Low frequency acoustic energy harvesting adopting slit Helmholtz resonator

In this study, a novel acoustic energy harvesting (AEH) device is proposed to realize low frequency acoustic energy harvesting in broadband. Based on the classical Helmholtz resonator, a novel AEH device with slits is proposed. The AEH components and mechanisms are analyzed, followed by an experimental evaluation of the fabricated sample. Experimental results show that for the proposed AEH device, the bandwidth near the acoustic resonant frequency is extended, which can be attributed to the thermos-viscous damping mechanism. This type of attribute is favorable for resonance tuning and increasing the adaptability of the AEH device. Under 100 dB sound pressure level (SPL) excitation, the measured harvested electrical power is 2.4 µW.