Surface curvature regulation of 3D kirigami soft gripper

Abstract

Kirigami principles have been integrated into flexible grippers, exploiting the shape transforming advantages to improve the grippers’ performance and broaden the varieties upon which can be operated. However, few studies have adopted the 3D polygonal auxetic kirigami as the main structure of the gripper, due to its complex spatial design process, narrowed means of fabrication and multi-freedom actuation. Herein, gripper deformation based on auxetic kirigami under a simple actuation of 1-DoF is studied via an energy minimization framework. Firstly, a spring potential energy minimization problem of the 3D kirigami with geometric constraints is solved to obtain its deployment path and energy landscape. Then the deformed surface is analyzed using discrete Gauss-Bonnet theorem, proposing a method to regulate the shape morphing into the targets. Finite element analysis is used to verify the kirigami design framework and shape prediction. Finally, different types of kirigami grippers are fabricated and tested, achieving effective conformation and grasping of typically shaped objects, while exhibiting universal, easily actuated characteristics. These findings contribute to advancing the field of robotic handling and manipulation, particularly in applications requiring gentle and compliant interactions with diverse and specifically delicate objects.