Edge effects in buckled thin films on elastomeric substrates

Buckled thin films on elastomeric substrates have many applications. Films of this type exhibit periodic, sinusoidal "wavy" relief profiles, except near edges that lie perpendicular to the wavevector associated with waves. In these locations, the amplitudes of the waves steadily decrease until the films become completely flat, in a manner that can be used to advantage in applications. This paper quantitatively describes the mechanics of this phenomenon. The finite element analysis shows that the edge effect results from the traction-free boundary condition. The edge-effect length is proportional to the thin-film thickness, and decreases with the increasing prestrain and substrate modulus. (C) 2007 American Institute of Physics.