title: Evolution of wrinkles in hard films on soft substrates.
abstract: A compressively strained film on a substrate can wrinkle into intricate patterns. This Rapid Communication studies the evolution of the wrinkle patterns. The film is modeled as an elastic nonlinear plate and the substrate a viscoelastic foundation. A spectral method is developed to evolve the nonlinear system. When the initial film strains are isotropic, the wrinkles evolve into a pattern with a motif of zigzag segments, in random orientations. When the initial film strains are anisotropic, the wrinkles evolve to an array of herringbones or stripes. The zigzag segments select a width, a length, and an elbow angle that minimize the total elastic energy.
authors.affiliation: Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Hong
authors.forename: Z
authors.initials: Z
authors.lastname: Suo