Ten years ago, a pair of university students created a fire extinguisher that put out flames using only the powerful sound waves from a 10-inch subwoofer. Their invention quickly went viral online, and Jimmy Fallon even invited them to showcase it on The Tonight Show.
However, after that brief surge of attention, the technology seemed to fade from public discussion.
That’s not to say people stopped trying. The students weren’t the first to demonstrate the idea—DARPA explored it back in 2012, and a review of scientific journals shows that many researchers have examined the concept.
Now, a startup says it has finally solved the challenge. Sonic Fire Tech has developed an acoustic fire suppression system that not only puts out fires but could also shield homes and buildings from wildfires. According to information obtained exclusively by TechCrunch, the company has secured $3.5 million in seed funding from investors such as Khosla Ventures and Third Sphere.
Wildfires cost the United States up to $424 billion each year. The issue has become so severe in states like California that insurance companies are declining to renew policies after repeated fires have devastated large areas.
Sonic Fire Tech has spent several years refining its technology. Michael Thomas, the chairman of the company’s board, had been experimenting with using sound to combat fires. When he hit a roadblock, he contacted Geoff Bruder on LinkedIn. Bruder, who previously worked at NASA, specialized in heat and acoustics.
“It’s a bit of a modern startup origin story,” Bruder, who serves as CEO and CTO, shared with TechCrunch.
Bruder found Thomas’s proposal compelling and began constructing a prototype. “I picked up a subwoofer and some supplies from Home Depot and AutoZone and thought, ‘Let’s see if we can outperform previous attempts,’” Bruder said. “We managed to extinguish a fire from seven feet away in my driveway.”
The team soon abandoned the subwoofer in favor of even lower frequencies. Bruder explained that using audible frequencies would require so much power that it could harm people’s hearing. “You basically have to scrap conventional speaker designs and start anew,” he explained.
There are several hypotheses about how acoustic energy interferes with combustion, but the silent demonstrations strongly indicate that Sonic Fire Tech is making progress.
The latest system features a reciprocating piston, similar to those in car engines but much larger. An electric motor drives a crankshaft, which moves a two-foot piston to generate infrasound—sound waves below the human hearing threshold, around 20 Hz.
“Because we engineered everything ourselves, we were able to lower the frequency beneath what people can hear, which allows for greater range and ensures safety,” Bruder noted.
Currently, Sonic Fire Tech’s system can extinguish flames from 25 feet away. Bruder said a larger version could be effective at distances up to 330 feet. The company intends to market and install the system at a cost of about 2% of a home’s value and is in discussions with insurance providers to get the technology certified.
To safeguard a residence, Sonic Fire Tech channels infrasound from a single generator through sturdy ducts installed along the roof ridge and beneath the eaves. The ducts on the ridge direct sound down the slope to target fires that may ignite in gutter debris, while those under the eaves aim toward the ground to suppress flames near the walls. The system activates automatically when sensors detect fire.
The home system uses about 500 watts of power, and in the event of an outage, Sonic Fire Tech plans to use lead-acid batteries as backup. Unlike sprinklers, it doesn’t need a water supply, which is often scarce in wildfire-prone regions.
The company is collaborating with PG&E and Southern California Edison to test the technology on homes, and it has also signed a letter of intent with a chemical storage site.
“The logical next step is, if we get certified as a sprinkler alternative, you could simply run a pipe into your house and protect your kitchen and any other area that needs safeguarding,” Bruder said.
