Acoustic Bubbles: Control and Interaction with Particles Adhered to a Solid Substrate

Abstract

Applications of acoustic cavitation [ frequently suffer from certain random aspects (e.g., stochastic bubble nucleation events) as well as from its sensitivity to external parameters (like gas content in the liquid). This renders for example a prediction of bubble distributions in size and space still a difficult task. To improve this situation by a better understanding of the fundamentals, a "bottom-up" approach has recently been followed which tried to model collective bubble phenomena and bubble structures on the basis of single bubbles and their interaction [. If the behavior of individual bubbles can be well captured by the models, it is hoped to gain significant insight into a larger system of acoustically driven bubbles. Indeed, several aspects of multi-bubble systems and structures could be explained by single bubble dynamics, for instance by the inversion of the primary Bjerknes force in strong ultrasonic fields. Nevertheless, many details of bubble dynamics stay partly unclear, and considerable efforts are undertaken to improve our understanding and to optimize applications of acoustic bubbles.