title: Massive amplification of surface-induced transport at superhydrophobic surfaces.
abstract: We study electro- and diffusio-osmosis of aqueous electrolytes at superhydrophobic surfaces by means of computer simulation and hydrodynamic theory. We demonstrate that the diffusio-osmotic flow at superhydrophobic surfaces can be amplified by more than 3 orders of magnitude relative to flow in channels with a zero interfacial slip. By contrast, little enhancement is observed at these surfaces for electro-osmotic flow. This amplification for diffusio-osmosis is due to the combined effects of enhanced slip and ion surface depletion or excess at the air-water interfaces on superhydrophobic surfaces. This effect is interpreted in terms of capillary driven Marangoni motion. A practical microfluidic pumping device is sketched on the basis of the slip-enhanced diffusio-osmosis at a superhydrophobic surface.
authors.affiliation: LPMCN, Université de Lyon, Université Lyon 1, France.
authors.forename: David M
authors.initials: DM
authors.lastname: Huang
authors.forename: Cécile
authors.initials: C
authors.lastname: Cottin-Bizonne
authors.forename: Christophe
authors.initials: C
authors.lastname: Ybert
authors.forename: Lydéric
authors.initials: L
authors.lastname: Bocquet