Design methodology for an Energy Neutral Health Monitoring Wireless Sensor Node

• Published in: 2016 Sixth International Symposium on Embedded Computing and System Design (ISED) pp. 308 - 312
• Main Authors: Pokhara, Ankur, Mishra, Biswajit
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2016
• Subjects: Batteries; Capacitors; Monitoring; Phasor measurement units; Photovoltaic cells; Transmitters; Wireless sensor networks
• ISSN: 2473-9413
• DOI: 10.1109/ISED.2016.7977103

This paper investigates an Energy Neutral System using Micro Energy Harvesters for a Health Monitoring Wireless Sensor Node (HM-WSN). We have implemented HM-WSN consisting of a solar cell energy harvester, a Power Management Unit (PMU) and the controller, sensor and transmitter acting as load. A battery extender and a switching logic circuit for sensor node is designed to evaluate the efficiency of the proposed system. The HM-WSN senses body temperature with improvement in lifetime of coincell. The HM-WSN is built using commercially available off the shelf (COTS) components and consumes 47.2μW for data being updated every 134s. It can be operated for approximately 1.32 years only on a coincell. Furthermore, the HM-WSN can be operated with solar energy at 200lux, achieving 93.72 years with a combination of a coincell with an additional capacitor of 2.2mF. It attains 4.07 years to 16.87 years lifetime with the load capacitor varying from 1mF to 1.5mF at 350lux lighting condition. With the same ambient condition and a 2mF load capacitor, HM-WSN attains complete energy autonomy.