An acoustic microfluidic-based device and method for spinning alignment of biological microparticles

Abstract

The application belongs to the field of biomedical detection, and particularly relates to a biological microparticle spin arrangement device and method based on acoustic microfluidics, which solves the technical problem that current existing technologies cannot efficiently, accurately and non-invasively control biological microparticles. The device comprises a piezoelectric substrate, a first interdigital electrode, a second interdigital electrode and a PDMS microfluid channel chip; microfluid is accessed to the PDMS microfluid channel chip; the microfluid is observed; a non-phase difference alternating current signal is simultaneously input to the first interdigital electrode and the second interdigital electrode, so that biological microparticles in the arrangement area form a two-dimensional pattern; a single-channel input signal passes through a high-speed four-quadrant signal generation circuit to generate a four-channel output signal with a phase difference of 90 DEG; the first interdigital electrode and the second interdigital electrode adjust the phase difference according to the control parameters, and a phase transition is generated at the acoustic pressure node of the biological microparticle arrangement, so that the biological microparticles in the spin area spin. The method and device can control the biological microparticles with high precision, low difficulty and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical detection, in particular to a biomedical detection, and more particularly to a device and method for arranging biological microparticles based on acoustic microfluidics. BACKGROUND

[0002] In the field of biomedical detection, a large number of biological probe molecules (such as proteins, antibodies, antigens, etc.) are usually fixed on a prepared chip for specific detection. By manipulating the spin arrangement of biological microparticles, the efficiency of specific interaction between biological molecules can be improved, and cells, proteins and other biological components can be accurately, quickly and high-informationally detected. Therefore, manipulating the arrangement and spin of biological microparticles, and patterning biological probe microarrays are of great significance in the forefront research, and have wide application prospects in rapid immobilization of biological probes, real-time detection of microorganisms, etc.

[0003] Methods for arranging biological microparticles involve optical, magnetic, electrical, and hydrodynamic technologies.

[0004] In optical technology, the optical torque generated by the interaction between light and biological microparticles drives the microparticles, and the spin angular momentum density distribution of the focusing field can be controlled to control the microparticles using the optical spin Hall effect. However, optical technology requires high-power lasers and high-numerical-aperture lenses to ensure the focusing accuracy, polarization stability and optical path adjustment accuracy of light, which has very high requirements for experimental equipment. At the same time, the energy intensity of the light field itself will interfere with the activity of biological microparticles, damage the structure of biological molecules and cause functional damage to biological microparticles.

[0005] In magnetic technology, biological microparticles with magnetism or magnetic response are manipulated by an external magnetic field to induce microparticle movement or change the movement state. However, magnetic technology requires high-precision magnetic field generators and control systems, as well as magnetically labeled target particles, and the uniformity and stability of the magnetic field are difficult to guarantee, and the labeling can cause damage to the activity of biological microparticles.

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

[0007] In hydrodynamic technology, the spin arrangement of microparticles is achieved by controlling the rotational flow of fluid and changing the parameters of the flow field. However, hydrodynamic technology requires the introduction of a fluid control system and a flow control algorithm, which increases the cost of equipment and the complexity and uncertainty of calculations due to possible defects in the algorithm.

[0008] Considering the technical accuracy, biocompatibility, and practical operation difficulty and cost, the above prior arts cannot efficiently, accurately and non-invasively manipulate biological microparticles at present. Therefore, it is a more realistic way to manipulate biological microparticles by acoustic energy to improve the biological detection efficiency. SUMMARY

[0009] In order to overcome the technical defects that the prior arts related to optics, magnetism, electricity, hydrodynamics cannot efficiently, accurately and non-invasively manipulate biological microparticles at present, the present application provides a biological microparticle spin arrangement device and method based on acoustic microfluidics.

