Continuously Stable Structure through Plastic Deformation
Robotics
Summary
The authors developed a soft robot hand that stays stable even when moving quickly or disturbed, by using a special plastic deformation design. This design allows the hand to keep its shape and hold objects without using extra energy, unlike some traditional soft robots. They added a paw pad inspired by animals to improve grip and sensing. Tests showed the hand can hold objects firmly without power and stay steady under strong shocks, making it useful for robots that need to move around and hold things for a long time.
Authors
Junlong Xiao, Yaoqiang Pan, Xuan Zhang, Michael Yu Wang, Chao Chen
Abstract
Soft robots have seen widespread adoption in interactive tasks due to their inherent compliance and adaptability. However, these advantages often come at the cost of stability, posing challenges in a dynamic environment. This limitation is especially critical in soft grippers, where instability under acceleration or external disturbances can result in grasp failure. In this study, we present a continuously stable structure through plastic deformation (CSSPD), integrated into a soft gripper. By leveraging the mechanism of plastic deformation, the gripper maintains continuous configurations without energy input, while the added stiffness ensures both static and dynamic stability. We introduce a bioinspired paw pad that significantly enhances stability and enables sensing-based rapid object grasping. Then we develop the mathematical model and optimize the kirigami structure of the metal layer. Experimental results show that the gripper can sustain a passive holding force of up to 16 N without energy input, achieving performance comparable to pneumatic actuation at 0.3 MPa. When combined with pneumatic actuation, it remains stable under pulsed accelerations of up to 400 m/s^2. It can also passively perch on tree branches for extended periods without power, demonstrating promise for mobile robotic applications.