Three-dimensional particle sorting chip based on acoustic streaming technology

Abstract

This invention provides a three-dimensional particle sorting chip based on acoustic fluid control technology, comprising: piezoelectric ceramic, a microfluidic system, interdigitated electrodes, and a piezoelectric substrate. The microfluidic system has a particle inlet, a sheath flow inlet, and a particle outlet, and is formed by stacking and encapsulating a glass cover, an upper glass chip, several intermediate separators, and a lower glass chip. It includes a bulk acoustic wave longitudinal sorting zone, a sheath flow aggregation zone, a surface acoustic wave (SAW) transverse sorting zone, and a particle separation zone. The bulk acoustic wave longitudinal sorting zone and the SAW transverse sorting zone perform longitudinal and transverse sorting of mixed particles, respectively. A pair of interdigitated electrodes are provided, distributed on both sides of the microfluidic system and tilted at a 15° angle to the microfluidic system. The piezoelectric substrate is made of lithium niobate material with a 128° tangential X-direction propagation. This invention achieves a high degree of integration between longitudinal bulk acoustic wave sorting and transverse SAW, which is beneficial for simultaneously achieving high throughput and high precision in the sorting of complex biological samples.

Description

Technical Field

[0001] This invention relates to the field of particle sorting chip technology, and in particular to a three-dimensional particle sorting chip based on acoustic flow control technology. Background Technology

[0002] Acoustic flow separation technology is based on the interaction between sound waves and fluids, as well as suspended particles within the fluid, to drive the separation of particulate matter and fluids. Sound waves are the propagation form of the vibration state of an object; waves generated at vibration frequencies in the megahertz range are called ultrasound. Ultrasound is widely used due to its good directionality, high energy, and strong penetrating power. When an external sound field is applied, particles suspended in a fluid are mainly subjected to acoustic radiation force and Stokes drag. The propagation of sound waves in a fluid generates a pressure gradient, thus producing an acoustic radiation force (ARF) in the sound field. The magnitude of the ARF is related to the wavelength and amplitude of the sound, as well as the physical properties of the fluid, particles, etc., such as size, stiffness, density, and compressibility. Therefore, particles with different properties can be separated using acoustic flow separation technology.

[0003] Traditional particle sorting (such as cells, particles, and nanotubes) is typically performed on a macroscopic scale, such as centrifugation and microfiltration. These methods have been developed and applied for many years, gaining reliable scientific validation and market acceptance. However, they generally suffer from drawbacks such as system complexity, cumbersome operation, and large sample volume requirements. Furthermore, the loss of target particles is easily caused during sample transfer, container replacement, and sample chemical processing.

[0004] Compared with traditional particle sorting technology, microfluidic chip-based sorting technology has advantages such as low sample consumption, high resolution and sensitivity, easy integration and miniaturization. Moreover, the entire process of sample injection, particle sorting and target particle identification can be realized continuously in microfluidic devices, which can reduce the loss of target particles.

[0005] Among numerous technologies, acoustic fluid control sorting combines the advantages of being label-free, non-contact, and biocompatible, making it suitable for the effective sorting of biological particles. Its principle involves applying an acoustic field around a microchannel, causing suspended particles in the fluid to be subjected to acoustic radiation forces. Under the combined influence of these forces and Stokes drag, the particles deviate from their original trajectories. Since the acoustic radiation force is related to density, size, and compressibility, particles with different properties exhibit different deviation trajectories. Therefore, particle sorting can be performed based on these different physical characteristics. The acoustic field used in this technology is multifunctional and highly controllable, causing virtually no damage to the vitality and properties of biological particles.

[0006] Based on the propagation of sound waves on the surface or inside the sound transmission medium, acoustic flow control technology can be divided into surface acoustic wave (SAW) sorting technology and bulk acoustic wave (BAW) sorting technology.

