Orientational ordering of buckling-induced microwrinkles on soft substrates

Orientational order in buckling-induced microwrinkles of elastic membranes on soft substrates is investigated both theoretically and experimentally. Anisotropic orientational correlation in wrinkles induced by isotropic compression is characterized using an orientational order parameter, and is explained by an effective elastic free energy that suppresses Gaussian curvature. We find that orientationally correlated domains tend to extend in ± 45° directions from the local wrinkle orientation. Excellent agreement is obtained between numerical, theoretical, and experimental results.