Sound waves could be the next big thing in fire-fighting technology. George Mason University engineering students Seth Robertson and Viet Tran have built a new kind of fire extinguisher that uses sound waves to extinguish fires as part of their senior research project – and it has a lot of potential to work in real world applications, both in everyday households and in outer space.
Their 20-pound sci-fi style device was built using $600 of their own money and multiple trials. It uses a booming bass sound to put out small fires, with no toxic chemicals or collateral damage from sprinklers involved. According to GM, the device or a version of it could potentially be mounted on drones to improve the safety of firefighters battling forest fires and urban blazes – or even in space.
“Fire is a huge issue in space,” says Tran. “In space, extinguisher contents spread all over. But you can direct sound waves without gravity.”
According to Phys.org, past research has already shown that sound waves affect fires, and other researchers have previously looked at their potential for putting out fires. The extinguisher made by Robertson and Tran is the first of its kind, a device that would actually be built and sold to put out fires using sound waves.
The engineering students started out with basic idea that sound waves are also mechanical or pressure waves that can impact objects – such as a burning material and the oxygen around it. They then tried several different approaches, such as aiming speakers at small fires and sending out different kinds of sound at different frequencies. What they learned was that high frequency sound didn’t do much, but low frequency waves were indeed able to put fires out.
With this in mind, they set out to make a portable device that could focus low frequency waves directly at a fire. The design they landed on is made up of an amplifer, a power source and a cardboard tube collimator that’s used to focus the waves. What they came up with is a small fire extinguisher that does its job without employing water or chemicals. And while they intended the fire extinguisher for use on simple, small kitchen fires, they now think it could have much broader applications.