A novel multimodal piezoelectric vibration energy harvester integrated with a practical read-out circuit

This paper introduces a novel multimodal piezoelectric harvester for converting low-frequency vibration into electricity. The harvester consists of a primary plate, four smart beams and proof masses. A finite element (FE) model is developed in COMSOL Multiphysics to estimate the electrical outputs for harmonic base excitation. Besides considering only a pure load resistor, a practical read-out circuit is employed to assess the harvester performance. The read-out circuit is also simulated in LTspice XVII^® software to verify the results of the FE model, and to calibrate the circuit itself. After further validation of the FE model with the results of experimental modal analysis using shaker excitation, parametric studies are conducted to understand the harvester's behaviour. The results demonstrate that the scavenger effectively harvests vibratory energy from its first four modes over a frequency band of around 10 Hz. Also, it can generate a significant amount of power across a wide range of frequencies by incorporating a tunable load resistance.