Perpustakaan Digital ITB

The human elbow joint enables a wide range of motion essential for daily activities. Limb amputation due to trauma, infection, or disease can significantly impair physical capability and emotional well-being. Conventional elbow prostheses, often constructed with rigid links and mechanical hinges, are typically expensive, heavy, and prone to wear, limiting their long-term usability and accessibility. To address these limitations, this study explores the use of compliant mechanisms and biomimetic design principles to develop a functional, lightweight, and cost-effective elbow joint prosthesis. This research introduces a novel prosthetic design that integrates compliant mechanisms with anatomical biomimicry, aiming to replicate the structure and motion of the natural elbow. A cross-axis flexural pivot was employed and modified to replicate the humerus and ulna bones. Additive manufacturing (3D printing) was used to enable high geometric complexity and customization. Additionally, cable and pulley system, actuated by a stepper motor, was incorporated to simulate the contraction and relaxation of human muscles. To enhance performance, a parametric study was conducted by comparing 18 design configurations of flexures for both flexion-extension and pronation-supination motions. Optimal designs were selected based on minimization of stress and actuation force as determined through FEA, followed by experimental validation. The optimal configuration for the flexion-extension mechanism was 4 flexures with 3 mm width and 0.5 mm thickness, while the pronation-supination mechanism used 2 flexures with the same dimensions. The resulting prototype fulfils the Design Requirement Objective (DRO) by achieving the required weight, range of motion, load capacity, and acceptable fatigue life, offering a promising foundation for future development and clinical application of upper-limb prosthetics.