase, the fluid is kept stationary, eliminating the influence of flow field disturbances on the equilibrium position of micro / nano particles. This ensures the uninterrupted correspondence between lateral displacement and physical properties, significantly improving measurement accuracy. During the collection phase, the pump is restarted, pushing the sorted micro / nano particles into their corresponding particle outlets, guaranteeing efficient physical collection. The pump's start / stop and the laser's on / off are coordinated by a control module, achieving full automation from sample introduction to measurement and collection.

[0026] A compact optical design based on a transparent carrier chip and a reflective optical path balances optical power enhancement and thermal management. By placing a substrate assembly at the bottom of the carrier chip, the laser light passing through the measurement channel is efficiently reflected back into the measurement and sorting channel, creating a superimposed optical field to enhance the interaction intensity between the light and the measurement channel. This ensures sufficient optical power while reducing the required incident light power. Taking advantage of the low absorption rate of the 400nm-1200nm wavelength band in water, the interference of photothermal effects on fluid laminar flow is effectively suppressed, ensuring the stability of the measurement environment. The overall optical path structure is simple, eliminating the need for complex optical components such as spatial light modulators and off-axis holograms, reducing the hardware cost of the device and possessing the potential for miniaturized deployment, which is beneficial for its widespread application in laboratory and field testing scenarios. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a diagram of a device for measuring and sorting the particle size and refractive index of micro / nano particles provided in this embodiment.

[0029] Figure 2 This is an example diagram showing the carrier chip working in conjunction with a laser in this embodiment.

[0030] Figure 3 This is an example diagram of the inlet channel, measurement and sorting channel, and several outlet channels in the carrier chip provided in this embodiment.

[0031] Figure 4 Example diagrams of the incident angle and polarization angle provided in this embodiment.

[0032] Figure 5 This is a flowchart illustrating a method for measuring and sorting the particle size and refractive index of micro / nano particles provided in this embodiment.

[0033] Reference numerals: 1-Control module, 2-Pump body, 3-Laser module, 4-Magnifying glass, 5-Camera module, 6-Reflector, 7-Substrate assembly, 8-Carrier chip, 9-Second liquid storage container, 10-First liquid storage container, 11-Liquid receiving container, 12-Measuring and sorting channel, 13-Inlet channel, n1 / d1-Liquid receiving container with first particle size or first refractive index, n2 / d2-Liquid receiving container with second particle size or second refractive index, n3 / d3-Liquid receiving container with third particle size or third refractive index, n4 / d4-Liquid receiving container with fourth particle size or fourth refractive index, n5 / d5-Liquid receiving container with fifth particle size or fifth refractive index, W1-Minor axis length of the elliptical spot, W2-Width of the measuring and sorting channel, W3-Width of the inlet channel, L1-Major axis length of the elliptical spot, L2-Length of the measuring and sorting channel. - Angle of incidence - Polarization angle. Detailed Implementation

[0034] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this application. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Existing micro-nano particle detection technologies suffer from problems such as reliance on fluorescent labeling, emphasis on binary sorting with a lack of single-particle quantitative characterization capabilities, complex and costly device structures, and interference from high-power laser-induced thermal effects on measurements.

[0038] This embodiment provides a technical solution that can solve the above problems. The specific implementation of this application will be described in detail below with reference to the accompanying drawings.

[0039] like Figure 1 and Figure 2 As shown, this embodiment provides a device for measuring and sorting the particle size and refractive index of micro-nano particles. The device includes several liquid storage containers, a measurement and sorting module, a magnifying glass 4, a reflector 6, several liquid receiving containers 11, a control module 1, and a pump body 2, a laser module 3, and a camera module 5, all of which are electrically connected to the control module 1. The measurement and sorting module includes a substrate assembly 7 and a carrier chip 8. The carrier chip 8 is disposed on the substrate assembly 7 and has an inlet channel 13, a measurement and sorting channel 12, and several outlet channels. The measurement and sorting channel 12 is provided with a scale. One end of the carrier chip 8 is provided with a particle inlet communicating with the inlet channel 13, and the other end is provided with several particle outlets respectively communicating with the several outlet channels. The particle outlets are communicated with the corresponding liquid receiving container 11. The inlet channel 13 is also communicated with the measurement and sorting channel 12, and the measurement and sorting channel 12 is communicated with the several outlet channels. The pump body 2 is connected to a plurality of the liquid storage containers, and the pump body 2 is also connected to the particle inlet; The laser module 3 is used to emit laser light, so that the laser light is incident on the measurement and sorting channel 12 in the carrier chip 8; The camera module 5, the reflector 6, and the magnifying glass 4 form a preset angle, so that the camera module 5 captures the particle image on the measurement and sorting channel 12 inside the carrier chip 8.

