Particulate sorting apparatus and method

Abstract

The invention relates to a particle sorting device and method.The device comprises a micro-channel, a bulk acoustic wave device and two first surface acoustic wave resonators, the two first surface acoustic wave resonators are located outside the micro-channel and used for generating standing waves with two wave nodes in the micro-channel, and the positions of the two wave nodes are the same as the positions of acoustic fluid tunnels on the two side edges of the bulk acoustic wave device; the effect of capturing particles by the acoustic fluid tunnels on the two side edges is enhanced; the two second surface acoustic wave resonators are positioned outside the micro-channel at the downstream of the bulk acoustic wave device and are used for generating a standing wave with a node in the micro-channel so as to move a part of particles released at the tail end of the bulk acoustic wave device to the position of the node; the particles which are released at the tail end of the bulk acoustic wave device and are not moved to the node positions generated by the two second surface acoustic wave resonators flow to the first sub-flow channel, and the particles which are released at the tail end of the bulk acoustic wave device and are moved to the node positions generated by the two second surface acoustic wave resonators flow to the second sub-flow channel. The sorting performance of the particles can be improved.

Description

Technical Field

[0001] This application relates to the fields of Micro-Electro-Mechanical System (MEMS) technology and microfluidics technology, and particularly refers to a particle sorting device and method. Background Art

[0002] During the detection of particles such as biological cells in a fluid based on a microfluidic system, in order to enhance the performance of detection (such as detecting particles such as cells and proteins), particle enrichment is usually performed first, and then the enriched particles or the target particles after sorting are detected.

[0003] Among them, the microfluidic system is mainly based on a microfluidic control chip, supplemented by an external driving physical field and a detection system, aiming to construct a miniaturized on-chip biochemical laboratory, that is, to integrate basic operation processes such as sample preparation, reaction, detection, separation, cell culture, screening, and lysis involved in the fields of biology and chemistry into a microchannel network at the micron scale, so as to more efficiently realize various functions of the biochemical laboratory at a lower cost.

[0004] Among them, the particle capture technology in a liquid is an important branch of microfluidics. Based on the capture of particles in a liquid, the captured particles can be further queued and released at fixed points to achieve sorting, detection, etc. In the particle capture and release technology, micro-vortices are generated in the liquid through the jet effect of a Bulk Acoustic Wave (BAW) device, and then an acoustic fluid tunnel effect is generated in the liquid corresponding to the edge of the BAW device, capturing the particles into the acoustic fluid tunnel, and then enabling the particles to queue up in the acoustic fluid tunnel and move to a certain position downstream of the BAW device (such as an end point of the BAW device) for release to achieve sorting. This acoustic-based solution has the advantages of low power consumption, small damage to cells, and strong versatility.

[0005] Generally speaking, for a BAW device, its particle capture ability can be controlled by controlling the driving power. For example, the stronger the power, the stronger the particle capture ability of the BAW device, which can be reflected in that the particle size that can be captured by the micro-vortex or the acoustic fluid tunnel is smaller, or the running trajectory of the captured particles is closer to the inner layer orbit of the micro-vortex or the acoustic fluid tunnel (see Figure 1a the schematic diagram of the particle running trajectory shown in the right figure). Since the microchannel is a space with boundaries (such as top restrictions), when the power of the BAW device increases beyond a certain threshold, the jet flow generated in the limited space is too strong, which will cause a fluid chaotic flow effect, increasing the instability of the micro-vortex or the acoustic fluid tunnel in the microchannel, and unable to form a stable micro-vortex or acoustic fluid tunnel, thus reducing the manipulation ability of capturing particles, etc.

[0006] How to improve the capture ability of microparticles and thus improve the sorting, detection and other capabilities is a technical problem to be solved. Summary of the Invention

[0007] In view of the above problems of the prior art, the present application provides a microparticle sorting device and method to improve the sorting, detection and other capabilities of microparticles.

