Multimodal Structural Color Graphics Based on Colloidal Photonic Microdome Arrays

Abstract

A hybrid structural color platform is presented that integrates colloidal photonic crystals with microscale hemispherical domes to achieve dynamically reconfigurable, multi‐modal visual responses. By combining angle‐dependent Bragg reflection and curvature‐driven total internal reflection (TIR) interference, the system enables four distinct optical states that are reversibly switched by viewing angle and microdome orientation. The microdome‐on‐film architecture is fabricated by molding photocurable silica suspensions into hemispherical dimples, where optimal shear flow enhances colloidal ordering. The optical output—including hue, brightness, and spatial distribution—is programmable by tuning the silica particle diameter at an optimal volume fraction, as well as the radius and areal density of the microdomes. Using these design principles, complex, angle‐sensitive color graphics are demonstrated that remain concealed under normal observation from the film side and are revealed in three distinct modes: tilted observation from the film side, and both normal and tilted observation from the microdome side. This tunable response results from the interplay between periodic nanoscale ordering and mesoscale curvature, providing fundamental insights into a robust and programmable photonic system. The strategy offers a scalable, lithography‐compatible route to functional structural coloration and opens new possibilities for applications in smart labels, anti‐counterfeiting technologies, and tunable optical devices.