Micro-actuators employing acoustic streaming caused by high-frequency ultrasonic waves

This paper proposes the application of acoustic streaming to the development of micro-actuators, such as micro-manipulators for small particles and micro-pumps for liquid. Since high-frequency ultrasonic waves induce acoustic streaming very efficiently only in the vicinity of the transducer, micro-manipulators are realised by using a two-dimensional ultrasonic transducer array and controlling the electrical power supplied to each transducer. It is also concluded that micro-pumps can be developed by combining a transducer array with a topographic channel structure for liquid flow.