A study into the application of piezoelectrics to modify ankle torques in active prosthetic feet using finite element analysis

Over the last fifty years there has been a steady advance in prosthetic foot technologies. These advances have primarily focused on more accurately mimicking the biologic foot for amputees. One eld of research currently being explored is active/powered prosthetic feet in which the movement of the foot is actively controlled through the use of electric motors. Some of these feet also seek to reproduce the ankle torques seen in the biologic foot. This thesis proposes to investigate the possibility of the integration of piezoelectrics into active prosthetic feet to more accurately reproduce these ankle torques. A general set of FEA models, simulations, and analysis tools have been developed for the design and testing of applications involving piezoelectric beam bending actuators. These tools were utilized to successfully replicate the ankle torques versus time pro les found in the literature through the application of a number of di erent con gurations of piezoelectric strips. It was found that while it was possible to replicate these toques with piezoelectrics alone, the required voltages were far too large to be practical.