Star Trek has the replicator that can make anything out of its constituent molecules. It isn't available (yet), but 3-D printing is, and it's starting to get traction as a new method of making industrial prototypes.
Researchers at the Massachusetts Institute of Technology are trying to push the technology further. Their goals: create whole working machines, and perhaps even buildings. Thus far, 3-D printing technology has been used to make shapes of plastic or metal that can be assembled later.
Peter Schmitt, an MIT PhD student, working with Media Lab consultant Bob Swartz, has printed out a whole clock, with all the parts in working order. The downside was that one of the clocks took 100 hours to make. But the concept of printing the parts in place (rather than separately to be assembled) works.
Neri Oxman, Assistant Professor of Media Arts and Sciences, and her graduate student Steven Keating are aiming for more than just small objects. They want to print out a whole building.
The obvious advantage to this would be creating shapes that an ordinary concrete mold can't duplicate. It wouldn't be the first time a new technique enabled construction of innovative design. Many of the stone carvings that Antoni Gaudi planned for the Sagrada Familia in Barcelona would have taken centuries to do by hand, but modern milling techniques invented long after his death cut that down considerably.
Oxman also wants to make concrete whose properties vary throughout the structure. That would allow the building to flex where necessary, while maintaining its structural strength. It would also allow for lighter structures. Natural structures do this routinely — human bone is quite strong, but it is only stiff and solid on its outer layers. That keeps bones strong enough to hold weight without becoming so heavy people couldn't move. Keating has already made sections of concrete like this as part of his research.
3-D printing works by putting down material layer by layer, to eventually create a three-dimensional shape. Most commercial versions use plastic or resin. At first, 3-D printers just extruded the plastic by itself, which was fine, but could only create shapes with enough support on the layer below. Later models used powder, mixing a binding agent or resin in each layer. This allowed the powder to support the shape until it was removed. There are also versions that use metals and even laser sintering processes. Some have seen use in the dental industry to make fillings and implants, while others have created metal shapes for use in injection molding or customized prosthetics. There's even a DIY version made by a man named Alvaro Fogassa, who outlines how he did it on his blog.
If you want to buy your own 3-D printer, you can, though it will set you back — Z Corporation makes several models, but they go for at least $15,000. Objet also sells "desktop" 3-D printers for $19,900. Machines that use metal cost even more. One company, Desktop Factory, of Pasadena, Calif., attempted to build and sell 3-D printers for under $5,000. But it closed up shop in 2009.
That said, you needn't buy your own 3-D printer or build one if you want to make cool stuff. Shapeways offers a service similar to cafepress.com, in which you can send designs to get "printed" and can even sell them. So while the MIT folks work at making 3-D printing more versatile, you can still call someone to make that Star Trek-inspired set of napkin rings you've always wanted.