Helmets may save lives, but they become less effective when they develop even small cracks. So in an attempt to alert bicyclists, motorcyclists, and construction workers when their helmets should retire, researchers in Germany are developing helmets made of polymer materials that start to smell foul when they crack. The bigger the crack, the fouler the odor.
How foul? Think formaldehyde. Which is somehow both absurd and brilliant--absurd because no one wants to reek of formaldehyde, and brilliant because, well, no one wants to reek of formaldehyde.
"Cyclists often replace their helmets unnecessarily after dropping them on the ground, … Read more