In August 2010, Navy Lt. Cmdr. Michael Llenza was perched in his jet ready to return to base in Bagram, Afghanistan, when a valve on the plane broke. “I was stuck,” he recalled. “The whole squadron was taking off and I’m sitting there.” The pilot would have to wait weeks for a replacement part to be shipped from a carrier in the Indian Ocean. A thought came to Llenza: “Wouldn’t it be great if I could walk back into the hangar and print out a part?”
What Llenza had in mind was three-dimensional printing, a burgeoning technology that allows its users to transform digital models into physical objects. Also called additive manufacturing, 3D printing works by extruding materials, including plastic, latex, and ceramic, through a printer nozzle layer-upon-layer until the object is fully shaped, like an inkjet printer with a vertical as well as horizontal axis. The process could have created a new valve for the lieutenant commander in a matter of hours rather than weeks, and for much less than cost of international shipping.