Dynamic sound field modulation and particle control device based on digital microfluidics

Abstract

The invention discloses a dynamic sound field modulation and particle control device based on digital microfluidics, which comprises a solution tank, a digital microfluidics system and a bulk acoustic wave resonator, the digital microfluidics system is used for dynamically modulating acoustic waves generated by the bulk acoustic wave resonator, the modulated acoustic waves act on a solution in the solution tank, and the solution in the solution tank is subjected to dynamic sound field modulation and particle control. And a local acoustic flow field is formed in the solution, so that the particles in the solution are driven, and the dynamic control of the particles is realized. The device has the beneficial effects that the device can modulate a single sound field, so that the single sound field is changed into a controllable dynamically-changing sound field, and the rapid movement of liquid drops can realize the rapid change of the sound field transmitted to the next stage; a designed digital micro-fluidic peripheral and a wedge-shaped clamping mechanism of a chip electrode can realize rapid replacement of a chip, can realize stable circuit connection, and also ensures sound field coupling between the chip and a sound production device at the front end and between the chip and a control solution tank at the rear end.

Description

Technical Field

[0001] The present invention belongs to the field of acoustic fluid technology, and in particular relates to a dynamic acoustic field modulation and particle manipulation device based on digital microfluidics. Background Art

[0002] Acoustic manipulation has the advantages of non-contact and remote operation, and its application fields are very wide, including drug delivery, cell screening, in vitro diagnosis, etc. The main component of the ultrasonic particle manipulation system is the ultrasonic transducer, which converts electrical energy into mechanical vibrations and can generate sound waves in the fluid medium. When the sound waves interact with the fluid medium, two forces are generated: acoustic streaming force (ASF) and acoustic radiation force (ARF).

[0003] Acoustic streaming is a steady fluid flow formed by the viscous attenuation of sound waves. When sound waves propagate in a fluid, the state of the fluid volume unit is characterized by the fluctuations of pressure and velocity. In an ideal fluid, the time average of the displacement of the fluid unit, that is, the net flow of the fluid, is zero everywhere. However, in real fluids, viscous attenuation causes the net displacement of the fluid unit in each oscillation cycle to be non-zero. This local effect leads to the formation of flow on a global scale, thus generating acoustic streaming.

[0004] The generation of acoustic radiation force is due to the transfer of wave momentum to absorbing or scattering objects in the attenuating medium. Its generation mechanism includes the dissipation of acoustic energy, reflection of the incident wave, gradient change of compression wave velocity, and spatial inhomogeneity of energy density in the standing wave.

[0005] Ultrasonic waves can directly manipulate particles by applying acoustic radiation force, or they can indirectly drive particle motion by generating acoustic flow through the acoustic pressure field. Particles are also affected by viscous drag when moving in a fluid. ARF is proportional to the cube of the particle radius, while ASF is proportional to the particle radius. Therefore, as the particle radius decreases, ARF decreases faster than ASF. At the submicron scale, ASF begins to play a dominant role in particle motion.

[0006] With the help of acoustic radiation forces, suspended cells can be actively guided and precisely arranged on nodes or antinodes according to their compressibility and density characteristics. These cell patterns can remain fixed or dynamically reconstructed by changing the frequency or phase. For example, Armstrong et al. used sound waves to align myoblasts in hydrogels to form muscle tissue with bundled myotubes. These acoustically arranged high-density tissue structures better replicate the structure in natural muscle tissue and exhibit anisotropic tensile mechanical properties. Acoustic manipulation combined with microfluidic systems can also achieve the sorting of cells of different types or sizes.

[0007] The acoustic metasurface can be used to modulate the sound field of bulk acoustic waves. By designing and manufacturing physical microstructures, the reflection, absorption, and transmission of sound waves can be effectively controlled to achieve effects such as directional transmission of sound waves, energy convergence, and ultrasonic particle suspension. For example, ultrasound can be focused transcranially by using an acoustic holographic lens to perform non-invasive deep brain neuromodulation. Kai Melde et al. can generate a three-dimensional holographic sound field by combining three orthogonally arranged bulk acoustic wave resonators and three acoustic metasurfaces, and perform three-dimensional patterning of particles and cells.

