Biological particle spinning arrangement device and method based on acoustic microfluidics

Abstract

The invention belongs to the field of biomedical detection, particularly relates to a biological particle spinning arrangement device and method based on acoustic microfluidics, and solves the technical problem that biological particles cannot be efficiently, accurately and nondestructively controlled in the prior art. The device comprises a piezoelectric substrate, a first interdigital electrode, a second interdigital electrode and a PDMS micro-channel chip, the microfluid is connected to the PDMS micro-channel chip; the microfluid is observed; inputting a phase-difference-free alternating current signal into the first interdigital electrode and the second interdigital electrode at the same time, so that the biological particles in the arrangement area form a two-dimensional pattern; a single-channel input signal passes through the high-speed four-quadrant signal generation circuit to generate a four-channel output signal with the phase difference of 90 degrees, the first interdigital electrode and the second interdigital electrode adjust the phase difference according to regulation and control parameters, and phase transition is generated at sound pressure nodes where biological particles are arranged, so that the biological particles in a spinning area spin. According to the method and the device, high-precision, low-difficulty and low-cost regulation and control can be carried out on the biological particles.

Description

Technical Field

[0001] The present invention relates to the field of biomedical detection technology, in particular to biomedical detection, and specifically to a biological particle spin arrangement device and method based on acoustic microfluidics. Background Art

[0002] In the field of biomedical testing, a large number of biological probe molecules (such as proteins, antibodies, antigens, etc.) are usually fixed on the manufactured chips for specific detection. By manipulating the spin arrangement of biological particles to improve the efficiency of specific interactions between biological molecules, cells, proteins and other biological components can be accurately, quickly and with large amounts of information detected. Therefore, manipulating the arrangement of biological particles and spin patterning of biological probe microarrays is of great significance for cutting-edge research, and has broad application prospects in the rapid immobilization of biological probes and instant detection of microorganisms.

[0003] The methods for spin arrangement of biological particles involve various techniques such as optics, magnetism, electricity, and hydrodynamics.

[0004] In optical technology, the optical torque generated by the interaction between light and biological particles drives the particles, and the optical spin Hall effect can be used to regulate the distribution of spin angular momentum density in the focusing field to control the particles. However, optical technology requires high-power lasers and high numerical aperture lenses to ensure the focusing accuracy, polarization state stability and optical path adjustment accuracy of light, which places extremely high demands on experimental equipment. At the same time, the energy intensity of the light field itself will interfere with cell activity and destroy the structure of biological molecules when manipulating biological particles, causing functional damage to biological particles.

[0005] In magnetic technology, biological particles with magnetic properties or magnetic response are manipulated by external magnetic fields to induce particle movement or change the state of motion. However, magnetic technology requires a high-precision magnetic field generator and control system as well as magnetically labeled target particles, in which the uniformity and stability of the magnetic field are difficult to ensure, and the labeling can damage the activity of biological particles.

[0006] In electrical technology, biological particles are controlled by applying specific voltages and phases. However, electrical technology requires high-energy electric fields and has limited precision, which destroys the structure and function of biological particles and makes it difficult to achieve high-precision control.

[0007] In hydrodynamics, the spin arrangement of particles is achieved by controlling the swirl of the fluid and changing the parameters of the flow field. However, hydrodynamics requires the introduction of fluid control systems and flow control algorithms, which increases equipment costs and increases the complexity and uncertainty of calculations due to possible defects in the algorithms.

[0008] Considering the technical accuracy, biocompatibility, practical operation difficulty and cost, none of the above existing technologies can effectively, accurately and non-destructively manipulate biological particles. Therefore, manipulating biological particles through acoustic energy to improve biological detection efficiency is a more realistic way. Summary of the invention

[0009] In order to overcome the technical defects that the existing technologies involving optics, magnetism, electricity, and hydrodynamics are currently unable to efficiently, accurately, and non-destructively manipulate biological particles, the present invention provides a biological particle spin arrangement device and method based on acoustic microfluidics.

