A wide-band piezoelectric energy-harvester for high-efficiency power generation at low frequencies

This paper presents a miniaturized piezoelectric vibration energy harvester that can generate over 1.5μW of average power at the frequency range of 9Hz to 19Hz under sinusoidal input acceleration of 1g. The harvester employs non-contact frequency up-conversion technique to excite two stages of generators, achieving wide-band low-frequency generating capability with a small size. The fabricated harvester was mounted on a moving bus to test its performance in a real-life situation and generated up to 1.11V of peak voltage and 123nW of peak power.