Better life through bubbles and biomedical ultrasound

Many environmental, biological, and engineered fluidic systems invariably involve bubbles suspended in a liquid. These bubbles can have a profound impact on the mechanical and acoustical properties of the multi-phase medium. When exposed to moderate-to-high amplitude acoustic forcing, bubbles can respond nonlinearly – a process known as acoustic cavitation. Cavitating bubbles can lead to a range of physical effects, including microstreaming, collapse microjets, inertially confined cavity collapses, and an associated host of mechanical and chemical effects. In this paper we provide a brief survey of linear bubble acoustics and cavitation effects. We provide examples of how these phenomena can be put to positive use in applications related to biomedical ultrasound imaging and high-intensity ultrasound therapy.