[0010] The invention provides a biological particle spin arrangement device based on acoustic microfluidics, comprising a piezoelectric substrate, a first interdigital electrode, a second interdigital electrode and a PDMS microfluidic chip, wherein the PDMS microfluidic chip is provided with an inlet, a first main channel, a main channel chamber, a second main channel and a sample outlet which are sealed and connected in sequence, the first main channel is an observation area, and the main channel chamber is an arrangement area and a spin area; the PDMS microfluidic chip is activated and bonded to the rear side of the upper surface of the piezoelectric substrate, the first interdigital electrode and the second interdigital electrode are arranged on the front side of the upper surface of the piezoelectric substrate, the first interdigital electrode and the second interdigital electrode are both uniform straight electrode finger strips, the first interdigital electrode and the second interdigital electrode are orthogonally distributed and the front ends are both arranged toward the main channel chamber, and the microfluidic channel substrate is provided with installation notches for avoiding the first interdigital electrode and the second interdigital electrode.

[0011] Preferably, the first interdigitated electrode includes an even number of electrode fingers, a first bus bar and a second bus bar and a plurality of reflective grids, the first bus bar and the second bus bar are arranged in parallel and symmetrically, the electrode fingers are divided into two groups and are respectively connected to the first bus bar and the second bus bar, and the electrode fingers connected to the first bus bar and the electrode fingers connected to the second bus bar are arranged alternately, the reflective grids are of the same width as the electrode fingers and are arranged in parallel, the interval between the reflective grid and the electrode fingers is equal to the finger width between adjacent electrode fingers, the electrode fingers are located between the first bus bar and the second bus bar, and both ends of the reflective grid are not connected to the first bus bar or the second bus bar; the second interdigitated electrode has the same structure as the first interdigitated electrode.

[0012] Preferably, in the first interdigitated electrode and the second interdigitated electrode, the electrode fingers, the first bus bar, the second bus bar, and the reflective grid are all composed of a chromium bonding layer with a thickness of 20 nm and a gold electrode layer with a thickness of 100 nm, the gold electrode layer is located on the chromium bonding layer, and the chromium bonding layer adheres the gold electrode layer to the upper surface of the piezoelectric substrate; the width L1 of the electrode fingers is 30 μm, the spacing L2 between adjacent electrode fingers is 30 μm, the length of the reflective grid, that is, the acoustic aperture W, is 2300 μm, the number of pairs of electrode fingers is 20 pairs, and the number of pairs of reflective grids is 10 pairs.

[0013] Preferably, the sample inlet is provided with a Z-direction liquid inlet pipe, which includes a liquid inlet elbow and a first vertical pipe, the liquid inlet elbow is connected to the top end of the first vertical pipe, and the bottom end of the first vertical pipe is connected to the sample inlet; the sample outlet is provided with a Z-direction liquid outlet pipe, which includes a liquid outlet elbow and a second vertical pipe, the liquid outlet elbow is connected to the top end of the second vertical pipe, and the bottom end of the second vertical pipe is connected to the sample outlet.

[0014] Preferably, the piezoelectric substrate is made of lithium niobate material that is cut by rotating 128° around the Y axis and the acoustic wave propagates along the X axis.

[0015] Preferably, the diameter of the first main channel and the second main channel is 200 μm, and the first main channel and the second main channel are respectively provided with multiple bends; the mainstream chamber is a square structure, and the mainstream chamber is diagonally connected to the first main channel and the second main channel, and the diagonal spacing of the mainstream chamber is 2300 μm. The bend of the first main channel, the bend of the second main channel, the four corners of the mainstream chamber, and the connection between the mainstream chamber and the first main channel and the second main channel are respectively set as rounded corners or beveled angles.

[0016] The present invention also provides a biological particle spin alignment method based on acoustic microfluidics, which is implemented based on a biological particle spin alignment device based on acoustic microfluidics described in the present invention, and includes the following steps: Step S1, connecting the microfluid: making the microfluid flow from the Z-direction liquid inlet pipeline, the sample inlet, the first main channel, the main flow chamber, the second main channel, the sample outlet to the Z-direction liquid outlet pipeline in sequence; Step S2, microfluid observation: observe the biological particles in the microfluid with an inverted fluorescence microscope, and observe the number and position of the biological particles flowing from the first main channel into the main flow chamber; Step S3, biological particle arrangement: according to the observation result of step S2, an AC signal without phase difference is selected and simultaneously input into the first interdigital electrode and the second interdigital electrode, so as to control the piezoelectric substrate to vibrate, and generate an acoustic surface standing wave of orthogonal superposition interference on the piezoelectric substrate, so that the biological particles in the arrangement area are gathered at the sound pressure node and dynamically arranged to form a two-dimensional pattern; Step S4, biological particle spin: a single-channel input signal is passed through a high-speed four-quadrant signal generating circuit to generate a four-channel output signal with a phase difference of 90°, wherein the output phases of the four-channel output signals are 0°, 90°, 180° and 270°, respectively. The four-channel output signal is applied to the first interdigital electrode or the second interdigital electrode as a control parameter, and the first interdigital electrode and the second interdigital electrode adjust the phase difference according to the control parameter obtained by simulation and emulation of the high-speed four-quadrant signal generating circuit, and a phase transition is generated at the sound pressure node where the biological particles are arranged, so that the biological particles in the spin area spin.

