Nanoswimmers in a ratchet potential: Effects of a transverse rocking force

Abstract

We study the dynamics of a chemical nanoswimmer in a ratchet potential, which is periodically rocked in the transverse direction. As a result of the mechanochemical coupling, the self-propulsion velocity becomes force-dependent and particle trajectories are rectified in the direction of the ratchet modulation. The magnitude and direction of the nanoswimmer mean velocity depend upon both the rocking amplitude and the frequency. Remarkably, for frequencies larger than the inverse correlation time of the rotational diffusion, the velocity exhibits oscillatory behaviour as a function of the amplitude and the frequency with multiple reversals of the sign. These findings suggest that mechanochemical coupling can be utilized for controlling the motion of chemically active particles at the nanoscale.