Design of curved photonic crystal using swelling induced instabilities

In this communication, we propose a new approach based on combining two self-assembly processes, the one responsible for curvature formation and the second responsible for assembling of colloids into crystal structure. The presented curved crystals are obtained by combining the intrinsic elastic instability of thin sheets with colloidal vertical convective self-assembly. The described strategy can be viewed as a proof of concept for designing and controlling the shape and optical response of colloidal crystals without altering the effective refractive index.