Institute of Fundamental Technological Research

In this study, we analyse the behaviour of antibubbles when subjected to an ultrasonic pulse. Speci cally, we derive oscillating behaviour of acoustic antibubbles with a negligible outer shell, resulting in a Rayleigh Plesset equation of antibubble dynamics. Furthermore, we compare theoretical behaviour of antibubbles to behaviour of regular gas bubbles. We conclude that antibubbles and regular bubbles respond to an acoustic wave in a very similar manner if the antibubble's liquid core radius is less than half the antibubble radius. For larger cores, antibubbles demonstrate highly harmonic behaviour, which would make them suitable vehicles in ultrasonic imaging and ultrasound-guided drug delivery.

An antibubble consists of a liquid droplet, surrounded by a gas, often with an encapsulating shell. Antibubbles of microscopic sizes suspended in fluids are acoustically active in the ultrasonic range. Antibubbles have applications in food processing and guided drug delivery. We study the sound generated from antibubbles, with droplet core sizes in the range of 0–90% of the equilibrium antibubble inner radius. The antibubble resonance frequency, the phase difference of the echo with respect to the incident acoustic pulse, and the presence of higher harmonics are strongly dependent of the core droplet size. Antibubbles oscillate highly nonlinearly around resonance size. This may allow for using antibubbles in clinical diagnostic imaging and targeted drug delivery.

Antibubble, Nonlinear, Echo, Rayleigh-Plesset, Targeted drug delivery

We study the sonication of stable particles that encapsulate a liquid core, so-called antibubbles. Acoustically active antibubbles can potentially be used for ultrasound-guided drug delivery. In this presentation, we derive the oscillating behaviour of acoustic antibubbles with a negligible outer shell, resulting in a Rayleigh-Plesset equation of antibubble dynamics. Furthermore, we compare the theoretical behaviour of antibubbles to that of regular gas bubbles. We conclude that antibubbles and regular bubbles are acoustically active in a very similar way, if the liquid core is less than half the antibubble radius. For larger cores, antibubbles demonstrate highly harmonic behaviour, which would make them suitable vehicles in ultrasonic imaging and ultrasound-guided drug delivery.

Harmonics, Antibubbles