Perpustakaan Digital ITB

This study presents the redesign and optimization of a low-cost underactuated transradial bionic hand using a whiffle tree mechanism. The goal is to improve finger synchronization and grasping dexterity without increasing system complexity or cost. Experimental characterization revealed significant differences in activation force and displacement among fingers, necessitating non-uniform load distribution. Using CAD modeling and Simulink Simscape simulation, multiple design iterations were evaluated through parameter estimation. The seventh test configuration achieved the most natural and dexterous motion, enabling a realistic spherical grip. It featured a 0.86 mm extension of the right vertical bar and an 8.84 mm extension of the left vertical bar, which allowed all four fingers to actuate smoothly and wrap around objects with improved contact. The design successfully grasped a pen and a half-filled water bottle, demonstrating enhanced functionality compared to prior designs. Although the optimized geometry reduced compatibility with the original locking mechanism, it significantly improved grasping performance. The results confirm that targeted geometric optimization can enhance the dexterity of affordable prosthetic hands, offering a viable path toward accessible and functional bionic solutions.