Tunable three-dimensional ZrO2 photonic crystals replicated from single butterfly wing scales

Abstract

Nature generates 150 000 to 200 000 Lepidoptera species (butterflies and moths). Each has more than one kind of wing scales with three dimensional complicated sub-microstructures. We hereby manipulate the original individual single wing scales (SWSs) of tropical butterfly M. didius and replicate them using ZrO₂. The micro-zone reflectance spectrum and the angle dependent properties of M. didius's cover scales (with reflective index 1.56) are first studied. New optical properties (red structural colors) are observed. Then, we synthesize their ZrO₂ SWS replicas (with nominal reflective index 2.12) using these SWSs as bio-templates. Results indicate that an SWS located on the M. didius wing is a highly anisotropic photonic crystal (PC) and exhibits a “prism effect”. Since one butterfly wing can supply more than 100 000 wing scales, this work presents a potential route for large-scale production of small complex photonic devices using SWS as building blocks, and can broaden present practical model pool for the PC research.