[0040] In this embodiment, the pump body 2 can be a microfluidic pump, the carrier chip 8 can be a microfluidic chip, and the substrate assembly 7 can be a high-reflectivity substrate assembly. The micro / nano particle solution to be tested and the driving solution that drives the flow of the micro / nano particle solution to be tested are stored in different storage containers. Under the control of the control module 1, the pump body 2 pushes the micro / nano particle solution to be tested or the driving solution into the inlet channel 13, and then pushes it into the measurement and sorting channel 12 through the inlet channel 13. The substrate assembly 7 is disposed at the bottom of the carrier chip 8 and is used to efficiently reflect the laser passing through the measurement and sorting channel 12 back into the channel to construct a superimposed light field and enhance the interaction intensity between the light and the micro / nano particles. The camera module 5 deflects the light path through the reflector 6 and magnifies it through the magnifying glass 4 to perform real-time imaging of the micro / nano particles in the measurement and sorting channel 12, and transmits the particle image to the control module 1. Based on the received particle image, the control module 1 identifies the position coordinates of the micro / nano particles in the measurement and sorting channel 12 to realize quantitative analysis of the physical parameters of the micro / nano particles to be tested and automated control of the sorting process.

[0041] Preferably, the control module 1 can be a computer for issuing control commands and monitoring particle images. The magnifying glass 4 can be a 10x lens. The camera module 5 can be a charge-coupled device (CCD) camera.

[0042] Specifically, the inlet channel 13 is used to introduce the micro / nano particles to be tested into a preset area. Its narrow width aims to focus the micro / nano particles into a single streamline, ensuring that the particles enter the subsequent light field with the same initial state. The outlet channel is connected to a corresponding liquid receiving container, which includes containers with a first particle size or first refractive index, a second particle size or second refractive index, a third particle size or third refractive index, a fourth particle size or fourth refractive index, and a fifth particle size or fifth refractive index. Different outlet channels correspond to the collection of micro / nano particles with different particle sizes or refractive indices.

[0043] Preferably, such as Figure 3As shown, the width W3 of the inlet channel 13 is smaller than the width W2 of the measurement and sorting channel 12, which enables the micro-nano particles to be focused into a single streamline, ensuring that all micro-nano particles enter the preset area in the same initial state, thereby improving the consistency of sorting.

[0044] Specifically, the laser emitted by the laser module 3 is an elliptical spot or a linear spot; the major axis of the elliptical spot or the linear spot is distributed along the length direction of the measurement and sorting channel 12.

[0045] In this embodiment, after laser shaping, an elliptical or linear spot is formed within the measurement and sorting channel 12. The minor axis of the spot is distributed along the width of the measurement and sorting channel 12, and its high intensity gradient generates a sufficiently strong minor axis gradient force, binding the micro- and nano-particles entering the spot region to the center line of the spot, thus restricting their movement along the minor axis. The major axis of the spot is distributed along the length of the measurement and sorting channel 12, providing a lateral displacement path for the micro- and nano-particles. Under the influence of the lateral light force along the major axis, micro- and nano-particles of different sizes or refractive indices will move to different equilibrium positions along the length of the measurement and sorting channel 12, thereby converting the differences in the physical properties of the micro- and nano-particles into measurable spatial displacement differences. When a linear spot is used, a longer displacement detection range can be provided, further improving the ability to resolve minute differences in physical properties.

[0046] Specifically, such as Figure 2 As shown, the major axis length L1 of the elliptical light spot ranges from 1mm to 10mm, and the minor axis length W1 of the elliptical light spot ranges from 50μm to 100μm.

