Thin and Flexible Inductively Coupled Transformer as Energy Harvester for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) form the backbone of data transfer for condition monitoring applications. Battery-less WSNs are attractive, as they do not require regular replacements of batteries. Vast numbers of sensors have been deployed in railway systems and facilities. As railway systems and building facilities have current-carrying cables readily available, this paper explores the use of an ultra-thin inductively coupled transformer for energy harvesting purpose. The transformer can be easily wrapped around a current-carrying AC power cable as an energy harvester to power up sensor nodes. It can also double up as a condition monitoring device that tracks the current behaviours of the power cable that is feeding an electrical system.