writer：Xinkai Li, Jize Liu, Dongdong Li, Shaoquan Huang, Kai Huang,* and Xinxing Zhang*
keywords：actuators, cellulose nanocrystals, color-changing, infrared/humidity sensitive, multi-stimuli responses
source：期刊
specific source：Advanced Science
Issue time：2021年

The combination of complex perception, defense, and camouflage

mechanisms is a pivotal instinctive ability that equips organisms with survival

advantages. The simulations of such fascinating multi-stimuli

responsiveness, including thigmotropism, bioluminescence, color-changing

ability, and so on, are of great significance for scientists to develop novel

biomimetic smart materials. However, most biomimetic color-changing or

luminescence materials can only realize a single stimulus-response, hence the

design and fabrication of multi-stimuli responsive materials with synergistic

color-changing are still on the way. Here, a bioinspired multi-stimuli

responsive actuator with color- and morphing-change abilities is developed by

taking advantage of the assembled cellulose nanocrystals-based cholesteric

liquid crystal structure and its water/temperature response behaviors. The

actuator exhibits superfast, reversible bi-directional humidity and

near-infrared (NIR) light actuating ability (humidity: 9 s; NIR light: 16 s),

accompanying with synergistic iridescent appearance which provides a visual

cue for the movement of actuators. This work paves the way for biomimetic

multi-stimuli responsive materials and will have a wide range of applications

such as optical anti-counterfeiting devices, information storage materials, and

smart soft robots.