[0017] Preferably, the high-speed four-quadrant signal generating circuit in step S4 includes a first single-channel differential circuit, a double frequency circuit, a second single-channel differential circuit, a duty cycle adjustment circuit and a divider circuit connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-channel differential circuit. The signal frequency remains unchanged, and the differential output signal has a phase difference of 180°. After the differential output signal is input into the double frequency circuit, the second single-channel differential circuit generates a dual output signal with a phase difference of 180°. After the dual output signal is processed by the duty cycle adjustment circuit, it is finally input into the divider circuit. The divider circuit includes two sub-module dividers, each sub-module divider can generate two signals with a phase shift of 90°, so the divider circuit finally outputs four signals with a phase shift of 90°.

[0018] Preferably, the particle size of the biological microparticles in the microfluidic is in the range of 700 nm to 20 μm.

[0019] Preferably, in step S4, when the phase of the radio frequency signal of the first interdigital electrode changes from 0° to 360° and the phase of the radio frequency signal of the second interdigital electrode remains unchanged, the biological particles produce an ACW counterclockwise spin phenomenon due to unbalanced force; when the phase of the radio frequency signal of the second interdigital electrode deflects from 0° to 360° and the phase of the radio frequency signal of the first interdigital electrode remains unchanged, the biological particles produce a CW clockwise spin phenomenon.

[0020] Compared with the prior art, the technical solution provided by the present invention has the following technical effects: the technical solution provided by the present invention has irreplaceable advantages in technical accuracy, biocompatibility, and practical operation difficulty. The operation object of the biological microparticle spin arrangement device and method based on acoustic microfluidics described in the present invention is highly scalable. The biological microparticle spin arrangement method based on acoustic microfluidics can perform high-precision, low-difficulty, and low-cost regulation on biological microparticles, and has high biocompatibility. It can manipulate biological microparticles ranging from tens of nanometers to hundreds of microns in size without contact, damage, or labeling, which has important practical significance; In addition, the biological microparticle spin arrangement method based on acoustic microfluidics can accurately and efficiently realize the rapid immobilization of biological probes without expensive and complex additional equipment. The biological microparticle spin arrangement device based on acoustic microfluidics provided by the present invention has low production cost, simple operation, and innovative overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a schematic structural diagram of a biological particle spin arrangement device based on acoustic microfluidics in a certain embodiment of the present invention; Figure 2 for Figure 1 A top view of Figure 3 is a schematic diagram of the structure of the first interdigital electrode or the second interdigital electrode in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the Z-direction liquid inlet pipeline and the Z-direction liquid outlet pipeline in an embodiment of the present invention; Figure 5 A flowchart of a biological particle spin arrangement method based on acoustic microfluidics described in an embodiment of the present invention; Figure 6 A simulation schematic diagram of a high-speed four-quadrant signal generating circuit in a biological particle spin arrangement method based on acoustic microfluidics described in an embodiment of the present invention; Figure 7 A simulation schematic diagram of a high-speed four-quadrant signal generating circuit in a biological particle spin arrangement method based on acoustic microfluidics described in an embodiment of the present invention; Figure 8 A schematic diagram of biological particle arrangement in a biological particle spin arrangement method based on acoustic microfluidics described in an embodiment of the present invention; Fig. 9 Schematic diagram of biological particle spins in a biological particle spin arrangement method based on acoustic microfluidics described in an embodiment of the present invention.

