Vibrational modes prediction for water-air bubbles trapped in circular microcavities

Abstract

Oscillating bubbles have proven to be a versatile tool for various microfluidic applications. Despite the existence of the extensive literature on the behavior of acoustically actuated bubbles, a ready-to-use approach, capable of predicting the oscillatory motion for the bubbles trapped in the circular microcavities, is still missing. In this study, we propose a theoretical model to quantify the resonant frequencies and viscous dissipation factors for a single trapped bubble and verify it experimentally. We further investigate an interaction of two coupled bubbles of equal and different radii. For the identical bubble pair, coupling results in controllable frequency shift from the modes of a single bubble, whereas the non-identical one can operate as a flow switch.