A Defense Advanced Research Projects Agency research team at Harvard University created a handheld electrode that puts out fire with no water, chemicals, or smothering.
While water primarily cools a flame, carbon dioxide suffocates it by diluting the surrounding oxygen. Chemical suppressants such as halons work to disrupt the combustion process. These technologies suffer from limitations such as collateral damage to valuable property, environmental toxicity and limited effectiveness in different types of fire. All existing suppressants are composed of matter and must be physically delivered and dispersed throughout the fire. This limits the rate at which fires can be extinguished and the ability to combat fires in confined spaces or behind obstacles.
According to Matthew Goodman, DARPA program manager, “we successfully suppressed small flames and limited re-ignition of those flames, as well as exhibited the ability to bend flames. These effects, to date are very local—scaling is a challenge that remains to be overcome.”
DARPA’s Instant Fire Suppression (IFS) program, which ended recently, sought to establish the feasibility of a novel flame-suppression system based on destabilization of flame plasma with electromagnetic fields and acoustics techniques. The DARPA research team at Harvard University has demonstrated suppression of small methane and related fuel fires by using a hand-held electrode, or wand.
“We’ve made scientific breakthroughs in our understanding and quantification of the interaction between electromagnetic and acoustic waves with flame plasma,” said Goodman. “Our goal was to advance understanding of this interaction and its applicability to flame plasma for suppressing flames.”
Fire in a combat vehicle or other confined space puts warfighters at risk. DARPA’s Instant Fire Suppression (IFS) program seeks to establish the feasibility of a novel flame-suppression system based on destabilization of flame plasma with electromagnetic fields, acoustics, ion injection, or other novel approaches. The key to transformative firefighting approaches may lie in the fundamental understanding of fire itself. Fire suppression technologies have focused largely on disrupting the chemical reactions involved in combustion. From a physics point of view, however, flames are cold plasmas comprising mobile electrons and slower positive ions. By using physics techniques rather than combustion chemistry, it may be possible to manipulate and extinguish flames. To achieve this, key scientific breakthroughs are needed to understand and quantify the interaction of electromagnetic and acoustic waves with the plasma in a flame. Research results will be used to determine the scalability of potential techniques. If scaling is achievable, the program will build a prototype fire suppression system for Class A and B fires inside a ship or HUMVEE-sized compartment.