Fabrication and experimental analysis of a novel flexible keel prosthetic foot utilizing functionally graded materials

The present study performs the fabrication and experimental performance analysis of a novel flexible keel prosthetic foot made up of functionally graded materials (FGMs). To obtain the desired mechanical properties, the keel of the prosthetic foot was fabricated by combining wood and carbon fibre-reinforced polymer (CFRP). The FGM in the foot was introduced by creating layers of a blend of burnt rice husk particles and silica rubber with different weight percentages (2%, 4%, 6%, 8%, 10%, and 12%). Moreover, a casting was performed to develop a keel prosthetic foot using a metal mould. Experimental tests were conducted to investigate the foot performance and compared with Solid Ankle Cushion Heel (SACH) foot designs by carrying out tests such as tensile test, hardness test, dorsiflexion analysis, and fatigue testing. Fatigue life and dorsiflexion angle values are found to be higher for the proposed design in comparison to the SACH foot. This study presents important insights into the potential benefits and practicality of using flexible keel prosthetic feet made from functionally graded materials. The enhanced mechanical characteristics and tailored design of these prosthetic feet can significantly improve user comfort, stability, and overall biomechanical performance.