[0047] In this embodiment, the major axis length L1 of the elliptical light spot is set to 1 mm to 10 mm. This range ensures a sufficiently long optical force interaction distance for the micro / nano particles, allowing them ample time and space to move to distinguishable equilibrium positions under the lateral optical force along the major axis. This avoids the indistinguishability caused by overlapping equilibrium positions of micro / nano particles with different properties due to insufficient interaction distance. The minor axis length W1 of the elliptical light spot is set to 50 μm to 100 μm. This range ensures a sufficiently steep light intensity gradient along the minor axis, generating a strong minor axis gradient force sufficient to overcome fluid disturbances and Brownian motion, thus stably binding the micro / nano particles to the center line of the light spot. The coordinated setting of the major and minor axes balances measurement range and capture stability, providing optical assurance for achieving high-precision quantitative characterization.

[0048] Specifically, the ratio of the major axis to the minor axis of the linear light spot is greater than 10:1.

[0049] In this embodiment, when a linear light spot is used, the ratio of its major axis to its minor axis is greater than 10:1. This large aspect ratio design allows the linear light spot to extend much further in the width direction of the measurement and sorting channel 12 than in the minor axis direction, significantly expanding the detection range of lateral displacement. For micro / nano particles with small differences in particle size or refractive index, the longer detection range allows them to be separated into different equilibrium positions with larger spacing under the drive of lateral light force along the major axis, thereby improving the ability to distinguish minute differences in the physical properties of micro / nano particles. At the same time, the extremely small width in the minor axis direction ensures that the minor axis gradient force is still strong enough to stably bind the micro / nano particles to the center line, ensuring that the lateral displacement of the micro / nano particles occurs strictly along the major axis direction, avoiding the deviation of micro / nano particles from the predetermined motion trajectory due to insufficient minor axis binding, which would affect the measurement accuracy.

[0050] Specifically, such as Figure 3 As shown, the width W2 of the measurement and sorting channel 12 is 200μm-500μm, the length L2 of the measurement and sorting channel 12 is 500μm-1000μm, and the depth of the measurement and sorting channel 12 is 150μm-500μm.

[0051] In this embodiment, the width W2 of the measurement and sorting channel 12 is set to 200 μm to 500 μm. This width range forms a reasonable geometric match with the major and minor axis lengths of the elliptical or linear light spot, ensuring that the light spot can cover the effective measurement area in the width direction of the measurement and sorting channel 12. This ensures that the micro- and nano-particles remain within the light field's influence range throughout the entire lateral displacement process, avoiding insufficient light intensity at the edge areas due to an excessively wide measurement and sorting channel 12, or limiting the displacement detection range due to an excessively narrow width of the measurement and sorting channel 12. The length L2 of the measurement and sorting channel 12 is set to 500 μm to 1000 μm, providing sufficient physical space for micro- and nano-particle sample introduction, light field capture, lateral displacement, and sorting outlet diversion, while avoiding an excessively long channel that would increase the response time. The depth of the measurement and sorting channel 12 is set to 150μm to 500μm. This depth range ensures that the micro-nano particles are not excessively constrained by the upper and lower walls when they flow freely in the measurement and sorting channel 12, and also ensures the consistency of the light field distribution of the laser within the depth range of the measurement and sorting channel 12. This keeps the difference in optical force experienced by the micro-nano particles at different depths within an acceptable range, thus improving the repeatability of the measurement results.

[0052] For example, Figure 2An elliptical laser spot is shown. The minor axis length W1 of the elliptical laser spot is distributed along the X-axis, which is the direction of solution flow. Under the action of the elliptical laser spot, an extremely high minor axis gradient force is generated, which is used to instantly capture and bind micro / nano particles to the center line of the elliptical laser spot. The major axis length L1 of the elliptical laser spot is distributed along the Y-axis, where the Y-axis measures the length of the sorting channel 12, providing sufficient space for lateral displacement of the micro / nano particles.

[0053] Specifically, such as Figure 4 As shown, the laser is incident at a preset angle. and polarization angle The incident light is obliquely incident on the measuring and sorting channel 12, wherein the incident angle is... The polarization angle is the angle between the incident direction of the laser and the normal direction perpendicular to the plane of the carrier chip 8. The angle between the electric field vector direction of the laser and the length direction of the measurement and sorting channel 12 is given.

