Study of Hybrid Microscopic and Macroscopic Buckling in UV Treated PDMS

Abstract

Plant leaves, insect wings, and other natural surfaces show interesting cases of out-of-plan deformations, which can be attributed to mechanical buckling. This paper deals with a specific type of elastic instabilities, where both microscopic (wrinkles) and macroscopic (global curvature) deformations occur simultaneously. To this end, PDMS narrow sheet was stretched, its surface oxidized, then released. Its deformation was measured and analyzed. A mechanical model considering the effect of wrinkle on elasticity was elaborated; the concept equivalent stiffness was introduced in order to represent this effect. The model was matched with testing results successfully. This model is an interesting tool to explain potentially number of elastic instability phenomena.