Not 3D Printing… But?
Microrobots Work Together to Build with Metal, Glass and Electronic Components http://www.technologyreview.com//news/526601/microrobots-working-together-build-with-metal-glass-and-electronics/ via DuckDuckGo for Android
http://www.technologyreview.com//news/526601/microrobots-working-together-build-with-metal-glass-and-electronics