Enhanced Energy Harvesting with a Piezoelectric Diatomic Sandwich Beam Shunted to an SECE Circuit

Abstract This study introduces a novel piezoelectric energy harvester based on a diatomic sandwich beam structure, offering a promising solution for wireless sensors and IoT nodes to operate without chemical batteries. The dynamic model is derived using homogenization theory and Hamilton's principle, with the electromechanical coupling model established via the Lagrange equation and modal assumptions. The model is verified through finite element analysis (FEM). The proposed sandwich beam outperforms a traditional uniform beam, yielding a 2.67-fold increase in voltage output, a 7.14-fold increase in power output, and a broader operational bandwidth. The effects of geometric and material parameters on energy efficiency are analyzed to guide design optimization. Additionally, a novel equivalent circuit model (ECM) for the piezoelectric diatomic sandwich beam (PDSB) is presented and integrated with a synchronized charge extraction (SECE) circuit, showing superior power stability and efficiency compared to a resistive shunt circuit. This research provides valuable methodologies for the design and analysis of sandwich beam-based piezoelectric energy harvesters, advancing their practical applications.