[0010] The present application provides a biological microparticle spin arrangement device based on acoustic microfluidics, comprising a piezoelectric substrate, a first interdigital electrode, a second interdigital electrode and a PDMS microfluidic chip, the PDMS microfluidic chip is provided with a sample inlet, a first main flow channel, a main flow chamber, a second main flow channel and a sample outlet connected in sequence, the first main flow channel is an observation area, and the main flow chamber is an arrangement area and a spin area; the PDMS microfluidic chip is activated and bonded to the back 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 linear electrode fingers, the first interdigital electrode and the second interdigital electrode are orthogonally distributed and the front ends of both are arranged towards the main flow chamber, and the microfluidic channel substrate is provided with mounting notches avoiding the first interdigital electrode and the second interdigital electrode.

[0011] Preferably, the first interdigital electrode comprises an even number of electrode fingers, a first bus bar and a second bus bar, and a plurality of reflection gratings, the first bus bar and the second bus bar are arranged in parallel and symmetrically, the electrode fingers are divided into two groups and connected to the first bus bar and the second bus bar respectively, the electrode fingers connected to the first bus bar and the electrode fingers connected to the second bus bar are arranged alternately, the reflection gratings are arranged in parallel with the electrode fingers and have the same width as the electrode fingers, the spacing between the reflection gratings and the electrode fingers is equal to the width of the adjacent electrode fingers, the electrode fingers are located between the first bus bar and the second bus bar, and the two ends of the reflection gratings are not connected to the first bus bar or the second bus bar; the second interdigital electrode has the same structure as the first interdigital electrode.

[0012] Preferably, in the first interdigital electrode and the second interdigital electrode, the electrode fingers, the first bus bar, the second bus bar and the reflection gratings are all composed of a chromium adhesive layer with a thickness of 20 nm and a gold electrode layer with a thickness of 100 nm, the gold electrode layer is located above the chromium adhesive layer, and the chromium adhesive 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 reflection gratings, i.e. the acoustic aperture W, is 2300 μm, the logarithm of the electrode fingers is 20 pairs, and the logarithm of the reflection gratings is 10 pairs.

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

[0014] Preferably, the piezoelectric substrate is made of lithium niobate material cut at 128° around the Y axis and with sound waves propagating along the X axis direction.

[0015] Preferably, the diameters of the first main flow channel and the second main flow channel are 200 μm, and the first main flow channel and the second main flow channel are respectively provided with a plurality of bends; the main flow chamber has a square structure, and the main flow chamber is connected to the first main flow channel and the second main flow channel through opposite corners, respectively; the opposite corner distance of the main flow chamber is 2300 μm, and the bends of the first main flow channel and the second main flow channel, the four corners of the main flow chamber, and the connection positions of the main flow chamber and the first main flow channel and the second main flow channel are all provided with round corners or bevels.

[0016] The application also provides a biological microparticle self-spinning arrangement method based on acoustic microfluidics, which is realized based on the biological microparticle self-spinning arrangement device based on acoustic microfluidics.

[0017] Step S1, access to microfluids: make the microfluids flow from the Z-direction liquid inlet pipe, the sample inlet, the first main flow channel, the main flow chamber, the second main flow channel, and the sample outlet to the Z-direction liquid outlet pipe in sequence;

[0018] Step S2, microfluid observation: observe the biological microparticles in the microfluids by means of an inverted fluorescence microscope, and observe the number and position of the biological microparticles flowing into the main flow chamber from the first main flow channel;

[0019] Step S3, biological microparticle arrangement: select a non-phase difference alternating current signal to input the first interdigital electrode and the second interdigital electrode at the same time according to the observation result of step S2, control the piezoelectric substrate to vibrate, generate a quadrature superimposed standing surface wave on the piezoelectric substrate, make the biological microparticles in the arrangement region gather at the acoustic pressure nodes and dynamically arrange to form a two-dimensional pattern;

[0020] Step S4, biological microparticle spin: the single-channel input signal passes through the high-speed four-quadrant signal generating circuit to generate four-channel output signals 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 signals are applied to the first interdigital electrode or the second interdigital electrode as the control parameters, and the first interdigital electrode and the second interdigital electrode adjust the phase difference according to the control parameters obtained by simulation and simulation of the high-speed four-quadrant signal generating circuit, so as to generate a phase transition at the acoustic pressure node of the biological microparticle arrangement, so that the biological microparticles in the spin area spin.

