Electrically tunable fast and reversible structural coloration of two-dimensional photonic crystals

Abstract

Photonic crystals (PCs) can regulate the propagation of light through them and show visible structural coloration when illuminated by white light. We achieve fast (response time less than 1 s) and reversible structural coloration of two dimensional (2D) PCs by integrating them with a dielectric elastomer actuator (DEA). For the in-plane actuation mode of DEA, we study the diffraction angle dependent structural coloration of 2D PCs vertically illuminated by white light under different actuation voltages experimentally and theoretically. We also optimize the DEA by considering its snap-through instability and actuation performance in our theoretical model. Furthermore, we first demonstrate that the out-of-plane actuation mode of DEA can also effectively tune the structural coloration of integrated 2D PCs. The tunable 2D PCs realized by DEA have applications in color changeable soft skin for camouflage and smart optical devices, such as adjustable optical grating.