[0008] The first aspect of the present application provides a microparticle sorting device, including:

[0009] A microchannel having a liquid containing microparticles therein;

[0010] A bulk acoustic wave device disposed at the bottom of the microchannel. The bulk acoustic wave device is in the shape of a leaf, and the two side edges forming the leaf shape extend in the direction of the microchannel and are parallel. The upstream end and the downstream end of the leaf shape form angles respectively, which are the head end and the tail end of the bulk acoustic wave device. When the bulk acoustic wave device is in a working state, it is used to generate an acoustic streaming tunnel in the microchannel corresponding to the edge of the bulk acoustic wave device to capture the microparticles in the liquid in the microchannel and release them at its tail end;

[0011] Two first surface acoustic wave resonators are disposed on both sides of the bulk acoustic wave device outside the microchannel, and are used to generate a standing wave in the microchannel, and the standing wave has two nodes. The positions of the two nodes are the same as the positions of the acoustic fluid tunnels on both sides of the bulk acoustic wave device to enhance the effect of capturing microparticles by the acoustic fluid tunnels on both sides;

[0012] Two second surface acoustic wave resonators are disposed on both sides outside the microchannel downstream of the bulk acoustic wave device, and are used to generate a standing wave in the microchannel, and the standing wave has one node to move some of the microparticles released at the tail end of the bulk acoustic wave device to the position of the node;

[0013] At least two sub-channels located at the downstream end of the flow channel. The at least two sub-channels include a first sub-channel and a second sub-channel. The inlet position of the first sub-channel corresponds to the tail end position of the bulk acoustic wave device, and the inlet position of the second sub-channel corresponds to the position of the node generated by the two second surface acoustic wave resonators. It is used to make the microparticles released at the tail end of the bulk acoustic wave device and not moved to the position of the node generated by the two second surface acoustic wave resonators flow to the first sub-channel, and the microparticles released at the tail end of the bulk acoustic wave device and moved to the position of the node generated by the two second surface acoustic wave resonators flow to the second sub-channel.

[0014] Optionally, a part of the surface acoustic wave resonator extends upstream along the side of the bulk acoustic wave device for a certain distance.

[0015] Optionally, enhancing the effect of the acoustic-fluidic tunnel in the enhanced side to capture microparticles includes at least one of the following: among the captured microparticles, there are microparticles with smaller sizes compared to those captured only using a bulk acoustic wave device; making the captured microparticles gather more towards the center of the acoustic-fluidic tunnel compared to those captured only using a bulk acoustic wave device.

[0016] Optionally, it further includes: arranging a microparticle enrichment device in at least one sub-channel; a detection device for detecting the microparticles enriched by the microparticle enrichment device.

[0017] Optionally, the first surface acoustic wave resonator, the second surface acoustic wave resonator and the micro-channel are arranged on the same substrate, and the first surface acoustic wave resonator and the second surface acoustic wave resonator propagate surface waves to the micro-channel through the substrate.

[0018] The second aspect of this application provides a microparticle sorting method, using any one of the above-mentioned microparticle sorting devices. This method includes:

[0019] Generating an acoustic-fluidic tunnel at the edge position of the bulk acoustic wave device in the micro-channel based on the bulk acoustic wave device to capture the microparticles in the liquid in the micro-channel and release them at the end of the bulk acoustic wave device;

[0020] Generating a standing wave with two nodes in the micro-channel based on two first surface acoustic wave resonators, and enhancing the effect of the acoustic-fluidic tunnel on both sides of the bulk acoustic wave device to capture microparticles through these two nodes;

[0021] Generating a standing wave with one node in the micro-channel based on two second surface acoustic wave resonators to move some of the microparticles released at the end of the bulk acoustic wave device to the position of this node;

[0022] The microparticles released at the end of the bulk acoustic wave device and not moved to the node position generated by the two second surface acoustic wave resonators flow to the first sub-channel, and the microparticles released at the end of the bulk acoustic wave device and moved to the node position generated by the two second surface acoustic wave resonators flow to the second sub-channel.

[0023] Optionally, it further includes: capturing and enriching the microparticles flowing into the sub-channel through a microparticle enrichment device in at least one sub-channel, and detecting them through a detection device.

[0024] Optionally, it further includes: turning off or reducing the power of the surface acoustic wave resonator to reduce the effect of the acoustic-fluidic tunnel to capture microparticles, so as to release some of the captured microparticles.

[0025] Optionally, it further includes: reducing the power of the bulk acoustic wave device to reduce the effect of the acoustic-fluidic tunnel to capture microparticles, so as to release some of the captured microparticles.

[0026] Optionally, the method further includes: adjusting the flow rate of the fluid in the microchannel to adjust the effect of the acoustic fluid tunnel in capturing particles.