[0021] Preferably, the high-speed four-quadrant signal generating circuit in step S4 comprises a first single-to-differential circuit, a frequency doubling circuit, a second single-to-differential circuit, a duty cycle adjustment circuit and a frequency divider circuit connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-to-differential circuit, and the signal frequency remains unchanged. The differential output signal has a phase difference of 180°. The differential output signal is input into the frequency doubling circuit, and then a double output signal with a phase difference of 180° is generated by the second single-to-differential circuit. The double output signal is processed by the duty cycle adjustment circuit and finally input into the frequency divider circuit. The frequency divider circuit includes two sub-modules, each of which can generate two signals with a phase shift of 90°. Therefore, the frequency divider circuit finally outputs four signals with a phase shift of 90°.

[0022] Preferably, the particle size of the biological microparticles in the microfluid is in the range of 700 nm to 20 μm.

[0023] Preferably, in step S4, when the phase of the radio frequency signal of the first interdigital electrode is changed from 0° to 360° and the phase of the radio frequency signal of the second interdigital electrode remains unchanged, the biological microparticles generate ACW counterclockwise spin phenomenon due to unbalanced force; when the phase of the radio frequency signal of the second interdigital electrode is deflected from 0° to 360° and the phase of the radio frequency signal of the first interdigital electrode remains unchanged, the biological microparticles generate CW clockwise spin phenomenon.

[0024] The technical scheme provided by the application has the following technical effects compared with the prior art: the technical scheme provided by the application has irreplaceable advantages in technical precision, biocompatibility and actual operation difficulty. The operation object of the acoustic microfluidic-based biological microparticle spin arrangement device and method is highly scalable, the acoustic microfluidic-based biological microparticle spin arrangement method can control biological microparticles with high precision, low difficulty and low cost, and has high biocompatibility, and can manipulate biological microparticles with a size of tens of nanometers to hundreds of microns without contact, damage or labeling, which has important practical significance. In addition, the acoustic microfluidic-based biological microparticle spin arrangement method can accurately and efficiently realize fast immobilization of biological probes without expensive and complex additional equipment, the acoustic microfluidic-based biological microparticle spin arrangement device provided by the application has low manufacturing cost, simple operation, and the overall structure is innovative. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0026] In order to more clearly illustrate the technical schemes in the embodiments of the application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0027] Figure 1 is a structural schematic view of an acoustic microfluidic-based biological microparticle spin arrangement device in some embodiments of the application;

[0028] Figure 2 is a top view of Figure 1

[0029] Figure 3 is a structural schematic view of the first interdigital electrode or the second interdigital electrode in some embodiments of the application;

[0030] Figure 4 is a structural schematic view of the Z-direction liquid inlet pipeline and the Z-direction liquid outlet pipeline in some embodiments of the application;

[0031] Figure 5 is a flowchart of an acoustic microfluidic-based biological microparticle spin arrangement method in some embodiments of the application;

[0032] Figure 6 is an analog schematic view of a high-speed four-quadrant signal generation circuit in an acoustic microfluidic-based biological microparticle spin arrangement method in some embodiments of the application; ​

[0033] Figure 7 Figure 1 is a simulation schematic diagram of a high-speed four-quadrant signal generation circuit in a method for arranging biological microparticles by self-spinning according to an embodiment of the present application;

[0034] Figure 8 Figure 2 is a schematic diagram of biological microparticle arrangement in a method for arranging biological microparticles by self-spinning according to an embodiment of the present application;

[0035] Figure 9 Figure 3 is a schematic diagram of biological microparticle self-spinning in a method for arranging biological microparticles by self-spinning according to an embodiment of the present application.