[0054] In this embodiment, the laser is incident at a preset angle. The polarization angle is obliquely incident on the measurement and sorting channel 12. For example... Figure 2 As shown, the angle of incidence Defined as the direction of laser beam propagation and the normal of the plane of the carrier chip ( ). Figure 2 The angle between the direction of the z-axis and the direction of the z-axis determines the propagation path of the laser within the measurement and sorting channel 12 and its reflection behavior on the substrate assembly 7. This is achieved by setting a suitable incident angle. After passing through the measurement and sorting channel 12, the laser reaches the substrate assembly at the bottom and is efficiently reflected back into the measurement and sorting channel 12. The incident and reflected light superimpose within the measurement and sorting channel 12 to form an interference light field, enhancing the optical intensity acting on the micro / nano particles. (Polarization angle) Defined as the direction of the electric field vector of the laser beam relative to the length direction of the measurement and sorting channel 12 ( Figure 2 The angle between the polarization angle and the direction of the y-axis. This angle directly determines the magnitude and direction of the lateral light force along the long axis. By precisely controlling the polarization angle, the component of the lateral light force along the length of the measurement and sorting channel 12 can be adjusted, so that the micro- and nano-particles are oriented and driven in the long axis direction, thereby realizing the transformation of the differences in the physical properties of micro- and nano-particles into distinguishable spatial displacements.

[0055] Specifically, the angular range of the incident angle The polarization angle is 10 degrees to 80 degrees. The angle range is 10 degrees to 80 degrees.

[0056] In this embodiment, the angle of incidence The angle is set within the range of 10 degrees to 80 degrees, preferably 30 degrees. This angle range ensures high reflectivity of the laser on the substrate component 7 and effective construction of the superimposed light field, avoiding the influence of the incident angle. If the angle is too small, the propagation paths of the reflected light and the incident light will highly overlap, making it impossible to form an effective superimposed light field. This also avoids issues caused by the angle of incidence. An excessively large polarization angle causes the laser to propagate almost parallel to the surface of the carrier chip 8, preventing it from reaching the micro- and nano-particles within the measurement and sorting channel. The setting is within the range of 10 to 80 degrees, preferably 45 degrees, which allows the long-axis lateral light force to obtain the optimal amplitude output within a wide adjustment range, reaching its maximum near 45 degrees. This setting provides a flexible force control space for micro / nano particle systems with different refractive index contrasts, enhancing the device's applicability to different types of micro / nano particles.

[0057] Specifically, the laser is a linearly polarized laser with a wavelength of 400nm-1200nm, and / or the output power of the laser is 1W-4W.

[0058] In this embodiment, the laser wavelength is between 400 nm and 1200 nm, preferably 532 nm. This wavelength band is located within the low-loss absorption window of the water medium, where the absorption coefficient of water is extremely low, approximately 10. -4 cm - The power density is on the order of magnitude, effectively suppressing fluid thermal convection caused by photothermal effects under high power density irradiation, thereby ensuring the stability of the laminar flow field in the measurement area and the repeatability of the micro / nano particle trajectory. The output power is set to 1W to 4W, preferably 3.1W. This power range ensures that sufficient long-axis lateral light force is generated under oblique incidence conditions to overcome residual fluid resistance and Brownian motion, enabling micro / nano particles to be effectively driven and stabilized in equilibrium positions, while avoiding photodamage to biological samples caused by excessive power.

[0059] In this embodiment, the substrate assembly 7 is a highly reflective substrate assembly with a reflectivity greater than 99% for the laser wavelength. This is used to efficiently reflect the laser light passing through the measurement and sorting channel, thereby constructing a superimposed light field within the measurement and sorting channel. The preset scale on the measurement and sorting channel 12 is a virtual spatial calibration scale, corresponding to a displacement distance. This is used by the control module 1 to obtain the precise physical position of the micro / nano particles by identifying their position coordinates in the particle image.

