Multifunctional reflectors in the carapace of scarab beetles

Abstract

The carapace of insects can generate optical information with vivid structural colors, which may be of paramount importance in the life and the evolution of most day-living animals. A cholesteric liquid crystal organization of chitin fibrils is recurrently at the origin of optical properties. We summarize some recent results on the carapace of scarab beetles with possible functions related to optical information and thermoregulation. In the case of Chrysina gloriosa, green bands include wavelength-selective micromirrors and silver stripes play the role of flat metallic reflector operating over the visible spectrum and into the NIR-IR spectrum. Bio-inspired materials might address broadband reflectors for energy savings, stealthiness, cryptography or wavelength-specific light modulators in routing technologies.