Prototype Hard Hat Alerts Workers of Danger

August 23, 2010 - Matt Reynolds, an assistant professor in the electrical and computer engineering department at Duke University, wanted a way to alert workers that dangerous equipment was nearby in the noisy environment of a construction site. He quickly came up with the idea of a beeper inside a hard hat. The trick was to find a way to make a beeper that worked without batteries. He's now done that with a prototype hard hat that uses radio waves to power a tiny microprocessor and beeper. The beeper gets all the power it needs from the transmitters on backhoes and bulldozers that keep track of their locations. The microprocessor monitors the strength and direction of the radio signal from the construction equipment and sounds the beeper if it determines that the hat’s wearer is too close. Here's the fuill story from Ann Eisenberg at NYTimes.