Asymmetric fluctuations and self-folding of active interfaces

Abstract

We study the structure and dynamics of the interface separating a passive fluid from a microtubule-based active fluid. Turbulent-like active flows power giant interfacial fluctuations, which exhibit pronounced asymmetry between regions of positive and negative curvature. Experiments, numerical simulations, and theoretical arguments reveal how the interface breaks up the spatial symmetry of the fundamental bend instability to generate local vortical flows that lead to asymmetric interface fluctuations. The magnitude of interface deformations increases with activity: In the high activity limit, the interface self-folds invaginating passive droplets and generating a foam-like phase, where active fluid is perforated with passive droplets. These results demonstrate how active stresses control the structure, dynamics, and break-up of soft, deformable, and reconfigurable liquid-liquid interfaces.

26 pages, 22 figures

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Cited by in corpus (11)

• Active phase separation: new phenomenology from non-equilibrium physics
• Hyperuniform interfaces in non-equilibrium phase coexistence
• Interface dynamics of wet active systems
• Deciphering the Scattering of Mechanically Driven Polymers using Deep Learning
• Active fluids form system-spanning filamentary networks
• Shape Switching and Tunable Oscillations of Adaptive Droplets
• Phase Separation in Mixtures of Nematic and Isotropic Fluids
• Turbulence to order transitions in activity patterned active nematics
• Conservation laws and slow dynamics determine the universality class of interfaces in active matter
• Interfacial instability of confined 3D active droplets
• Shape-specific fluctuations of an active colloidal interface