Rationally designed colorimetric metasurfaces for healthcare applications

Iridescent structural color is abundant in nature, arising in the saturated blues of the Morpho butterfly wing or the greens of jeweled beetle shells. At the micrometer scale and smaller, these naturally occurring, three-dimensionally (3D)-architected photonic crystals are composed of ordered, geometrically anisotropic features which exhibit distinct interactions with light at varying angles of incidence or polarization state. Due to their 3D hierarchical architecture, these nature-derived systems are unique sources of polarization-sensitive structural color with high color purity and brightness. Here, we explore the exemplary polarization-sensitive properties of nature-derived photonic crystals and identify their key photonic and optically anisotropic features. We then leverage this knowledge to develop a new class of nature-inspired, 3D-architected colorimetric metasurfaces to enhance polarization-sensitive structural color response beyond what is observed in nature.