On the Joint Stiffness Design of 3D Printed Monolithic Fingers

This paper introduces two novel approaches for adjusting the stiffness of robotic gripper joints both offline and in real-time. The first method, called WaveJoints, is a passive design technique for task-specific 3D-printed soft-rigid grippers, where stiffness is predefined and adjusted through geometric parameters. The second method employs Twisted String Actuation (TSA) to achieve active real-time joint stiffness regulation, allowing robotic fingers to adapt dynamically to various manipulation tasks. Unlike the task-specific approach of WaveJoints, TSA provides versatile and spontaneous adaptation to the task. The combination of these methods enhances robotic manipulation across different environments by addressing both dynamic and static stiffness requirements.