Dewetting at soft interfaces

We observe by optical interferometry the removal of a thin liquid film (thickness in the range of 100 nm) intercalated between a soft rubber and a hydrophobic glass plate. The film dewets by nucleation and growth of a single solid/rubber contact. The dry patch is surrounded by a very flat rim that collects the liquid. We find that (i) the shape of the rim squeezed by the rubber is quasistatic, and (ii) the radius R(t) of the contact increases with time t according to an unusual power law R(t) proportional to t(3/4). These results can be interpreted in terms of a hydrodynamic model, assuming viscous dissipation in the moving rim while the rubber is purely elastic.