[0024] In the figure: 10, piezoelectric substrate; 21, first interdigitated electrode; 22, second interdigitated electrode; 210, electrode finger strip; 211, first bus bar; 212, second bus bar; 213, reflection grid; 30, PDMS microfluidic chip; 31, injection port; 32, first main channel; 33, main channel chamber; 34, second main channel; 35, injection port; 36, Z-direction liquid inlet pipe; 361, liquid inlet elbow; 362, first vertical pipe; 37, Z-direction liquid outlet pipe; 371, liquid outlet elbow; 372, second vertical pipe. DETAILED DESCRIPTION

[0025] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0026] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0028] The following is combined with Figures 1 to 9 The specific embodiments of the present invention are described in detail.

[0029] In one embodiment, Figure 1 and Figure 2As shown, a biological particle spin arrangement device based on acoustic microfluidics is disclosed, including a piezoelectric substrate 10, a first interdigitated electrode 21, a second interdigitated electrode 22 and a PDMS microfluidic chip 30, wherein the PDMS microfluidic chip 30 is provided with an inlet 31, a first main channel 32, a main channel chamber 33, a second main channel 34 and a sample outlet 35 which are sealed and connected in sequence, the first main channel 32 is an observation area, and the main channel chamber 33 is an arrangement area and a spin area; the PDMS microfluidic chip 30 is activated and bonded to the rear side of the upper surface of the piezoelectric substrate 10, the first interdigitated electrode 21 and the second interdigitated electrode 22 are arranged on the front side of the upper surface of the piezoelectric substrate 10, the first interdigitated electrode 21 and the second interdigitated electrode 22 are both uniform linear electrode fingers 210, the first interdigitated electrode 21 and the second interdigitated electrode 22 are orthogonally distributed and the front ends are both arranged toward the main channel chamber 33, and the microfluidic channel substrate is provided with installation notches for avoiding the first interdigitated electrode 21 and the second interdigitated electrode 22. The PDMS microfluidic chip 30 is made by molding. PDMS and curing agent are fully mixed at a ratio of 10:1 and vacuumed until bubbles disappear completely. Then, the mixture is poured into a silicon-based microfluidic mold treated with a release agent and baked at 80°C for 20 min to obtain a cured channel with a height of 50 μm. The PDMS microfluidic chip 30 and the piezoelectric substrate 10 are activated and bonded by oxygen plasma etching technology to form a complete biological microparticle manipulation device based on acoustic microfluidics.

[0030] Based on the above embodiments, in a preferred embodiment, Figure 3As shown, the first interdigitated electrode 21 includes an even number of electrode fingers 210, a first bus bar 211 and a second bus bar 212, and a plurality of reflective grids 213. The first bus bar 211 and the second bus bar 212 are arranged in parallel and symmetrically. The electrode fingers 210 are divided into two groups and are respectively connected to the first bus bar 211 and the second bus bar 212. The electrode fingers 210 connected to the first bus bar 211 and the electrode fingers 210 connected to the second bus bar 212 are arranged alternately. The reflective grids 213 are of the same width as the electrode fingers 210 and are arranged in parallel. The interval between the reflective grids 213 and the electrode fingers 210 is equal to the finger width between adjacent electrode fingers 210. The electrode fingers 210 are located between the first bus bar 211 and the second bus bar 212. Both ends of the reflective grids 213 are not connected to the first bus bar 211 or the second bus bar 212. The second interdigitated electrode 22 has the same structure as the first interdigitated electrode 21. The reflective grid 213 refers to a metal strip having the same width and spacing as the electrode finger strip 210, and the two ends of the reflective grid 213 are not connected to the first bus bar 211 and the second bus bar 212. The first interdigital electrode 21 and the second interdigital electrode 21 are respectively connected to the output port of the power amplifier through their respective first bus bars 211 and second bus bars 212, and the power amplifier is connected to the signal generator. The first interdigital electrode 21 and the second interdigital electrode 22 are respectively patterned by photolithography technology, and then formed by magnetron sputtering and ion beam etching processes. The structure and size of the first interdigital electrode 21 and the second interdigital electrode 22 are completely consistent, and the method of use and characteristics are exactly the same.

