Biomimetic photonic crystals with mechanochromic properties bases on cuticular Scales of the weevil Entimus imperialis
Many insects form biological photonic crystals which generate structural colors that are ecophysiologically essential for the animals. These periodic photonic structures are functional modifications of the cuticle, a hierarchically structured composite material forming the exoskeleton of the animals. Within the Insecta, two groups have evolved three-dimensional photonic crystals with one of the three fundamental bicontinuous cubic structures, the G-structure (Gyroid) in butterflies and the Dstructure (Diamond) in beetles from the family Curculionidae (weevils). Whether the choice of structure type during evolution was influenced by mechanical constraints is unknown, since the mechanical behavior of these structures has not been studied yet. Many applications of photonic crystals are based on dynamic changes of the optical response induced by external stimuli, like mechanical deformation in mechanochromic photonic crystals. The aim of this project is to combine a biotemplating approach with a theoretical study and simulations of the mechanical behavior of bicontinuous cubic structures to develop biomimetic photonic crystals with tailored optical and mechanical properties for potential mechanochromic applications based on the photonic D-structures in cuticular scales of the weevil Entimus imperialis.