Analytical modeling and FEM simulation of slotted piezoelectric arrays for vibration energy harvesting

This work investigates a cantilever-based piezoelectric energy harvester incorporating designs with different slot shapes. The finite element method and analytical modeling are employed to study and compare several slot geometries, including rectangular, triangular, symmetric H, asymmetric H, and inverted triangular designs. The results show that slot geometry and position strongly affect both output power and resonant frequency. The symmetric H-slot delivers nearly double the power output of the solid beam under the same conditions, along with a tenfold increase in voltage. The symmetric H-slot design achieves 0.64 mW at 47 Hz, corresponding to a normalized power density of 0.54 mW·cm⁻³·g⁻²·Hz⁻¹, confirming the effectiveness of the proposed structural modification in enhancing energy harvesting efficiency. Extending the design to slotted cantilever arrays revealed that uniform arrays provide a maximum power output of 1.86 mW, whereas varied-length H-slot arrays sacrifice power for a broader 5.8 Hz bandwidth with stable performance above 50% of peak.