[0007] The bulk acoustic wave sorting chip can achieve vertical sorting of particles, and includes a transducer layer, coupling layer, matching layer, fluid layer, and reflective layer, such as... Figure 1 The diagram shows a layered resonator. The transducer layer generates sound waves, the fluid layer contains the fluid medium and suspended particles, and the reflective layer reflects the sound waves, which superimpose with the incident wave to form a standing wave. Typical bulk acoustic wave sorting chips can sort two different types of particles. By separating the fluid layer, sorting multiple types of particles can be achieved. However, due to the height limitation of the fluid layer, it can only sort a maximum of three types of particles, making miniaturization and integration difficult, and hindering high-precision sorting of micron-sized particles.

[0008] Surface acoustic wave (SAW) sorting chips enable lateral particle sorting in the horizontal direction. They consist of a piezoelectric substrate, an interdigital transducer (IDT), and a microfluidic system. The IDT generates a periodically distributed electric field under an alternating electrical signal. The piezoelectric substrate deforms and vibrates under the reverse pressure effect, generating SAW waves. These waves propagate along the substrate surface, enter the bottom of the central cavity, and then refract or leak into the fluid at a Rayleigh angle. Particles in the fluid are manipulated through acoustic radiation and Stokes drag. SAW waves are classified into traveling surface acoustic waves (TSAW) and standing surface acoustic waves (SSAW). Currently, a tilted SAW sorting chip is more widely used. This type of chip uses interdigital electrodes at an angle to the microfluidic channel, ensuring that the pressure nodes and antinodes within the channel are at an angle to the fluid flow direction. Particles flowing in an acoustic field will pass through multiple pairs of pressure nodes and antinodes under the influence of acoustic radiation force and Stokes drag, which is equivalent to moving in a repetitive acoustic field. The differences in the lateral trajectories of particles of different sizes are amplified. Surface acoustic wave (SAW) sorting chips can achieve the sorting of various particles through multi-stage SAW sorting design. However, this multi-stage sorting requires corresponding interdigitated electrodes in each stage, making device design and manufacturing more complex and difficult to achieve efficient sorting of various particles.

[0009] In summary, current research on bulk acoustic wave (BAW) sorting and surface acoustic wave (SAW) sorting technologies based on different sorting mechanisms can only achieve single two-dimensional sorting, and is limited in terms of sorting throughput, purity, and accuracy. BAW-based sorting technology can only achieve vertical sorting of particles. Typical BAW sorting chips can sort two different types of particles. Separating the fluid layer can achieve sorting of multiple types of particles, but due to the height limitation of the fluid layer, it can only sort a maximum of three types of particles, making it difficult to miniaturize and integrate devices, and also difficult to achieve high-precision sorting of micron-sized particles. SAW sorting can only achieve horizontal sorting of particles, requiring a high degree of dilution of the sample to be sorted, necessitating a certain pretreatment process, and also has a relatively low sorting throughput. Summary of the Invention

[0010] Based on this, it is necessary to provide a three-dimensional particle sorting chip based on acoustic fluid control technology to address the above-mentioned technical problems. This chip achieves a high degree of integration of longitudinal bulk acoustic wave sorting and transverse surface acoustic wave sorting on the same device. It uses bulk acoustic waves for high-throughput preliminary sorting and surface acoustic waves for high-precision secondary sorting, thus solving the problem that the target acoustic fluid control sorting chip has a single sorting mechanism and cannot simultaneously achieve high throughput and high precision when sorting complex biological samples.

[0011] A three-dimensional particle sorting chip based on acoustic fluid control technology includes: a piezoelectric ceramic, a microfluidic system, interdigitated electrodes, and a piezoelectric substrate; the microfluidic system and interdigitated electrodes are disposed on the piezoelectric substrate, and the piezoelectric ceramic is disposed on the microfluidic system; the microfluidic system is provided with a particle inlet, a sheath flow inlet, and a particle outlet, and is formed by stacking and encapsulating a glass cover, an upper glass chip, several intermediate separators, and a lower glass chip; from the particle inlet to the particle outlet, a bulk acoustic wave longitudinal sorting zone, a sheath flow aggregation zone, a surface acoustic wave transverse sorting zone, and a particle separation zone are sequentially provided; the bulk acoustic wave longitudinal sorting zone uses a half-wavelength layered resonator mode to longitudinally sort mixed particles, and the surface acoustic wave transverse sorting zone uses an inclined surface acoustic wave to transversely sort mixed particles; a pair of interdigitated electrodes are provided, distributed on both sides of the microfluidic system, and inclined at a 15° angle to the microfluidic system; the piezoelectric substrate is made of lithium niobate material that propagates in the X direction at a 128° Y-axis.

