Perpustakaan Digital ITB

This study presents the development of a three-degree-of-freedom (3-DoF) prosthetic wrist joint designed to replicate natural and asymmetrical wrist biomechanics for Activities of Daily Living (ADLs). Compliant mechanisms were employed to achieve flexion–extension (FE), radial–ulnar deviation (RUD), and supination–pronation (SP), by simulating through finite element analysis (FEA) and prototypes fabricated by 3D printing. PETG was identified as the optimal material, balancing flexibility, strength, and fatigue resistance, with projected lifetimes of >70,000 cycles for the FE–RUD stage and 39,321 cycles for the SP stage. The final design combined a Flex-16 compliant revolute joint for FE–RUD and an Inner–Outer Ring Flexure Pivot (IORFP) for SP. Experimental validation showed that the FE–RUD mechanism achieved 40° and 38° ranges of motion, while the SP mechanism reached 53° with stable rotation due to non-zero off-axis stiffness. Incorporating the dart throwing motion (DTM) framework enabled accurate coupled FE–RUD trajectories along the natural oblique path, reducing user effort compared to independent motion. Seven ADLs were successfully performed, confirming functional reliability and user comfort. By reducing part count and eliminating conventional joints, the compliant mechanism approach yielded a lightweight, compact, and low-cost prosthetic wrist, demonstrating strong potential for accessible and biomechanically accurate prosthetic solutions.