It is well known by far that biological organisms could arrange themselves in sophisticated and complex structures, which compete or overcome the top technology products available and which exhibit peculiar optical behavior. In recent years, the porous silica structures (frustules) created by living diatoms are under study for several nano-engineering applications based on bio-mimetic approaches. The diatoms are microscopic algae enclosed between two valves of hydrated amorphous silica. They spontaneously …