[0027] The particle sorting scheme provided in the present application improves the particle capture capability during the particle sorting process, for example, it can capture particles of smaller size, and make the particles gather closer to the center of the acoustic fluid tunnel, thereby improving the enrichment or aggregation capability, and further brings about the ability of particles to be more focused along the acoustic fluid tunnel, as well as the focusing capability of release at a fixed point (such as the end of a bulk acoustic wave device), thereby improving the sorting performance (for example, due to the focusing of the release point, the release position to the downstream sorting channel is more precise). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1a is a schematic diagram of the jet phenomenon and the secondary flow phenomenon generated by the bulk acoustic wave device provided in the embodiment of the present application;

[0029] Figure 1b is a schematic diagram of an acoustic fluid tunnel provided in an embodiment of the present application;

[0030] Figure 2a is a schematic diagram of the principle of a particle sorting device provided in the first embodiment of the present application;

[0031] Figure 2b is a schematic diagram of a standing wave of a first SAW and a standing wave of a second SAW;

[0032] Figure 3a is a schematic top view of a specific implementation of a particle sorting device provided in an embodiment of the present application;

[0033] Figure 3b yes Figure 3a A schematic diagram of a side view of

[0034] Figure 4 This is a simulation diagram of the BAW and the first SAW capturing particles provided in an embodiment of the present application.

[0035] Description of reference numerals:

[0036] 1-inlet tube, 2-substrate, 3-first surface acoustic wave resonator, 4-second surface acoustic wave resonator, 5-outlet tube, 6-particle enrichment device, 7-leaf-shaped bulk acoustic wave device.

[0037] It should be understood that the size and shape of each block diagram in the above structural diagram are for reference only and should not constitute an exclusive interpretation of the embodiment of the present invention. The relative position and inclusion relationship between the blocks presented in the structural diagram are only schematic representations of the structural association between the blocks, and do not limit the physical connection method of the embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following describes the technical solutions provided in this application with reference to the accompanying drawings and examples. It should be understood that the system structures and service scenarios provided in the embodiments of this application are mainly used to illustrate the possible implementation manners of the technical solutions of this application, and should not be construed as the only limitation to the technical solutions of this application. Those of ordinary skill in the art will know that with the evolution of system structures and the emergence of new service scenarios, the technical solutions provided in this application are equally applicable to similar technical problems.

[0039] It should be understood that the particle sorting solutions provided in the embodiments of this application include particle sorting devices and methods. Since the principles of these technical solutions for solving problems are the same or similar, in the following introduction of specific embodiments, some repetitions may not be elaborated again, but it should be regarded that there are mutual references between these specific embodiments and they can be combined with each other.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. In case of inconsistency, the meaning described in this specification or the meaning obtained according to the content recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application. In order to accurately describe the technical content in this application and to accurately understand the present invention, the following explanations or definitions of the terms used in this specification are given before describing the specific embodiments:

[0041] 1) Bulk acoustic wave device: A high-frequency resonator, which can be a device that generates mechanical vibrations by applying a voltage based on the piezoelectric effect. In a liquid, a volume force can be generated based on the bulk acoustic wave to push the liquid to form a jet and trigger a fluid micro-vortex. In this application, a piezoelectric resonator that generates no less than 0.5 gigahertz (gigahertz is GHz) during operation is used. Preferably, it is a piezoelectric resonator that generates no less than 1 GHz and no more than 30 GHz during operation. For example, it can be a piezoelectric resonator of 2G - 2.5 GHz.

[0042] Among them, the bulk acoustic wave device can include a thin film bulk acoustic wave device (FBAR) and a solidly mounted resonator (SMR).

[0043] 2) Jet phenomenon: A phenomenon generated when the acoustic wave of a bulk acoustic wave device acts on a liquid. The regional vibration generated at the working interface of the bulk acoustic wave device can form a traveling wave in the liquid and exert a continuous thrust on the local liquid in the liquid environment, causing at least a part of this part of the liquid to move linearly along the direction of acoustic wave propagation. This linear motion phenomenon is called the jet phenomenon.

[0044] Secondary flow phenomenon: including eddy current and thermal reflux, is another phenomenon generated when a bulk acoustic wave device acts on a liquid, including the eddy current (or micro-eddy) caused by the local circulation of the liquid pushed by the jet, and the thermal reflux generated by the heat of the bulk acoustic wave device.

[0045] The jet phenomenon and the secondary flow phenomenon can be seen in Figure 1a the shown images and schematic diagrams. The Figure 1a schematic diagram showing the capture of microparticles using eddy current (i.e., micro-eddy) is shown therein.

