Not far from Washington D.C., a team of civilian scientists at Virginia’s Fort Belvoir use chemistry to keep U.S. soldiers safe from explosives. Aaron LaPointe, who leads the Army’s Night Vision and Electronic Sensor Directorate’s anti-mine research, demonstrated a pistol-shaped air sniffer called “FIDO.”
FIDO is built around a polymer coating on the inside of a narrow tube. When exposed to light, the polymer generates its own glow. When exposed to nitro-aromatic compounds — particles commonly emitted by explosives — that glow blinks off.
In an explosive-free environment, FIDO’s audio output sounds like a Geiger counter. When explosives are present, FIDO screams. LaPointe demonstrated the machine’s sensitivity by holding an empty vial in front of it.
“At one point, I put a small spec of TNT in here, and then I pulled it out,” he says.
The remnants were enough to trigger a reaction — a strong one. LaPointe says these devices help soldiers find “targets of interest” in “areas of interest.”
Between the machine’s calibration and the soldier's training, they can tell the difference between harmless spent gunpowder and the very real threat of an improvised bomb.
[Music: "Green Eyes (Instrumental)" by Coldplay from A Rush of Blood to the Head]