Instability and Pattern Formation of Thin Liquid Films Sandwiched between Soft Elastomer Layers

Abstract

The surface instability of trilayer films consisting of a fluid layer sandwiched in between the two thin elastomer capping layers was studied. The solid-liquid-solid sandwiched films will form well-defined periodic surface buckling spontaneously. In the present study, the flow of the sandwiched liquid layer was approximated by the theory of lubrication. The elastic capping films was modeled with the nonlinear theory of a thin plate. A linear stability analysis identified the growth rate and the critical wave number of the surface undulation of trilayer films. The analysis showed that applied deformation in the capping layers regulated the surface buckling and resulted in well-defined periodic surface corrugation with tunable wavelength. The result of this study may provide a mechanism to control the morphology of the films in a mechanical way.