Simple fabrication of ring-like microwrinkle patterns

Spontaneously formed microwrinkle patterns on a metal-capped elastomer surface are modulated by introducing lithographic structures on the original surface as spatial triggers for directed wrinkle formation. The lithographic patterns are fabricated by utilizing a thin polymer film with hexagonally packed micro pores as a lithographic mask. The wrinkle crests tend to form along the small ridges of the lithographic ring-like structure. We find the compression direction-dependent reversible modulation of the directed wrinkle pattern by compressive strain.