[0046] 3) Acoustic-fluid tunnel: When the bulk acoustic wave device is excited by an input signal, it generates ultra-high frequency vibrations to emit bulk acoustic waves. The bulk acoustic waves propagate in the fluid, causing the directional movement of the fluid (jet phenomenon), and further forming fluid micro-eddies. One of the phenomena is that several tiny fluid micro-eddies can be generated at the chip edge of the bulk acoustic wave device in the fluid (as Figure 1a shown). These fluid micro-eddies can capture microparticles in the liquid. Combining the position distribution of these fluid micro-eddies, it presents the phenomenon that the microparticles in the liquid are distributed at the chip edge of the bulk acoustic wave device. Since the microparticles in the fluid will flow through these fluid micro-eddies distributed at the chip edge, the paths formed by these fluid micro-eddies for the microparticles to flow through (as Figure 1b shown) are called acoustic-fluid tunnels in this application.

[0047] 4) Surface Acoustic Wave (SAW) resonator: Usually formed by interdigital electrodes, and the acoustic waves propagate directionally along the surface of the substrate where the interdigital electrodes are located. When acting on a liquid, standing waves can be generated in the liquid, and the standing waves include antinodes and nodes. When the SAW resonator is used to manipulate microparticles in a microchannel, the microparticles can be moved to the nodes.

[0048] 5) Microparticles: Refer to geometric bodies with a specific shape within a certain size range. For example, microscopic particles located in a liquid environment and distinguishable from the liquid environment (i.e., insoluble) and movable in the liquid environment can be regarded as the microparticles described in this application.

[0049] In some embodiments, the diameter range of the microparticles can range from the nanoscale to the millimeter scale. The microparticles can include: cells, molecules, molecular polymers, long-chain molecules, DNA nucleic acids, inorganic microparticles, metal microparticles, composite microparticles, magnetic microparticles, quantum dots, microbeads (or microspheres, used for modifying functions, such as modifying proteins, specific substances, etc.). In some embodiments, the microparticles can also be non-solid, for example, they can be in the form of droplets, such as droplets in another immiscible liquid medium, such as water droplets (or water beads) in the oil phase in a microchannel, or oil droplets (or oil beads) in the water phase.

[0050] 6) Reasonable ranges of parameters, as well as positive and negative correlations between parameters: The reasonable ranges refer to the ranges of parameters that conform to the solution of this application. For example, the particle size is within a reasonable range, the power is controlled within a reasonable range, etc. These ranges can be obtained based on experiments. A positive correlation between parameters means that one parameter increases as another parameter increases, and a negative correlation means that one parameter increases as another parameter decreases. Each parameter mentioned in this application cannot be infinitely small or infinitely large. Therefore, without special instructions, the values of each parameter mentioned in this application are all within reasonable numerical ranges. For example, when describing that parameter A is positively correlated with parameter B, it means that within a certain value range, parameter A is positively correlated with parameter B, and it can be predicted that beyond this range, parameter B is no longer positively correlated with parameter A (when parameter B reaches a saturation state after parameter A increases to a certain value, then parameter B no longer increases as parameter A increases). Then this value range is the reasonable numerical range.

[0051] This application provides an improved particle sorting solution. By the cooperation of the bulk acoustic wave device and the SAW device, the particle capture ability can be improved, smaller-sized particles can be captured, or the running trajectory of the captured particles can be closer to the inner layer orbit of the microvortex or the acoustic fluid tunnel, that is, the aggregation effect is stronger, thereby improving the subsequent particle sorting performance.

[0052] Next, the solution provided by this application will be introduced in detail with reference to the drawings and embodiments.

[0053] The first embodiment of this application provides a particle manipulation device. Referring to Figure 2a 、 Figure 2b 、 Figure 3a 、 Figure 3b as shown, this manipulation device includes:

[0054] A microchannel, which contains a liquid with particles therein;

[0055] A bulk acoustic wave device 7, which is arranged at the bottom of the microchannel. The bulk acoustic wave device 7 is in the shape of a leaf (the leaf shape in this application is approximately fusiform as shown in Figure 2b ). The two side edges forming the leaf shape extend in the microchannel direction and are arranged in parallel. The upstream end and the downstream end forming the leaf shape form angles respectively, which are the head end and the tail end of the bulk acoustic wave device 7. When the bulk acoustic wave device 7 is in a working state, it is used to generate an acoustic fluid tunnel at the edge corresponding to the bulk acoustic wave device 7 in the microchannel to capture the particles in the liquid in the microchannel and release them at its tail end;

