Combined influence of substrate relief and mechanical compression on topographical evolution of surface wrinkling

Abstract

Controlled surface wrinkling could provide ordered and hierarchical structures in micro- and nano-meter scale. Here combined influence of out-of-plane compressive stress and in-plane substrate relief in Au/PDMS bilayer system was experimentally investigated to explore morphological evolution of surface wrinkling. Compared with single influence from out-of-plane compression or in-plane relief, the combined effect mainly reflected in two aspects: edge effect and rearrangement effect. Edge effect applied morphological change on the compressed fields near the edges, but patterns almost restored to the original shape after stress relaxation. Rearrangement effect made relaxed patterns on the rectangular convex regions to rearrange and led to the failure of shape memory effect. The results demonstrated that the combined effect could partly rearrange the original structures, which would be utilized to fabricate the complicated structures.