  We show the existence of a resonant behavior of the current of Brownian
particles confined in a pulsating channel. The interplay between the periodic
oscillations of the shape of the channel and a force applied along its axis
leads to an increase of the particle current as a function of the noise level.
A regime of current inversion is also observed for particular values of the
oscillation frequency and the applied force. The model proposed to obtain these
new behaviors of the current is based on the Fick-Jacobs equation in which the
entropic barrier and the effective diffusion coefficient depend on time. The
phenomenon observed could be used to optimize transport in microfluidic devices
or biological channels.
