Surface instability and wrinkling pattern evolution on a fluid-supported inhomogeneous film

Fluid-supported film structures widely exist in nature and can have profound potential technological applications. The surface instability and morphological transition of a fluid-supported film with a defect part induced by an in-plane compression are explored. The effects of the geometry and material properties of the defect part on the initial buckling load are studied through a theoretical model. Finite-element simulations are carried out to analyze the whole dynamic buckling process, with an emphasis on the initial buckling load and the wrinkling pattern evolution. Results indicate that the length and the modulus ratios of the defect part to other parts of the film have significant influences on the initial buckling load, and the modulus ratio is also found to play an important role in the pattern evolution. The study could find applications in controlling the surface morphology of fluid-supported films and provide help in better understanding some biological tissue morphology phenomenon.