Street smarts: Monitors being created to watch for road, bridge defects

October 17, 2013

Assistant professor of civil and environmental engineering  Nizar Lajnef tests a sensor he and his team have developed that will monitor the integrity of roads and bridges. Photo by G.L. Kohuth. As the state of Michigan looks to improve its infrastructure -- roads and bridges -- a team of Michigan State University College of Engineering researchers think they may have one solution.  

Nizar Lajnef, an assistant professor of civil and environment engineering, and Shantanu Chakrabartty, an associate professor of electrical and computer engineering, are creating smart infrastructure sensors that are powered by the pavement and bridges they are designed to monitor.  

“We are working on sensors that extract their power from the vibration and strain of their environment,” Lajnef said. “There is no external source of power -- no batteries. They are completely self-powered.” 

Prototype work began as part of Lajnef’s doctoral research in 2008 at MSU. It has evolved into a national project with the U.S. Department of Transportation that has already generated one patent, three patent applications and three USDOT grants totaling $1.7 million, including $1.4 million of new funding. 

The goal: To create very small sensors that can self-diagnose damage and mechanical failure in pavements and bridges. 

“This passive system harvests its energy from the infrastructure that becomes its host,” Lajnef said. “We have completely removed batteries and all interface electronics from the process. It’s different from any of the current systems being used today.” 

The sensor prototype uses less than 800 nanowatts of power, which is significantly less than in today’s existing technology. Data is collected wirelessly using handheld readers that scan the structure. Lajnef said part of the research will evaluate whether smart phones can be used for the collection of data.  

Prototypes are currently being tested at the U.S. Federal Highway Administration’s Turner Fairbanks Highway Research Facility, near Washington, D.C. The objective is to monitor infrastructure degradation, which is critical for maintenance and safety.

 “Additional information on bridges and pavements would save a lot of money, which we hope our zero-maintenance sensors will do,” Lajnef added. 

In addition, the researchers also are developing new methods to understand the data that are being generated by the sensors. 

Other members of the research team include Rigoberto Burgueno, an MSU associate professor of civil and environmental engineering, and Karim Chatti, professor of civil and environmental engineering, and acting associate dean for engineering research.