To study the dewetting dynamics of thin liquid films from visco-elastic materials we consider intermediate steps. First, the very soft substrate is described with a phase field model accounting for nonlinear elasticity and for the possibility of phase separation. In this talk, I present the components the two-phase system and derive a weak formulation from which we build our 2d code.
Secondly, a three phase system including an air, liquid and elastic substrate phase is described using two phase field variables. Here, the choice of system parameters, including the interface size $\varepsilon>0$ and the mobility in the Cahn-Hilliard equation, are crucial for the numerical efficiency of this model. We use an adaptive mesh refinement to facilitate the computations, especially at the three phase contact line.
A future step will be to replace the elastic solid phase in the latter model with the two-phase system described at first.