Optimization of Wideband Piezoelectric Energy Harvester

Abstract

In condition surveillance applications, mechanical vibration monitoring is becoming newlineincreasingly popular. Wireless sensor nodes enabled with IoT are suitable for monitoring newlinevibrations. These nodes are used to gather and communicate the information regarding newlinestate of machine or system. Wireless sensor nodes are generally powered by batteries, newlinewhich, depending on the application, gets exhausted in a relatively small time. This newlineleads to enormous labor cost for battery substitutions, particularly where thousand newlinenodes in network are located remotely or are extensively spread. Piezoelectric vibration newlineenergy harvesting provides a potential solution to concerns of battery life and its heavy newlinemaintenance, particularly in industrial environments where vibration is omnipresent. newlineOwing to the time varying, random and multi-frequency nature of environmental vibration newlinesources, the operational bandwidth of Vibration Energy Harvester (VEH) is gaining lot newlineof interest. Most VEH have narrower bandwidth with usable output power at certain newlinefrequencies. Time-varying vibration source activity renders harvesting difficult. There newlineis a need for tunable or wideband vibration energy harvesters. Efforts to increase the newlineoperational frequency range have been made by introducing nonlinear structures and newlinetechniques. The main motive of this research is to optimize wideband piezoelectric newlineenergy harvester for low frequency applications. newlineThe research mainly focused on a novel cantilever structure that provides dual band newlineoutput using two distinct modes of operations. Resonant frequency of the device changes newlinewith change in Centre of Gravity (CoG) of proof-mass resulting into first band of the newlinedevice. Without any external force, CoG of the proof-mass gets auto-tuned. Cylinders newlinerotational and vibrational motion creates impact on beam s surface as well as on walls of newlineproof mass that leads to generate second band of the device output. The optimal power is newlineanalyzed by changing the resistive load during experimentation. newlineThough multi-band output device provide