[0056] Two first surface acoustic wave resonators 3 (hereinafter referred to as SAW for surface acoustic wave resonator) are arranged on both sides of the bulk acoustic wave device 7 outside the microchannel, and are used to generate standing waves in the microchannel, and the standing waves have two nodes, and the positions of the two nodes are the same as the positions of the acoustic fluid tunnels on both sides of the bulk acoustic wave device 7, so as to enhance the effect of capturing particles by the acoustic fluid tunnels on both sides;

[0057] Two second surface acoustic wave resonators 4 are arranged on both sides outside the microchannel downstream of the bulk acoustic wave device 7, and are used to generate standing waves in the microchannel, and the standing waves have one node, so as to move some of the particles released at the end of the bulk acoustic wave device 7 to the position of the node;

[0058] At least two sub-channels located at the downstream end of the flow channel, the at least two sub-channels include a first sub-channel and a second sub-channel, the inlet position of the first sub-channel corresponds to the end position of the bulk acoustic wave device 7, and the inlet position of the second sub-channel corresponds to the position of the node generated by the two second SAWs, and is used to make the particles released at the end of the bulk acoustic wave device 7 and not moved to the position of the node generated by the two second SAWs flow to the first sub-channel, and the particles released at the end of the bulk acoustic wave device 7 and moved to the position of the node generated by the two second SAWs flow to the second sub-channel.

[0059] Among them, the particle size of the particles moved to the position of the node generated by the two second SAWs will be larger than that of the particles released at the end of the bulk acoustic wave device 7 and not moved to the position of the node generated by the two second SAWs, because the particles with larger particle sizes are more affected by the force of the standing waves generated by the two second SAWs and are more likely to be moved to the node position.

[0060] In some embodiments, there are particle enrichment devices 6 and detection devices in at least one sub-channel. The particle enrichment device 6 can be realized by a bulk acoustic wave device in the shape of a regular pentagon, which is located at the bottom of the corresponding sub-channel and captures particles through micro-vortices on the side for enrichment. The detection device can be an optical device facing the particle enrichment device 6, such as a fluorescence detection device, for detecting the enriched particles (the particles can be pre-fluorescently modified), and the detection device can also be an electron microscope, etc.

[0061] Among them, the surface wave propagation directions of the two first SAWs and two second SWAs located outside the microchannel all face the microchannel. The first SAW, the second SAW and the microchannel can be arranged on the same substrate 2, and the surface waves are propagated to the microchannel through the substrate 2.

[0062] In some embodiments, enhancing the effect of the acoustic fluidic tunnel in capturing microparticles includes: among the captured microparticles, there are microparticles with smaller sizes compared to those captured only using the bulk acoustic wave device 7. Thus, manipulation techniques for smaller-sized microparticles can be applied.

[0063] In some embodiments, enhancing the effect of the acoustic fluidic tunnel in capturing microparticles includes: making the captured microparticles gather more towards the center of the acoustic fluidic tunnel. The simulation diagram of c in Figure 4 can be referred to for this effect. Thus, a further aggregation effect of the captured microparticles can be achieved, which is beneficial for enrichment detection (such as checking the modified fluorescence intensity, the higher the aggregation degree, the stronger the fluorescence intensity), or manipulation of the movement trajectory (the movement trajectory is more focused).

[0064] In some embodiments, the widths of the two first SAWs (the width direction refers to the direction parallel to the interdigital fingers of the SAW) can match the lengths of the two side edges of the bulk acoustic wave device 7, for example, they have the same size.

[0065] In other embodiments, the widths of the two first SAW devices can be longer than the lengths of the two side edges of the bulk acoustic wave device 7, and the extended part extends upstream for a certain distance with respect to the two side edges of the bulk acoustic wave device 7. Thus, before the microparticles in the fluid in the microchannel reach the bulk acoustic wave device 7, some microparticles can be migrated to the two antinode positions of the standing wave formed by the two first SAWs, and then can enter the acoustic fluidic tunnels on the two side edges of the bulk acoustic wave device 7. That is, a preliminary aggregation of microparticles is formed through the two first SAWs.

[0066] As Figure 3a and Figure 3b show a specific implementation manner of the microparticle sorting device. In this figure, a sampling tube 1 is connected to the upstream of the microchannel, and the downstream of the microchannel has three sub-channels, which are respectively connected to the sampling tubes 5. The microparticle enrichment device 6 uses a pentagonal BAW device.