[0060] like Figure 2 As shown in the embodiments of this application, a method for measuring and sorting the particle size and refractive index of micro / nano particles is also provided. This method is implemented using the aforementioned device for measuring and sorting the particle size and refractive index of micro / nano particles, wherein the liquid storage container includes a first liquid storage container and a second liquid storage container. Optionally, the method can be further subdivided into the following steps: S100, The control module controls the camera module to continuously capture particle images of the measurement and sorting channel, and the control module monitors the particle images; In this embodiment, the control module drives the camera module to acquire images of the measurement and sorting channel in real time, and transmits the acquired particle images to the control module for analysis. The control module continuously monitors the particle images using an image recognition algorithm to detect whether micro- or nano-particles have entered the preset area of ​​the measurement and sorting channel, providing trigger signals for subsequent single-particle sampling and light field capture operations.

[0061] S200, The control module controls the pump body to turn on, and the pump body pushes the solution in the first liquid storage container into the particle inlet; wherein, the solution in the first liquid storage container is a solution of the micro-nano particles to be tested; In this embodiment, after confirming that it is in monitoring mode, the control module sends an start command to the pump. The pump pushes the solution of the micro / nano particles to be tested, stored in the first liquid storage container, into the measurement and sorting channel through the particle inlet at a preset flow rate. The solution in the first liquid storage container contains the micro / nano particles to be tested. Driven by the pump, the micro / nano particles enter the measurement and sorting channel with the solution and are imaged in real time by the camera module.

[0062] S300. When the control module detects that a single micro / nano particle to be tested has entered the preset area of ​​the measurement and sorting channel in the particle image, the control module shuts down the pump. In this embodiment, the control module analyzes the particle images acquired by the camera module in real time. Upon detecting a single micro / nano particle entering a preset area of ​​the measurement and sorting channel, it immediately sends a shutdown command to the pump. The preset area is the area irradiated by the light spot. The pump stops driving the solution, keeping the fluid in the measurement and sorting channel stationary. This single-particle-after-pump-stop control strategy ensures that the particles remain in a static fluid environment during subsequent light field interaction, eliminating the influence of flow field disturbances on the equilibrium position of the micro / nano particles and ensuring that the single-value correspondence between lateral displacement distance and physical properties remains undisturbed.

[0063] S400, The control module controls the laser module to turn on, and the laser emitted by the laser module is incident on the micro-nano particles to be tested in the measurement and sorting channel, and the micro-nano particles to be tested are captured by the short axis gradient force of the laser. In this embodiment, the control module sends an activation command to the laser module after the pump is shut down. The linearly polarized laser emitted by the laser module is shaped and incident into the measurement and sorting channel as an elliptical or linear spot. The high-intensity gradient along the short axis of the spot generates a strong short-axis gradient force, which binds the micro / nano particles to be measured to the center line of the spot, restricting their movement along the short axis and allowing them to move only along the long axis.

[0064] S500, the micro / nano particles to be tested are laterally displaced along the length direction of the measurement and sorting channel under the action of the lateral light force of the laser along the long axis, and stop at the corresponding equilibrium position; In this embodiment, while the short-axis gradient force binds the micro / nanoparticles to the center line of the laser spot, the linear polarization characteristics of the laser generate a long-axis lateral force under asymmetric scattering conditions. This long-axis lateral force drives the micro / nanoparticles to undergo lateral displacement along the long axis of the laser spot, i.e., the length direction of the measurement and sorting channel. Driven by the long-axis lateral force, the micro / nanoparticles move along the length direction of the channel, while simultaneously being acted upon by the long-axis gradient force along the long axis of the laser spot. When the micro / nanoparticles move to a certain position, the long-axis lateral force and the long-axis gradient force reach an equilibrium state where they are equal in magnitude and opposite in direction, and the micro / nanoparticles stop at that position. The equilibrium points of the long-axis lateral force and the long-axis gradient force experienced by particles of different sizes or refractive indices are different, and therefore the corresponding equilibrium positions are also different, thus transforming the differences in the physical properties of the micro / nanoparticles into distinguishable differences in spatial displacement.

