Resonance Cassie-Wenzel wetting transition for horizontally vibrated drops deposited on a rough surface

Langmuir. 2007 Nov 20;23(24):12217-21. doi: 10.1021/la7016374. Epub 2007 Oct 23.

Abstract

The transition between the Cassie and Wenzel wetting regimes has been observed under horizontal vibrations of a water drop placed on the rough micrometrically scaled polymer pattern. The observed transition has a distinct resonance character. The resonance frequencies as established experimentally coincide with the calculated eigenfrequencies of capillary-gravity standing waves on the drop surface. The resonance Cassie-Wenzel transition is related to the displacement of the triple line caused by both the inertia force and the increase in the Laplace pressure. This strengthens the idea that the Cassie-Wenzel wetting transition is most likely a 1D affair stipulated by the triple-line behavior. The study of the vibrated drop deposited on the rough surface supplied valuable information concerning the Cassie-Wenzel wetting transition.