Continuously Stable Structure through Plastic Deformation

2026-07-17

AI Summary

This study addresses the challenge of grasp instability in soft robotic grippers under dynamic disturbances. The authors propose a novel soft gripper integrating a plastic deformation mechanism with bioinspired palm pads. Leveraging a Kirigami-inspired metallic layer, the design achieves continuous stable configurations through passive plastic deformation without external energy input, sustaining a passive grasping force of 16 N—equivalent to that generated by 0.3 MPa pneumatic actuation. Combined with tactile-sensing-enabled bioinspired palm pads, the gripper enables rapid, perception-driven grasping. This work pioneers the use of plastic deformation in soft grippers to achieve zero-power stability, significantly enhancing both static and dynamic performance: it maintains secure grasps under impulsive accelerations up to 400 m/s² and supports prolonged, power-free perching on branches.

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.

Problem

• soft robotics
• stability
• grasping
• dynamic environment
• passive holding

Innovation

• plastic deformation
• continuously stable structure
• soft gripper
• kirigami structure
• passive holding