[0012] In one embodiment, the interdigitated electrode is a uniform interdigitated electrode used to excite surface acoustic waves of a specific wavelength; the pattern of the interdigitated electrode is obtained by depositing a 20nm chromium thin film and a 180nm silver thin film on the piezoelectric substrate by electron beam evaporation, and then removing the silver and chromium double metal films by ultrafast laser localization.

[0013] In one embodiment, the microfluidic system is made of soda-lime glass. The upper and lower glass chips are obtained by ultrafast laser cutting and epoxy resin curing by ultraviolet irradiation, and the glass chips are bonded non-destructively at room temperature.

[0014] In one embodiment, the bulk acoustic wave longitudinal sorting zone uses the piezoelectric ceramic as a transducer to generate sound waves, the glass cover as a transmission layer, and the lithium niobate substrate of the surface acoustic wave device as a reflective layer to reflect sound waves, which are superimposed with the incident wave to form a standing wave.

[0015] In one embodiment, the upper glass chip, the intermediate separator, and the lower glass chip are stacked and packaged to form an acoustic resonant cavity. The intermediate separator divides the acoustic resonant cavity into an upper chamber and a lower chamber to allow the fluid to form a stable laminar flow within the chamber. The upper chamber is provided with a mixing particle inlet and an outlet connected to the surface acoustic wave lateral sorting zone. The lower chamber is provided with a sheath flow inlet and an outlet connected to the surface acoustic wave lateral sorting zone.

[0016] In one embodiment, the surface acoustic wave lateral sorting zone adjusts the surface acoustic wave parameters to set the pressure node and antinode at a 15° angle to the fluid flow direction, thereby causing lateral trajectory differences in particles of different sizes, and the outlet is connected to the particle separation zone.

[0017] In one embodiment, the particle separation zone is connected to the outlet of the surface acoustic wave transverse sorting zone, and is provided with left and right particle outlets for separating and flowing out particles of different sizes after sorting.

[0018] Compared to existing technologies, the advantages and beneficial effects of this invention are as follows: A microfluidic system and interdigitated electrodes are disposed on a piezoelectric substrate, and piezoelectric ceramics are disposed on the microfluidic system. The microfluidic system is provided with a particle inlet, a sheath flow inlet, and a particle outlet, and is formed by stacking and encapsulating a glass cover, an upper glass chip, several intermediate separators, and a lower glass chip. From the particle inlet to the particle outlet, the microfluidic system sequentially includes a bulk acoustic wave longitudinal sorting zone, a sheath flow aggregation zone, a surface acoustic wave transverse sorting zone, and a particle separation zone. The bulk acoustic wave longitudinal sorting zone uses a half-wavelength resonator mode to longitudinally sort the mixed particles, and the surface acoustic wave transverse sorting zone… The selection area employs inclined surface acoustic waves to perform lateral sorting of mixed particles, sequentially sorting them laterally and longitudinally, thus improving the sorting accuracy. A pair of interdigitated electrodes are provided, distributed on both sides of the microfluidic system and inclined at a 15° angle to the system. The piezoelectric substrate is made of lithium niobate material with a 128° tangential X-direction propagation, achieving a high degree of integration between longitudinal bulk acoustic wave sorting and lateral surface acoustic wave sorting. High-throughput initial sorting is performed using bulk acoustic waves, while high-precision secondary sorting is performed using surface acoustic waves. This avoids the problem of a single sorting mechanism and is conducive to the simultaneous realization of high throughput and high precision in the sorting of complex biological samples. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a layered resonator in the prior art.

[0020] Figure 2 A schematic diagram of the structure of a three-dimensional particle sorting chip based on acoustic fluid control technology in one embodiment.

