Structural color prints combined with microlens arrays for sustainable autostereoscopic displays

Structural colour printing is a sustainable printing technology that avoids the use of environmentally harmful dyes or pigments. Structural colours are produced from the interaction of light with nanostructures through physical mechanisms such as scattering, instead of selective absorption caused by chemical properties. Because of these physical mechanisms, structural colours are durable and non-fading, which find them potential applications in artworks and security prints. However, structural colour prints have a fixed two-dimensional image appearance that limits the perception of three-dimensional information. An effective solution is to combine structural colour prints with microlens arrays. This solution enables three-dimensional information to be perceived by the naked eyes under white light illumination without the use of specialized optics. As microlens arrays are compact and lightweight, they can be easily integrated with structural colour prints. Here, we demonstrate that the combination of structural colour prints with microlens arrays produces dynamic moiré and autostereoscopic effects that can be used to display-three-dimensional information. To achieve these effects, we fabricate polymer structures on glass substrate using straightforward fabrication methods (primarily, two-photon polymerization lithography). Furthermore, these structures can be dissolved using organic solvents for recycling the substrate. We believe that this work contributes towards displaying a colourful and three-dimensional world with a sustainable future.