A new type of MEMS ultrasonic separator based on 2-D normal mode

Separation of suspended particles with ultrasonic radiation force suggests advantages in MEMS. But there are some difficulties to position the outlets in MEMS ultrasonic separator based on one-dimensional (1-D) resonance. In this paper, a new type of MEMS ultrasonic resonance separator, where two anti-phase PZT-transducers are employed to generalize two-dimensional (2-D) normal mode, is exhibited and analyzed. This new separator is designed to form clean and turbid streams along lateral direction. Then the outlets would be easily located along the flow. A mathematics model of sound field in fluid layer is applied to analyze this new 2-D resonance separator. The structure of this new separator is also exhibited, and the ultrasonic radiation force potential of (1, 1) normal mode in the fluid layer are calculated. Then the limitation for the properties of the particles and the fluid in this separator is deduced according to the solution. At last, the experiment result is exhibited and the advantages of this new separator are proved.