[0036] In the figure: 10, piezoelectric substrate; 21, first interdigital electrode; 22, second interdigital electrode; 210, electrode finger; 211, first bus bar; 212, second bus bar; 213, reflective grid; 30, PDMS microfluidic chip; 31, sample inlet; 32, first main flow channel; 33, main flow chamber; 34, second main flow channel; 35, sample outlet; 36, Z-direction liquid inlet pipeline; 361, liquid inlet elbow; 362, first vertical pipeline; 37, Z-direction liquid outlet pipeline; 371, liquid outlet elbow; 372, second vertical pipeline. DETAILED DESCRIPTION

[0037] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the schemes of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0038] In the description, it should be noted that the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance. It should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein; obviously, the examples in the specification are only some of the embodiments of the present application, not all the embodiments.

[0040] The specific embodiments of the present application will be described in detail below. Figures 1 to 9 The specific embodiments of the present application will be described in detail below.

[0041] In one embodiment, as shown in Figure 1 and Figure 2 An acoustic microfluidic-based biological microparticle spin alignment device is disclosed, comprising a piezoelectric substrate 10, a first interdigital electrode 21, a second interdigital electrode 22 and a PDMS microfluidic chip 30, the PDMS microfluidic chip 30 is provided with a sample inlet 31, a first main flow channel 32, a main flow chamber 33, a second main flow channel 34 and a sample outlet 35 connected in sequence, the first main flow channel 32 is an observation area, and the main flow chamber 33 is an alignment area and a spin area; the PDMS microfluidic chip 30 is activated and bonded to the back side of the upper surface of the piezoelectric substrate 10, the first interdigital electrode 21 and the second interdigital electrode 22 are arranged on the front side of the upper surface of the piezoelectric substrate 10, the first interdigital electrode 21 and the second interdigital electrode 22 are both uniform linear electrode fingers 210, the first interdigital electrode 21 and the second interdigital electrode 22 are orthogonally distributed and the front ends of both are arranged towards the main flow chamber 33, and the microfluidic channel substrate is provided with a mounting notch avoiding the first interdigital electrode 21 and the second interdigital electrode 22. The PDMS microfluidic chip 30 is made by molding method, the PDMS and curing agent are fully mixed at a ratio of 10:1 and vacuumized until the bubbles completely disappear, poured into a silicon-based microfluidic mold treated with a release agent, heated at 80℃ for 20 min, and a cured channel with a height of 50μm is obtained. The PDMS microfluidic chip 30 and the piezoelectric substrate 10 are activated and bonded by oxygen plasma etching technology, forming a complete acoustic microfluidic-based biological microparticle manipulation device.

[0042] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in Figure 3As shown, the first interdigital 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 gratings 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 connected to the first bus bar 211 and the second bus bar 212 respectively. 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 gratings 213 are arranged in parallel with the electrode fingers 210 and have the same width as the electrode fingers 210. The interval between the reflective gratings 213 and the electrode fingers 210 is equal to the width of the electrode fingers 210. The electrode fingers 210 are located between the first bus bar 211 and the second bus bar 212. The two ends of the reflective gratings 213 are not connected to the first bus bar 211 or the second bus bar 212. The second interdigital electrode 22 has the same structure as the first interdigital electrode 21. The reflective gratings 213 are metal strips with the same width and interval as the electrode fingers 210, and the two ends of the reflective gratings 213 are not connected to the first bus bar 211 or the second bus bar 212. The first interdigital electrode 21 and the second interdigital electrode 22 are respectively connected to the output port of the power amplifier through the first bus bar 211 and the second bus bar 212 respectively. The power amplifier is connected to the signal generator. The first interdigital electrode 21 and the second interdigital electrode 22 are respectively prepared by photolithography technology, and then prepared by magnetron sputtering and ion beam etching process. The structure and size of the first interdigital electrode 21 and the second interdigital electrode 22 are completely consistent, and the use method and characteristics are completely the same.

