A survey on ambient energy sources and harvesting methods for structural health monitoring applications

Structural health monitoring is widely used for maintaining and monitoring various structures in different areas. In general, the structural health monitoring system life span depends on the capability of the batteries, but it can be increased by energy harvesting approaches to autonomously produce power. These autonomously powered structural health monitoring systems have received increasing attention over the past decades. This article reviews recent developments in the ambient energy sources and energy harvesting methods for structural health monitoring applications. First, the earliest and most common method of harvesting energy from sunlight and wind is discussed. Then, vibration and thermal gradient energy harvesting methods are reviewed together with their feasibilities. Finally, radio frequency energy harvesting, a unique method developed in recent years, is highlighted. A double-resonant coil ferrite rod antenna for radio frequency energy harvesting in medium frequency band is proposed. Simulation results indicate that the proposed double-resonant coil ferrite rod antenna can increase the gain by 2.8 dBi and the receiving voltage by 25.77% compared with a conventional single-resonant coil ferrite rod antenna.