Effects of aspect ratio and arrangement of PZT-7A piezoelectric fillers on energy harvesting performance of PVDF composite cantilevers

Abstract

Piezoelectric composites have emerged as promising materials for highly durable and flexible energy harvesters and sensors, requiring comprehensive modeling frameworks for accurate performance evaluation. This study investigates the influence of PZT-7A piezoelectric filler characteristics, including aspect ratio (AR), volume fraction, and spatial arrangement on the energy harvesting performance of polyvinylidene fluoride (PVDF) matrix composite cantilevers. The research employs a two-stage computational approach: first, a micromechanical finite element (FE) homogenization method determines the effective electromechanical properties of PZT-7A/PVDF composites; second, these properties are implemented in parallel bimorph piezoelectric vibration energy harvester (PVEH) models to predict voltage and power outputs. The results demonstrate significant dependencies of PVEH performance on filler parameters. For random spherical inclusions at 30% volume fraction under optimal electrical resistance, the maximum power density reaches 30.64 μW/cm2. Additionally, the study examines performance enhancement through structural modification, showing that semi-elliptical hollow patterning increases power density output of the PVEH specifically for PZT-7A as active layers. These findings provide critical insights into the design and optimization of piezoelectric composite-based energy harvesting systems. © IMechE 2025