Role of kinks in the dynamics of contact lines receding on superhydrophobic surfaces.

We have investigated the depinning of the contact line on superhydrophobic surfaces with anisotropic periodic textures. By direct observation of the contact line conformation, we show that the mobility is mediated by kink defects. Full 3D simulations of the shape of the liquid surface near the solid confirm that kinks account for the measured wetting properties. This behavior, which is similar to the Peierls-Nabarro mechanism for dislocations, may open perspectives for the optimization of wetting hysteresis by design.