[0021] Figure 3 for Figure 2 A schematic diagram of the microchannel system.

[0022] Figure 4 for Figure 2 Schematic diagram of the regional division of a microchannel system.

[0023] Figure 5 This is a schematic diagram of particle sorting in the longitudinal sorting zone of bulk acoustic waves in one embodiment.

[0024] Figure 6 This is a schematic diagram of particle sorting in the transverse sorting zone of surface acoustic waves in one embodiment. Detailed Implementation

[0025] Before describing the specific embodiments of the present invention, the overall concept of the present invention will be explained as follows:

[0026] This invention is mainly based on the particle sorting process. Currently, particle sorting mainly adopts a single sorting technology, which can only achieve single two-dimensional sorting. It has the problem that the sorting mechanism of the acoustic fluid control sorting chip is single and high throughput and high precision cannot be achieved simultaneously when sorting complex biological samples.

[0027] Therefore, this invention proposes a three-dimensional particle sorting chip based on acoustic fluid control technology, which achieves a high degree of integration of longitudinal bulk acoustic wave sorting and transverse surface acoustic wave sorting on the same device. It uses bulk acoustic waves for high-throughput preliminary sorting and surface acoustic waves for high-precision secondary sorting, enabling three-dimensional particle sorting and achieving high-throughput and high-precision sorting of particles of various sizes (including but not limited to cells, particles, nanotubes, etc.).

[0028] Having introduced the overall concept of the present invention, to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] In one embodiment, taking the separation of four particle sizes as an example, the four particle sizes, from largest to smallest, are: first-size particle, second-size particle, third-size particle, and fourth-size particle, with sizes of 20μm, 10μm, 5μm, and 1μm respectively. The piezoelectric ceramic 10 is required to have a resonant frequency around 1MHz; the piezoelectric substrate 40 has a diameter of 3 inches and a thickness of 1mm; the interdigital electrode 30 has a finger width and a finger strip width of 50μm, and an acoustic aperture of 20mm, which can excite surface acoustic waves with a wavelength of 200μm; the glass cover 24 has a thickness of 1.4mm, the upper glass chip 25 has a thickness of 210μm, the middle separator 26 has a thickness of 50μm, and the lower glass chip 27 has a thickness of 400μm.

[0030] like Figure 2-4As shown, a three-dimensional particle sorting chip based on acoustic fluid control technology is provided, including: a piezoelectric ceramic 10, a microfluidic system 20, interdigitated electrodes 30, and a piezoelectric substrate 40; the microfluidic system 20 and the interdigitated electrodes 30 are disposed on the piezoelectric substrate 40, and the piezoelectric ceramic 10 is disposed on the microfluidic system 20; the microfluidic system 20 is provided with a particle inlet 21, a sheath flow inlet 22, and a particle outlet 23; the microfluidic system 20 is formed by stacking and encapsulating a glass cover 24, an upper glass chip 25, an intermediate separator 26, and a lower glass chip 27, extending from the particle inlet 21 to... The particle outlet 23 is sequentially provided with a bulk acoustic wave longitudinal sorting zone 50, a sheath flow aggregation zone 60, a surface acoustic wave transverse sorting zone 70, and a particle separation zone 80. The bulk acoustic wave longitudinal sorting zone 50 uses a half-wavelength layered resonator mode to longitudinally sort the mixed particles, and the surface acoustic wave transverse sorting zone 70 uses an inclined surface standing wave to transversely sort the mixed particles. A pair of interdigital electrodes 30 are provided, distributed on both sides of the microfluidic system 20, and inclined at a 15° angle to the microfluidic system 20. The piezoelectric substrate 40 is made of lithium niobate material that propagates tangentially in the X direction at 128°.

