Simulation of a novel bridge MEMS-PZT energy harvester for tire pressure system

Abstract

Self-powering is becoming an important issue for autonomous sensor systems. By having an on-the-go power source the life span increases in comparison to a limited battery source. In this paper, simulation of an innovative design for a piezoelectric energy harvester for Tire Pressure Measurement System (TPMS) is presented. The MEMS-based thin-film PZT harvester structure is in the form of a bridge with a big central seismic mass and multiple electrodes. This design takes the advantage of the S-profile bending and a short beam length to concentrate the piezoelectric effect in a small segment along the beam and maximize the power output for a given displacement. From simulation in Comsol Multiphysics, the 9mm × 5mm bridge, seismic mass of 8.7mg and resonance frequency of 615Hz, generates 1 μW by mechanical pulses excitation equivalent to driving at 60 km/h (roughly 180G).