Controllable Wrinkling of Thin Films on Pre-Stretched Elastomers Induced by Gravity

Abstract

We study wrinkling instability of a thin elastic film on a pre-stretched soft elastomer induced by the gravity of periodic array of the rods homogenously clamped on the surface of the film. By using linear perturbation analysis, we show that the periodic array of the rods can drive the wrinkling instability of the film when the gravitational force of the rods attains the threshold, and the film will wrinkle into stripes parallel to the tensile direction of the pre-stretched elastomer. Our calculation results give the stability criterion of the system, and the threshold of the gravitational force and the wavelength of the wrinkling patterns are obtained, which can be controlled by tuning the magnitude of the pre-stretch and properties of the thin film and the soft elastomer. These results may provide a regulating strategy for generating precise surface patterns in similar rod structures.

Harnessing Gravity‐Induced Instability of Soft Materials: Mechanics and Application

“…To further investigate the control of wrinkling patterns, they explored the potential of controlling gravity-induced wrinkles in thin films by subjecting the soft substrate to pre-stretching. [83] The results suggested that when the gravity of the pillars reaches a critical value, the wrinkles in the thin films form striped patterns parallel to the pre-tension direction. The wavelength of these patterns is determined not only by the bending stiffness of the film but also by the pre-stretch of the soft substrate.…”