Students Invent Device using Low-Frequency Sounds Waves to Extinguish Fire

George Mason University undergrads Seth Robertson and Viet Tran invented a device that uses sound waves to extinguish fires. The electrical and computer engineering majors developed the fire extinguisher for a senior project, but they were so successful that the work will likely continue long after they graduate this May.

The students had seen research by DARPA and others that proved sound waves could disrupt flames, but no one had made a commercially viable prototype yet. The concept works because sound waves are pressure waves. At the right frequency, sound waves can agitate air enough to displace oxygen and extinguish a fire. With $600 of their own money, Robertson and Tran made a 20-pound fire extinguisher out of a sound generator, an amplifier, power source, and a focusing tube made out of cardboard. An oscilloscope measured the waves while they tested different frequencies. At first, they thought that ultra-high frequencies would work. They tested 20,000 and 30,000 hertz and saw the flames flickering but not going out. Then they tried low frequencies in the range of 30 to 60 hertz and the fires extinguished.

They originally thought that their fire extinguisher would be used as a chemical-free alternative for putting out small kitchen fires, but now they envision even more uses. A local fire department has asked them to test their device on a structure fire, and they also have ideas for attaching the technology to drones to put out forest fires. They even see it as being useful in space travel, where traditional fire extinguishers have trouble because a lack of gravity means the chemicals and water can’t be properly directed.

A provisional patent application gives them a year to talk publicly about the invention and test the market to determine whether to continue development. So far they have only put out fires started with rubbing alcohol, but they look forward to additional testing and improving their design. No matter what happens with their invention, both students have promising futures ahead. Robertson currently works for the Department of Defense and has been offered a permanent position at Hanscom Air Force Base in Massachusetts, while Tran has an internship at Zodiac Aerospace in Dulles with the promise of a full-time job upon graduation.

As a whole engineering is just finding simple solutions to complicated problems. You know, engineering is all about finding a way to make the impossible possible.

Seth Robertson