title: Geometric pumping in autophoretic channels.
abstract: 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.
authors.affiliation: LadHyX - Département de Mécanique, Ecole Polytechnique - CNRS, 91128 Palaiseau, France. sebastien.michelin@ladhyx.polytechnique.fr.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Michelin
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Montenegro-Johnson
authors.forename: Gabriele
authors.initials: G
authors.lastname: De Canio
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lobato-Dauzier
authors.forename: Eric
authors.initials: E
authors.lastname: Lauga
mesh_terms: D046210:Microfluidic Analytical Techniques; D012996:Solutions / Q000737:chemistry; D014783:Viscosity
chemical_list: D012996:Solutions