Optical Properties of Micro and Nanostructured Bioinspired Materials

Abstract

The nature shows us a great many situations where the optics plays a crucial part; this is particularly the case for birds and insects whose color is usually associated with their behavior as a factor of recognition. This variation of coloration depends on the illumination and depending on the direction of observation: it is the phenomenon of iridescence. The material forming for example the elytra of beetles is the chitin and its refractive index is close to that of ordinary glass. The SEM observation shows that the material is in the form of multilayer separated by layers of air. These layers disturb the refractive index of chitin and cause multiple reflections which interfere and explain the phenomenon of iridescence. The models clearly confirm this interpretation (1), but they also show that it is possible to produce structured surfaces in the laboratory with properties similar to natural structures. By using design ideas from nature we are able to work towards the development of applications in a range of different technologies. This paper aims to develop methods for producing samples based on natural structures where optical properties can be interesting. We will review typical bio-inspired photonic structures and focus on the biomimetic fabrications. These samples will be characterized by various methods in order to understand its properties.