Design and Modeling of a Patterned-Electret-Based Energy Harvester for Tire Pressure Monitoring Systems

Tire pressure monitoring systems (TPMS) are applications where energy harvesting may prove useful as a power source. In this paper, we present the design, modeling, and simulation of a microscale energy harvester for TPMS systems, located on the inner liner of the car tire. We discuss design considerations for electret-based energy harvesters and present a specific design. An electrical equivalent circuit model with parameters extracted from finite element analysis is presented and used to predict the performance of the device using both measured tire vibrations and colored noise. We find that sufficient power for the TPMS application can be generated at 50 km/h driving speed with a device with a 400 mu m x 3.8mm x 4.34mm silicon proof mass.