The wavelength of wrinkles in elastic sheets on curved topographies
A thin elastic sheet will buckle when it is compressed, leading to the familiar wrinkle patterns on our foreheads, on plastic-wrapped objects, and on crinkly leaves. Wrinkling has recently been used as a noninvasive probe of thin film properties and mechanical environment. However, the current understanding of wrinkle wavelength is limited to parallel undulations on flat topographies. We propose a local law for wavelength that extends to spatially-varying wrinkle patterns in curved settings. We find excellent agreement with our experiments on thin polymer films floating on curved liquid surfaces.