[0031] In this embodiment, the microfluidic system 20 and interdigitated electrodes 30 are disposed on the piezoelectric substrate 40, and the piezoelectric ceramic 10 is disposed on the microfluidic system 20. The microfluidic system 20 is provided with a particle inlet 21, a sheath flow inlet 22, and a particle outlet 23, and is formed by stacking and encapsulating a glass cover 24, an upper glass chip 25, an intermediate separator 26, and a lower glass chip 27. From the particle inlet 21 to the particle outlet 23, the microfluidic system 20 is provided with a bulk acoustic wave longitudinal sorting zone 50, a sheath flow aggregation zone 60, a surface acoustic wave transverse sorting zone 70, and a particle separation zone 80. The bulk acoustic wave longitudinal sorting zone 50 uses a half-wavelength resonator mode to longitudinally sort the mixed particles. The surface acoustic wave (SAW) lateral sorting zone 70 uses inclined surface standing waves to laterally sort mixed particles, performing lateral and longitudinal sorting of mixed particles sequentially, thus improving the sorting accuracy of mixed particles. A pair of interdigitated electrodes 30 are provided, distributed on both sides of the microfluidic system 20, and inclined at a 15° angle to the microfluidic system 20. The piezoelectric substrate 40 is made of lithium niobate material with a 128° tangential X-direction propagation, realizing a high degree of integration between longitudinal bulk acoustic wave sorting and lateral SAW. High-throughput preliminary sorting is performed by bulk acoustic waves, and high-precision secondary sorting is performed by SAW. This avoids the problem of a single sorting mechanism and is conducive to the simultaneous realization of high throughput and high precision in the sorting of complex biological samples.

[0032] Among them, the piezoelectric ceramic 10 is made of PZT (titanium lead-acid piezoelectric ceramic), and the resonant frequency is calculated according to the size requirements of the sorted particles.

[0033] In one embodiment, taking the separation of four particle sizes as an example, the four particle sizes are, in descending order: first-size particle, second-size particle, third-size particle, and fourth-size particle.

[0034] Among them, the interdigitated electrode 30 adopts a uniform interdigitated electrode to excite surface acoustic waves of a specific wavelength; the pattern of the interdigitated electrode 30 is obtained by depositing a 20nm chromium thin film and a 180nm silver thin film on the piezoelectric substrate 40 by electron beam evaporation, and then removing the silver and chromium double metal thin films by ultrafast laser localization.

[0035] Specifically, the interdigitated electrode 30 is a uniform interdigitated electrode that can excite surface acoustic waves of a specific wavelength, which is calculated based on the size requirements of the sorted particles. The interdigitated electrode 30 is placed at a 15° tilt angle to the microfluidic system 20. When preparing the interdigitated electrode 30, a 20nm chromium thin film and a 180nm silver thin film are deposited on the piezoelectric substrate 40 by electron beam evaporation, and then the silver and chromium double metal films are removed by ultrafast laser localization to obtain the desired interdigitated electrode pattern.

[0036] The microfluidic system 20 is made of soda-lime glass. The upper glass chip 25 and the lower glass chip 27 are obtained by ultrafast laser cutting and epoxy resin curing by ultraviolet irradiation, and the glass chips are bonded non-destructively at room temperature.

[0037] Specifically, the microfluidic system 20 is formed by stacking and encapsulating a glass cover plate 24, an upper glass chip 25, an intermediate separator 26, and a lower glass chip 27, all of which are made of soda-lime glass, which has a high refractive index and good optical properties. The thickness of each layer of the microfluidic system 20 is calculated according to the working requirements of the layered resonator. During fabrication, ultrafast laser cutting is used to obtain glass chips with a special hollow structure, and epoxy resin is cured by ultraviolet light irradiation to perform non-destructive bonding of the glass chips at room temperature.

[0038] In the longitudinal sorting zone 50 of the bulk acoustic wave, the piezoelectric ceramic 10 is used as a transducer to generate sound waves, the glass cover plate 24 is used as a transmission layer, and the lithium niobate substrate of the surface acoustic wave device is used as a reflection layer to reflect sound waves, which are superimposed with the incident wave to form a standing wave.

[0039] Specifically, the longitudinal sorting zone 50 of the bulk acoustic wave adopts a half-wavelength layered resonator mode for easy integration, and uses piezoelectric ceramic 10 as a transducer to generate acoustic waves; glass cover 24 as a transmission layer; and lithium niobate substrate of surface acoustic wave device as a reflective layer to reflect acoustic waves, which are superimposed with the incident wave to form a standing wave.