[0031] On the basis of the above embodiments, in a preferred embodiment, in the first interdigitated electrode 21 and the second interdigitated electrode 22, the electrode fingers 210, the first bus bar 211, the second bus bar 212, and the reflective grating 213 are all composed of a chromium bonding layer with a thickness of 20 nm and a gold electrode layer with a thickness of 100 nm, the gold electrode layer is located on the chromium bonding layer, and the chromium bonding layer adheres the gold electrode layer to the upper surface of the piezoelectric substrate 10; the width L1 of the electrode fingers 210 is 30 μm, the spacing L2 between adjacent electrode fingers 210 is 30 μm, the length of the reflective grating 213, that is, the acoustic aperture W is 2300 μm, the number of pairs of electrode fingers 210 is 20 pairs, and the number of pairs of reflective gratings 213 is 10 pairs.

[0032] Based on the above embodiments, in a preferred embodiment, Figure 4As shown, the sample inlet 31 is provided with a Z-direction liquid inlet pipe 36, which includes a liquid inlet elbow 361 and a first vertical pipe 362, the liquid inlet elbow 361 is connected to the top of the first vertical pipe 362, and the bottom of the first vertical pipe 362 is connected to the sample inlet 31; the sample outlet 35 is provided with a Z-direction liquid outlet pipe 37, which includes a liquid outlet elbow 371 and a second vertical pipe 372, the liquid outlet elbow 371 is connected to the top of the second vertical pipe 372, and the bottom of the second vertical pipe 372 is connected to the sample outlet 35. Specifically, the cross-sections of the liquid inlet elbow 361 and the liquid outlet elbow 371 are circular.

[0033] On the basis of the above embodiments, in a preferred embodiment, the piezoelectric substrate 10 is made of lithium niobate material which is cut by rotating 128° around the Y axis and the acoustic wave propagates along the X axis direction.

[0034] On the basis of the above embodiments, in a preferred embodiment, the diameter of the first main channel 32 and the second main channel 34 is 200 μm, and the first main channel 32 and the second main channel 34 are respectively provided with a plurality of bends; the main flow chamber 33 is a square structure, and the main flow chamber 33 is connected to the first main channel 32 and the second main channel 34 through diagonals, and the diagonal spacing of the main flow chamber 33 is 2300 μm, and the bends of the first main channel 32, the bends of the second main channel 34, the four corners of the main flow chamber 33, and the connection points of the main flow chamber 33 with the first main channel 32 and the second main channel 34 are all set to be rounded or beveled. The setting of rounded and beveled corners can ensure smooth flow of the fluid without dead angles in the flow path, which is conducive to reducing the residue and blockage of biological particles in the PDMS microfluidic chip 30, thereby reducing the problem of cross-contamination of observed samples.

[0035] The present invention also provides a method for spin arrangement of biological particles based on acoustic microfluidics, such as Figure 5 As shown, it is realized based on a biological particle spin arrangement device based on acoustic microfluidics according to the present invention, and includes the following steps: Step S1, connecting the microfluid: making the microfluid flow from the Z-direction liquid inlet pipe 36, the injection port 31, the first main channel 32, the main flow chamber 33, the second main channel 34, the outlet port 35 to the Z-direction liquid outlet pipe 37 in sequence; Step S2, microfluid observation: observe the biological particles in the microfluid with an inverted fluorescence microscope, and observe the number and position of the biological particles entering the main flow chamber 33 from the first main flow channel 32; Step S3, biological particle arrangement: According to the observation result of step S2, an AC signal without phase difference is selected and simultaneously input into the first interdigital electrode 21 and the second interdigital electrode 22, the piezoelectric substrate 10 is controlled to vibrate, and an acoustic surface standing wave of orthogonal superposition interference is generated on the piezoelectric substrate 10, so that the biological particles in the arrangement area are gathered at the sound pressure node and dynamically arranged to form a two-dimensional pattern, as shown in detail. Figure 8 ; Step S4, biological particle spin: a single-channel input signal is passed through a high-speed four-quadrant signal generating circuit to generate a four-channel output signal with a phase difference of 90°, wherein the output phases of the four-channel output signals are 0°, 90°, 180° and 270° respectively, and the four-channel output signal is applied to the first interdigital electrode 21 or the second interdigital electrode 22 as a control parameter, and the first interdigital electrode 21 and the second interdigital electrode 22 adjust the phase difference according to the control parameter obtained by the simulation and emulation of the high-speed four-quadrant signal generating circuit, and a phase transition is generated at the sound pressure node where the biological particles are arranged, so that the biological particles in the spin region spin, as shown in detail. Fig. 9 .

