In cycling, the first line of defense against brain injury is the helmet. A properly fitted, regulation helmet can save your life in the event of a crash. But if the integrity of the helmet is compromised–if cracked or crushed in an accident–it loses its ability to protect your head. Unfortunately, a dangerous crack isn’t always obvious to the naked eye, so just examining a helmet after impact may not be enough.
Now, scientists have developed a helmet that emits a foul odor if cracked or crushed–the plastic of the helmet contains microcapsules that exude stinky odors when damaged. An article in ScienceDaily describes how it works:
A layer of melamine formaldehyde resin encloses the capsules so that they are completely airtight and mechanically sealed. It also protects the tiny pods, which are subjected to temperatures of 200 to 300 degrees during injection molding as well as static pressures of up to 100 bar.
Although these helmets are not available yet, they are currently being tested. Watch for them in the coming years–it just may be the stink that saves your brain.