New Sensors Developed to Monitor Cracks on Bridges


A crack on a bridge's asphalt. / Photo by: Maxpixel


Several emerging technologies have enabled real-time detection of disturbances or damages in logistics, shipment, and healthcare. A team of scientists applied live monitoring of bridges using sensors to help maintenance engineers.

In the recent efforts of scientists at Sandia National Laboratories, a bridge in the United States has been equipped with eight real-time sensors that are interconnected to a network. The sensors can alert engineers whenever a crack occurs, which may need repairs if it reaches a specific length. The function of the sensors may help supervise critical conditions of bridges, extend the lifetime of the structures, and improve the safety of travelers.

The sensors are a part of the Structural Monitoring Systems which include the use of a vacuum pump. Once activated, the system checks the sensors from time to time while a dedicated wireless transmitter handles the automatic call or text, used to notify engineers about detected cracks. The entire system is powered by a lithium-ion battery that charges using a solar panel.

The sensors are called Comparative Vacuum Monitoring, made of thin, flexible Teflon, which have galleries or rows of little channels. The design factor of the sensors allows it to be placed or welded in parts of structures where cracks are expected to form. The tiny devices can identify cracks the size of a dime. For production, the sensors may be produced in a variety of forms to complement the structure it needs to monitor.

"In 15 years of testing Comparative Vacuum Monitoring sensors, they have achieved a tremendous track record for producing dependable structural health monitoring. Once they get incorporated into more systems, in areas of concern, it's just going to make aircraft, trains, and bridges safer as time goes on," said Tom Rice, a mechanical test engineer in charge of testing different types of structural health monitoring systems.