A brand new 3D printing technique working 100 times faster than conventional 3D printing and making objects within minutes by simply lifting them out of a pool of resin, has been created by scientists from the University of North Carolina. The technique, which could transform 3D printing, works up to 100 times faster than current methods and produces objects that are considerably stronger.
And if the machine looks like the product of a science fiction author’s imagination, it may be because its inventors were inspired by the Terminator 2 killer robot, T-1000, that rises menacingly from a puddle of molten metal in the film. “We were inspired by the Terminator 2 scene,” said Joseph DeSimone, a professor of chemistry at the University of North Carolina and a founder of the company, Carbon3D. “Why couldn’t you have an object rise out of a puddle in real time with essentially no waste?”
The new technique, called continuous liquid interface production (Clip), features a moving platform that lifts printed objects gently out of a reservoir of liquid resin. The technique combines pulses of light, which solidify the resin, and oxygen, which prevents it from solidifying, to craft intricate three-dimensional objects. Crucially, it works continually, unlike current printers that construct objects by building layer upon layer.
“3D printing is actually a misnomer; it is actually 2D printing over and over again,” DeSimone said. “There are mushrooms that grow faster than 3D printed parts.” In a demonstration, it took the Clip printer seven minutes to produce a hollow geometric ball – a task which would have taken about 10 hours with a conventional 3D printer.
Printing finished parts at speeds competitive with current manufacturing processes is “a game changer”, said DeSimone. In a study, published in the journal Science, DeSimone and colleagues describe how their technique combines the manipulation of oxygen and light. At the base of the liquid resin reservoir, is an oxygen permeable window – similar to a contact lens – which leads to an oxygen rich “dead zone”, less than 1mm thick, at the bottom of the tank. Oxygen stops the resin from solidifying, even when light is projected through it, meaning that the solidification happens just above the dead zone. The precise shape that solidifies is controlled by light projections through the permeable window. Since the liquid layer is always present beneath the slowly-forming object, there is no need to wait for new resin to flow in and the object can be pulled upwards steadily.
The continuity of the process also means that Clip produces much stronger objects than the slate-like structure of objects printed in layers, which can be sturdy in one direction, but will shatter under force in the other. The 3D-printed gun may have made the headlines, but it would have been useless at withstanding an explosion in practice. Jonathan Rowley, of Digits2Widgets, a 3D printing company in London, said the strength factor was even more impressive than the new technique’s speed. “At the moment most 3D printers produce crap slowly and I don’t need crap fast. If you add the speed of this technology to the extra strength it provides it means you could produce parts that start to compete with traditional manufacturing. It’s probably something of a big deal.”