The ritual of shoe removal has become familiar to air travelers flying inside and out of the United States, but most people still don’t like it. It takes time to do and slows down the security line.
Shoe removal was started because in December 2001 Richard Reid, a British man who said he was connected to Al-Qaeda, tried hiding plastic explosives (which he tried to detonate with matches) in his shoes while on a transatlantic flight from Paris to Miami. Reid was subdued and is now in prison in the United States.
Matthew Staymates of the National Institute of Standards and Technology in Gaithersburg, Maryland, thinks he and his colleagues might have developed a way around having every passenger remove shoes for screening. The trick is to pick up trace amounts of explosives. Staymates came up with a device that blows particles off surfaces and analyze them.
The air jets to blow the particles off the passenger’s shoe would be located in some strategic locations. One version of the device might be a kiosk-style contraption the passengers would step into (similar to the body scanners in use at many airports). The sampling system can collect particles in a few seconds.
The big finding here isn’t a new method of analyzing the chemicals, but using fluid dynamics to design the air flow in such a way that it dislodges the bits of explosive or precursor chemicals form the surface of the shoes. Staymates described his work today at the American Physical Society’s Division of Fluid Dynamics Meeting in Baltimore.