A piezoelectric sandwich structure for harvesting energy from tire strain to power up intelligent tire sensors

Intelligent tires are used in autonomous vehicles where a considerable amount of monitoring shall be placed to avoid fatal damages. Accordingly, parameters like tire pressure, temperature, friction and contact-patch dimensions in an autonomous vehicle should be continuously tracked via sensors embedded on tires. These sensors need a source for power to operate properly. Energy harvesting systems can play an important role in extracting energy from sources that are already being wasted while there is a potential to sustain the amount of energy for sensors. In this study, a new geometry of strain-based piezoelectric energy harvester inspired from geometry of Cymbal piezoelectric energy harvesters is proposed to preserve a significant fraction of tire strain energy. Multiphysics modeling and finite element analysis using COMSOL Multiphysics software are employed and the output electric energy and voltage of the energy harvester are about 7 V, 5 mW and 90 mu J/rev, respectively. The obtained amount of output energy is sufficient to power tire sensors.