Electric power generation using piezoelectric resonator for power-free sensor node

This paper describes a power-free sensor node operated by ambient vibration energy. An electric power generator is based on a vibration-to-electric energy converter using a piezoelectric resonator. The power generator consists of a piezoelectric resonator, and a power control circuit for recharging. Key technologies are the analysis model that compensates for inertia moment of the piezoelectric resonator, and the power control circuit that stores scavenged current charge to supply instant power for radio communication. The condition optimization for the size of the resonator is match of resonance frequency, which achieves highly efficient resonator. The power control circuit that stores electric power of the 180 μW and supplies electric power of 30 mW. As a result, the power generator achieves 5 minute intermittent operation of a power-free sensor node.