Flexible and stretchable chromatic fibers with high sensing reversibility.

Chromatic polymers, such as polydiacetylene (PDA) that display color changes under stimulations, have been widely explored as sensors and displays. However, the PDA-based materials are generally rigid and irreversible in the chromatic transition. Herein, a flexible and stretchable PDA composite fiber is produced by incorporating peptide-modified PDA into aligned carbon nanotubes on an elastic fiber substrate. It performs a rapid and reversible chromatic transition in response to electrical current that can be repeated for 1000 cycles without fatigue. Due to their high flexibility and stretchability, these chromatic fibers can be integrated into different patterns and woven into smart textiles for displaying and sensing applications.