  We show that full-image micro-PIV analysis in combination with images of
transient particle motion is a powerful tool for experimental studies of
acoustic radiation forces and acoustic streaming in microfluidic chambers under
piezo-actuation in the MHz range. The measured steady-state motion of both
large 5 um and small 1 um particles can be understood in terms of the acoustic
eigenmodes or standing ultra-sound waves in the given experimental
microsystems. This interpretation is supported by numerical solutions of the
corresponding acoustic wave equation.
