Thermal Energy Harvested to Power Digital Shm Hardware

A digital signal processor based evaluation board has been utilized in the development of hardware for the impedance-based structural health monitoring technique. This hardware employs digital output to generate a rectangular excitation pulse train for structural excitation, and receives a digital input to sense the structural response. The DC power supply to this hardware is now replaced with standard nickel metal hydride and lithium ion batteries. Power required to perform all the autonomous impedance-based SHM operations is supplied from a battery. The battery is recharged using only a thermoelectric generator across a temperature gradient, with the appropriate harvesting circuitry, to make the system completely autonomous. Both the battery discharge and recharging characteristics are described. The time available for SHM operation with the battery, along with the system duty cycle are also disclosed.