Device uses sound to detect nerve gas

A U.S. Army researcher created a device that will allow first responders to detect multiple dangerous chemicals using lasers and sensitive microphones.

Kristan Gurton developed the technique using the concept of photoacoustic effect. When materials absorb light they generate specific sound waves. The device emits lasers as its light source and picks up the sounds chemicals make using the microphones, Business Insider reports.

"Photoacoustics is an excellent analytic tool, but is somewhat limited in the sense that one traditionally only measures one absorption parameter at a time," Gurton, an experimental physicist at the U.S. Army Research Laboratory in Adelphi, Md., said, according to Business Insider.

Gurton created a sensor that can detect sounds put off by multiple chemical weapons when they are struck with six different lasers. Because each laser has a different effect upon hitting even tiny amounts of gas, distinct sounds are emitted for each distinct chemical.

"Different agents will affect the relative 'loudness' of each tone," Gurton said, according to Business Insider. "So for one gas, some tones will be louder than others, and it is these differences that allow for species identification."

Gurton said that the method could be used to protect soldiers or during civilian applications when harmful gas detection is required. The technology can be made as small as a milk carton and is relatively inexpensive to produce.