Controllable Passive Suction Cups With Mechanical Programmability for Soft Robotics

ABSTRACT The commonly used suction cups need ongoing innovation for simpler designs, stronger suction, and reduced energy consumption. Here, a group of passive suction cups with mechanical programmability is proposed, capable of maintaining adaptive suction on complex surfaces by utilizing the compliance of their thin‐membrane structures. By incorporating annular ribs and covering skeletons into the membrane, the suction cups achieve effective, controllable adhesion with tunable friction. The controllable adhesion results from the dependence of the annular ribs' deformation on the lifting speed, resulting in a stress difference of more than without employing excessive electronic components. This suction cup demonstrates strong grasping performance both underwater and on inclined surfaces with minimal preload ( kPa). By leveraging the transmission of the covering skeleton under tangential loads, we propose a strategy to tune its static or sliding friction via different input torques. A mobile robot is further constructed that can crawl omnidirectionally with a simple gait. When placed on a vertical wall, the robot can achieve a controllable switch between rapid sliding descent (76.87 ) and gradual upward climbing (2.30 ). Overall, our passive suction cups with controllable behaviors can be utilized to build soft robotic systems with mechanical programmability.