Thermo-responsive color-changeable photonic materials: A review

Structural colors derived from nature have attracted extensive interest due to their unique optical performances and various applications in the field of biomimetic optics. Many organisms have evolved different strategies to respond to external stimuli, so as to obtain attention or hide themselves by changing their surface color. Inspired by this, various biomimetic micro/nanostructures with periodic size have been developed and realized tunable structural colors. Functional materials utilizing the synergy of thermal polymer and photonic microstructure to realize the temperature-responsive structural colors have broad application prospects in the fields of sensor, display, anti-counterfeiting and biomedical treatments, etc. In this review, the research progress on photonic crystals or other mechanisms for generating structural colors with various thermo-sensitive polymers is systematically summarized. The artificial systems with diverse types of temperature-stimulated reactions are presented. Finally, emerging research directions and current challenges in this field are also discussed.