Hydrodynamically Controlled Active Escape Dynamics.

Escape of many active systems over potential barriers is subject to hydrodynamic interactions, but little is known about the active hydrodynamics in such nonequilibrium escape processes. Here, we combine simulations and theoretical analysis to examine how the hydrodynamics impacts the physics controlling escape dynamics of active particles, based on a model system comprising active particles confined in macromolecular networks. We find that the hydrodynamic effect critically mediates the escape dynamics of active particles, manifesting as hydrodynamics-induced active rotation of the particle and increased potential barrier due to the long-ranged interactions. Analytical theories are derived, capturing the simulation results and explaining the physical origin underlying such nonequilibrium features controlled by hydrodynamic interactions. The work not only provides new insights in understanding the active escape dynamics in complex fluids, but may also be of immediate interest to tune hydrodynamics-mediated dynamics subject to confining potentials.