Rough wetting

If a rough surface is put in contact with a wetting liquid, the roughness may be spontaneously invaded depending on the surface pattern and the wetting properties of the liquid. Here, we study the conditions for observing such an imbibition and present practical achievements where the wetting properties of the surface can be predicted and tuned by the design of a solid texture. The contact angle of a drop on such a surface ( where solid and liquid coexist) is discussed. Finally, the dynamics of the liquid lm is found to obey a diffusive-type law, as in the case of porous wicking.