Morphological transitions of active Brownian particle aggregates on porous walls

Abstract

Motility-induced wall aggregation of active Brownian particles (ABPs) is a well-studied phenomenon. Here, we study the aggregation of ABPs on porous walls, which allows the particles to penetrate through at large motility. We show that the active aggregates undergo a morphological transition from a connected dense-phase to disconnected droplets with an increase in wall porosity and the particle self-motility, similar to wetting-dewetting transitions in equilibrium fluids. We show that both morphologically distinct states are stable, and independent of initial conditions at least in some parameter regions. Our analysis reveals that changes in wall porosity affect the intrinsic properties of the aggregates and changes the effective wall-aggregate interfacial tension, consistent with the appearance of the morphological transition. Accordingly, a close analysis of the density, as well as orientational distribution, indicates that the underlying reason for such morphological transitions is not necessarily specific to the systems with porous walls, and it can be possible to observe in a larger class of confined, active systems by tuning the properties of confining walls.

7 pages, 4 figures

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Cited by in corpus (9)

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• Time-dependent properties of interacting active matter: dynamical behavior of one-dimensional systems of self-propelled particles
• Active particles with polar alignment in ring-shaped confinement
• Influence of interaction softness in phase separation of active particles
• Percolation transition in phase separating active fluid
• Collective dynamics of active dumbbells near a circular obstacle
• Active wetting transitions induced by rotational noise at solid interfaces
• Percolation transitions in the binary mixture of active Brownian particles with different softness
• Wetting transition of active Brownian particles on a thin membrane