Laser Pouch Motors: Selective and Wireless Activation of Soft Actuators by Laser-Powered Liquid-to-Gas Phase Change

Untethered control of soft-bodied robots is attractive for interactions in a variety of unstructured and dynamic environments. However, soft robotics systems are currently limited in terms of wireless, selective, and scalable control of multiple actuators. Therefore, we propose a method to wirelessly drive multiple soft actuators by laser projection. A small amount of low-boiling-point liquid inside a planar thin pouch can be heated by a laser and evaporated to inflate the whole body. Laser projection enables both wireless energy supply and the selection of target actuators. Further, the low-boiling-point liquid serves as an actuation source and as a receiver of laser irradiation. Thus, we do not need additional components such as electric circuits and batteries to achieve simple and scalable implementation of multiple soft actuators. We evaluated the mechanical properties and demonstrated that the system can wirelessly control the gestures of fingers of a robot hand. We also verified that our method can activate a group of mobile soft robots simultaneously and individually while tracking the actuator positions. Our approach contributes to the scalable deployment of soft robotic systems by removing tethers for power and communication.