Three-dimensional Simulation Analysis And Experimental Investigation Of Surface Acoustic Wave Particle Separator

SAW technology is emerging science and technology for miniaturization and multi-functionality of electronic devices and has great potential in the fields of physical sensing,quantum filtering,and microfluidics.Currently,among microfluidic devices,acoustic surface wave technology has been widely used for manipulating,transporting,and sorting microparticles and biological cells due to its simple preparation and easy operation.In this paper,an SSAWs microfluidic sorting device has been designed and fabricated for sorting 15μm and 5μm microparticles through 3D simulation modeling.Our main contributions are as follows:An efficient three-dimensional standing wave acoustic surface wave microfluidic sorting simulation model was proposed to study the separation of micron particles based on the design and working principle of acoustic surface wave devices.The model improves the simulation accuracy by considering the attenuation of the sound surface wave propagation on the piezoelectric substrate and simplifies the modeling of the piezoelectric substrate and microchannel walls by determining the effective propagation region of the piezoelectric substrate,which reduces the total number of simulation cells by 65% after the simplification.Subsequently,we analyzed the effects of the parameters of voltage,tilt angle,and flow rate on the particle separation and determined the optimal parameter range to guide the subsequent experiments.Based on the results obtained from the simulation model,a new sheath flow microchannel structure was designed,and a standing wave SAW microfluidic sorting device was prepared in the laboratory by MEMS technology.In addition,a multilayer orifice plate clamping structure was developed to enhance the maximum flow rate of the microfluidic channel,which effectively improved the confinement performance of the channel in the test,and the device was able to ensure continuous injection for more than 2 hours without leakage at a total input flow rate of 100 μl/min.The experimental strategy was established,and the experimental platform was built,in order to evaluate the displacement of the 15μm and 5μm particles prepared devices at various input flows and input voltages experimentally.Good experimental observations were obtained by the guidance of simulation results.Subsequently,the validity of the proposed simulation model was further investigated,and the experimental results and simulation results were compared and analyzed at input voltages of 8 V and 10 V.The experimental and simulation predictions were in good agreement,indicating that the proposed 3D simulation model has the ability to guide the design of the SAW microfluidic devices.