The Nano Air Vehicle (NAV) Program will develop and demonstrate an extremely small (less than 7.5 cm), ultra-lightweight (less than 10 grams) air vehicle system with the potential to perform indoor and outdoor military missions.
The program will explore novel, bio-inspired, conventional and unconventional configurations to provide the warfighter with unprecedented capability for urban mission operations.
The nanocopter, called the Katana and designed by Lockheed Martin, is in addition to DARPA’s other micro-ornithopter robot concept (pictured here). Read here for more in depth background to the Katana’s progenitor, the Samurai.
 Although there doesn’t seem to be anything especially “nano” about it apart from being, y’know, really small.