Traffic tunnels are often built in some of the most rugged and remote areas, which subjects them to extreme environmental forces while making them difficult to access. Ideally, the structural health of tunnels could be monitored in a way that requires minimal human maintenance while ensuring that the tunnels are consistently safe to drive through.
In a typical structural health monitoring system, an array of sensors placed throughout the tunnel or other structure provides continuous monitoring, giving an early warning sign of any problems, such as damage due to corrosion or impact. When batteries are used to power the sensor arrays, replacing the batteries becomes an expensive and time-consuming endeavor.
With this drawback in mind, researchers are developing a power unit that harvests the vibrations from passing traffic to power the wireless sensor nodes of a structural health monitoring system for tunnels. The power harvesting unit could reduce maintenance costs and improve the performance of the sensor network.