Michigan’s infrastructure includes complex networks of roadways, bridges, water delivery systems, and communication technology. Maintaining these infrastructure assets is a near-constant job that requires a great deal of monitoring and testing—and funding. The Michigan Department of Transportation (MDOT) projects that it will spend more than $1.4 billion annually to repair the state’s roads and bridges over the next five years (MDOT 2017). In spite of these costs, we rely on these networks to maintain our way of life; failure to maintain them threatens public safety and impedes economic growth.
One of the challenges of keeping our infrastructure in good shape is identifying vulnerabilities and prioritizing investments. Technology is helping address this challenge, thanks in large part to URC researchers, who are developing cutting-edge sensor technologies that will expand our abilities to monitor infrastructure, improve wireless networks, and enhance water quality.
At MSU, researchers—in collaboration with Washington University in St. Louis, and the University of Southern California—have received funding from the Federal Highway Administration and the National Science Foundation to demonstrate the potential of new sensor technology to monitor and report on the integrity of the Mackinac Bridge. This technology could change how we monitor our infrastructure, because unlike traditional technology, these sensors do not require batteries or wired electricity. Instead, they self-generate power, much like a self-winding watch, from the vibrations caused by normal traffic. These sensors report data wirelessly, allowing them to be embedded in previously inaccessible spots in bridges, highways, and buildings. Researchers can access the information simply by driving over the bridge with a laptop.
The project team—led by MSU’s Nizar Lajnef, associate professor of civil and environmental engineering—identified the Mackinac Bridge as an ideal location to test the accuracy and performance of the sensors. “We could test this innovative technology on any number of bridges, but what location could be better than an engineering icon like the Mackinac Bridge?” he said to Gaslight Media in 2016. In September 2016, Lajnef and his project partners installed their sensor technology on the Mackinac Bridge. The team will monitor the sensors over a three-year period; if the sensors perform as intended they will be brought to other locations.
The Mackinac Bridge demonstration has created a virtual, cloud-based structure for the sensors, allowing project engineers to connect wirelessly to access information quickly in case of an emergency, such as an earthquake, flood or terror attack. This cloud-based network also enhances ongoing maintenance efforts by continuously monitoring the bridge’s structural integrity. Historically, bridge inspections have been conducted by workers visually, but the research team expects that these sensors will provide a digital picture of the bridge over time, helping identify issues as they occur instead of after they are problems. If something goes wrong, sensors can report that data to the cloud, and engineers can quickly determine whether a certain part of the bridge experiences abnormal levels of strain and target an emergency response.
“There is huge potential and benefit for sensors like these on structures beyond the Mackinac Bridge, and we’re excited these prototypes are being tested here,” said Bob Sweeney, executive secretary of the Mackinac Bridge Authority. “We meticulously maintain and inspect the bridge each year, and sensors like these will complement our efforts, giving us even more information on the bridge’s condition to help keep it well maintained and safe for many years to come” (Gaslight Media 2016).
Professor Lajnef and his team hope the Mackinac Bridge demonstration will allow the technology to be further refined and eventually lead to widespread implementation. This technology could have far-reaching benefits—making people’s lives safer and reducing the cost of bridge maintenance.
In addition to attaching sensors to infrastructure that span bodies of water, URC researchers are also using sensor technology to monitor what is in the water we drink. Ensuring drinking water quality is a key infrastructure challenge that if not handled correctly poses real health risks to the public, as exemplified by the recent Flint water crisis. Standard testing kits require users to run their water for several minutes, causing the test to miss any lead that leaches into the water from the home’s own pipes. To combat this issue, a team of professors at U-M headed by Mark Burns, the T.C. Chang professor of chemical engineering, have designed a potentially low-cost, electronic lead sensor that could monitor water supplies and alert residents and officials to the presence of lead within days. Researchers envision that these sensors could be placed at key points in a municipality’s water system as well as in homes to map lead levels across the system. While the technology is still in early development, U-M researchers are seeking partners to bring the technology to market.
On a scale even broader than these two projects is an innovative research project taking place at WSU that involves the coordination of thousands of sensors deployed over wide geographic areas. Professor Abusayeed Saifullah is leading an effort to create a highly scalable wireless sensor network that can be used over wide areas to monitor large civil infrastructure, oil fields, and national borders. The project, funded by the National Science Foundation, is still in the early stages of development, but has the potential to provide greater monitoring power and accuracy for largescale, potentially vulnerable sites.
As showcased by the research being conducted at URC institutions, sensor technology has broad applications throughout our society. It can help identify structural defects in bridges, identify contaminants in our drinking water, and provide a large-scale wireless network to improve homeland security efforts. Beyond these applications, sensors have the potential to create “smarter” civil engineering and infrastructure that can improve public safety, protect public health, and help our economy run more efficiently.