Comprehensive simulation study on AlN, ZnO, and PZT-5H piezoelectric materials for microcantilever-based MEMS energy harvesters: Mechanical and electrical insights

Abstract

The piezoelectric effect involves the generation of electric charge in specific materials when subjected to mechanical stress or strain. This phenomenon is utilized in applications such as sensors, actuators, and energy harvesters. Microelectromechanical systems (MEMS) based piezoelectric energy harvesters are especially useful for powering microelectronic devices and sensors, reducing dependency on batteries in situations where regular battery maintenance and/or replacement is either difficult or impractical. While individual piezoelectric materials like aluminum nitride (AlN), zinc oxide (ZnO) and lead zirconate titanate (PZT) have been extensively studied, comparative analyses within a single context are important for designers, but seldom reported. Accordingly, this article presents a comprehensive study on MEMS energy harvesters, focusing on well-known materials like AlN, ZnO, and PZT-5H. Using finite element method based COMSOL Multiphysics software tool, the proposed energy harvesters are simulated and analyzed for their mechanical and electrical properties to evaluate the performance for typical applications. The resonant frequencies for AlN, ZnO, and PZT-5H harvesters are identified at 3300, 2900, and 2800 Hz, respectively, with corresponding power outputs of about 1.28, 190.5, and 0.004 nW under a “1 g” acceleration. This precise evaluation facilitates designers on informed material selection based on performance metrics, enhancing MEMS energy harvester development. Notably, the significantly higher power output for ZnO compared to AlN and PZT-5H challenges conventional material preferences and offers new possibilities for efficient energy harvesting solutions. © IMechE 2024.