Chromatophores, the specialized pigment-containing organs found in cephalopods, have long inspired biomaterials research due to their remarkable dynamic color-changing capabilities. In this study, we introduce an artificial chromatophore system leveraging osmotic annealing as a trigger for reversible color switching. Our approach involves the fabrication of double emulsion droplets using polystyrene nanoparticles functionalized with xanthommatin, the primary pigment present in cephalopod skin. By precisely controlling particle size and pigment loading density, we elucidate the intricate interplay between pigmentary and structural colors, showcasing the influence of osmotic annealing on these dynamics. This research not only offers a deeper understanding of natural chromatophore mechanisms but also presents a novel biomimetic strategy for developing advanced color-changing biomaterials. The scalability and tunability of our approach hold significant promise for applications in biomaterials science, including bio-inspired sensors, adaptive camouflage, and beyond.
