LOW FRICTION FLOWS OF LIQUIDS AT NANOPATTERNED INTERFACES

Cécile Cottin-Bizonne (1) , Jean-Louis Barrat (1) , Lyderic Bocquet (1) , Elisabeth Charlaix (1)

1 LPMCN - Laboratoire de Physique de la Matière Condensée et Nanostructures

With the recent important development of microfluidicsystems, miniaturization of flow devices has become a real challenge. Microchannels, however, are characterized by a large surface to volume ratio, so that surface properties strongly affect flow resistance in submicrometric devices. We present here results showing that the concerted effect of wetting .properties and surface roughness may considerably reduce friction of the fluid past the boundaries. The slippage of the fluid at the channel boundaries is shown to be drastically increased by using surfaces that are patterned at the nanometer scale. This effect occurs in the regime where the surface pattern is partially dewetted, in the spirit of the 'superhydrophobic' effects thathave been recently discovered at the macroscopicscales.Our results show for the first time that,in contrast to the common belief, surface friction may be reduced by surface roughness. They also open the possibility of a controlled realization of the 'nanobubbles' thathave long been suspected to play a role in interfacial slippage

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matière Molle [cond-mat.soft]; Mécanique statistique [cond-mat.stat-mech]

Cécile Cottin-Bizonne, Jean-Louis Barrat, Lyderic Bocquet, Elisabeth Charlaix. LOW FRICTION FLOWS OF LIQUIDS AT NANOPATTERNED INTERFACES. Nature Materials, 2003, 2, pp.238. ⟨10.1038/nmat857⟩. ⟨hal-00000275⟩