Design and Experimental Validation of a Soft, Shape-Programmable Multi-fold Gripper
摘要
The increasing need for flexibility in industrial automation has prompted the development of adaptable grippers capable of handling objects with varying shapes and sizes. This paper introduces a novel pneumatically actuated multi-fold gripper with a programmable deformation mechanism. The core of the gripper is a flexible ring actuator with an internal air channel. By inserting star-shaped forms during the first actuation, folds formation in the ring’s inner wall can be controlled, allowing for the definition of discrete folds. Experimental tests using inserts with 4, 5, and 8 tips demonstrated successful and repeatable programming of the ring’s deformation pattern, which remained stable over multiple actuations and after a one-week rest period. Attempts to generate only two folds were unsuccessful, likely due to uncontrolled stress distribution and material limitations. The multi-fold gripper is manufactured additively using a combination of SLS and PolyJet technologies, enabling rapid customization. This method provides a simple, low-cost approach to pre-shaping soft grippers, reducing the energy losses typically associated with deformation. The concept of using localized structural memory introduces a new design pathway for soft robotic actuators. Future work should explore automatic deformation programming through embedded structural features created during the additive manufacturing process.