time studying the anatomy of birds and their flight capabilities. As demonstrated by various sketches and notes he left behind, he even attempted to create a "flying machine". Although unsuccessful, it was one of the earliest examples of biomimicry. Molecular biomimetics Molecular biomimetics involves the design of optical materials based on specific molecules and/or macromolecules to induce coloration. Molecularly Imprinted Polymers (MIPs) are specifically aimed at sensing macromolecules. They can also form them into specific structures that change color. Pigment-inspired materials aiming for specific molecular light absorption have been developed as for example melanin-inspired films prepared by polymerization of melanin precursors such as dopamine and 5,6-dihydroxyindole to provoke color saturation. Polydopamine is a synthetic polymer with color properties similar to melanin. It can also act to enhance the vibrancy and stability of structural colors. Materials based on the multi-layer stacking of guanine molecular crystals found in living organisms (e.g. fish and chameleons) have been proposed as potential reflective coatings and solar reflectors. Protein-based optical materials, for instance self-assembling reflectin proteins found in cephalopods and silk, have incited interest in artificial materials for camouflage systems, electronic paper (e-paper) and biomedical applications. Non-protein biological macromolecules such as DNA have also been utilized for bio-inspired optics. The most abundant biopolymer on earth, cellulose, has been also utilized as a principal component for bio-optics. Modification of wood or other cellulose sources can mitigate scattering and absorption of light leading to optically interesting materials such as transparent wood and paper. Pressure and solvent polarity affect the color of a manufactured cellulose membrane, to the point of detection by the naked eye. Cellulose can also be used as nanofibrils or nanocrystals after treatments. One such treatment involves a nitrating agent to form nitrocellulose. Cellulose nanocrystals can polarize light. Bioinspired periodic/aperiodic structures Structural color is a type of coloration that arises from the interaction of light with nano-sized structures. This interaction is possible because these photonic structures are of the same size as the wavelength of light. Through a mechanism of constructive and destructive interference, certain colors get amplified, while others diminish. Photonic structures are abundant in nature, existing in a wide range of organisms. Different organisms use different structures, each with a different morphology designed to obtain the desired effect. Examples of this are the photonic crystal underlying the bright colors in peacock feathers or the tree-like structures responsible for the bright blue in some Morpho