[0008] The above-mentioned method of using acoustic metasurfaces to modulate the sound field, or by arranging multiple acoustic devices to generate acoustic standing waves, can already achieve patterned arrangement of particles and cells. However, this technology basically produces a static modulated sound field, or only generates a regular linear or dot array pattern. If the sound field changes, different metasurface structures need to be redesigned and manufactured. Therefore, real-time dynamic modulation of the sound field can give acoustic operations more flexibility and has broader application prospects. Summary of the invention

[0009] The invention discloses a dynamic sound field modulation and particle manipulation device based on digital microfluidics, which can realize dynamic manipulation of particles.

[0010] A dynamic acoustic field modulation and particle manipulation device based on digital microfluidics, including a solution tank, a digital microfluidics system, and a bulk acoustic wave resonator.

[0011] The digital microfluidic system is used to dynamically modulate the sound waves generated by the bulk acoustic wave resonator. The modulated sound waves act on the solution in the solution tank to form a local acoustic flow field in the solution, thereby driving the particles in the solution and realizing dynamic manipulation of the particles.

[0012] Among them, the dynamic acoustic field modulation and particle manipulation device based on digital microfluidics, the digital microfluidics system includes a digital microfluidic chip, the digital microfluidic chip is composed of an upper electrode plate and a lower electrode plate, between the upper electrode plate and the lower electrode plate are droplets that can be controlled to move, the bulk acoustic wave resonator is located on the lower side of the lower electrode plate, and the solution tank is located on the upper side of the upper electrode plate.

[0013] Among them, the dynamic sound field modulation and particle manipulation device based on digital microfluidics also includes a frame, a base, a chip mounting plate and a base. The acoustic wave resonator is arranged in the frame, and the base and the base are fixedly connected by bolts; the PCB board is installed in the base, the chip mounting plate has a through hole, the bolts pass through the through hole, the chip mounting plate can slide up and down between the base and the base, the digital microfluidic chip is installed on the chip mounting plate, the wedge-shaped gasket is inserted between the chip mounting plate and the base, the upper side of the wedge-shaped gasket is a plane, and the lower side is a wedge-shaped surface adapted to the base, the digital microfluidic chip is in contact with the PCB board and is electrically connected to the digital microfluidic control host, the base and the base are placed on the acoustic wave resonator, and the digital microfluidic chip and the acoustic wave resonator are in contact with each other through their own weight.

[0014] Among them, in the dynamic acoustic field modulation and particle manipulation device based on digital microfluidics, the bottom of the digital microfluidic chip is in close contact with the bulk acoustic wave resonator, and coupling is performed by adding water or ultrasonic coupling agent between them to improve the transmission efficiency of bulk acoustic waves between the interfaces.

[0015] Among them, the dynamic sound field modulation and particle manipulation device based on digital microfluidics also includes a clamping mechanism, which includes a clamping block, a silicone gasket, a ball head pull rod, a straight connecting rod, a bent connecting rod and a cam. The two clamping blocks are symmetrically arranged on the left and right, one end of the clamping block is rotatably connected to the frame, and the other end is hinged to the ball head pull rod, one end of the straight connecting rod is connected to the ball head pull rod, and the other end is hinged to the cam, one end of the bent connecting rod is hinged to the cam, and the other end is connected to the ball head pull rod hinged to the clamping block on the other side, and the cam is rotatably arranged on the frame.

[0016] Wherein, in the dynamic sound field modulation and particle manipulation device based on digital microfluidics, the silicone gasket is arranged at the inner side of the clamping block.

[0017] Beneficial effects of the present invention:

[0018] (1) The device of the present invention can modulate a single sound field to make it a controllable dynamically changing sound field. The rapid movement of the droplets can achieve rapid changes in the sound field transmitted to the next level.

[0019] (2) The designed wedge-shaped clamping mechanism of the digital microfluidic peripherals and chip electrodes can realize the rapid replacement of the chip and achieve stable circuit connection, while also ensuring the acoustic field coupling between the chip and the front-end sound-generating device and the back-end control solution tank;

[0020] (3) The clamping mechanism enables good integration of BAW resonator and digital microfluidic control system;

[0021] (4) The horizontal clamping force of the clamping mechanism allows for slight changes in the vertical dimensions of the system when it is assembled vertically;

[0022] (5) The open solution tank can reduce the limitations of controlling particles and facilitate the transfer and observation of particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall system of the present invention, FIG. A is an overall assembly diagram, and FIG. B is an exploded schematic diagram of the main parts;

