Improved ultrasonic micro array separation using far field ultrasonic excitation

Abstract

This paper reports improved separation efficiency of an ultrasonic standing wave separator microchannel array by means of ultrasonic far field excitation. By putting an aluminium spacer between the transducer and the channel array, the acoustic power transmission region is moved into the ultrasonic far field decreasing the local intensity variations which is induced in close vicinity to the transducer. This generates a more stable acoustic separation, which enables better separation performance and higher separation efficiency