  Micromotors pushed by biological entities, like motile bacteria, constitute a
fascinating way to convert chemical energy into mechanical work at the
micrometer scale. Here we show, by using numerical simulations, that a properly
designed asymmetric object can be spontaneously set into the desired motion
when immersed in a chaotic bacterial bath. Our findings open the way to
conceive new hybrid microdevices exploiting the mechanical power production of
bacterial organisms. Moreover, the system provides an example of how, in
contrast with equilibrium thermal baths, the irreversible chaotic motion of
active particles can be rectified by asymmetric environments.
