Actuating micro devices with acoustic white noise

Abstract

We present a theoretical calculation of the actuation of a model micro system, such as a microelectromechanical system (MEMS), by the acoustic pressure of white noise. This is a classical analog of the Casimir effect, thus the name Casimir acoustic pressure. Unlike the quantum case, the acoustic Casimir pressure can be attractive or repulsive depending on the frequency bandwidth of the acoustic noise. As a case study, a one-degree-of-freedom simple-lumped system in an acoustic resonant cavity is considered. By properly selecting the frequency bandwidth of the acoustic field, the acoustic pressure can be tuned to increase the stability in existing microswitch systems by selectively changing the sign of the force. The acoustic intensity and frequency bandwidth are introduced as two additional control parameters in capacitive micorswitches. Applications of this concept in microfluidics will be also discussed.