Living Optical Networks in Orchid Leaves as Inspiration for Light Harvesting and Redistribution in Soft, Curvilinear Material Formats

Plants and animals produce highly evolved, hierarchical systems that combine physicochemical material parameters with functional micro- and nanostructures to manage energy, motion, and species survival. These systems, besides providing cues on bottom-up manufacturing of technological structures, can give insight on strategies for efficient energy management. In this study, we investigate the light harvesting and redistribution capabilities of tropical orchid leaves, which employ a cell-based optical network. Unlike regular orchid leaves, the outer epidermal cells of these leaves exhibit a distinctive short-range order lattice and rounded shape, facilitating optical cross-communication. The planar redistribution of light incident on the leaf is enabled by the distinctively rounded shape of the outer epidermal cells and by their arrangement in a short-range ordered lattice. Successful replication of live leaves in a free-standing biopolymer film validates the observation and opens avenues for the exploration of non-traditional energy harvesting interfaces that are soft, conformal, and curvilinear.