  In this fluid dynamics video we show acoustic cavitation occurring from pits
etched on a silicon surface. By immersing the surface in a liquid, gas pockets
are entrapped in the pits which upon ultrasonic insonation, are observed to
shed cavitation bubbles. Modulating the driving pressure it is possible to
induce different behaviours based on the force balance that determines the
interaction among bubbles and the silicon surface. This system can be used for
several applications like sonochemical water treatment, cleaning of surfaces
with deposited materials such as biofilms.