[0036] In step S2 of the present invention, when microfluid observation is performed, biological particles are input into the first main channel 32 through the injection port 31. When the biological particles in motion flow through the first main channel 32, the observation module is excited by the light signal to realize the observation of the biological particles. Specifically, the observation module includes a laser excitation block, a fluorescent light source, a fluorescent illuminator, an excitation block switching device, and an inverted microscope. The excitation block switching device is adjusted to the wavelength region that matches the scattered light signal of the biological particles, and the laser excitation block, the fluorescent light source, and the fluorescent illuminator generate lasers and form laser spots after being shaped by the inverted microscope for observation. The purpose of microfluid observation is to observe the number and position of biological particles through an inverted fluorescent microscope, so that they are gathered in the mainstream chamber 33 to the greatest extent, so as to improve the utilization efficiency of arrangement and spin. The observation area is located in the first main channel 32, and the arrangement area is located in the mainstream chamber 33. The arrangement area works according to the judgment result of the observation area. The first interdigital electrodes 21 and the second interdigital electrodes 22 cause the piezoelectric substrate 10 to vibrate, generating traveling surface acoustic waves. When the traveling surface acoustic waves propagate to the mainstream chamber 33, they interfere with each other orthogonally, periodically coupling the acoustic flow with the two-dimensional high-resolution surface acoustic standing wave field, and finally generating surface acoustic standing waves, forming sound pressure nodes and anti-sound pressure nodes, and the distance between the sound pressure nodes is 1 / 4 of the wavelength of the surface acoustic wave. times. The biological particles between adjacent anti-sound pressure nodes will be attracted by the sound pressure nodes, move toward the sound pressure nodes between them, and finally gather at the sound pressure nodes, dynamically arranged to form a two-dimensional pattern. Acoustic energy will not damage the structure and function of biological particles, and is fast and accurate in manipulating the biological particles from scattered arrangement to array patterning. The phase difference signal obtained by simulating the high-speed four-quadrant signal generation circuit is applied to the first interdigital electrode 21 or the second interdigital electrode 22, and the interference superimposed standing waves produce corresponding dynamic changes, changing the equilibrium state of the biological particle clusters gathered and arranged near the sound pressure nodes.

[0037] Based on the above embodiments, in a preferred embodiment, Figure 6 and Figure 7 As shown, the high-speed four-quadrant signal generating circuit in step S4 includes a first single-channel differential circuit, a double frequency circuit, a second single-channel differential circuit, a duty cycle adjustment circuit and a divider circuit which are connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-channel differential circuit. The signal frequency remains unchanged, and the differential output signal has a phase difference of 180°. After the differential output signal is input into the double frequency circuit, the second single-channel differential circuit generates a dual output signal with a phase difference of 180°. After the dual output signal is processed by the duty cycle adjustment circuit, it is finally input into the divider circuit. The divider circuit includes two submodule dividers, each of which can generate two signals with a phase shift of 90°. Therefore, the divider circuit finally outputs four signals with a phase shift of 90°.

[0038] On the basis of the above embodiments, in a preferred embodiment, the particle size range of the biological microparticles in the microfluid is 700nm~20μm. The operation object of the method described in the present invention is highly scalable, and can manipulate biological microparticles ranging from tens of nanometers to hundreds of microns in size, which has important practical significance. At the same time, the method can manipulate biological microparticles under non-contact and non-destructive conditions, providing a liquid living tissue regulation method that does not require labeling and has good biocompatibility. In addition, the method described in the present invention does not require expensive and complex additional equipment, and can achieve accurate and efficient rapid immobilization of biological probes and instant detection of microorganisms through arrangement and spin manipulation.

[0039] On the basis of the above embodiments, in a preferred embodiment, in step S4, when the phase of the radio frequency signal of the first interdigital electrode 21 changes from 0° to 360° and the phase of the radio frequency signal of the second interdigital electrode 22 remains unchanged, the biological particles produce ACW counterclockwise spin due to unbalanced force; when the phase of the radio frequency signal of the second interdigital electrode 22 deflects from 0° to 360° and the phase of the radio frequency signal of the first interdigital electrode 21 remains unchanged, the biological particles produce CW clockwise spin. The electroacoustic conversion caused by the signal difference can instantly and accurately control the acoustic energy received by the biological particles, improve the spinning efficiency of the biological particles, and further enhance the interaction efficiency between particles.

