Abstract

Bubble dynamics and cavitation have traditionally been studied in the context of underwater acoustics and, more recently, biomedical applications. I will discuss how the deformation and flow fields generated by acoustically-driven bubbles can be used to drive self-assembly of novel microstructures in complex fluids. Bubble dynamics driven at ultrasonic frequencies probe time scales as short as 10ˉ³−10ˉ⁶ s, comparable to the smallest relaxation time scales for complex fluids containing suspended particles or macromolecules. I will describe how, in this dynamical regime, dynamic capillary interactions arise between colloidal particles adsorbed at a fluid interface, producing particle networks that dominate the mechanics of these complex interfaces under flow. I will also describe a new flow-induced mechanism caused by bubble dynamics, that produces ordered microstructures in colloidal gels. This mechanism can enable energy-efficient processing methods of colloidal-gel materials, including inks, battery electrodes, construction materials. I will also discuss the emerging approach of using bubble dynamics to probe the high-frequency viscoelastic properties of complex fluids and soft materials, which has brought together the communities of cavitation and rheology to address new challenges in characterization of soft materials.

Cassyni Link below:

https://cassyni.com/events/AyG2QQDJ3FQqksbaTP2zAh