Complex collective dynamics of active torque-driven colloids at interfaces

Abstract

Modern self-assembly techniques aiming to produce complex structural order or functional diversity often rely on non-equilibrium conditions in the system.Light, electric or magnetic fields are predominantly used to modify interaction profiles of colloidal particles during self-assembly or induce complex outof-equilibrium dynamic ordering. The energy injection rate, and properties of the environment are important control parameters that influence the outcome of active (dynamic) self-assembly. The current review is focused on a case of collective dynamics and self-assembly of particles with externally driven torques coupled to a liquid or solid interface. The complexity of interactions in such systems is further enriched by strong hydrodynamic coupling between particles.Unconventionally ordered dynamic self-assembled patterns, spontaneous symmetry breaking phenomena, self-propulsion and collective transport have been reported in torque-driven colloids. Some of the features of the complex collective behavior and dynamic pattern formation in those active systems have been successfully captured in simulations.

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Dynamic and programmable self-assembly of micro-rafts at the air-water interface

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