[0040] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A biological particle spin alignment device based on acoustic microfluidics, characterized in that: The invention comprises a piezoelectric substrate (10), a first interdigitated electrode (21), a second interdigitated electrode (22) and a PDMS microfluidic chip (30). The PDMS microfluidic chip (30) is provided with an inlet (31), a first main channel (32), a main channel chamber (33), a second main channel (34) and a sample outlet (35) which are sealed and connected in sequence. The first main channel (32) is an observation area, and the main channel chamber (33) is an arrangement area and a spin area. The PDMS microfluidic chip (30) is activated and bonded to the rear side of the upper surface of the piezoelectric substrate (10). The first interdigitated electrode (21) and the second interdigitated electrode (22) are arranged on the front side of the upper surface of the piezoelectric substrate (10). The first interdigitated electrode (21) and the second interdigitated electrode (22) are both uniform linear electrode fingers (210). The first interdigitated electrode (21) and the second interdigitated electrode (22) are orthogonally distributed and the front ends of the first interdigitated electrode (21) and the second interdigitated electrode (22) are both oriented toward the main channel chamber (33). 33) is provided, and a mounting notch for avoiding the first interdigital electrode (21) and the second interdigital electrode (22) is provided on the microfluidic channel substrate.

2. The biological particle spin alignment device based on acoustic microfluidics according to claim 1, characterized in that: The first interdigitated electrode (21) comprises an even number of electrode fingers (210), a first bus bar (211) and a second bus bar (212), and a plurality of reflective grids (213); the first bus bar (211) and the second bus bar (212) are arranged in parallel and symmetrically; the electrode fingers (210) are divided into two groups and are respectively connected to the first bus bar (211) and the second bus bar (212); and the electrode fingers (210) connected to the first bus bar (211) and the electrode fingers (210) connected to the second bus bar (212) are connected to the first bus bar (211). ) are arranged in an interlaced manner, the reflective grid (213) and the electrode finger strips (210) are of equal width and are arranged in parallel, the interval between the reflective grid (213) and the electrode finger strips (210) is equal to the finger width between adjacent electrode finger strips (210), the electrode finger strips (210) are located between the first bus bar (211) and the second bus bar (212), and the two ends of the reflective grid (213) are not connected to the first bus bar (211) or the second bus bar (212); and the second interdigitated electrodes (22) have the same structure as the first interdigitated electrodes (21).

3. The biological particle spin alignment device based on acoustic microfluidics according to claim 2, characterized in that: In the first interdigitated electrode (21) and the second interdigitated electrode (22), the electrode fingers (210), the first bus bar (211), the second bus bar (212), and the reflective grating (213) are all composed of a chromium bonding layer with a thickness of 20 nm and a gold electrode layer with a thickness of 100 nm, the gold electrode layer is located on the chromium bonding layer, and the chromium bonding layer adheres the gold electrode layer to the upper surface of the piezoelectric substrate (10); the width L1 of the electrode fingers (210) is 30 μm, the spacing L2 between adjacent electrode fingers (210) is 30 μm, the length of the reflective grating (213), i.e., the acoustic aperture W, is 2300 μm, the number of pairs of electrode fingers (210) is 20 pairs, and the number of pairs of reflective gratings (213) is 10 pairs.

4. The biological particle spin alignment device based on acoustic microfluidics according to any one of claims 1 to 3, characterized in that: The sample inlet (31) is provided with a Z-direction liquid inlet pipe (36), the Z-direction liquid inlet pipe (36) comprises a liquid inlet elbow (361) and a first vertical pipe (362), the liquid inlet elbow (361) is connected to the top end of the first vertical pipe (362), and the bottom end of the first vertical pipe (362) is connected to the sample inlet (31); the sample outlet (35) is provided with a Z-direction liquid outlet pipe (37), the Z-direction liquid outlet pipe (37) comprises a liquid outlet elbow (371) and a second vertical pipe (372), the liquid outlet elbow (371) is connected to the top end of the second vertical pipe (372), and the bottom end of the second vertical pipe (372) is connected to the sample outlet (35).

