Bioinspired material surfaces - Science or engineering?

Natural systems are able to produce material surfaces with unique properties. The formation of complex three-dimensional structures in nature is of fundamental importance to break the limits imposed by available construction elements. Structuring into ordered, and especially into irregular or disordered, systems is the key to define new roadmaps to innovative engineering materials. Basic consideration on the importance of disordered structures in biology can be most efficiently demonstrated on natural optical materials, which is the focus of this viewpoint.