ABSTRACT
This chapter discusses the use of piezoelectric microelectromechanical systems (MEMS) energy-harvesting devices to supply power to a miniature wireless sensor node. It considers a generic unidimensional model of an energy harvester followed by more detailed analytical models of actual geometrical structures common in MEMS implementations of piezoelectric energy harvesters. The chapter discusses various methods of implementing the presented models, ranging from the finite-element method to VHDL-AMS behavioral models. It describes the most important factor that is the influence of various device parameters on the overall efficiency of energy conversion. The chapter presents all the modeling results with experimental data that obtained with actual piezoelectric MEMS energy-harvesting devices. Structures using high-quality piezoelectric materials are strongly coupled, which means that the nature of the electrical load connected to the electrodes encompassing the piezoelectric material influences the mechanical behavior of the system. The presented model takes into account three types of damping: structural, viscous, and dielectric losses in the piezoelectric element.
