Photonic architectures in beetles: twists and iridescence

Abstract

The order Coleoptera is, by any standard, a prodigious showcase for the extraordi nary creativity and flexibility of the evolutionary process. Concurrent with a desire to overcome the present limitations of optical coating technologies, a number of novel and elegant reflectance mechanisms have been discovered in the realms of biological systems including 3D photonic crystals and quasi-ordered coherent scattering arrays. Beetles, in particular, possess many desirable and, crucially, tunable properties from a biomimetic perspective. Here, we provide a detailed discussion of two coleopteran structures, namely 1D multilayers and helically arranged 'Bouligand' structures, and consider their putative entomological functions and potential applications in bioinspired technologies.