A piezoelectric frequency-increased power generator for scavenging low-frequency ambient vibration

This paper presents the design, fabrication, and testing of a piezoelectric inertial micro power generator for scavenging low-frequency non-periodic vibrations. A mechanism up-converts the ambient vibration frequency to a higher internal operation frequency, in order to achieve better electromechanical coupling and efficiency: enhancing the generators performance at very low frequencies (< 30 Hz). The generator incorporates a bulk piezoelectric ceramic machined using ultrafast laser ablation. The fabricated device generated a peak power of 100 ¿W and an average power of 3.25 ¿W from an input acceleration of 9.8 m/s² at 10 Hz. The device operates over a frequency range of 24 Hz. The internal volume of the generator is 1.2 cm³.