With This 3-D Printer, Objects Emerge From a Plastic Soup

The Carbon3D printer magically pulls complex shapes out of a dish of plastic goop. It creates objects in minutes that can take hours on a MakerBot.
The Carbon3D printer magically pulls complex shapes out of a dish of plastic goop. It creates objects in minutes that...
Spencer Lowell

It might be the future of manufacturing, but 3-D printing is built on a 2-D foundation: A MakerBot is essentially an inkjet printer that spits out plastic instead of ink. Keep printing in the same spot, over and over, and the layers will eventually form a 3-D object from the bottom up. But an outfit called Carbon3D is taking the opposite tack: Its new rig creates objects from the top down, in one continuous motion. It’s faster and eliminates the layering that can result in weak, jagged objects.

Inspired by the mercurial T-1000 bot from Terminator 2, University of North Carolina professor Joseph DeSimone wanted to make objects emerge from liquid. The process is based on a 30-year-old printing technology called stereo­lithography. It starts with a bath of liquid resin that hardens when exposed to UV light. A projector underneath deliv­ers targeted blasts of UV to shape the form from below as the overhead platform lifts, drawing the object out of the soup.

The method has some limits. Oxygen inhibits the chemical reaction that solidifies the resin, slowing the process some­what. But rather than fighting that limitation, DeSimone harnessed it. A sheet of glass between the projector and the resin is gas-permeable like a contact lens, and the oxygen keeps the resin from hardening too soon, before the object is com­plete.

Exploded view of Carbon 3D printer. 1. Object-building platform
2. UV-curable liquid resin
3. Microthin layer of oxygenated resin
4. Oxygen-permeable glass
5. Ultraviolet-light projector
BROWN BIRD DESIGN

Even with this effect, the Carbon3D can print up to 100 times faster than leading 3-D and stereolithographic printers. In a video that ricocheted around the Internet after DeSimone pre­sented it at TED, the device pulls a model of the Eiffel Tower out of the goo, as if it had just been sitting in the liquid all along.

Carbon3D has a team developing new materials for the printer. “We're pioneering new resins for our machine and also working with the chemical industry to evolve what’s already available,” says Rob Schoeben, the com­pany’s chief marketing and strategy officer. “As long as a material is in the polymer family, we should be able to do it.”

The machine has vast potential. Rather than warehousing and shipping car parts, technicians could make components for older models on the spot from designs stored in the cloud. Aeronautical engineers could print high-strength, low-weight lattice structures to replace, for example, components in passenger seats, lightening the payload and increasing fuel efficiency in planes. And Carbon3D could prove invaluable for medical applications: Custom molds could be made onsite at a dentist’s office, and stents or other emergency implants could be custom-printed on-demand in the hospital.

Right now, Carbon3D has prototypes running at auto behemoth Ford in Dearborn, Michigan, at an athletic apparel company, and at a special-effects house in San Fernando, California, with an eye to hitting the market in 2016. But it has no shape-shifting bots that are hell bent on destroying humanity. Yet.