[0024] Figure 2 It is a cross-sectional schematic diagram of the internal structure of the system;

[0025] Figure 3 Schematic diagram of a wedge-shaped clamping mechanism for a digital microfluidic chip electrode, wherein Figure A is a state to be clamped, and Figure B is a clamped state;

[0026] Figure 4 It is a schematic diagram of the stable clamping principle of the clamping mechanism through the cooperation between the connecting rod dead point and the cam;

[0027] Figure 5 It is a schematic diagram of the system integrated clamping mechanism in the open state, and Figures A, B, and C are the isometric view, front view, and top view respectively;

[0028] Figure 6 It is a schematic diagram of the system integrated clamping mechanism in the clamping state, and Figures A, B, and C are the isometric view, front view, and top view respectively;

[0029] Figure 7 Schematic diagram of the principle of droplet control of acoustic field in digital microfluidics. DETAILED DESCRIPTION

[0030] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, not all.

[0031] A dynamic acoustic field modulation and particle manipulation device based on digital microfluidics, comprising a solution tank 1, a digital microfluidics system 2, and a bulk acoustic wave resonator 3.

[0032] The digital microfluidic system 2 is used to dynamically modulate the sound waves generated by the bulk acoustic wave resonator 3. The modulated sound waves act on the solution in the solution tank 1 to form a local acoustic flow field in the solution, thereby driving the particles in the solution and realizing dynamic manipulation of the particles.

[0033] The digital microfluidic system 2 includes a digital microfluidic chip 5, which is composed of an upper plate 22 and a lower plate 24. Between the upper plate 22 and the lower plate 24 is a liquid drop 21 whose movement can be controlled. The bulk acoustic wave resonator 3 is located at the lower side of the lower plate 24, and the solution tank 1 is located at the upper side of the upper plate 22.

[0034] like Figure 1 , 2 As shown, the dynamic sound field modulation and particle manipulation device based on digital microfluidics also includes a frame 9, a base 7, a chip mounting plate 6 and a base 11, the acoustic wave resonator 3 is arranged in the frame 9, and the base 7 and the base 11 are fixedly connected by bolts; the PCB board 10 is installed in the base 11, the chip mounting plate 6 has a through hole, the bolts pass through the through hole, the chip mounting plate 6 can slide up and down between the base 7 and the base 11, the digital microfluidic chip 5 is installed on the chip mounting plate 6, and the wedge-shaped gasket 8 is inserted between the chip mounting plate 6 and the base 7. The upper side of the wedge-shaped gasket 8 is a plane, and the lower side is a wedge-shaped surface adapted to the base 7. The digital microfluidic chip 5 is in contact with the PCB board 10 and is electrically connected to the digital microfluidic control host, and the base 7 and the base 11 are placed on the acoustic wave resonator 3, and the digital microfluidic chip 5 and the acoustic wave resonator 3 are in contact with each other by their own weight.

[0035] Digital microfluidic chip electrode wedge clamping mechanism. Figure 3 Schematic diagram of the wedge-shaped clamping mechanism of the digital microfluidic chip electrode. Figure 3 As shown in A, when the wedge-shaped gasket 8 is not fully inserted, the digital microfluidic chip 5 does not contact the electrode 10-1 of the PCB board 10. At this time, the digital microfluidic chip 5 can be pushed out to replace the chip. Figure 3-Ⅰ The enlarged view of the electrodes shows that the electrode 10-1 of the PCB board and the electrode 5-1 of the lower plate of the digital microfluidic chip are in a separated state. Figure 3 B), the chip mounting plate 6 is lifted horizontally, and the electrode 10-1 of the PCB board is in close contact with the electrode 5-1 of the lower plate 24 of the digital microfluidic chip 5, achieving a stable circuit connection. The designed limit step of the wedge-shaped gasket prevents the clamping force from being too large, so that it is in a good clamping state and convenient to pull out the wedge-shaped gasket.