[0065] S600: The control module obtains the equilibrium position of the micro / nano particle to be tested based on the particle image, and obtains the lateral displacement distance between the equilibrium position of the micro / nano particle to be tested and the center of the laser spot. Based on the lateral displacement distance and a preset mapping table including the mapping relationship between the particle size, refractive index and lateral displacement distance of the micro / nano particle, the particle size or refractive index of the micro / nano particle to be tested is obtained. In this embodiment, the control module continuously acquires images of microparticles via a camera module. When a micro / nanoparticle stops moving within the measurement and sorting channel, the control module reads the lateral displacement distance of its final equilibrium position relative to the center of the light spot. This displacement distance is obtained based on a preset scale on the measurement and sorting channel. The control module uses an image recognition algorithm to accurately locate the particle's position coordinates within the channel. The control module has a built-in preset mapping table, a standard calibration database, recording the corresponding mapping relationships between the lateral equilibrium displacement, particle size, and refractive index of micro / nanoparticles with known properties under preset light field parameters. The control module matches the read lateral displacement distance with the mapping table to calculate and obtain the particle size and refractive index of the micro / nanoparticle under test.

[0066] Specifically, obtaining the particle size or refractive index of the micro / nano particle under test based on the lateral displacement distance and a preset mapping table including the mapping relationship between the particle size, refractive index, and lateral displacement distance of the micro / nano particle includes: If the particle size of the micro / nano particle to be tested is known, the refractive index of the micro / nano particle to be tested can be obtained based on the particle size of the micro / nano particle to be tested and the mapping table. If the refractive index of the micro / nano particle to be tested is known, the particle size of the micro / nano particle to be tested can be obtained based on the refractive index of the micro / nano particle to be tested and the mapping table.

[0067] In this embodiment, the mapping table is obtained as follows: before measuring unknown particles, the lateral displacement distances of micro / nano particles with different refractive indices at known particle sizes or with different particle sizes at known refractive indices are repeatedly measured extensively. Data analysis is then performed to obtain the center equilibrium distance and its uncertainty for particles with known particle sizes or refractive indices, thereby establishing a quantitative mapping relationship between particle size, refractive index, and lateral displacement distance. In actual measurements, even if the lateral displacement distance of the same unknown particle fluctuates during multiple measurements, the control module can quantitatively analyze its particle size or refractive index based on this mapping table, ensuring the reliability of the measurement results.

[0068] S700, the control module controls the laser module to shut down and restarts the pump body. The pump body pushes the solution in the second storage container into the measurement and sorting channel, and pushes the micro-nano particles to be tested at the corresponding equilibrium position into the nearest outlet channel among all the outlet channels. The particles then reach the corresponding receiving container through the outlet channel and the corresponding particle outlet, thus completing the sorting of the micro-nano particles to be tested.

[0069] In this embodiment, after completing the quantitative analysis, the control module sends a shutdown command to the laser module, and the laser stops irradiating. The control module then restarts the pump and switches the pump's input source to the second liquid storage container. Preferably, the second liquid storage container can contain a pure aqueous solution, which serves as the driving solution to push the sorted micro / nano particles along the measurement and sorting channel. The micro / nano particles flow with the driving solution to the nearest outlet channel connected to the measurement and sorting channel. Since micro / nano particles with different physical properties remain at different lateral equilibrium positions, each equilibrium position corresponds to a nearest outlet channel. Therefore, the micro / nano particles are pushed into the outlet channel closest to their equilibrium position, and then reach the corresponding channel outlet, where they are precisely collected by the corresponding receiving container. After completing one cycle, the system resets, waiting for the next micro / nano particle to enter the measurement area, and begins the next measurement and sorting cycle.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A device for measuring and sorting the particle size and refractive index of micro / nano particles, characterized in that, The device includes several liquid storage containers, a measurement and sorting module, a magnifying glass, a reflector, several liquid receiving containers, a control module, and a pump, a laser module, and a camera module, all of which are electrically connected to the control module. The measurement and sorting module includes a substrate assembly and a carrier chip. The carrier chip is disposed on the substrate assembly and has an inlet channel, a measurement and sorting channel, and several outlet channels. The measurement and sorting channel is provided with a scale. One end of the carrier chip is provided with a particle inlet communicating with the inlet channel, and the other end is provided with several particle outlets respectively communicating with the several outlet channels. The particle outlets are communicated with the corresponding liquid receiving containers. The inlet channel is also communicated with the measurement and sorting channel, and the measurement and sorting channel is communicated with the several outlet channels. The pump body is connected to several of the liquid storage containers, and the pump body is also connected to the particle inlet; The laser module is used to emit laser light, so that the laser light is incident on the measurement and sorting channel within the carrier chip; The camera module, the reflector, and the magnifying glass form a preset angle, enabling the camera module to capture images of particles on the measurement and sorting channel within the carrier chip.

