Low-voltage driven flexible double-layer electrothermal actuator for smart human-machine interactions

Abstract Self-driven smart materials have a wide range of applications in smart textiles, artificial muscles, soft robots, human-machine interactions and so on. Flexible electrothermally driven smart materials are essentially required in self-driven smart devices due to their excellent flexibility and simple operation. However, there are still some issues should be solved such as the high driving voltage, how to achieve excellent driving performance at low voltage is highly desired. In this work, three kinds of flexible double-layer electrothermal actuators (ETAs) are made of “U”-shaped graphite paper and polyimide (PI) film. The thermal expansion coefficients of graphite and PI vary widely and graphite has excellent electrothermal performance, which enable flexible double-layer ETA has a good driving performance at low voltage in a short time. The bending angle of the actuator can reach 248.6° and the bending curvature can reach 1.23 cm −1 at 6 V such low driving voltage in ten seconds, meanwhile, exhibits excellent driving performance and high durability. Two ETAs were assembled into a flexible smart gripper and the gripper can achieve the desired driving performance while applying a low voltage. By combining the actuator with the robot design the smart robot that can execute commands for grasping objects smoothly while moving freely. It has great potential in various human-machine interactions fields and intelligent drive fields.