Kengla stares into a computer monitor, clicks through what seems like a hundred menus and initiates three cartridges loaded into a print head that hovers over a petri dish atop a small platform. One cartridge contains cartilage cells, another contains biodegradable scaffold material and the third contains a water soluble gel, which temporarily provides support until it’s later washed away. Back and forth the print head shuttles with a pneumatic whoosh, switching between the cartridges, constructing the organ in stacked, successive layers, each 150 microns thick. A high-intensity light and microscope allow Kengla to follow the machine’s progress on a monitor. After 45 minutes, the shape of an ear begins to emerge.
Perfection remains a few years in the future. Still, the printing of organs—and cartilage and skin and tissue—holds great promise for transforming health care and extending longevity. Transplanted organs created from a patient’s own tissues won’t be rejected. Waiting times for kidneys and other donor organs will decrease, and organ traffickers could be put out of business (the World Health Organization estimates there were almost 11,000 organs sold on the black market in 2010). Prescription drug companies are eager to test drugs and other therapies on rapidly prototyped organs or tissue, instead of on animals or human beings.
Anthony Atala, who leads the Institute for Regenerative Medicine, predicts that it’s only a matter of years before hospitals have machines that can print skin—from subcutaneous fat up through keratinocytes to hair follicles, oil glands and melanocytes—directly onto a patient’s body. “Skin is the least complex organ,” Atala says. “Then we’ll see tubular structures, then hollow and then non-hollow organs.” Including, eventually, a heart? “I hope in my lifetime,” he says, laughing. “And I’m still very young.” (Atala is 54.)
Dealing with complexity is what additive manufacturing is best at. Engineers for Lotus Renault GP, in pursuit of lighter, faster and more fuel-efficient Formula 1 race cars, use stereolithography and laser sintering to experiment with cooling ducts and fins, eliminating material that’s inessential to function. And the process is quick. Pat Warner, Lotus Renault GP’s advanced digital manufacturing manager, says he can turn around parts in two days instead of ten weeks.
It’s high-end applications like this that have raised 3-D printing’s public profile. “The aviation industry has more than 22,000 printed parts flying right now, and people are walking on 3-D printed orthopedic implants,” says Terry Wohlers, the president of the independent consulting firm Wohlers Associates. “These are very regulated, very demanding industries and these parts are performing well.”
Canadian designer Jim Kor is building a three-wheeled, teardrop-shaped car that weighs just 1,200 pounds. Kor shaves weight by combining multiple parts. The dashboard, for example, is printed with ducts attached, eliminating the need for multiple joints and their connecting plastic and metal parts. Somewhat less dramatically, bakers are extruding icing from print heads to decorate cakes; stop-motion animators are using rapid-prototyping 3-D printers to create thousands of nuanced facial expressions for film characters; mathematicians use the technology to model complex geometric shapes; and 3-D photo booths are scanning people and printing miniature replicas of their heads or entire bodies.
Additive manufacturing would not have flowered without major advances in computer-directed modeling. A decade ago, it took weeks to generate a digital 3-D model; now it takes only hours. Design software has become more accessible, and scanners, too, have become more powerful and easier to use—even at home. This past March, Microsoft announced a forthcoming software release that will endow its Kinect for Windows computer sensor with the ability to quickly create detailed 3-D models of people and objects.
Engineers and product designers scan an existing object or contour by shooting thousands of points of light at it and loading the “point cloud”—a 3-D ghost image of the original—into a computer. Multiple scans are aligned and filtered, points are connected to their near neighbors to form polygons, holes are filled and blemishes removed. Finally, with a click of the mouse, the surface of the image is smoothed to form a shrink-wrapped version of the original. Off to the printer the digital file goes.
And if the client doesn’t like the finished print? Not a big deal: The supply chain is a computer file, not parts from around the world, and there’s no need to retool machines to make design changes. The trajectory from idea to approval to manufacturing to marketing to sale is, again, vastly accelerated.