title: Deformation of an asymmetric thin film.
abstract: Experiments have investigated shape changes of polymer films induced by asymmetric swelling by a chemical vapor. Inspired by recent work on the shaping of elastic sheets by non-Euclidean metrics [Y. Klein, E. Efrati, and E. Sharon, Science 315, 1116 (2007)], we represent the effect of chemical vapors by a change in the target metric tensor. In this problem, unlike that earlier work, the target metric is asymmetric between the two sides of the film. Changing this metric induces a curvature of the film, which may curve into a partial cylinder or a partial sphere. We calculate the elastic energy for each of these shapes and show that the sphere is favored for films smaller than a critical size, which depends on the film thickness, while the cylinder is favored for larger films.
authors.affiliation: Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Geng
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Selinger
mesh_terms: D003198:Computer Simulation; D055119:Elastic Modulus; D008567:Membranes, Artificial; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial; D011108:Polymers