Engineering students at the Naval Postgraduate School in Monterey, Calif., for instance, are now experimenting with chemical taggants on unmanned aerial vehicles (UAVs) like the ones being used in Afghanistan. Sure, the shape-changing chemical robot that slips through cracks may be more Ray Bradbury than battlefield-ready. But the Pentagon, in its perpetual quest to find the next weapon or soldier-saving device – and with scientific assurances that it's possible – is already investing millions to develop it.
"We're not about 20 years, or 10 years, or even five years away – a lot of this could be out in the field in under two years," says Mitchell Zatkin, former director of programmable matter at the Defense Advanced Research Projects Agency, or DARPA, the Pentagon's premier research office.
The development of a new generation of military robots, including armed drones, may eventually mark one of the biggest revolutions in warfare in generations. Throughout history, from the crossbow to the cannon to the aircraft carrier, one weapon has supplanted another as nations have strived to create increasingly lethal means of allowing armies to project power from afar.