Mechanochromism of Structural-Colored Materials

Structural colors widespread in nature have been theoretically in-depth studied and manufactured through the artificial approaches such as self-assembly and nanolithography thanks to the rapidly developing nanotechnology. Structural colors based on elastomers and hydrogels can be readily modulated upon mechanical stimuli, via adjusting the structural parameters such as interplanar spacing and diffractive angle. Recent breakthroughs in mechanochromic structural-colored materials has not only enriched their varieties but also strengthened their competences remarkably. The emerging mechanoresponsive materials have been applied in various fields such as sensors, displays, anti-counterfeiting, and healthcare. This review focuses on the recent progresses in mechanochromic structural-colored materials with different architectures including photonic crystals, liquid crystals, and photonic glasses. A discussion on their structures and fabrications are presented, along with their merits and demerits by comparison. Special attention is given to the application potentials of these mechanochromic materials in diverse domains, followed by detailed discussion of their mechanism. Last but not least, the current challenges as well as the trends of structural-colored mechanochromic materials are proposed.