Energy harvesting performance of fluid-immersed bimorph FG-GPLRC sandwich microplates in thermal gradient and magnetic field environments: A modified strain gradient theory approach

Abstract

This study presents a novel investigation into the energy harvesting capabilities of fluid-immersed bimorph functionally graded graphene nanoplatelet reinforced composite (FG-GPLRC) sandwich microplates under combined thermal gradient and magnetic field environments, considering various boundary conditions. To address the critical research gap in understanding size-dependent behavior of such systems, a theoretical framework combining modified strain gradient theory (MSGT) with first-order shear deformation theory (FSDT) is developed. The fluid-structure interaction forces are obtained through Navier-Stokes equations, while Hamilton's principle and Gauss's law are employed to derive the governing equations. Both the Halpin-Tsai micromechanical model and the law of mixtures are utilized to predict the effective material properties of FG-GPLRC with different graphene platelet distributions. The analysis reveals that series electrical configurations yield superior voltage and power output compared to parallel configurations in fluid-immersed environments. It is also shown that graphene platelet distribution patterns significantly influence energy harvesting efficiency, and thermal gradient effects substantially impact the system's performance. Comprehensive parametric analyses are provided examining the effects of piezoelectric connection types, boundary conditions, graphene distribution and loading, temperature variations, fluid depth, electrical load, and geometric dimensions on energy harvesting performance. The results of these analyses advance the understanding of micro-scale energy harvesting systems and provide valuable design guidelines for future applications.