You know that scene in Terminator 2 when the T-1000 emerges from a shallow pool of metallic liquid? It’s a classic. It’s also what inspired researchers at the University of North Carolina and North Carolina State University to rethink the mechanics of 3-D printing.
Instead of printing objects by stacking thin layers on top of one another—a process that can take days, depending on what you’re printing—they built a device that produces a complete object from a pool of goop.
Their machine is called CLIP, which is an acronym for what it does: “continuous liquid interface production.” It pulls a new, fully formed object out of liquid resin by shining an ultraviolet light beneath the pool. The UV projector is connected to a computerized blueprint of the object. One cross-section at a time, the light solidifies a silhouette of the object. The UV light moves through a contact lens-like window between the liquid and the light projector.
The window is permeable to oxygen so it allows for just the right amount of oxygen to pass through into a thin layer that prevents the resin from solidifying too soon. As the mechanical hand pulls up the goop, the light projects more and more of the image, and the object grows continuously until it is completely formed.