[0043] On the basis of the above-mentioned embodiments, in a preferred embodiment, the electrode fingers 210, the first bus bar 211, the second bus bar 212, and the reflective gratings 213 in the first interdigital electrode 21 and the second interdigital electrode 22 are composed of a chromium adhesive 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 adhesive layer, and the chromium adhesive 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 interval L2 between adjacent electrode fingers 210 is 30 μm, the length of the reflective gratings 213, i.e. the acoustic aperture W, is 2300 μm, the number of pairs of the electrode fingers 210 is 20 pairs, and the number of pairs of the reflective gratings 213 is 10 pairs.

[0044] On the basis of the above-mentioned embodiments, in a preferred embodiment, as Figure 4As shown, the sample inlet 31 is provided with a Z-direction liquid inlet pipe 36, the Z-direction liquid inlet pipe 36 includes 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 with 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 includes 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 with the sample outlet 35. Specifically, the cross section of the liquid inlet elbow 361 and the liquid outlet elbow 371 is circular.

[0045] On the basis of the above-mentioned embodiments, in a preferred embodiment, the piezoelectric substrate 10 is made of lithium niobate material cut at 128° around the Y axis and with the sound wave propagating along the X axis direction.

[0046] On the basis of the above-mentioned embodiments, in a preferred embodiment, the diameters of the first main flow channel 32 and the second main flow channel 34 are 200 μm, and the first main flow channel 32 and the second main flow channel 34 are respectively provided with a plurality of bends; the main flow chamber 33 has a square structure, and the main flow chamber 33 is connected with the first main flow channel 32 and the second main flow channel 34 through opposite angles, respectively; the opposite angle distance of the main flow chamber 33 is 2300 μm, and the bends of the first main flow channel 32 and the second main flow channel 34, the four corners of the main flow chamber 33, and the connection positions of the main flow chamber 33 with the first main flow channel 32 and the second main flow channel 34 are all provided with round corners or bevels. The round corners and bevels can ensure smooth fluid flow, have no flow dead angle, and are beneficial to reducing the residue and blockage of biological microparticles in the PDMS micro-flow channel chip 30, thereby reducing the sample cross-contamination problem in observation.

[0047] The application further provides a biological microparticle self-spinning arrangement method based on acoustic micro-fluidics. Figure 5 As shown, it is realized based on the biological microparticle self-spinning arrangement device based on acoustic micro-fluidics, and includes the following steps:

[0048] Step S1, access to micro-fluid: make the micro-fluid flow from the Z-direction liquid inlet pipe 36, the sample inlet 31, the first main flow channel 32, the main flow chamber 33, the second main flow channel 34, the sample outlet 35 to the Z-direction liquid outlet pipe 37 in sequence;

[0049] Step S2, micro-fluid observation: observe the biological microparticles in the micro-fluid by means of an inverted fluorescence microscope, and observe the number and position of the biological microparticles flowing into the main flow chamber 33 from the first main flow channel 32;

[0050] Step S3, biological particle arrangement: according to the observation result of step S2, the non-phase difference alternating current signal is selected and input to the first interdigital electrode 21 and the second interdigital electrode 22, the vibration of the piezoelectric substrate 10 is controlled, the acoustic surface standing wave of the orthogonal superposition interference is generated on the piezoelectric substrate 10, the biological particles in the arrangement area are gathered and dynamically arranged to form a two-dimensional pattern at the acoustic pressure node, and specific reference can be made to Figure 8 ;

[0051] Step S4, biological particle spin: the single-channel input signal generates four-channel output signals with a phase difference of 90° through a high-speed four-quadrant signal generating circuit, wherein the output phases of the four-channel output signals are 0°, 90°, 180° and 270° respectively, the four-channel output signals are 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 simulated and simulated by the high-speed four-quadrant signal generating circuit, so that the biological particles in the spin area spin at the acoustic pressure node of the biological particle arrangement, and specific reference can be made to Figure 9 .

