Liquid metal universal grippers for gentle, adaptable, multiscale manipulation

The amoeba can flow like liquid to change its morphology to effectively capture and excrete various prey. Inspired by the amoeba, we present a liquid metal universal gripper capable of effective grasping and active releasing of targets with various shapes, sizes, and stiffnesses in liquid and air. We unveil a surface tension induced active release mechanism enabling tunable active release of micro-objects. The gripper operates across 14 orders of magnitude in weight (from 10−12 g to 200 g) and achieves a low gripping contact pressure of ~10 Pa for handling delicate items. It can capture and release moving objects within milliseconds without precise alignment. An environment-agnostic surface activity design extends its functionality to a non-electrolyte environment. The gripper offers notable performance metrics over existing robotic grippers in multiscale operation, low contact pressure, and tunable releasing speed, representing a notable solution for living organisms and microscale objects. Robotic grippers struggle to handle fragile and varied objects across environments. Here, the authors introduce a liquid metal gripper that adapts its shape and stiffness for gentle, multiscale grasping and active release.