[0040] The upper glass chip 25, the middle separator 26, and the lower glass core 27 are stacked and packaged to form an acoustic resonant cavity. The middle separator 26 divides the acoustic resonant cavity into an upper chamber and a lower chamber to enable the fluid to form a stable laminar flow within the chamber. The upper chamber is provided with a mixed particle inlet and the outlet is connected to the surface acoustic wave lateral sorting zone. The lower chamber is provided with a sheath flow inlet and the outlet is connected to the surface acoustic wave lateral sorting zone.

[0041] Specifically, functionally, the chip mainly comprises four regions: a longitudinal bulk acoustic wave sorting region 50, a sheath flow aggregation region 60, a transverse surface acoustic wave sorting region 70, and a particle separation region 80. An acoustic resonant cavity is formed by stacking and packaging an upper glass chip 25, an intermediate separator 26, and a lower glass chip 27. This part is designed according to a lateral flow distribution structure. The intermediate separator 26 divides the acoustic resonant cavity into upper and lower chambers. The upper chamber has a mixing particle inlet, and the lower chamber has a sheath flow inlet. The outlets of both chambers are connected to the subsequent transverse surface acoustic wave sorting region 70. The fluid can form a stable laminar flow within the two chambers, providing a structural basis for flow separation.

[0042] In one embodiment, such as Figure 5 As shown, the working process of the longitudinal sorting zone 50 of the bulk acoustic wave is as follows: Particles flow in from the inlet of the upper chamber and enter the acoustic resonant cavity. Due to the different acoustic radiation forces experienced by different particles, they generate a difference in motion trajectory when moving towards the half-height plane of the channel, i.e., the standing wave interface, and enter different flow layers. Among them, the first and second size particles with greater force are close to the standing wave plane and flow out from the lower chamber, while the third and fourth size particles with less force remain in the upper chamber and enter the subsequent upper flow channel, thereby realizing the longitudinal sorting of different particles based on bulk acoustic waves.

[0043] The surface acoustic wave lateral sorting zone 70 adjusts the surface acoustic wave parameters to set the pressure node and the antinode to a state at a 15° angle with the fluid flow direction, so as to produce lateral trajectory differences for particles of different sizes, and the outlet is connected to the particle separation zone 80.

[0044] Specifically, after the particles complete the longitudinal sorting by bulk acoustic waves, they enter the transverse sorting zone 70 via the upper and lower chambers for further high-precision sorting. Since larger particles (first and second size) enter the lower chamber after the longitudinal bulk acoustic wave sorting, and smaller particles (third and fourth size) enter the upper chamber, the subsequent sheath flow aggregation, surface acoustic wave sorting, and particle separation processes are carried out independently in the upper and lower chambers. In the sheath flow aggregation zone 60, the sheath flow is used to aggregate the particles on the right side of the flow channel.

[0045] like Figure 6As shown, in the upper and lower chambers of the surface acoustic wave (SAW) lateral sorting zone 70, the pressure nodes and antinodes are set at a 15° angle to the fluid flow direction by adjusting the SAW parameters. Under the action of acoustic radiation force and Stokes drag, particles pass through multiple pairs of pressure nodes and antinodes. Particles of two sizes move in the repeated sound field, producing a difference in lateral trajectory. Particles from the upper and lower chambers flow out from the left and right side channels respectively, facilitating particle separation. After undergoing two processes—bulk acoustic wave longitudinal sorting and SAW lateral sorting—the mixed particles achieve high-precision sorting, improving the sorting accuracy and enabling high-throughput sorting of various mixed particles.

[0046] The particle separation zone 80 is connected to the surface acoustic wave transverse sorting zone 70 and is provided with particle outlets on the left and right sides to separate and discharge particles of different sizes after sorting.