[0067] The second embodiment of the present application also provides a microparticle sorting method, which uses the microparticle sorting device described in the first embodiment or any one of its optional embodiments to manipulate microparticles. The method includes:

[0068] Put the bulk acoustic wave device 7 in a working state to generate an acoustic fluidic tunnel corresponding to the edge of the bulk acoustic wave device 7 in the microchannel, so as to capture the microparticles in the liquid in the microchannel and release them at its end;

[0069] Put the two first SAWs in a working state to generate a standing wave with two antinodes in the microchannel, and enhance the effect of the acoustic fluidic tunnels on the two side edges of the bulk acoustic wave device 7 in capturing microparticles through the two antinodes;

[0070] Put two second SAWs in working state to generate a standing wave with one node in the microchannel, so as to move some of the particles released at the end of the bulk acoustic wave device 7 to the node position;

[0071] The particles released at the end of the bulk acoustic wave device 7 and not moved to the node position generated by the two second SAWs flow into the first sub-channel, and the particles released at the end of the bulk acoustic wave device 7 and moved to the node position generated by the two second SAWs flow into the second sub-channel.

[0072] In some embodiments, it further includes: capturing and enriching the particles flowing into the sub-channel through the particle enrichment device 6 in at least one sub-channel, and detecting through the detection device.

[0073] In some embodiments, it further includes: turning off or reducing the power of the first SAW to reduce the effect of the acoustic fluid tunnel capturing particles, so as to release some of the captured particles. Among them, the released particles are smaller in particle size than the unreleased particles.

[0074] In some embodiments, it further includes: reducing the power of the bulk acoustic wave device 7 to reduce the effect of the acoustic fluid tunnel capturing particles, so as to release some of the captured particles. Among them, the released particles are smaller in particle size than the unreleased particles.

[0075] In some embodiments, it further includes: adjusting the flow rate of the fluid in the microchannel to adjust the effect of the acoustic fluid tunnel capturing particles. Among them, the faster the flow rate, the shorter the residence time of the particles in the microchannel, and the weaker the capturing effect.

[0076] Next, the reason why the present application can improve the particle manipulation ability based on the cooperation of the bulk acoustic wave device and the two first SAWs is further introduced. Among them, the microchannel is designed to be 50 μm in height, the particles are 1 μm particles, and the bulk acoustic wave device uses BAW. Then, the two first SAWs and BAW are started separately, and the simulation is obtained by starting BAW and the two first SAWs simultaneously Figure 4 The shown simulation diagram.

[0077] See Figure 4 Figure a in it is the simulation diagram of the flow field velocity distribution with only the first SAW started in the microchannel. The right diagram represents the simulation of the enrichment situation of 1-μm-diameter particles in the microchannel. It can be found that due to the attenuation of the acoustic radiation force, starting only the first SAW has a weak enrichment effect on 1-μm particles. In the right diagram, the particles pointed by the arrow near the bottom are the enriched particles, and the particles pointed by the arrow near the top are the unenriched particles.

[0078] Among them, the acoustic radiation forces of the two first SAW devices form a standing wave in the microchannel, migrating the nanoparticles in the microchannel to near the wave nodes, forming the focusing of the particles, so as to confine the randomly dispersed nanoparticles in the microchannel to a certain position (i.e., the wave node position). Figure 4 Above the highest flow velocity point at the bottom of the microchannel in a, it is the lowest flow velocity point, that is, the wave node.

[0079] See Figure 4 In Figure b in, it is a simulation diagram of the flow field velocity distribution when only the BAW is activated in the microchannel. As shown in the flow field diagram on the left, the maximum flow field velocity can reach 0.176 m / s. The right diagram represents the simulation of the distribution of 1-μm particles in the microchannel after the BAW is turned on. Most of the particles are distributed on the outer orbit of the micro-vortex (generated by the excitation of the BAW) corresponding to the acoustic fluid tunnel, as shown by the arrows in the figure.

[0080] Among them, the acoustic radiation force of the BAW device pushes the nanoparticles to the central region of the acoustic streaming micro-vortex. The nanoparticles pass through a helical trajectory in the acoustic streaming micro-vortex and gradually reach the equilibrium position and are distributed along its orbit. Figure 4 In the simulation diagram in Figure b in, it is a simulation diagram of capturing 1-μm particles at a relatively high power by continuously increasing the power of the BAW to improve the capture ability of the BAW. When the power is further increased, the capture ability for 1-μm particles will decrease. It is speculated that due to the combination of too strong jet flow and the limitation of the microchannel, it is difficult for the fluid to generate a stable micro-vortex.

