"We think that popular 3-D printing is actually misnamed — it's really just 2-D printing over and over again," said Joseph DeSimone, a professor of chemistry at University of North Carolina and North Carolina State as well as one of Carbon3D's co-founders. "The strides in that area have mostly been driven by mechanical engineers figuring our how to make things layer by layer to precisely create an object. We're two chemists and a physicist, so we came in with a different perspective."
Just as the evil T-1000 rises from its puddle of metal alloys, objects created by the new printer seem to ooze into existence from the ether. They come out fast, too: 25 to 100 times faster than anything on the market now, according to the study published in Science.
DeSimone and his colleagues call their new process "continuous liquid interface production technology," or CLIP.
CLIP places a pool of resin over a digital light projection system. A special window between the resin and light allows both light and oxygen to travel through (much like a contact lens, DeSimone explained).
To create an object, CLIP projects specific bursts of light and oxygen. Light hardens the resin, and oxygen keeps it from hardening. By controlling light and oxygen exposure in tandem, intricate shapes and latices can be made in one piece instead of the many layers of material that usually make up a 3-D printed object.
Those layers are defects, keeping the object from being a smooth surface. To minimize them, designers have to spend even longer printing the objects out.
"These hurdles mean that 3-D printing can be amazing for making prototypes, but just not as good for creating a commercial product in a lot of applications," said Carbon3D's chief marketing officer Rob Schoeben. "That's what we're most interested in changing."
Watching CLIP in action is impressive, and so are the objects it's already produced. DeSimone hopes that the technique's knack for making small, smooth objects will help make breakthroughs in the tiny sensors we rely on for smartphones and fitness bands, as well as in making microneedles and other drug delivery systems.
DeSimone has always turned his students into entrepreneurs in the lab, but Carbon3D is the first company he left the classroom to develop. "This is a field that's like breathing for me," he said, "and we have an opportunity to make a big impact."
His co-founder and fellow UNC professor Edward Samulski agreed, saying that the basic principle — keeping a polymer from forming with oxygen — is something they frequently encountered in the classroom.
"We all teach this in our undergraduate courses," Samulski said. "It illustrates what 1937 Nobel Laureate Albert Szent-Gyorgyi said: 'Discovery consists of seeing what everybody has seen and thinking what nobody has thought.' "