Fig. 3
From: Inducing drop to bubble transformation via resonance in ultrasound
Surface area variation and cavity inflation during bubble formation. The sound intensity was increased at uR = 1.00 mm/s. a Surface area (normalized by the surface area of a spherical drop) variation for drops of different liquids with similar five stage behavior. The abrupt area expansion occurs at different time intervals, i.e. emitter–reflector distance, but corresponds to similar surface area marked by the dashed line. b Cavity volume of silicone oil (normalized by the initial drop volume) as a function of time. The inset graph shows that the maximum inflation rate, dV/dt, corresponds to the same critical volume V* for all the liquids
