Ridge Localizations and Networks in Thin Films Compressed by the Incremental Release of a Large Equi-biaxial Pre-stretch in the Substrate

Two‐dimensional ridge structures are induced by equi‐biaxial compression with large equi‐biaxial pre‐stretch in a thin film by using a micro‐fluidics technique. Whereas wrinkles tend to be uniformly distributed, ridges are localized. The wrinkle‐to‐ridge transition is unstable (subcritical), resulting in large amplitude changes. The nature and morphology of the ridges is studied and quantified by experiments and numerical simulations.