[0036] The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics also includes a clamping mechanism. The digital microfluidic chip 5 is in close contact with the bulk acoustic wave resonator 3 from below, and coupling is performed by adding water or ultrasonic coupling agent between them to improve the transmission efficiency of bulk acoustic waves between the interfaces. Since the digital microfluidic chip is made of glass, in the process of clamping the bulk acoustic wave resonator and the digital microfluidic chip to make them in close contact, a clamping force is applied in the vertical direction to keep the two fixed, which can easily cause the glass chip to break. Therefore, the present invention designs a horizontal clamping mechanism to stably fix the digital microfluidic chip and the bulk acoustic wave resonator after they are in close contact.

[0037] like Figure 5 As shown, the clamping mechanism includes a clamping block 13, a silicone gasket 14, a ball head tie rod 15, a straight connecting rod 16, a bent connecting rod 18 and a cam 17. The clamping block 13 is symmetrically arranged in two positions. One end of the clamping block 13 is rotatably connected to the frame 9, and the other end is hinged to the ball head tie rod 15. One end of the straight connecting rod 16 is connected to the ball head tie rod 15, and the other end is hinged to the cam 17. One end of the bent connecting rod 18 is hinged to the cam 17, and the other end is connected to the ball head tie rod 15 hinged to the clamping block 13 on the other side. The cam 17 is rotatably arranged on the frame 9. The silicone gasket 14 is arranged at the inner side of the clamping block 13.

[0038] The rotation of the cam drives the straight link 16 and the bent link 18 to move, and the two links drive the clamping block 13 to swing, thereby realizing the clamping process. The silicone pad 14 is used for buffering displacement and continuously applying the clamping force.

[0039] The combination of the straight link 16 and the bent link 18 is adopted because the links will overlap in their tracks during movement, and cannot complete the movement process of driving the clamping block to clamp and lock. The raised portion of the bent link 18 can bypass the hinge of the straight link 16 during movement. The force of the bent link 18 is still at the hinge at both ends, and the force form is still a two-force rod. Figure 4 The ② position can play the role of the connecting rod dead point.

[0040] Figure 6 This is the state when the clamping mechanism is locked. At this time, both connecting rods have passed the dead point position and the cam 17 has been clamped. Figure A is an isometric view, Figure B is a front view, and Figure C is a top view. Figure 5 By contrast, the front view shows the process of the cam 17 driving the connecting rod to move, and the top view shows the process of the clamping block 13 swinging and clamping.

[0041] like Figure 6 As shown, the present invention adopts a crank rocker mechanism to perform the clamping action, and the cam 17 is manually rotated to drive the rocker mechanism 13 to swing in the horizontal plane, and the left and right rocker mechanisms 13 perform the clamping action.

[0042] The dead point of the crank-rocker mechanism and the cam clamping work together to perform locking after clamping. The dead point position that can be utilized in the structure of the present invention is unstable. When the crank mechanism is subjected to disturbances such as vibration, it is easy to deviate from the dead point position, resulting in loose clamping, which is an unstable balance. Therefore, the present invention introduces a cam clamping mechanism. After the rod rotates 10°, the cam is clamped. Within this 10° range, the system is in a state of stable balanced clamping. Because the clamping force at the dead point position is the largest, it is not easy to reverse back to the dead point position after rotating past the dead point position, but continued rotation will cause the cam mechanism to clamp further and it is not easy to continue to rotate. Therefore, the dead point position designed by the present invention and the cam clamping work together can enable the mechanism to achieve stable clamping.

[0043] Figure 4 The figure is the principle diagram of the horizontal clamping mechanism. Only the right connecting rod mechanism is listed in the figure to introduce the motion principle. The left connecting rod mechanism is centrally symmetrical about the axis of the cam. Figure 4 As shown, the clamping mechanism is mainly composed of a cam and a connecting rod. One end of the connecting rod is hinged to the cam, and the other end can move horizontally. The manual rotation of the cam can drive the right end of the connecting rod to move horizontally. The counterclockwise rotation of the cam shown in the figure can be turned from position ① to position ②, and then to position ③. Among them, position ② is the dead point of the connecting rod mechanism. The connecting rod and the cam shaft are in a straight line. The right end of the connecting rod applies a horizontal force. This position cannot drive the connecting rod to move. Only by rotating the cam can the rod move. However, position ② is an unstable dead point. A slight disturbance will cause it to leave the dead point and move further and further away from the dead point under the action of the horizontal clamping force to the right of the right end of the connecting rod.

