Design of piezo-micro-electro-mechanical systems for low frequency energy harvesting

The exibility associated with piezoelectric materials makes them very attractive for power harvesting. Piezoelectric materials possess a large amount of mechanical energy that can be converted into electrical energy, and they can withstand large strain magnitude. The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters. While the functional elements of MEMS are miniaturized structures, sensors, actuators, and microelectronics, the most notable (and perhaps most interesting) elements are the microsensors and microactuators. Microsensors and microactuators are appropriately categorized as “transducers,” which are defined as devices that convert energy from one form to another. In the case of microsensors, the device typically converts a measured mechanical signal into an electrical signal. Mechanical compression or tension on a poled piezoelectric ceramic element changes the dipole moment, creating a voltage. Compression along the direction of polarization, or tension perpendicular to the direction of polarization, generates voltage of the same polarity as the polling voltage. Hence, by changing device physics, we may get a sensor with higher output with low power consumption and reduced size of the device. The proposed piezoelectric sensor will be designed in COMSOL software and respective characteristics analysis will be observed.