The walls are alive... with sophisticated sensors that can sniff out potential terrorists, according to Popular Science:
Researchers at brain trust Fraunhofer Institute for Communication, Information Processing andErgonomics (FKIE) in Wachtberg, Germany have developed a network of "chemical noses" that can not only smell chemicals hidden on a person, but also identify the carrier as he or she moves through a crowded space.
This means that someone entering an airport with individual chemical components, that can be used to make an explosive later, can be tracked right from the door itself. Sensitive sensors located in walls would "sniff" out the chemicals, triggering a discreet security alarm. The sequence of triggered alarms would allow security personnel to determine which direction the chemical-carrying person was moving, and a software program would zoom in on one individual in the crowd. Cameras all over the airport would track the suspect as he moves and ...