Microfluidic motion generation with loosely-focused acoustic waves

This paper presents a novel approach for producing microfluidic motions by loosely-focused acoustic waves (generated by a piezoelectric ZnO thin film). Results show that the acoustic-waves generated by RF sources, with frequencies corresponding to thickness-mode resonances of the piezoelectric film, are very effective in moving liquid around when the waves are loosely focused. The device operates without any significant temperature increase in the liquid, and will be very attractive for mixing or transporting temperature-sensitive fluids.