ENGINEERS routinely inspect bridges and other structures for cracks and corrosion. But because they can’t always be there in person, one highly intelligent bridge knows what to do when trouble arises: send them an e-mail.
The long spans and slender cables of the Jindo Bridge in South Korea are dotted with a small army of electronic sentinels — tiny wireless sensors and microprocessors that monitor the bridge’s structural health. The network constantly analyzes factors like vibration, wind and humidity, and promptly reports anomalies to a computer that then passes along the news. (As of last week, the bridge said it was just fine.)
The Jindo Bridge network has 663 wireless sensors, each providing a channel of information at an installation cost of about $100, far less than the thousands of dollars typically needed to install each wired channel, said Dr. B.F. Spencer Jr., a professor of civil and environmental engineering at the University of Illinois at Urbana-Champaign. Dr. Spencer directs the American-based arm of the bridge project, which also includes the University of Tokyo and the Korean Advanced Institute of Science and Technology. Batteries on the bridge network are expected to last about three years before they need replacement.
Article Source: http://www.nytimes.com/2011/03/13/business/13novel.html?_r=1&ref=technology
Publication Date: 13 March 2011