Use of piezoelectric energy harvesting devices for charging batteries

Piezoelectric materials can be used as mechanisms to transfer ambient vibrations into electrical energy that can be stored and used to power other devices. With the recent surge of micro scale devices, Piezoelectric power generation can provide a conventional alternative to traditional power sources used to operate certain types of sensors/actuators, telemetry, and MEMS devices. In this paper, two types of piezoelectric materials were experimentally investigated for use as power harvesting devices. The two types being the commonly used monolithic piezoelectric (PZT) and Macro Fiber Composites (MFC), which were recently developed at the NASA Langley Center. Our experimental results estimate the efficiency of these devices and identify the feasibility of their use in real world applications. In general the power produced by the vibration of a piezoelectric device is on the order of a few milliwatts which is far too little to power for most applications. Therefore, each the transducer is used to charge nickel metal hydride batteries of varying sizes to compare their performance and ability of to store electrical power. The results presented in this paper show the potential of piezoelectric materials for use in power harvesting applications.