Spatial forcing of self-organized microwrinkles by periodic nanopatterns

The effects of periodic nanopatterns on the position, wavelength, and orientations of self-organized microwrinkles was tested. Uniaxial compressive strain was exerted in the perpendicular direction to the line/orientation of the bumps to induce self-organization of the microwrinkles. The wrinkle crests directed by a row of short lines of bumps are found to continue to the other row without creating a topological defect, indicating that the small bumps having an appropriate periodicity can induce microwrinkles which have a perfect order over a large area. The modulated wrinkles are stabilized by the periodic bumps where the wrinkle crests are adjusted to be in phase with the bumps. The images of the patterns under different compression directions at constant 4% strain indicate that the wrinkle orientation is forced around 0° by the trigger lines.