[0052] In step S2 of the present application, when the microfluid observation is specifically performed, the biological particles are input to the first main flow channel 32 through the sample inlet 31, and when the biological particles in motion flow through the first main flow channel 32, the observation of the biological particles is realized through the light signal excitation observation module. 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. Adjust the excitation block switching device to the wavelength region consistent with the scattered light signal of the biological particles, and the laser excitation block, the fluorescent light source and the fluorescent illuminator generate laser and form a laser spot after shaping by the inverted microscope for observation. The role of microfluid observation is to observe the number and position of biological particles through an inverted fluorescent microscope, so that they are maximally gathered in the main flow chamber 33, thereby facilitating the utilization efficiency of arrangement and spin. The observation area is located in the first main flow channel 32, the arrangement area is located in the main flow chamber 33, and the arrangement area works according to the judgment result of the observation area. The first interdigital electrode 21 and the second interdigital electrode 22 make the piezoelectric substrate 10 vibrate to generate an acoustic surface traveling wave, when the acoustic surface traveling wave propagates to the main flow chamber 33, the acoustic surface traveling wave is orthogonally superimposed and interfered, the periodic coupling acoustic flow and the two-dimensional high-resolution acoustic surface standing wave field are coupled, and finally the acoustic surface standing wave is generated to form the acoustic pressure node and the anti-acoustic pressure node, the distance between the acoustic pressure nodes is The biological particles between adjacent anti-sound pressure nodes will be attracted by the sound pressure nodes and move towards the sound pressure nodes between them, and finally gather at the sound pressure nodes and dynamically arrange to form a two-dimensional pattern. The sound energy will not damage the structure and function of the biological particles, and the biological particles can be quickly and accurately manipulated 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 superposition of the standing wave generates corresponding dynamic changes, which change the equilibrium state of the biological particle clusters gathered and arranged near the sound pressure nodes.

[0053] On the basis of the above-mentioned embodiments, in a preferred embodiment, as shown in Figure 6 and Figure 7 The high-speed four-quadrant signal generation circuit in step S4 includes a first single-to-differential circuit, a frequency doubling circuit, a second single-to-differential circuit, a duty cycle adjustment circuit and a frequency divider circuit connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-to-differential circuit, and the signal frequency remains unchanged. The differential output signal has a phase difference of 180°. The differential output signal is input to the frequency doubling circuit, and then a double output signal with a phase difference of 180° is generated by the second single-to-differential circuit. After the double output signal is processed by the duty cycle adjustment circuit, it is finally input into the frequency divider circuit. The frequency divider circuit includes two sub-modules of frequency dividers, each of which can generate two signals with a phase shift of 90°. Therefore, the frequency divider circuit finally outputs four signals with a phase shift of 90°.

[0054] On the basis of the above-mentioned embodiments, in a preferred embodiment, the particle size of the biological particles in the microfluid is in the range of 700 nm to 20 μm. The operating object of the method of the present application is highly scalable, and can manipulate biological particles with a size of several tens of nanometers to several hundred microns, which has important practical significance. At the same time, the method can be used to manipulate biological particles under non-contact and non-invasive conditions, and provides a liquid living tissue manipulation method without labeling and good biocompatibility. In addition, the method of the present application does not require expensive and complex additional equipment, and can realize accurate and efficient biological probe rapid immobilization and microorganism instant detection through arrangement and spin manipulation.

[0055] On the basis of the above-mentioned embodiments, in a preferred embodiment, in step S4, when the radio frequency signal phase of the first interdigital electrode 21 is transformed from 0° to 360° while the radio frequency signal phase of the second interdigital electrode 22 remains unchanged, the biological microparticles generate ACW counterclockwise spin phenomenon due to unbalanced force; when the radio frequency signal phase of the second interdigital electrode 22 is deflected from 0° to 360° while the radio frequency signal phase of the first interdigital electrode 21 remains unchanged, the biological microparticles generate CW clockwise spin phenomenon. The electroacoustic conversion caused by the signal difference can instantly and accurately control the acoustic energy received by the biological microparticles, improve the spin efficiency of the biological microparticles, and further strengthen the interaction efficiency between particles.

