Roll-to-roll printable metamaterials unlock multiscale, tunable colouration

Researchers demonstrate a printable meta-assembly strategy that embeds low-cost polystyrene nanoparticles in a PDMS matrix to form a nanolattice-based microconic optical interface. This design enables precise coupling of guided and reflected waves to produce tunable color patterns across seven orders of length scale, achievable with metre-scale, single-pixel customization via continuous roll-to-roll manufacturing. By adjusting nanoparticle size and the printed feature diameter, designers can tailor color separation and integration, yielding vibrant, stable colors suitable for eco-friendly coloration, intelligent displays, and information security. The work showcases scalable, designable metamaterials and proves robustness under UV, heat, solvents, washing, and mechanical deformation.