Materials Horizons Blog

Inspired by natural iridescence in fish skin, scientists in Germany have developed a graphene-based coating that changes colour when deformed. It could provide a simple way to warn of hidden damage in buildings, bridges and other structures.

Many materials are coloured by chemical pigments, which absorb light at particular wavelengths and reflect the remaining light, which we see as colour. Other materials, however, are given colour by periodically arranged microscopic surface structures. These cause interference between reflected light waves, amplifying them at specific visible frequencies. This strategy is used in some of nature’s most vibrant materials, from fish scales to peacock feathers, butterfly wings and cephalopod skins.