Recent Advances in Energy Harvesting Technologies for Structural Health Monitoring Applications

Joseph Davidson,Changki Mo

doi:10.1155/2014/410316

Abstract

This paper reviews recent developments in energy harvesting technologies for structural health monitoring applications. Many industries have a great deal of interest in obtaining technology that can be used to monitor the health of machinery and structures. In particular, the need for autonomous monitoring of structures has been ever-increasing in recent years. Autonomous SHM systems typically include embedded sensors, data acquisition, wireless communication, and energy harvesting systems. Among all of these components, this paper focuses on the energy harvesting technologies. Since low-power sensors and wireless communications are used in newer SHM systems, a number of researchers have recently investigated techniques to extract energy from the local environment to power these stand-alone systems. Ambient energy sources include vibration, thermal gradients, solar, wind, pressure, etc. If the structure has a rich enough loading, then it may be possible to extract the needed power directly from the structure itself. Harvesting energy using piezoelectric materials by converting applied stress to electricity is most common. Other methods to harvest energy such as electromagnetic, magnetostrictive, or thermoelectric generator are also reviewed. Lastly, an energy harvester with frequency tuning capability is demonstrated.

Highlights

Rapid advances in wireless technologies and low-power electronics have enabled the increased use of autonomous systems for the monitoring of structural health
Because many wireless sensor nodes are powered by traditional batteries that must be replaced, recent research has focused on developing systems that can be powered by harvesting ambient energy, such as mechanical vibrations, solar, and wind, directly from their environments
As solar panels/energy harvesters are a relatively well-developed technology, the research reviewed in this paper focuses on implementation and validation of the complete network rather than further recent enhancements of the harvesting method or developments in photovoltaic technology

Summary

Introduction

Rapid advances in wireless technologies and low-power electronics have enabled the increased use of autonomous systems for the monitoring of structural health. Because many wireless sensor nodes are powered by traditional batteries that must be replaced, recent research has focused on developing systems that can be powered by harvesting ambient energy, such as mechanical vibrations, solar, and wind, directly from their environments. This paper reviews developments from 2008 to 2013 in the methods of energy harvesting for the powering of wireless SHM systems. The focus of the paper is the method of energy harvesting, though many of the references reviewed discuss other design considerations like power management, sensor network implementation, and so forth. The specific energy sources considered include ambient mechanical vibrations, wind and aeroelastic vibrations, rotational kinetic energy, thermal energy, and solar energy These are some of the most frequently exploited energy sources, and a broad survey of their typical power densities has already. To highlight some of the advantages of tunable energy harvesters the authors present some of their own experimental results for a piezoelectric cantilever energy harvester with frequency tuning capability designed for the monitoring of an industrial ventilation system

Sources of Energy

Nonlinear Energy Harvesting

Findings

Conclusion