Bio-inspired Structural Colors and Their Applications

Structural colors, generated by the interaction of interference, diffraction, and scattering between incident light and periodic nanostructured surfaces with features of the same scale with incident visible light wavelengths, have recently attracted intense interest in a wide range of research fields, due to their advantages such as various brilliant colors, long-term stability and environmental friendliness, low energy consumption, and mysterious biological functions, etc. Tremendous efforts have been made to design structural colors and considerable progresses have been achieved in the past few decades. However, there are still significant challenges and obstacles, such as durability, portability, compatibility, recyclability, mass production of structural-color materials, etc., needed to be solved by rational structural design and novel manufacturing strategies. In this review, we summarized the recent progress of bio-inspired structural colors and their applications. First, we introduced several typical natural structural colors displayed by living organisms from fundamental optical phenomena, including interference, diffraction grating, scattering, photonic crystals effect, and the combination of different phenomena, etc. Subsequently, we reviewed recent progress in bio-inspired artificial structural colors generated from the advanced micro/nanoscale manufacturing strategies to relevant biomimetic approaches, including self-assembly, template methods, phase conversion, magnetron sputtering, and atomic layer deposition, etc. Besides, we also presented the current and potential applications of structural colors in various fields, such as displays, anti-counterfeiting, wearable electronics, stealth, and printing, etc. Finally, we discussed the challenges and future development directions of structural colors, aiming to push forward the research and applications of structural-color materials.