Bioinspired Dynamic Camouflage in Programmable Thermochromic‐Patterned Photonic Films for Sophisticated Anti‐Counterfeiting

Abstract Although the encrypted anti‐counterfeiting technology based on infiltration‐controlled photonic crystals has attracted widespread attention, the information has only hidden and display states. The more diverse and complex encryption effect requires a continuous and programmable color transformation. Inspired by the dynamic camouflage in chameleons and cephalopods, a programmable thermochromic patterned photonic film is developed for encrypted anti‐counterfeiting, which is constructed by infiltrating thermoresponsive poly(oligo ethylene glycol acrylate) copolymers in SiO 2 ‐coated ZnS photonic crystals. The responsive temperature range is determined by the lower critical solution temperature of filled copolymers, which is tunable by controlling the ratios of different monomers in copolymerization. Based on this, the responsive range is adjusted to 5–55 °C and decoding temperature is set at 20 °C. The pattern is hidden either when the water temperature is >55 °C or <5 °C. Only when the water temperature accurately matches the decoding temperature (20 °C), do the different areas display the preset colors, resulting in the complete pattern being revealed. The design of this programmable thermochromic patterned photonic film indicates a new direction for the encrypted anti‐counterfeiting technology, which can carry more abundant information and encrypt them more complex and sophisticated.