Monday 24 February 2025

Researchers have developed a new portable tool that could improve how firefighters douse fires, making the process more efficient and far less risky.

Built as an alternative to traditional firefighting countermeasures like toxic chemical foams or hydrants whose use can strain water resources, this device works to suppress flames using the power of conductive aerosols, small particles that can direct electricity.

These aerosols are carried by vortex rings – small doughnut-shaped bands of air – that transform the particles into short pulses of wind that convert nearby oxygen into ozone.

Disrupting the natural combustion process

Once released, their accelerated airflow generates rapid turbulence, disrupting the natural combustion process and quickly extinguishing the target fire, says John LaRocco, lead author of the study and a research scientist in psychiatry at the Ohio State University College of Medicine. 

"Using a combination of electricity and this vortex ring technology, we found a more efficient way of solving an environmental problem that will improve our quality of life," says LaRocco. 

(A) Angled view of the vortex launcher, with 11cm front hole diameter and mounted components denoted. (B) Sideways view of the launcher, with device dimensions and battery denoted.

The launcher device resembles a small bucket, attached to an arm brace. Firefighters would aim the bucket towards the fire, and the bucket would use bursts of compressed air or an elastic diaphragm to deliver aerosols in an electric arc to fight the fire.

The idea to create this low-cost, safe and portable device originally began as a method to help refine current fire management techniques, says Qudsia Tahmina, co-author of the study and an associate professor in electrical and computer engineering.

Chemical combinations

The study's first step was to determine what chemical combinations would best make up the conductive aerosols. Once seven mixtures were tested across two trials, the most conductive of them, a coarse copper solution, was chosen as vortex ring material.

After the study's simulations showed that the device would succeed in suppressing fires, researchers aimed to test how they could further optimise the launcher's power.

To do this, they tested two versions of their prototype: a compressed air launcher with a conical muzzle that generated vortex rings by releasing compressed air and an elastic diaphragm launcher with a square-edged muzzle that generated vortex rings with an elastic membrane.

Although the compressed air vortex generator was significantly more efficient than its counterpart, their work revealed that both prototypes had an effective range of nearly two metres, or about 6.5ft. 

"In both instances, we were blown away by the invention," says LaRocco.

The study was recently published in the journal Technologies.

Depending on the size of a fire and how many firefighters are deployed to battle it, it is likely that several of these devices would be required in a real-life emergency.

Very scalable

"The design of our Vortex Launcher is actually really simple in nature," says John Simonis, another co-author of the study and an undergraduate student in electrical and computer engineering, "One of the benefits of that simplicity is it's also very scalable."

"It's manoeuvrable in tight spaces so that you can walk through doors and indoor environments, but also large enough to have the practical benefits of generating those vortex rings," he says.

Since vortex rings also retain their shape as they dissipate, they can carry chemical payloads over longer distances – an advantage over other methods –that will make firefighters safer as they wouldn't have to risk injury by getting close to the flames to put them out.

The study concludes that their device could be further developed by integrating multimodal sensors or image analysis into the system. These computer vision upgrades would allow the launcher to target fires caused by a wide variety of sources, says Simonis.

The research also has future implications for industrial automation and aerospace technologies, where the device could be used to protect military vehicles and even spacecraft interiors from fires.

"There are lots of applications for our device to make a difference," says Simonis.