Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications

Abstract

Structural coloring is production of color by surfaces that have microstructure fine enough to interfere with visible light; this phenomenon provides a novel paradigm for color printing. Plasmonic color is an emergent property of the interaction between light and metallic surfaces. This phenomenon can surpass the diffraction limit and achieve near unlimited lifetime. We categorize plasmonic color filters according to their designs (hole, rod, metal–insulator–metal, grating), and also describe structures supported by Mie resonance. We discuss the principles, and the merits and demerits of each color filter. We also discuss a new concept of color filters with tunability and reconfigurability, which enable printing of structural color to yield dynamic coloring at will. Approaches for dynamic coloring are classified as liquid crystal, chemical transition and mechanical deformation. At the end of review, we highlight a scale-up of fabrication methods, including nanoimprinting, self-assembly and laser-induced process that may enable real-world application of structural coloring.

Lithium Niobate Metasurfaces

“…Such distinct structural resonances of the LN metasurfaces provide accesses to artificial structural colors. As LN shows high transparency covering the visible spectral range, it is an ideal platform to realize the high‐efficiency structural colors in transmission mode, which is in remarkable contrast to the reflection colors demonstrated by the plasmonic, Si or perovskite‐based metasurfaces . The bright field transmission optical microscope images of a group of metasurfaces with period varying from 300 to 800 nm in 100 nm increment (duty cycle:62.5%) are shown in Figure a.…”

Programmable Atom Equivalents: Atomic Crystallization as a Framework for Synthesizing Nanoparticle Superlattices

“…In NP‐based materials, properties are garnered through the collective properties of the constituent composite materials (i.e., PAE core composition, Section . ), but, more importantly, emergent properties can arise from an ordered, nanoscale structure, which PAEs are able to provide with exquisite programmability (Section .). While many of the properties that will be discussed in this subsection have only been proposed and not yet realized, it is important to note that PAEs do indeed provide a unique platform for studying structure–property relationships.…”

3D‐Printed Microrobots with Integrated Structural Color for Identification and Tracking

“…Using additive manufacturing methods, structural color can be achieved by integrating fiber structures with an outer layer of microspheres which assemble into a color‐expressing photonic crystal structure . However, there are other fabrication techniques that offer a wider range of expressed colors consisting of patterns made up of or lined with a metal or high‐index dielectric material . Multiple studies use laser lithography to create repetitive extrusions out of polymer substrates or dielectrics such as silicone .…”