Dynamic Camouflage Materials Based on Silk-Reflectin Chimeras

Abstract : Reflectins are a unique group of structural proteins involved in dynamic camouflage systems in marine organisms. Initial cloning of reflectins, followed by thin film displays of the bioengineered protein, suggest interesting optical features when the recombinant protein is appropriately organized. These useful features include self-assembly and coloration patterns associated with material interference patterns. The goal of this project is to examine the fundamental relationships between reflectin chemistry, assembly, organization and functional dynamic optical properties. Specifically, we build on recent efforts to bioengineer silk-reflectin chimeric proteins, with the silk component serving as one of the organizing elements for material functions and a key structural component for mechanically robust and versatile material formats. The reflectin component will serve as the dynamic optical element. Further contributions may also come from the silk due to its novel light guiding properties and diffractive optics. Variants in silk block sizes, in reflectin domains obtained from the native reflectin repeats, and different materials assembly approaches will be studied, including thin film/coating and fiber formats. Optical properties will be determined from the recombinant proteins in solution and in the solid state.