Reprogrammable soft actuators based on a photochromic organic-inorganic hybrid membrane with modulatable NIR...

Shape-transformation soft actuators that can quickly respond to external stimuli have been potential candidates in biomimetic soft robots and flexible driving devices. However, the lack of shape reprogrammability restricts their complexity of deformation as well as reusability in practical application. Herein, we present a unique reprogrammable actuator based on asymmetric bilayer compounding with UV-modulated photochromic complex (NEU20) through a sequential polymerization process. The UV-induced electron transfer photochromic behavior synergistic with NIR photothermal effect of NEU20 fillers endows the soft actuator with rapid (∼90°/s) and customizable actuation under external NIR stimuli. Through the joint modulation of UV exposure region and duration, the UV-induced photothermal conversion efficiency is also adjustable at each local, facilitating the spatio-temporally programmable actuation process of the hybrid bilayer actuator. Significantly, the programmed actuation process of the actuator also features thermal-erasing and UV-reprogramming capacities, highlighting the unique recyclability of the hybrid actuator. In addition, the proposed reprogrammable actuator also demonstrates good universality in combination with other thermal-responsive active material systems. This work offers insight into the design and fabrication of reprogrammable soft actuators, shining enlightenment for potential application in bioinspired soft robots and smart mechanical devices.