Characterization of Natural and Synthetic Fiber-Reinforced Composites for Sport Prosthetic Feet Applications

Sports prosthetic feet reinforced with natural and synthetic fibers offer a promising solution for developing lightweight, cost-effective, and sustainable biomedical components. In this study, epoxy-based composite laminates reinforced with Hemp, Sisal, and Bamboo fibers were fabricated for potential sports prosthetic foot applications. Different reinforcement configurations (3, 6, 9, and 12 plies) were investigated, while hybrid laminates were produced by incorporating three carbon fiber layers to enhance overall performance. The fabricated composites were evaluated in terms of density, water absorption, fiber volume fraction, hardness, and microstructural characteristics using scanning electron microscopy (SEM).The results demonstrated that increasing the number of reinforcement layers increased fiber volume fraction and improved overall composite performance. Among the natural fiber composites, Hemp laminates exhibited the highest density (1.412 g/cm3), hardness (80.2 Shore D), and fiber volume fraction (43%), together with the lowest water absorption (2.78%). The incorporation of carbon fiber layers further enhanced all investigated properties. The hybrid Hemp/carbon laminate (12H+3C) achieved the highest density (1.624 g/cm3), highest hardness (81.5 Shore D), highest fiber volume fraction (48%), and lowest water absorption (1.31%). SEM observations suggested that carbon fiber hybridization reduced visible voids, improved fiber–matrix interaction, and produced a more compact microstructure.The findings indicate that hybrid natural fiber/carbon composites, particularly Hemp/carbon laminates, offer a favorable combination of mechanical performance, moisture resistance, lightweight characteristics, and sustainability, making them promising candidates for sports prosthetic foot applications.