A Vibration Based Piezo Electric Energy Scavenging Interface with Feedback Monitoring

he increasing utilization of portable, implantable and wireless systems in medical, industrial and military applications increases the need for compact and efficient energy harvesting devices to be used for powering these systems. Energy harvesters that generate energy from ambient sources such as heat, light and vibration reduces the dependence of these devices on external power supplies and batteries. Due to the availability, vibration is particularly important. Some vibration sources in the environment are vehicle motion, human movements and seismic vibrations. Using piezoelectric, electrostatic and electromagnetic transduction, the efficiency of these systems is proportional with the value of the vibration frequency. Based on these observations, in this paper we present a self supplied energy generator, which includes MEMS harvester hybridly integrated with its power management circuitry for autonomous charging of an energy reservoir. This is a piezo electric vibration based energy harvester using power management IC with feedback monitoring. The system is completely self-supplied by the harvester vibration energy, and has no dependence on a previously charged energy reservoir.