[0056] The above description is only a specific implementation of the present application, enabling those skilled in the art to understand or implement the present application. Although the foregoing embodiments are described in detail, those skilled in the art should understand that the technical solutions described in the foregoing embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and should be covered in the protection scope of the claims.

Claims

1. A biological microparticle spin alignment device based on acoustic microfluidics, characterized in that, The piezoelectric substrate (10), the first interdigital electrode (21), the second interdigital electrode (22) and the PDMS microfluid channel chip (30) are included, the PDMS microfluid channel chip (30) is provided with a sampling inlet (31), a first main flow channel (32), a main flow chamber (33), a second main flow channel (34) and a sample outlet (35) which are sequentially and tightly connected, the first main flow channel (32) is an observation area, and the main flow chamber (33) is an arrangement area and a spin area; after the PDMS microfluid channel chip (30) is activated and bonded to the rear side of the upper surface of the piezoelectric substrate (10), the first interdigital electrode (21) and the second interdigital electrode (22) are arranged on the front side of the upper surface of the piezoelectric substrate (10), the first interdigital electrode (21) and the second interdigital electrode (22) are both uniform linear electrode fingers (210), the first interdigital electrode (21) and the second interdigital electrode (22) are orthogonally distributed and the front ends of the first interdigital electrode (21) and the second interdigital electrode (22) are both arranged towards the main flow chamber (33), and the microfluid channel substrate is provided with mounting notches for avoiding the first interdigital electrode (21) and the second interdigital electrode (22).

2. The acoustic microfluidic based bio-particle spin alignment device of claim 1, wherein, The first interdigital electrode (21) includes an even number of electrode fingers (210), a first bus bar (211), a second bus bar (212) and a plurality of reflection gratings (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 connected to the first bus bar (211) and the second bus bar (212) respectively, 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 reflection gratings (213) are arranged in parallel with the electrode fingers (210) and have the same width as the electrode fingers (210), the interval between the reflection gratings (213) and the electrode fingers (210) is equal to the width of the adjacent electrode fingers (210), the electrode fingers (210) are located between the first bus bar (211) and the second bus bar (212), and the two ends of the reflection gratings (213) are not connected to the first bus bar (211) or the second bus bar (212); the second interdigital electrode (22) has the same structure as the first interdigital electrode (21).

3. The acoustic microfluidic based bio-particle spin alignment device of claim 2, wherein, In the first interdigital electrode (21) and the second interdigital electrode (22), the electrode fingers (210), the first bus bar (211), the second bus bar (212) and the reflection gratings (213) are all composed of a chromium adhesive layer with a thickness of 20 nm and a gold electrode layer with a thickness of 100 nm, the gold electrode layer is located above the chromium adhesive layer, and the chromium adhesive 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 mu m, the interval L2 between the adjacent electrode fingers (210) is 30 mu m, the length of the reflection gratings (213) is 2300 mu m, the logarithm of the electrode fingers (210) is 20 pairs, and the logarithm of the reflection gratings (213) is 10 pairs.

4. The acoustic microfluidic based bio-particle spin alignment device according to any one of claims 1 to 3, wherein, The sample inlet (31) is provided with a Z-direction liquid inlet pipe (36) comprising a liquid inlet elbow (361) and a first vertical pipe (362), the liquid inlet elbow (361) being connected to the top end of the first vertical pipe (362), and the bottom end of the first vertical pipe (362) being connected to the sample inlet (31); the sample outlet (35) is provided with a Z-direction liquid outlet pipe (37) comprising a liquid outlet elbow (371) and a second vertical pipe (372), the liquid outlet elbow (371) being connected to the top end of the second vertical pipe (372), and the bottom end of the second vertical pipe (372) being connected to the sample outlet (35).

5. The acoustic microfluidic based bio-particle spin alignment device of claim 4, wherein, The piezoelectric substrate (10) is made of lithium niobate material cut at 128° around the Y axis and with sound waves propagating along the X axis.

