Topography-driven delamination of thin patch adhered to wrinkling surface

In this paper we investigated the mechanics of topography-driven delamination of a thin elastic patch attached to a wrinkling surface of film-substrate system through both theoretical modelling and finite element simulation. The process of topography-driven delamination could be divided into three stages: wrinkling before delamination occurrence, initiation of delamination and evolution of delamination blister. The topography-driven delamination was found to be dominantly induced by interfacial shear traction and initiate at the location in the middle of peak and valley. The analytical expressions of critical strain and the corresponding critical wrinkling amplitude for topography-driven delamination were derived explicitly and rigorously based on a patch-film-substrate trilayer model. The dependence of the size of delamination blister on the compressive strain was obtained as well using an energy minimization method. The theoretical model was compared with finite element simulation results for validation and a close agreement was observed. At last the theoretical prediction was applied to guide the design of flexible electronics on wrinkling human skin and the design of a new class of active anti-biofouling coating through wrinkling surface texture.