I. Introduction
Energy harvesting devices seek to capture energy present in the surrounding environment and convert it into electrical energy [1]. Piezoelectric (PE) harvesters are efficient harvesting devices that are composed of piezoelectric materials that convert mechanical vibrational energy into electrical energy [1], [3], [4]. Due to the presence of mechanical vibrations in various environments, including automobiles, buildings, and industrial machinery, PE vibration harvesting devices have attracted research interest for use in mobile electronics and remote wireless sensors as an enhancement or replacement for conventional battery power [1]–[3]. Batteries need to be replaced on a frequent basis, while the PE harvester reduces or eliminates the need to replace these battery packs.