Design and Analysis of Energy Neutral Wireless Sensor Nodes for Health and Environmental Monitoring Applications

Abstract

This thesis demonstrates investigation of an Energy Neutral System using EnergyHarvesters for Wireless Sensor Nodes (WSNs). For this purpose, we have implementedan Energy Harvesting system which consists of three parts: Energy Harvester(Solar cell), Power Management Unit (PMU) and a load (microcontrollerwith sensor and transmitter). A battery extender and a switching logic circuit forsensor node is developed to evaluate the efficiency of the proposed system. In thiswork we have implemented energy harvesting solutions for two different WSNs:for health and environmental monitoring applications. Health monitoring WSNis implemented to sense body temperature whereas Environmental monitoringWSN is used for sensing room temperature and humidity. Also the improvementin lifetime of coin cell for both the WSNs are calculated.A software algorithm has been developed to extend the proposed solar energyharvesting architecture for different applications and different WSNs. Furtherto this, an architecture for multiple energy harvesting has been proposed whichcan be used to connect multiple energy harvesters to the sensor node. Also anarchitecture for interfacing multiple sensors has been proposed. The architectureproposed in this work for introducing energy harvesting solutions to attain energyautonomy for multiple sensor WSN is implemented using commercially availableoff the shelf components.