5. The biological particle spin alignment device based on acoustic microfluidics according to claim 4, characterized in that: The piezoelectric substrate (10) is made of lithium niobate material which is cut by rotating 128 degrees around the Y axis and the sound wave propagates along the X axis direction.

6. The biological particle spin alignment device based on acoustic microfluidics according to claim 5, characterized in that: The diameter of the first main channel (32) and the second main channel (34) is 200 μm, and the first main channel (32) and the second main channel (34) are respectively provided with a plurality of bends; the main flow chamber (33) is a square structure, and the main flow chamber (33) is connected to the first main channel (32) and the second main channel (34) through diagonals, and the diagonal spacing of the main flow chamber (33) is 2300 μm. The bend of the first main channel (32), the bend of the second main channel (34), the four corners of the main flow chamber (33) and the connection between the main flow chamber (33) and the first main channel (32) and the second main channel (34) are all set to be rounded or beveled.

7. A method for spin alignment of biological particles based on acoustic microfluidics, characterized in that: The method is implemented based on the biological particle spin alignment device based on acoustic microfluidics according to claim 6, and comprises the following steps: Step S1, connecting the microfluid: allowing the microfluid to flow from the Z-direction liquid inlet pipe (36), the injection port (31), the first main channel (32), the main flow chamber (33), the second main channel (34), the outlet port (35) to the Z-direction liquid outlet pipe (37); Step S2, microfluid observation: using an inverted fluorescence microscope to observe the biological particles in the microfluid, and to observe the number and position of the biological particles flowing from the first main channel (32) into the main flow chamber (33); Step S3, biological particle arrangement: according to the observation result of step S2, an AC signal without phase difference is selected and simultaneously input into the first interdigital electrode (21) and the second interdigital electrode (22), so as to control the piezoelectric substrate (10) to vibrate, and generate an acoustic surface standing wave of orthogonal superposition interference on the piezoelectric substrate (10), so that the biological particles in the arrangement area are gathered at the sound pressure node and dynamically arranged to form a two-dimensional pattern; Step S4, biological particle spin: a single-channel input signal is passed through a high-speed four-quadrant signal generating circuit to generate a four-channel output signal with a phase difference of 90°, wherein the output phases of the four-channel output signal are 0°, 90°, 180° and 270° respectively, and the four-channel output signal is applied to the first interdigital electrode (21) or the second interdigital electrode (22) as a control parameter, and the first interdigital electrode (21) and the second interdigital electrode (22) adjust the phase difference according to the control parameter obtained by simulation and emulation of the high-speed four-quadrant signal generating circuit, and generate a phase transition at the sound pressure node where the biological particles are arranged, so that the biological particles in the spin area spin.

8. The method for biological particle spin alignment based on acoustic microfluidics according to claim 7, characterized in that: The high-speed four-quadrant signal generating circuit in step S4 includes a first single-channel differential circuit, a double frequency circuit, a second single-channel differential circuit, a duty cycle adjustment circuit and a divider circuit which are connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-channel differential circuit. The signal frequency remains unchanged, and the differential output signal has a phase difference of 180°. After the differential output signal is input into the double frequency circuit, the second single-channel differential circuit generates a dual output signal with a phase difference of 180°. After the dual output signal is processed by the duty cycle adjustment circuit, it is finally input into the divider circuit. The divider circuit includes two sub-module dividers, each of which can generate two signals with a phase shift of 90°. Therefore, the divider circuit finally outputs four signals with a phase shift of 90°.

9. The method for biological particle spin alignment based on acoustic microfluidics according to claim 8, characterized in that: The particle size of biological particles in microfluidics ranges from 700nm to 20μm.

10. The method for biological particle spin alignment based on acoustic microfluidics according to claim 9, characterized in that: In step S4, when the phase of the radio frequency signal of the first interdigital electrode (21) changes from 0° to 360° and the phase of the radio frequency signal of the second interdigital electrode (22) remains unchanged, the biological particles produce an ACW counterclockwise spin phenomenon due to unbalanced force; when the phase of the radio frequency signal of the second interdigital electrode (22) deflects from 0° to 360° and the phase of the radio frequency signal of the first interdigital electrode (21) remains unchanged, the biological particles produce a CW clockwise spin phenomenon.

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