3D printers are all about layers. Extruders pour plastic layer after layer until an object is complete. A new type of 3D printer out of the Institute for Advanced Architecture of Catalonia has completely rethought that process.
Say hello to Mataerial, the anti-gravity object modeling 3D printer. In short, it's a robotic arm with a special extruder that uses a material that instantly hardens upon being exposed to air. With it, the Mataerial 3D printer can create objects that defy gravity.
In its current state, the Mataerial can only print rods. You could make some really cool post-modern art pieces with it, but it's not exactly useful to industry yet. Of course, that may all change as 3D printing evolves to the point where we can create houses, freestanding structures and other impressive objects with the help of 3D printers.[h/t: Fabbaloo blog]