[0081] See Figure 4 In Figure c in, it is a simulation diagram of the superposition of the flow field velocity distributions after the two first SAWs and the BAW are turned on at the same time. Among them, the standing wave nodes formed by the two first SAWs are located at the micro-vortices (acoustic fluid tunnels) corresponding to the two edges of the BAW. When the two devices work simultaneously, as shown in the left flow field diagram, the maximum flow field velocity can reach 0.22 m / s (indicating a stronger capture ability). On the other hand, the 1-μm particles in the microchannel are affected by the acoustic radiation forces from both the first SAW and the BAW at the same time, and their movement trajectories are closer to the center of the acoustic fluid micro-vortex, as shown by the arrows in the right particle enrichment diagram.

[0082] As can be seen from the above, under the action of the acoustic radiation forces of the two first SAWs and the BAW, the movement trajectories are closer to the center of the acoustic fluid micro-vortex, which also means a stronger aggregation effect. Since 1-μm particles are used in the simulation, this means that particles smaller than 1 μm can be captured on the outer orbit of the micro-vortex.

[0083] Among them, the above simulation diagram is a diagram of the flow velocity field. It can be seen that the flow velocity field formed by simultaneously turning on the two first SAWs and BAWs is still a relatively stable flow velocity field. Considering the reason, one is the flow field formed by the jet generated by the BAW and the flow field of the standing wave generated by the first SAW. The superposition of these two flow fields (in fact, there will be mutual influence between the flow fields formed by simultaneously turning on the first SAW and BAW. For the sake of simplifying the analysis, here it is only simply considered as superposition) does not enhance the jet field like increasing the BAW, but the superposition of different flow fields, so it still maintains a relatively stable flow velocity field.

[0084] Next, further analyze from the perspective of mechanics. Here, the gravity of the particles, the viscous force in the liquid, etc. are not considered for the time being. Among them, the particles in the microchannel are subjected to the drag force of the fluid (which makes the particles move downstream with the fluid) and the drag force of the micro-vortices formed by the acoustic radiation of the BAW (which makes the particles move on the micro-vortex orbit). The larger the particle size, the greater the acoustic force. Therefore, when only using the BAW to capture the particles in the microchannel, the particles captured by the micro-vortices are on the micro-vortex orbit. The larger the particle size, the closer it is to the inner layer orbit of the micro-vortex, and the smaller the particle size, the closer it is to the outer layer orbit of the micro-vortex. Too small particles are subjected to too small acoustic force and cannot be captured. When the two first SAWs are turned on simultaneously, the first SAW acting on the particles in the fluid will push the particles towards the standing wave nodes, which can be understood as providing a force towards the node position for the particles. Since in the embodiment of the present application, the standing wave node position corresponds to the position of the edge acoustic fluid tunnel (i.e., the micro-vortex) of the BAW, that is, by starting the two first SAWs, each particle is increased by a force towards the micro-vortex. Based on this force, the particles can more easily enter the micro-vortex or the inner layer orbit of the micro-vortex, thereby improving the control performance of particle capture, aggregation, etc.

[0085] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods are not limited to the above embodiments and can also be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical or other forms.

[0086] In addition, the terms "first, second, third, etc." or module A, module B, module C, etc. in the specification and claims are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that, under the allowed circumstances, the specific order or sequence can be interchanged so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0087] The term "comprising" as used in the description and claims should not be construed as limited to the content listed thereafter; it does not exclude other elements or steps. Therefore, it should be interpreted as specifying the presence of the stated features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps or components and their groups. Thus, the expression "an apparatus comprising devices A and B" should not be limited to an apparatus consisting only of components A and B.

[0088] As used herein, "an embodiment" or "embodiments" means that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. Thus, the phrases "in an embodiment" or "in embodiments" that appear throughout this specification are not necessarily all referring to the same embodiment, but may. Additionally, in one or more embodiments, the various specific features, structures, or characteristics can be combined in any suitable manner, as will be apparent to those of ordinary skill in the art from this disclosure.

[0089] Note that the above is only the preferred embodiment of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and without departing from the concept of the present application, more other equivalent embodiments can be included, all of which fall within the scope of protection of the present application.

