MANUFACTURING AND ANALYSIS OF PROSTHETIC FOOT USING COMPOSITE MATERIAL

Abstract

The design and development of prosthetic feet play a crucial role in enhancing mobility, comfort, and overall quality of life for amputees, as an effective prosthetic must support body weight, enable a natural gait, and absorb shock during walking. However, conventional designs such as the SACH foot often lack sufficient flexibility, durability, and responsiveness for dynamic activities, while high-performance alternatives like carbon fiber-based models remain costly, creating a need for a lightweight, cost-effective solution with improved performance. This study addresses this gap by designing, manufacturing, and evaluating a composite prosthetic foot using carbon fiber, fiberglass, and Kevlar to optimize strength, durability, and affordability. The prosthetic was divided into a Keel and Heel, fabricated using layered composites (11 carbon fiber layers with additional reinforcement, 2 fiberglass layers, and 2 Kevlar layers), with a 15° dorsiflexion angle to simulate natural gait, and analyzed using ANSYS 14.5 for deformation, stress distribution, and safety factor, alongside mechanical testing. The developed prosthetic foot weighed 412 g and demonstrated effective gait simulation for below-knee and through-knee amputees, with tensile properties reaching yield strengths of 138.057 MPa and 102.486 MPa, ultimate strengths of 174.2 MPa and 146.257 MPa, and elastic moduli of 2.384 GPa and 5.616 GPa for two sample groups. The design maintained structural safety under normal loading with safety factors above 0.86 but became unsafe beyond 96 kg body weight, with reduced lifespan above 86 kg.