[0044] In order to solve the above-mentioned problem of instability at the dead point, the present invention also introduces a cam structure. When the connecting rod moves to position ③, the cam is clamped and is not easy to rotate counterclockwise. When the connecting rod is between positions ② and ③, it can be in a stable locked state. Because if there is a disturbance that causes the left end of the connecting rod to move counterclockwise to position ②, the clamping force will increase. If it moves clockwise to position ③, the clamping force of the cam mechanism will increase. Only by rotating the manual rotating cam counterclockwise can the connecting rod pass the dead point position and the right end of the connecting rod move to the right.

[0045] Principle of acoustic field modulation: Due to the different acoustic impedance matching between solids, liquids and gases, the propagation ability of sound waves at the solid-liquid interface and the solid-gas interface varies greatly. The calculation formula for acoustic impedance is: .

[0046] When sound waves propagate from one medium to another at an acoustic interface, some reflection and some transmission will occur. The acoustic reflection coefficient R of the interface between two materials can be calculated from their acoustic impedance.

[0047] Assuming that the acoustic impedance of medium 1 is Z1 and the acoustic impedance of medium 2 is Z2, the formula for the acoustic reflection coefficient 𝑅 is:

[0048]

[0049] This formula represents the reflection of sound waves at the interface of two media with different acoustic impedances. The value of the reflection coefficient R is between -1 and 1: when R=0, it means that the acoustic impedances of the two media are equal, there is no reflection, and all sound waves are transmitted to the second medium. When R=1 or R=-1, it means complete reflection, and the sound waves cannot be transmitted to the second medium. When R is between -1 and 1, part of the sound wave is reflected and part of the sound wave is transmitted.

[0050] like Figure 7 As shown, the droplets in the middle layer are in contact with the glass plates in the up and down directions, and the rest of the area around the droplets is air. There are two different paths in the process of sound waves transmitting upward. One path passes through the air 23, and the other passes through the droplets 21. Due to the large difference in acoustic impedance between air and glass, a large amount of sound wave energy will be reflected between the two media of glass and air, hindering the propagation of sound wave energy. The difference in acoustic impedance between liquids and solids is not large, so more sound wave energy can be transmitted upward. As a result, a large-scale sound field 25 can be transformed into a small-scale sound field 20 by passing through the droplets and transmitted to the top, completing the modulation of the sound field.

[0051] Digital microfluidic acoustic field modulation principle. With the help of the principle of dielectric electrowetting, the digital microfluidic (DMF) system can achieve highly flexible and precise droplet manipulation on a picoliter scale. The digital microfluidic chip consists of two glass plates with electrodes arranged on them. Between the upper and lower plates are droplets that can be controlled to move. By switching the electrodes on or off and changing the voltage applied to the droplet position, it can easily control the movement of the droplet.

[0052] The movement of droplets in digital microfluidic chips is very flexible and fast. The movement and distribution of droplets can dynamically control whether the sound wave energy at different positions can be transmitted to the next level, thereby changing the state of the sound field transmitted to the solution tank.

[0053] The modulated small-scale sound field is transmitted to the solution tank above. The acoustic flow, acoustic radiation force generated by the body sound wave and the viscous resistance of the particles moving in the solution work together to drive the movement of the particles in the solution tank.

[0054] The microparticles may be carbon particles, polystyrene microspheres or cells. According to an embodiment of the present invention, the particles are in an aqueous medium.

[0055] Figure 7The principle of dynamic modulation of the acoustic field by a digital microfluidic system is demonstrated. The digital microfluidic chip consists of an upper plate 22, a droplet 21, and a lower plate 24. The upper plate 22 is ITO glass, and the lower plate 24 is provided with electrodes. The surfaces of both plates are coated with hydrophobic materials. By switching the on and off of the electrode of the lower plate 24, the applied voltage can change the hydrophilicity and hydrophobicity of the droplet 21, thereby controlling the movement of the droplet 21.

[0056] The bulk acoustic wave resonator at the bottom of the digital microfluidic chip generates a large-scale uniform sound field 25. The upper and lower plates of the digital microfluidic chip are both made of glass, and the droplets are surrounded by air 23. Due to the different matching degrees of acoustic impedance, in the process of the sound field 25 at the bottom being transmitted upward, the sound waves transmitted to the air 23 interface are almost all reflected, and the sound field can only pass through the position where the droplets 21 are. Therefore, the large-scale sound field can be converted into a small-scale sound field 20 after being modulated by the droplets 21. As the droplets 21 move, the modulated sound field 20 will also change with the droplets. In addition, multiple droplets 21 can modulate the sound field at the same time.

