Rutgers University scientists say they can use common wi-fi signals to detect weapons, bombs, and chemicals in bags, pointing the way towards a possible new, low-cost class of security scanner technology.
According to study co-author Yingying (Jennifer) Chen, a professor in the Department of Electrical and Computer Engineering at Rutgers-New Brunswick, a security scanner based on wi-fi signals would be easy to set up, reduce security screening costs, and avoid invading privacy such as when screeners open and inspect bags, backpacks, and luggage.
Wi-fi, or wireless, signals in most public places can penetrate bags to get the dimensions of dangerous metal objects and identify them, including weapons, aluminum cans, laptops, and batteries for bombs, the study said. Wi-fi can also be used to estimate the volume of liquids such as water, acid, alcohol, and other chemicals for explosives, according to the researchers.
“This could have a great impact in protecting the public from dangerous objects. There’s a growing need for that now,” Chen said in a prepared statement.
The study said wi-fi waves, which travel at different speeds through different materials, were able to detect dangerous objects 95 percent of the time in the initial test, which was meant to demonstrate the viability of the technology. The trial used only an antenna, a laptop, and basic wi-fi signal. Researchers looked for 15 metal and liquid objects in 15 types of bags. A final product, they said, could be fine-tuned and made more effective.
The market for security scanners seems to be a growing one. Los Angeles recently announced plans to deploy $100,000 mobile security scanners at bus and train stations. The new devices will scan passengers for weapons as they walk past, with no need to step through a scanner.