Batteryless Tire Pressure Real-Time Monitoring System Driven by an Ultralow Frequency Piezoelectric Rotational Energy Harvester

Tire pressure monitoring system (TPMS) has been brought into the stringent regulatory frameworks of many countries in the automotive market. However, common commercial TPMSs must rely on a life-limited battery, which brings about some safety risks and environmental problems. It is worthy to note that energy harvesting approaches are promising to realize a batteryless TPMS. In this article, a rotation-driven piezoelectric energy harvester with eight typical nonlinear buckled bridges is proposed to effectively scavenge ultralow frequency kinetic energy. Thinned bulk PZT film is employed as the piezoelectric functional layer based on its excellent electromechanical factor. Gear-induced interwell oscillation mechanism ensures the effective deformation of the piezoelectric buckled bridges. The developed harvester can generate the effective output power of 8.9 mW under the optimal resistance of 3 kΩ at 8.3 Hz rotational frequency. The 47, 100, and 330 μF capacitors can be saturated at 14.5, 15.1, and 14.5 V during 10, 19, and 51 s, respectively. Additionally, a commercial TPMS can be effectively powered by this harvester when it works at more than a critical frequency locating at 3.0-3.7 Hz. The commercial TPMS can be operated in realtime when the applied rotational frequency is more than 8.3 Hz.