  Many microfluidic devices use macroscopic pressure differentials to overcome
viscous friction and generate flows in microchannels. In this work, we
investigate how the chemical and geometric properties of the channel walls can
drive a net flow by exploiting the autophoretic slip flows induced along active
walls by local concentration gradients of a solute species. We show that
chemical patterning of the wall is not required to generate and control a net
flux within the channel, rather channel geometry alone is sufficient. Using
numerical simulations, we determine how geometric characteristics of the wall
influence channel flow rate, and confirm our results analytically in the
asymptotic limit of lubrication theory.