6. The acoustic microfluidic based biological microparticle spin alignment device of claim 5, wherein, The first main flow channel (32) and the second main flow channel (34) have a diameter of 200 μm, and are respectively provided with a plurality of bends; the main flow chamber (33) has a square structure, and is connected to the first main flow channel (32) and the second main flow channel (34) through opposite corners, respectively; the opposite corner spacing of the main flow chamber (33) is 2300 μm, and the bends of the first main flow channel (32) and the second main flow channel (34), the four corners of the main flow chamber (33), and the connection of the main flow chamber (33) with the first main flow channel (32) and the second main flow channel (34) are all provided with rounded corners or bevels.

7. A method for aligning the spins of biological microparticles based on acoustic microfluidics, characterized in that, The method is implemented based on the device for arranging biological microparticles by using acoustic microfluidics according to claim 6, and comprises the following steps: Step S1, accessing the microfluid: making the microfluid flow from the Z-direction liquid inlet pipe (36), the sample inlet (31), the first main flow channel (32), the main flow chamber (33), the second main flow channel (34), the sample outlet (35) to the Z-direction liquid outlet pipe (37) in sequence; Step S2, microfluid observation: observing the biological microparticles in the microfluid by using an inverted fluorescence microscope, and observing the number and position of the biological microparticles flowing into the main flow chamber (33) from the first main flow channel (32); Step S3, biological microparticle arrangement: selecting an in-phase alternating current signal according to the observation result of step S2, and inputting the first interdigital electrode (21) and the second interdigital electrode (22) with the in-phase alternating current signal, controlling the piezoelectric substrate (10) to vibrate, generating a quadrature superimposed standing surface wave on the piezoelectric substrate (10), and making the biological microparticles in the arrangement region gather at the acoustic pressure nodes and dynamically arrange to form a two-dimensional pattern. Step S4, biological microparticle spin: the single-channel input signal passes through the high-speed four-quadrant signal generation circuit to generate four-channel output signals 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 signals are applied to the first interdigital electrode (21) or the second interdigital electrode (22) as the control parameters, and the first interdigital electrode (21) and the second interdigital electrode (22) adjust the phase difference according to the control parameters obtained by simulation and simulation of the high-speed four-quadrant signal generation circuit, so that the phase transition occurs at the acoustic pressure node of the biological microparticle arrangement, and the biological microparticles in the spin area spin.

8. The method according to claim 7, wherein the method is based on acoustic microfluidic self-assembly of biological microparticles. The high-speed four-quadrant signal generation circuit in step S4 includes a first single-to-differential circuit, a frequency doubling circuit, a second single-to-differential circuit, a duty cycle adjustment circuit and a frequency divider circuit connected in sequence. The single-channel input signal generates a differential output signal after passing through the first single-to-differential circuit, and the signal frequency remains unchanged. The differential output signal has a phase difference of 180°. The differential output signal is input into the frequency doubling circuit, and then the second single-to-differential circuit generates a double output signal with a phase difference of 180°. The double output signal is processed by the duty cycle adjustment circuit and finally input into the frequency divider circuit. The frequency divider circuit includes two sub-modules, each of which can generate two signals with a phase shift of 90°. Therefore, the frequency divider circuit finally outputs four signals with a phase shift of 90°.

9. The method of claim 8, wherein the acoustic microfluidic-based bio-particle spin alignment method further comprises: The particle size of the biological microparticles in the microfluid is in the range of 700 nm to 20 μm.

10. The method of claim 9, wherein the acoustic microfluidic-based bio-particle spin alignment method is characterized by, 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 microparticles produce ACW counterclockwise spin phenomenon due to unbalanced force; when the phase of the radio frequency signal of the second interdigital electrode (22) changes from 0° to 360° and the phase of the radio frequency signal of the first interdigital electrode (21) remains unchanged, the biological microparticles produce CW clockwise spin phenomenon.

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