12 - Broadband reflecting fibers with tailored structures inspired by desert ants

Many organisms form photonic structures which generate optical effects that are essential for their survival. The majority of these structures exhibit periodical order, but nature has also evolved disordered photonic structures, which display function-related optical properties that could not be achieved with periodically ordered structures consisting of the same materials. Insects like our model organism, the Sahara silver ant Cataglyphis bombycina have adapted to the extreme solar irradiation of their habitat by densely covering their body with setae. These fiber-shaped photonic structures have an intriguing, disordered hierarchical architecture and shield the animal from sunlight through broadband reflection. The essential structural and compositional parameters responsible for the efficiency of their reflection properties have not been studied yet. The aim of this project is to combine structural, compositional and optical characterization with a theoretical study to elucidate the correlations between disordered structure and broadband reflection of the setae. The results will enable us to establish design rules for a novel class of synthetic organic textile fibers with highly efficient broadband reflection properties that are generated by an irregular architecture and tailored structural disorder on the micro- and nanoscopic length scale.