Modeling and Analysis of Electrical Circuit Connections in the Piezoelectric Cantilever Array for Vibration Energy Harvester

The use of energy-efficient and environmentally-friendly low-power sensors technologies has impacted the advancement of vibration energy harvesting systems. The standard piezoelectric cantilever beam has numerous limitations, such as a limited operating range and decreased output power due to mismatch of operating frequency and its surrounding frequencies. A broadband approach to energy harvesting is crucial for capturing electrical energy from random ambient vibrations. In this study, a model of the piezoelectric energy harvesters is established to assess the effectiveness of a multi-cantilever system. This research explores the impact of two distinct electrical connection configurations for the cantilevers, specifically series and parallel circuit arrangements, on boosting the power output and expanding the bandwidth. An array consisting of four similar piezoelectric cantilevers with different resonant frequencies were positioned alongside each other to function as a system for producing electrical output across a frequency range between 100Hz to 400Hz. The bandwidth of the multi-cantilever system was effectively expanded from 100Hz to 200 Hz for a 4-beam system, which is twice its original single cantilever output for both the series and parallel configurations. The peak output voltage of the system is also notably higher, at least a two-fold increase over the individual cantilever beams.