This Wireless Explosives Detector Is the Size of a Postage Stamp

For public safety agencies, sniffing out explosives and other contraband is a tricky task. Handheld explosive detectors can be as small as a purse, but still must be manually operated. Permanently mounted sensors need to be even bigger. Dogs are useful in some scenarios, but they’re expensive to deploy en masse and must always have a handler.
That’s why GE Global Research is working on a new way to detect dangerous substances, one that costs about a nickel, can be deployed anywhere, and doesn’t need human supervision. The device is a tiny RFID tag that activates only when it detects certain explosives or oxidizing agents. In effect, it could replace gigantic explosive scanners with something a couple inches across.
Developed in partnership with the Technical Support Working Group (TSWG), an inter-agency task force dedicated to anti-terrorism, the new RFID tag could dramatically drive down the cost of scanning for dangerous materials in places like cargo ports and airports.

Conventional RFID tags that have been converted into sensors by applying a sensing material on one side of the tag. The sensing material is white. GE Global Research

RFID tags use electromagnetic fields to transfer data, and are commonly found on things like key cards to open doors and EZPass toll transponders. GE is keeping mum on the details of how they’re being used here, but says it’s developed “a sensing material that responds to explosives and oxidizers” than can be built into the device. Radislav Potyrailo, a GE scientist, compared the tags to a smoke alarm or CO2 sensor. “We have developed sensing materials that are quite sensitive for this type of detection.”
The tags can be placed in cargo containers, shipping packages, airports, and government buildings, to name a few. The team believes they’ll be able to sit dormant for months and still trigger effectively, without any need for power or recharging. Effectively, the tag can be slapped nearly anywhere and only activate once a target chemical is found. The range at which they can be read depends on the strength of the pickup antenna of the reader, typically anywhere from a few inches to a few dozen feet. That may seem limited, because GE believes can cost just pennies each, they can be installed in vast numbers very cheaply, basically everywhere.
Currently, GE’s focus is on explosives and oxidizers (frequently used in improvised explosive devices), but the team believes it can develop similar tags to detect biological matter like spores or bacteria. Commercialization could arrive as soon as the next few years