Figure 3.

Stretched bilayered thin film: Irreversible nature of growth under isotropic and anisotropic conditions. As the film is biaxially stretched, the bottom layer, shown here, gradually grows up to ϑ^g = 2.2 corresponding to more than 100% area growth, while the top layer, not shown, deforms elastically at to ϑ^g = 1.0 and stores elastic energy. Once the load is removed, the bilayered film deforms out of plane. Isotropy of the elastic layer results in a symmetric out-of-plane coiling, top row. Anisotropy of the elastic layer results in an anisotropic out-of-plane coiling, bottom row.