Gmoke sez, "Two grad students at Harvard have developed a method to print sheets of miniature drones, the Harvard Monolithic Bee or Mobee, that pop-up into their final form. So far they've got them to flap their titanium wings but they don't yet seem to be able to fly. Their construction technique can be used for very many other small devices too."
Pop-up Fabrication of the Harvard Monolithic Bee (Mobee)
(Thanks, Gmoke!)