A new 3D printer uses light to shape objects

Several schemes now exist to assemble, or “print,” three-dimensional objects through repeated 1D or 2D operations. But such point-by-point or layer-by-layer approaches often create ragged-edged figures, constrain their shapes, and can take hours. A group led by Brett Kelly and his thesis adviser, Hayden Taylor, both at the University of California, Berkeley, and collaborators at Lawrence Livermore National Laboratory have developed a 3D printing technique that circumvents those limitations. The method, called computed axial lithography, selectively solidifies parts of a photosensitive liquid polymer by exposing it to a dynamically evolving light field. In practice, the researchers project a series of computed 2D images from multiple angles onto a rotating cylinder of the liquid. The superposition of exposures produces an energy dose sufficient to solidify the material into the desired shape—the 40-mm-tall version of Auguste Rodin’s The Thinker pictured above, in this case—in a matter of minutes.