Bending, curling, and twisting in polymeric bilayers.

Polyolefin thermoplastic elastomer (POE) bilayers of varying length (L) to width (W) ratio are formed through traditional polymer processing. Each layer is completely isotropic but the bilayers have an elastic recovery mismatch such that when stretched, one layer recovers to a different extent than the other. Upon stretching bilayers from low to moderate strains and releasing the bilayer bends (curvature, κ, κ < 1/L).