NCCR Bio-Inspired Materials Principal Investigator, Professor Ullrich Steiner (Soft Matter Physics, Adolphe Merkle Institute), has been awarded a prestigious ERC Advanced Grant by the European Research Council. Worth €2.5 million over five years, the grant will fund research into furthering the understanding of structural color found in nature.

Dazzling color effects are sometimes created by complex nanostructures that cause certain wavelengths of white light to be superimposed and eliminated. The resulting colors arise from this interference.  Butterfly wings, for example, are covered with complex multilayer structures of thousands of microscopically small scales to create spectacular hues.

In theory, these striking colors should only be produced by an ordered structure. In practice though, they often appear from apparently disorderly structures found in plants and animals. Professor Steiner’s project and his co-workers will focus on determining if in fact there is some underlying order in these seemingly random morphologies to help explain the presence of structural colors. The overall goal of the PrISMoID (Photonic Structural Materials with Controlled Disorder) project is not only to provide a fundamental understanding of the interplay of structural correlations with optical interference in disordered materials, but also to establish design rules for simple manufacturing processes.

Structural colors have several advantages. Unlike with pigments, they do not fade with time and sunlight, and they display iridescence, or color variation with respect to the angle at which they are viewed. These features can be especially useful for security features in banknotes, packaging or labels, and could even be used to create pigment-free colors on food.