Date of Award

January 2022

Document Type


Degree Name

Master of Engineering (MEngr)


Mechanical Engineering

First Advisor

Djedje-Kossu Zahui


The piezo-mechanical battery is designed to store energy in a flat spiral spring and harvest the kinetic energy of the unwinding spring using piezoelectric unimorph cantilever beams. The system, initially proposed on a micro scale, was designed to function on a macro scale. The power spring of the system was designed to deliver enough torque to run the system and provide enough force to the escapement mechanism to excite the cantilever beams. The gear system is designed as a compound epicyclic gear system with a gear ratio of 55:1. The cantilever beams were designed to act as springs as well as harvesters in the system. The runtime of the system was estimated to be 220 seconds. The proposed design was tested numerically as well as experimentally to prove that the system integration works. Experiments to prove the power output from a piezoelectric cantilever beam were also carried out. The maximum torque delivered by the spring is 0.08Nm and the dimensions of the escapement mechanism translates the output torque to 0.37N of force on the cantilever beams. The final assembly of the device is 4 inches tall and 7 inches across and so the objective of portability was somewhat achieved.