A Novel High-Performance Dual Semicircular Arc Piezoelectric Energy Harvester

To broaden the bandwidth of the piezoelectric energy harvester (PEH) and improve its power density, a dual semicircular arc PEH (DSA-PEH) is designed in this work. This harvester has three piezoelectric layer configurations: single-outer-layer, single-inner-layer, and dual-layer connected in series. A two-degree-of-freedom (2-DOF) lumped parametric model and an electromechanical coupling model with the rectifier circuit are developed to analyze the resonant frequency and output performance. Measured results show that the DSA-PEH with dual piezoelectric layers connected in series has the most superior performance among the three configurations. After optimizing the radian and position of the piezoelectric layers, this DSA-PEH has a broad bandwidth of 52 Hz. Meanwhile, in the 1st mode of this DSA-PEH, the maximum output power is 3.74 mW with the normalized power density (NPD) of
$180.3~\mu $
W
$\cdot $
g
$^{\mathbf {-{2}}}\cdot $
mm
$^{\mathbf {-{3}}}$
; in the 2nd mode, the maximum output power remains at 3.54 mW, with the NPD of
$170.8~\mu $
W
$\cdot $
g
$^{\mathbf {-{2}}}\cdot $
mm
$^{\mathbf {-{3}}}$
. The DSA-PEH exhibits a broad bandwidth and high power density, enabling it to supply power effectively in environments with large frequency fluctuations. In addition, the DSA-PEH has the capability to harvest energy in multiple directions. Therefore, the DSA-PEH can be applied to many fields, such as wearable devices, microsensors, and so on.