The Dynamics of SAW Streaming and its Application to Fluid Devices

Abstract

AbstractVarious liquid motions such as streaming and droplet formation on the surface of surface acoustic wave (SAW) propagating substrate are called SAW streaming. In this paper, the liquid dynamic motions excited by the SAW fabricated on 128° rot. Y-X LiNb03 at the frequency of 50 MHz with various pulse widths are demonstrated. The SAW streaming system are also tested for use as a micropump. Theoretically, SAW streaming force can be derived based on the acoustic streaming theory. The calculated SAW streaming force is found to be very large and strong enough to expel a droplet from a liquid surface.Nonlinear behavior in a water drop vibration induced by the SAW streaming force is also experimentally investigated as a model of inverse bubble oscillation. We succeed in detecting the transformation of the water drop vibration with a single pulse frequency spectrum to 1/2 and its harmonics.