An Untethered Magnetic- and Light-Responsive Rotary Gripper: Shedding Light on Photoresponsive Liquid Crystal Actuators

Abstract

Here, a remotely controlled dual magneto- and photoresponsive soft robotic gripper is reported, capable of loading, transport, rotation, and release of cargo. The untethered soft actuator consists of a magnetically responsive polydimethylsiloxane layer containing magnetic iron powder coated onto the central region of a light-responsive liquid crystal polymer film hosting photochromic azobenzene dyes. Light is used to trigger the actuator to autonomously grab and pick up cargo with a high degree of control. Magnetic response is employed to conduct the locomotion as magnetic guidance, allowing the gripper to have both translational freedom and rotational freedom in its locomotion, differentiating the device from other soft robotic grippers. Control can be attained even in enclosed and/or confined spaces, through solely remote actuation. Through combined video, mechanical, and thermal analyses, the actuation mechanism of the light-responsive liquid crystal network is investigated, shedding light on the decisive role of the temperature evolution in governing both rate of motion and deformation amplitude of the light-responsive soft actuator.