Claims

1. A particle sorting device, characterized in that, Comprising: A microchannel having a liquid containing microparticles therein; A bulk acoustic wave device disposed at the bottom of the microchannel. The bulk acoustic wave device is in the shape of a leaf. The two side edges forming the leaf shape extend in the microchannel direction and are arranged in parallel. The upstream end and the downstream end forming the leaf shape form angles respectively, which are the head end and the tail end of the bulk acoustic wave device. When the bulk acoustic wave device is in the working state, it is used to generate an acoustic streaming tunnel in the microchannel corresponding to the edge of the bulk acoustic wave device to capture the microparticles in the liquid in the microchannel and release them at its tail end; Two first surface acoustic wave resonators disposed outside the microchannel and on both sides of the bulk acoustic wave device, used to generate a standing wave in the microchannel, and the standing wave has two nodes. The positions of the two nodes are the same as the positions of the acoustic fluid tunnels on both sides of the bulk acoustic wave device to enhance the effect of capturing microparticles by the acoustic fluid tunnels on both sides; Two second surface acoustic wave resonators disposed on both sides outside the microchannel downstream of the bulk acoustic wave device, used to generate a standing wave in the microchannel, and the standing wave has one node to move some of the microparticles released at the tail end of the bulk acoustic wave device to the position of this node; At least two sub-channels located at the downstream end of the flow channel. The at least two sub-channels include a first sub-channel and a second sub-channel. The inlet position of the first sub-channel corresponds to the position of the tail end of the bulk acoustic wave device, and the inlet position of the second sub-channel corresponds to the position of the node generated by the two second surface acoustic wave resonators, used to make the microparticles released at the tail end of the bulk acoustic wave device and not moved to the position of the node generated by the two second surface acoustic wave resonators flow into the first sub-channel, and the microparticles released at the tail end of the bulk acoustic wave device and moved to the position of the node generated by the two second surface acoustic wave resonators flow into the second sub-channel.

2. The device according to claim 1, characterized in that, A part of the surface acoustic wave resonator extends a certain distance upstream of the microchannel relative to the side of the bulk acoustic wave device.

3. The device according to claim 1, characterized in that, The effect of enhancing the capture of microparticles by the acoustic fluid tunnel on the side includes at least one of the following: Among the captured microparticles, there are microparticles with smaller sizes compared to the microparticles captured only by using the bulk acoustic wave device; Make the captured microparticles gather more towards the center of the acoustic fluid tunnel compared to the microparticles captured only by using the bulk acoustic wave device.

4. The device according to claim 1, characterized in that, Also comprising: A microparticle enrichment device is provided in at least one sub-channel; A detection device for detecting the microparticles enriched by the microparticle enrichment device.

5. The device according to claim 1, characterized in that, The first surface acoustic wave resonator, the second surface acoustic wave resonator and the microchannel are disposed on the same substrate, and the first surface acoustic wave resonator and the second surface acoustic wave resonator transmit surface waves to the microchannel through the substrate.

6. A method for particle sorting, using the particle sorting device according to any one of claims 1-5, characterized in that, Comprising: Based on the bulk acoustic wave device generating an acoustic streaming tunnel at the edge position of the bulk acoustic wave device in the microchannel to capture the microparticles in the liquid in the microchannel and release them at the tail end of the bulk acoustic wave device; Based on the two first surface acoustic wave resonators generating a standing wave with two nodes in the microchannel, and enhancing the effect of capturing microparticles by the acoustic fluid tunnels on both sides of the bulk acoustic wave device through the two nodes; Based on the two second surface acoustic wave resonators generating a standing wave with one node in the microchannel to move some of the microparticles released at the tail end of the bulk acoustic wave device to the position of this node; Particles released at the end of the bulk acoustic wave device and not moved to the node positions generated by the two second surface acoustic wave resonators flow into the first sub-channel, and particles released at the end of the bulk acoustic wave device and moved to the node positions generated by the two second surface acoustic wave resonators flow into the second sub-channel.

7. The method according to claim 6, wherein Further comprising: In at least one sub-channel, a particle enrichment device captures and enriches the particles flowing into the sub-channel, and a detection device performs detection.

8. The method according to claim 6, wherein Further comprising: Turn off or reduce the power of the surface acoustic wave resonator to reduce the effect of the acoustic fluid tunnel capturing particles and release some of the captured particles.

9. The method according to claim 6, wherein Further comprising: Reduce the power of the bulk acoustic wave device to reduce the effect of the acoustic fluid tunnel capturing particles and release some of the captured particles.

10. The method according to claim 6, wherein Further comprising: Adjust the flow rate of the fluid in the micro-channel to adjust the effect of the acoustic fluid tunnel capturing particles.

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