Microfluidic system and operation method thereof

An operation method for a microfluidic system, comprising:

• providing the microfluidic system, comprising:
• a microcavity, an ultrasound transmitter assembly, and a phononic crystal plate;
• wherein
• the microcavity is configured to accommodate a solution containing microparticles;
• the ultrasound transmitter assembly is configured to transmit ultrasonic waves to the phononic crystal plate, wherein the ultrasonic waves have a frequency which is the same as a resonance frequency of the phononic crystal plate, the ultrasound transmitter assembly comprises:
• a signal generator, a power amplifier, and an ultrasonic transducer, and the ultrasonic transducer contacts with the microcavity;
• the phononic crystal plate is configured to be placed in the solution and generate a local acoustic field on a surface of the phononic crystal plate under excitation of the ultrasonic waves, and induce an acoustic microstreaming vortex to generate an acoustic streaming shear stress on the microparticles;
• the phononic crystal plate defines therein cavities, the respective cavities are arranged periodically in the phononic crystal plate, and all the respective cavities are filled with gas;
• the phononic crystal plate comprises:
• a first plate, a second plate, and a third plate;
• the second plate comprises a first surface and a second surface opposite to the first surface, the cavities are periodically arranged in the second plate, and all the cavities penetrate through the first surface and the second surface;
• the first plate and the third plate are respectively fixed to the first surface and the second surface of the second plate, respectively;
• the first plate, the second plate, and the third plate are all made from a polydimethylsiloxane, and the first plate, the second plate, and the third plate are all flexible plates;
• and
• both the first plate and the third plate are in connection with the second plate via bonding;
• determining the resonance frequency of the phononic crystal plate;
• placing the phononic crystal plate into the microcavity;
• filling the microcavity with the solution containing microparticles;
• and controlling the ultrasound transmitter assembly to emit ultrasonic waves having a frequency which is the same as the resonance frequency of the phononic plate, thereby generating the local acoustic field on the surface of the phononic crystal plate under the excitation of the ultrasonic waves, inducing an acoustic microstreaming vortex, and generating the acoustic streaming shear stress on the microparticles.