Large-scale production of high-quality elastic structural color films based on hydrogen bond and colloidal charge co-driven silica microsphere self-assembly

Photonic crystals (PCs) could revolutionize the modern engineering field. However, the commonly used large-scale roll-to-roll fabrication techniques are limited by the utilization of complex materials and devices. In this work, a method combining evaporative self-assembly and roll-to-roll precision printing was used for the ultrafast fabrication of large-area colloidal crystals. In this process, hydrogen bonding and colloidal charge cooperate to promote the formation of highly ordered colloidal crystals from SiO₂ particles with virtually crack-free textures. The as-fabricated PCs films exhibits excellent optical and mechanical properties, including uniform and saturated colors (1 > ΔE·ab for 27 orthogonal points), long service life (>12 months), a wide operating temperature range (25–90 °C), superior bending resistance (>190,000 cycles), good folding resistance (>320 cycles), and excellent reversibility (>27,000 cycles). This work provides new insights into the self-assembly of colloidal SiO₂ particles that will enable the application of PCs films in the back covers of mobile phones and multicolor displays.