Abstract: Waterwheel plant Aldrovanda vesiculosa is found to achieve trap closure in 20–100 ms underwater, which is ten times faster than that of the terrestrial plant Venus flytrap. Although a lot of bioinspired underwater grippers have been developed for rapid actuation, these devices are still limited by their closure responses (typically>180 ms), which is considerably slower than that of the aquatic plant. Herein we proposed and demonstrated a new mechanism for Aldrovanda’s rapid closure through morphological observation, theoretical modeling, and numerical simulation. Inspired by this mechanism, we presented a centimeter-scale biomimetic underwater gripper, which achieves fast underwater closure in 70 ms—approaching the plant’s natural speed. A buckling dynamics model was additionally proposed for the high-precision prediction and control of the gripper’s core actuation. This new design principle would contribute to developing high-performance rapid underwater actuation systems.

Key words: Biomimetic gripper')">Biomimetic gripper, Bistable structure, Underwater operation, Rapid grasping, Aldrovanda vesiculosa