Iridescent surfaces such as opals, beetle exoskeletons and butterfly wings have unique colour properties due to their microscopic surface structure, and researchers have recently discovered how to mimic these.
They used techniques such as nanoparticle assembly and plasma etching to create water-repelling structural colours from polymer.
The colour is the result of a repetitive pattern of structure, while the water repellence comes from the roughness of the surface.
Structural colours will not fade like conventional pigments and the ability to waterproof them gives these surfaces self-cleaning properties, making their potential uses quite varied, including possible use in solar panels.
Read more at University of Pennsylvania