Wall accumulation of self-propelled spheres

The dynamics of a self-propelled Brownian sphere confined between two planar hard walls is investigated by computer simulations and analytic solutions of the corresponding Fokker-Planck equation. It is shown that an accumulation of self-propelled particles, often linked to the hydrodynamic dipole interaction, can be already obtained from the combination of Brownian motion and self-propulsion. The surface excess is calculated as a function of particle velocity, wall separation, and translational and rotational diffusion coefficients. In limits of narrow channels or small propulsion velocities, analytical solutions and numerical results are in excellent agreement. Copyright (C) EPLA, 2013