Bouncing or sticky droplets: Impalement transitions on superhydrophobic micropatterned surfaces
Denis Bartolo(Centre National de la Recherche Scientifique), Farid Bouamrirene(Centre National de la Recherche Scientifique), Emilie Verneuil(Centre National de la Recherche Scientifique), Axel Buguin(Centre National de la Recherche Scientifique), Pascal Silberzan(Centre National de la Recherche Scientifique), Sébastien Moulinet(Centre National de la Recherche Scientifique)
Cited by 660Open Access
Abstract
When a liquid drops impinges a hydrophobic rough surface it can either bounce off the surface (fakir droplets) or be impaled and strongly stuck on it (Wenzel droplets). The analysis of drop impact and quasi static ''loading'' experiments on model microfabricated surfaces allows to clearly identify the forces hindering the impalement transitions. A simple semi-quantitative model is proposed to account for the observed relation between the surface topography and the robustness of fakir non-wetting states. Motivated by potential applications in microfluidics and in the fabrication of self cleaning surfaces, we finally propose some guidelines to design robust superhydrophobic surfaces.