[0047] Specifically, the particle separation zone 80 is connected to the outlet of the surface acoustic wave transverse sorting zone 70, and is provided with particle outlets on both the left and right sides to allow particles of different sizes to flow out through different outlets after separation. In the lower chamber, larger first-size particles flow out from the first particle outlet 231 of the left channel, and smaller second-size particles flow out from the second particle outlet 232 of the right channel; in the upper chamber, larger third-size particles flow out from the third particle outlet 233 of the left channel, and smaller fourth-size particles flow out from the fourth particle outlet 234 of the right channel, thereby achieving high-channel, high-precision sorting of mixed particles.

[0048] In one embodiment, when it is necessary to simultaneously sort four or more mixed particles, the acoustic resonant cavity can be divided into multiple chambers by adding intermediate partitions. The parameters of the bulk acoustic wave and surface acoustic wave can be adjusted, and sheath flow inlets and particle outlets can be added accordingly to facilitate the sorting of multiple mixed particles, thereby achieving high-throughput particle sorting. For example, when sorting six mixed particles is required, two intermediate partitions are set in the microfluidic system to divide the acoustic resonant cavity into upper, middle, and lower chambers. Sheath flow inlets and six particle outlets are correspondingly set in the three chambers to achieve the sorting of six particles.

[0049] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered within the scope of protection of the present invention.

Claims

1. A three-dimensional particle sorting chip based on acoustofluidics technology, characterized in that, include: Piezoelectric ceramics, microfluidic systems, interdigitated electrodes, and piezoelectric substrates; The microfluidic system and interdigitated electrodes are disposed on the piezoelectric substrate, and the piezoelectric ceramic is disposed on the microfluidic system; The microfluidic system is provided with a particle inlet, a sheath flow inlet, and a particle outlet, and is formed by stacking and encapsulating a glass cover, an upper glass chip, an intermediate separator, and a lower glass chip. From the particle inlet to the particle outlet, a bulk acoustic wave longitudinal sorting zone, a sheath flow aggregation zone, a surface acoustic wave transverse sorting zone, and a particle separation zone are sequentially arranged. The bulk acoustic wave longitudinal sorting zone uses a half-wavelength layered resonator mode to longitudinally sort the mixed particles. The piezoelectric ceramic is used as a transducer in the bulk acoustic wave longitudinal sorting zone to generate sound waves, and the glass cover... The upper glass chip, the middle separator, and the lower glass chip are stacked and packaged to form an acoustic resonant cavity. The middle separator divides the acoustic resonant cavity into an upper chamber and a lower chamber to allow the fluid to form a stable laminar flow within the chamber. The upper chamber is provided with a mixed particle inlet and an outlet connected to the lateral sorting zone of the surface acoustic wave. The lower chamber is provided with a sheath flow inlet and an outlet connected to the lateral sorting zone of the surface acoustic wave. The lateral sorting zone of surface acoustic waves uses inclined surface acoustic standing waves to laterally sort the mixed particles. The interdigitated electrodes are provided in pairs, distributed on both sides of the microfluidic system, and inclined at a 15° angle to the microfluidic system; The piezoelectric substrate is made of lithium niobate material propagating in the X direction at a 128° Y-axis.

2. The three-dimensional particle sorting chip based on acoustofluidics of claim 1, wherein, The interdigitated electrodes are uniform interdigitated electrodes used to excite surface acoustic waves of a specific wavelength. The pattern of the interdigitated electrodes is obtained by depositing a 20nm chromium thin film and a 180nm silver thin film on the piezoelectric substrate by electron beam evaporation, and then removing the silver and chromium double metal films by ultrafast laser localization.

3. A three-dimensional particle sorting chip based on acoustic flow control technology according to claim 1, characterized in that, The microfluidic system is made of soda-lime glass. The upper and lower glass chips are obtained by ultrafast laser cutting and epoxy resin curing by ultraviolet irradiation, and the glass chips are bonded non-destructively at room temperature.

4. A three-dimensional particle sorting chip based on acoustic flow control technology according to claim 1, characterized in that, The particle separation zone is connected to the outlet of the surface acoustic wave transverse sorting zone and is provided with particle outlets on the left and right sides to separate and discharge particles of different sizes after sorting.

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