BRIDGES: Mackinac Bridge to be test site for stress sensors

The sensor prototypes will be placed at several spots around the country

September 06, 2016

A Michigan State University (MSU) engineering professor plans to install sensors on the Mackinac Bridge to monitor stress on the aging structure.

Professor Nizar Lajnef told the Lansing State Journal the stress sensors that will be placed on the bridge later this month are a test of a project he’s been working on for seven years with funding from the Federal Highway Administration.

A recent grant of $1.5 million to MSU, Washington University at St. Louis and the University of Nevada-Reno will put sensor prototypes in place at several spots around the country. If it works, the stress sensors could become commonplace on structures around the country.

Lajnef's team created a sensor that charges itself from the energy of movement across the bridge, so it requires little in the way of maintenance. He projects the production cost to be less than $1 apiece.

The sensors wirelessly transmit data about the structure's response to traffic. After a baseline is created, any variance could indicate a problem.

The 5-mile-long 58-year-old Mackinac Bridge that connects Michigan’s two peninsulas is the third-longest suspension bridge in the world.