2. The apparatus according to claim 1, characterized in that, The laser emitted by the laser module is an elliptical or linear spot; the major axis of the elliptical or linear spot is distributed along the length of the measurement and sorting channel.

3. The apparatus according to claim 2, characterized in that, The major axis of the elliptical light spot ranges from 1 mm to 10 mm, and the minor axis of the elliptical light spot ranges from 50 μm to 100 μm.

4. The apparatus according to claim 2, characterized in that, The ratio of the major axis to the minor axis of the linear light spot is greater than 10:

1.

5. The apparatus according to claim 2, characterized in that, The width of the measurement and sorting channel is 200μm-500μm, the length of the measurement and sorting channel is 500μm-1000μm, and the depth of the measurement and sorting channel is 150μm-500μm.

6. The apparatus according to claim 2, characterized in that, The laser is obliquely incident on the measurement and sorting channel at a preset incident angle and polarization angle, wherein the incident angle is the angle between the incident direction of the laser and the normal direction perpendicular to the plane of the carrier chip; and the polarization angle is the angle between the electric field vector direction of the laser and the length direction of the measurement and sorting channel.

7. The apparatus according to claim 6, characterized in that, The incident angle ranges from 10 degrees to 80 degrees, and the polarization angle ranges from 10 degrees to 80 degrees.

8. The apparatus according to any one of claims 1-7, characterized in that, The laser is a linearly polarized laser with a wavelength of 400nm-1200nm, and / or the output power of the laser is 1W-4W.

9. A method for measuring and sorting the particle size and refractive index of micro / nano particles, characterized in that, The method is implemented in the micro / nano particle size and refractive index measurement and sorting device according to any one of claims 1-8, wherein the liquid storage container includes a first liquid storage container and a second liquid storage container; the method includes: The control module controls the camera module to continuously capture particle images of the measurement and sorting channel, and the control module monitors the particle images; The control module controls the pump to turn on, and the pump pushes the solution in the first liquid storage container into the particle inlet; wherein, the solution in the first liquid storage container is a solution of the micro-nano particles to be tested; When the control module detects that a single micro / nano particle to be tested has entered the preset area of ​​the measurement and sorting channel in the particle image, the control module shuts down the pump. The control module controls the laser module to turn on, and the laser emitted by the laser module is incident on the micro-nano particles to be tested in the measurement and sorting channel, and the micro-nano particles to be tested are captured by the short axis gradient force of the laser. The micro / nano particles to be tested are laterally displaced along the length direction of the measurement and sorting channel under the action of the lateral optical force of the laser along the long axis, and stop at the corresponding equilibrium position; The control module obtains the equilibrium position of the micro / nano particle under test based on the particle image, and obtains the lateral displacement distance between the equilibrium position of the micro / nano particle under test and the center of the laser spot. Based on the lateral displacement distance and a preset mapping table including the mapping relationship between the particle size, refractive index and lateral displacement distance of the micro / nano particle, the control module obtains the particle size or refractive index of the micro / nano particle under test. The control module controls the laser module to shut down and restarts the pump. The pump pushes the solution from the second storage container into the measurement and sorting channel, and pushes the micro-nano particles to be tested at the corresponding equilibrium position into the nearest outlet channel among all the outlet channels. The particles then reach the corresponding receiving container through the outlet channel and the corresponding particle outlet, thus completing the sorting of the micro-nano particles to be tested.

10. The method according to claim 9, characterized in that, The method of obtaining the particle size or refractive index of the micro / nano particle under test based on the lateral displacement distance and a preset mapping table that includes the mapping relationship between the particle size, refractive index, and lateral displacement distance of the micro / nano particle includes: If the particle size of the micro / nano particle to be tested is known, the refractive index of the micro / nano particle to be tested can be obtained based on the particle size of the micro / nano particle to be tested and the mapping table. If the refractive index of the micro / nano particle to be tested is known, the particle size of the micro / nano particle to be tested can be obtained based on the refractive index of the micro / nano particle to be tested and the mapping table.

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