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arXiv · 2208.06044

Dynamics of active liquid interfaces

Raymond Adkins·Itamar Kolvin·Zhihong You·Sven Witthaus·M. Cristina Marchetti·Zvonimir Dogic
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Abstract

Controlling interfaces of phase separating fluid mixtures is key to creating diverse functional soft materials. Traditionally, this is accomplished with surface-modifying chemical agents. Using experiment and theory, we study how mechanical activity shapes soft interfaces that separate an active and a passive fluid. Chaotic flows in the active fluid give rise to giant interfacial fluctuations and non-inertial propagating active waves. At high activities, stresses disrupt interface continuity and drive droplet generation, producing an emulsion-like active state comprised of finite-sized droplets. When in contact with a solid boundary, active interfaces exhibit non-equilibrium wetting transitions, wherein the fluid climbs the wall against gravity. These results demonstrate the promise of mechanically driven interfaces for creating a new class of soft active matter.

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cond-mat.softcond-mat.mtrl-scinlin.CDphysics.flu-dyn

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Raymond Adkins, Itamar Kolvin, Zhihong You, Sven Witthaus, M. Cristina Marchetti, Zvonimir Dogic. 2022-08-11. Dynamics of active liquid interfaces. https://doi.org/10.1126/science.abo5423

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