Shear horizontal surface acoustic wave induced microfluidic flow

In this letter, we demonstrate that surface acoustic waves (SAWs) excited on 36 degrees Y-X LiTaO3 have both Rayleigh and shear horizontal components, which can result in different acoustic streaming patterns in micro-droplets. The shear horizontal surface acoustic wave streaming pattern exhibits a quasi-stable counterflow in the SAW propagation direction with velocities of up to 16 mm/s, with minimal damping observed within the droplets. A pumping function was realized at a threshold power of 30 dBm with a large rotation vector on hydrophobically treated devices. (C) 2011 American Institute of Physics