[0057] The solution tank is arranged above the digital microfluidic chip and connected to the digital microfluidic chip through water or ultrasonic coupling agent. The solution tank contains a solution. The particles are in the solution. The particles can be carbon particles, polystyrene or cells. The acoustic field modulated by the dynamic modulation method of the body acoustic wave acoustic field acts on the solution in the solution tank. The acoustic flow, acoustic radiation force and viscous resistance of the particles when moving in the solution work together to drive the movement of the particles in the solution, so as to achieve the capture, transfer and patterning of the particles.

[0058] The present invention is not limited to the particles mentioned in the above examples. According to the method proposed by the present invention, the suspended particles not mentioned above or the particles settled at the bottom of the solution can be manipulated.

[0059] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “up”, “down”, “left”, “right”, “clockwise” and “counterclockwise” are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0060] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A dynamic acoustic field modulation and particle manipulation device based on digital microfluidics, characterized by: It includes a solution tank (1), a digital microfluidic system (2), and a bulk acoustic wave resonator (3); The digital microfluidic system (2) is used to dynamically modulate the sound waves generated by the bulk acoustic wave resonator (3); the modulated sound waves act on the solution in the solution tank (1), forming a local acoustic flow field in the solution, thereby driving the particles in the solution and realizing dynamic manipulation of the particles.

2. The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics according to claim 1, characterized in that: The digital microfluidic system (2) comprises a digital microfluidic chip (5), the digital microfluidic chip (5) being composed of an upper electrode plate (22) and a lower electrode plate (24), a liquid droplet (21) whose movement can be controlled is disposed between the upper electrode plate (22) and the lower electrode plate (24), the bulk acoustic wave resonator (3) being located at the lower side of the lower electrode plate (24), and the solution tank (1) being located at the upper side of the upper electrode plate (22).

3. The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics as claimed in claim 1, characterized in that: It also comprises a frame (9), a base (7), a chip mounting plate (6) and a base (11); the acoustic wave resonator (3) is arranged in the frame (9); the base (7) and the base (11) are fixedly connected by bolts; the PCB board (10) is mounted in the base (11); the chip mounting plate (6) has a through hole, the bolts pass through the through hole, the chip mounting plate (6) can slide up and down between the base (7) and the base (11); the digital microfluidic chip (5) is mounted on the chip mounting plate (6); the wedge-shaped gasket (8) is inserted between the chip mounting plate (6) and the base (7); the upper side surface of the wedge-shaped gasket (8) is a plane, and the lower side surface is a wedge-shaped surface adapted to the base (7); the digital microfluidic chip (5) is in contact with the PCB board (10) and is electrically connected to the digital microfluidic control host; the base (7) and the base (11) are placed on the acoustic wave resonator (3); the digital microfluidic chip (5) and the acoustic wave resonator (3) are in contact with each other by their own weight.

4. The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics as claimed in claim 2, characterized in that: The bottom of the digital microfluidic chip (5) is in close contact with the bulk acoustic wave resonator (3), and coupling is performed by adding water or an ultrasonic coupling agent therebetween, thereby improving the transmission efficiency of the bulk acoustic wave at the interface.

5. The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics as claimed in claim 3, characterized in that: The invention also comprises a clamping mechanism, wherein the clamping mechanism comprises a clamping block (13), a silicone gasket (14), a ball head pull rod (15), a straight connecting rod (16), a bent connecting rod (18) and a cam (17). The clamping block (13) is provided with two symmetrical portions on the left and right sides. One end of the clamping block (13) is rotatably connected to the frame (9), and the other end is hinged to the ball head pull rod (15). One end of the straight connecting rod (16) is connected to the ball head pull rod (15), and the other end is hinged to the cam (17). One end of the bent connecting rod (18) is hinged to the cam (17), and the other end is connected to the ball head pull rod (15) hinged to the clamping block (13) on the other side. The cam (17) is rotatably provided on the frame (9).

6. The dynamic acoustic field modulation and particle manipulation device based on digital microfluidics as claimed in claim 5, characterized in that: The silicone gasket (14) is arranged at the inner side of the clamping block (13).

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