Invited Seminar at CES on 8 January 2020 at 3:00 pm titled "[CANCELLED]Evolutionary Photonics: Structure, Function, Development and Biomimetics of Self-assembled Organismal Photonic Nanostructures" by Vinod Kumar Saranathan from National University of Sin
Colors in Nature can be produced either chemically, by the selective light absorption by pigments, or physically, by light interference from biophotonic nanostructures. Intriguingly, there are almost no known violet, blue or green pigments in animals. And yet these structurally produced colors are ubiquitous in nature and constitute an important aspect of the overall appearance of organisms, as they are frequently used in camouflage, and in social and sexual communication. As the underlying biophotonic nanostructures are overwhelmingly diverse in form and function, their structural and optical characterization has hitherto remained challenging despite centuries of research, which is where I have made rapid and significant contributions. Although there is a burgeoning interest on structural colors from biologists, physicists and engineers, we currently lack an explicit comparative framework, which is essential to understand how these biological signals function, and evolve in organisms. Moreover, the mechanisms controlling the morphogenesis of these complex, biologically patterned nanostructures are much too large to be described by conventional cell or molecular biology, and much too small to be captured by traditional developmental biology. As a consequence, we know very little about the development of photonic nanostructures within cells, beyond the realisation that they are self-assembled intra-cellularly by mechanobiological, phase separation and micro-phase separation like processes. Biophotonic nanostructures are also of broader interest to materials science and engineering, since the facile synthetic fabrication of three-dimensional photonic nanostructures at these rather large optical length scales (200-500 nm) is challenging. Organismal structural colors that have evolved over millions of years to function in a variety of signalling contexts are an ideal source to look for naturally optimized solutions to technological problems in sensing, photonics, etc. In this talk, I will summarise our current knowledge about the structure, function and morphogenesis of biophotonic nanostructures and how this can be leveraged for the biomimetic or bio-inspired synthesis of next generation photonic meta-materials and devices.