Reprogrammable, light-driven and sensing actuators based on Chinese ink composite: A synergetic use of shape-memory and self-healing strategies

Abstract

Smart actuators have great prospects in soft robotics. Reprogrammable function is essential for shape-reprogramming of actuators to achieve arbitrary shapes and diverse deformations, which is a key feature for next-generation actuators. However, it remains a huge challenge to develop a facile strategy to prepare reprogramming and multi-functional actuators. Herein, we report a synergetic strategy to fabricate reprogrammable, light-driven and sensing actuators based on Chinese ink and waterborne polyurethane (PU) composite. The entire ink/PU actuator is self-healing, as both the ink and PU films can be self-healed with the aid of water. Through synergistically using the shape-memory of PU and self-healing property of ink/PU composite, the initial configurations of ink/PU actuators can be fixed and assembled into arbitrary shapes, including tendril-shape, heart-shape, accordion-shape, letter-shapes and so on. These programmed actuators demonstrate complex deformations reversibly under near-infrared light irradiation. Importantly, the same actuator can be reprogrammed and light-actuated again. Moreover, introducing conductive ink layer integrates temperature sensing function into the actuator. Finally, a bionic butterfly robot is constructed, which can not only flap wings under light irradiation, but also sense human touching. This study will open a new path to reprogrammable, self-healing, and light-driven soft robots with multi-functions and complex deformations.