Interfacial jetting phenomena induced by focused surface vibrations

Phys Rev Lett. 2009 Jul 10;103(2):024501. doi: 10.1103/PhysRevLett.103.024501. Epub 2009 Jul 7.

Abstract

We exploit large accelerations associated with surface acoustic waves to drive an extraordinary fluid jetting phenomena. Laterally focusing the acoustic energy to a small region beneath a drop placed on the surface causes rapid interfacial destabilization. Above a critical Weber number We, an elongated jet forms for drops with dimensions greater than the fluid sound wavelength. Further increases in We lead to single droplet pinch-off and subsequent axisymmetric breakup to form multiple droplets. A simple equation based on a momentum balance is derived to predict the jet velocity.