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 10–3 - 10–6 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.
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Publication:B. Saint-Michel, G. Petekidis, V. Garbin, Tuning local microstructure of colloidal gels by ultrasound-activated deformable inclusions, Soft Matter 18, 2092 (2022); D. Baresch and V. Garbin, Acoustic trapping of microbubbles in complex environments and controlled payload release, Proceedings of the National Academy of Sciences 117, 15490 (2020); M. De Corato, B. Saint-Michel, G. Makrigiorgios, Y. Dimakopoulos, J. Tsamopoulos, V. Garbin, Oscillations of small bubbles and medium yielding in elastoviscoplastic fluids, Physical Review Fluids 4, 073301 (2019); B. Dollet, P. Marmottant, V. Garbin, Bubble dynamics in soft and biological matter, Annual Review of Fluid Mechanics 51, 331 (2019); A. Huerre, M. De Corato, V. Garbin, Dynamic capillary assembly of colloids at interfaces with 10,000g accelerations, Nature Communications 9, 3620 (2018); V. Poulichet and V. Garbin, Ultrafast desorption of colloidal particles from fluid interfaces, Proceedings of the National Academy of Sciences 112, 5932 (2015)
