Toward Durable Prosthetic Feet: Mechanical and Tribological Evaluation of Polyurethane Elastomers

Elastomeric materials play a crucial role in determining the durability, comfort, and service life of prosthetic feet. Although various elastomers have been explored for this application, systematic evaluation of polyurethane formulations that integrate mechanical and tribological performance remains limited. This study investigates two types of polyurethane elastomers (A70 and A80) with different polyol–isocyanate ratios to identify an optimal formulation for prosthetic foot applications. Mechanical properties were evaluated through tensile, tear, hardness, and density tests, while friction and wear behavior were assessed using a pin-on-disk tribometer. A commercial prosthetic foot elastomer available in the Indonesian market was used as a benchmark. The results show that A80-based formulations generally provide superior tensile and tear strength compared to A70 variants. Among all specimens, A80-3 exhibits the lowest wear volume and stable friction performance, while maintaining hardness comparable to the commercial product. Although its density remains higher than the benchmark, the improved wear resistance indicates potential for extended service life. These findings offer practical guidance for durability-oriented material selection in the development of cost-efficient prosthetic feet.