  Brownian transport of self-propelled overdamped microswimmers (like Janus
particles) in a two-dimensional periodically compartmentalized channel is
numerically investigated for different compartment geometries, boundary
collisional dynamics, and particle rotational diffusion. The resulting
time-correlated active Brownian motion is subject to rectification in the
presence of spatial asymmetry. We prove that ratcheting of Janus particles can
be orders of magnitude stronger than for ordinary thermal potential ratchets
and thus experimentally accessible. In particular, autonomous pumping of a
large mixture of passive particles can be induced by just adding a small
fraction of Janus particles.
