Scalable, ultra-resistant structural colors based on network metamaterials

Structural colors have drawn wide attention for their potential as a future printing technology for various applications,ranging from biomimetic tissues to adaptive camouflage materials.However,an efficient approach to realize robust colors with a scalable fabrication technique is still lacking,hampering the realization of practical applications with this platform.Here,we develop a new approach based on large-scale network metamaterials that combine dealloyed subwavelength structures at the nanoscale with lossless,ultra-thin dielectric coatings.By using theory and experiments,we show how subwavelength dielectric coatings control a mechanism of resonant light coupling with epsilon-near-zero regions generated in the metallic network,generating the formation of saturated structural colors that cover a wide portion of the spectrum.Ellipsometry measurements support the efficient observation of these colors,even at angles of 70°.The network-like architecture of these nanomaterials allows for high mechanical resistance,which is quantified in a series of nano-scratch tests.With such remarkable properties,these metastructures represent a robust design technology for real-world,large-scale commercial applications.