Fabrication of Chiral Materials in Nano- and Microscale

Artificial chiral materials at the nano- and microscales have unique optical properties, known as optical activities, that correspond to preferential interactions with circularly polarized light. Unlike the chiroptical responses of biomaterials, nano- and microscale materials with artificial chirality can present intense and tunable chiroptical responses in a broad range of frequencies from the ultraviolet to terahertz regimes. These particular properties of artificial chiral materials have been highlighted because of their potential use in photoelectronic and biomedical applications. The precise fabrication and manipulation of such small-scale materials are among the most important factors affecting their applicability; however, improvements remain necessary. From this perspective, we provide an overview of this field with introductions to types of artificial chiral materials, major parameters in the determination of chiroptical properties, fabrication methods that focus on mechanical-instability-induced buckling methods, and inclined-angle deposition methods. We also present application areas and outlooks.