Finite Element Analysis of Particle Size Effects on Piezoelectric Nanogenerator Performance

This study presents a multiscale finite element investigation into how particle dimensions influence the performance of piezoelectric nanogenerators (PENGs) based on PDMS/${\text{BaTiO}}_3$ nanocomposites. Using COMSOL Multiphysics, we developed a comprehensive computational framework to analyze the effects of ${\text{BaTiO}}_3$ particle size (50 nm, 100 nm, 2 $\mu$m and 5 $\mu$m) and loading concentration (10%, 15%, 20%, and 25%) on energy harvesting efficiency. Our model integrates an advanced stochastic algorithm for particle distribution and employs representative volume element (RVE) analysis to accurately capture the material's heterogeneous microstructure. The model's validity was established through rigorous comparison with theoretical predictions of resonance frequencies and experimental power density measurements, demonstrating excellent agreement across multiple operating conditions. Our findings reveal that nanoscale ${\text{BaTiO}}_3$ particles (50–100 nm) generate substantially higher power densities compared to their microscale counterparts (2–5 $\mu$m), with peak performance observed at 15–20 wt.% particle concentration. The results emphasize the significance of particle size in enhancing PENG efficiency, providing a basis for improved material design and device optimization.