New 3D Printing Process Creates Solid Objects Using Rays of Light

On the Starship Enterprise, replicators were devices that were used "to dematerialise matter and then reconstitute it in another form," according to Startrek.com.

For Captain Picard's hungry crew, in particular, that usually meant nostalgically reconstituting meals on demand to appease a sudden craving.

Though we remain a long way away from being able to transmogrify matter into a chocolate sundae on command, a team of real-life researchers has created a 3D printer that can create entire objects simultaneously instead of creating them one painstaking layer at a time like most printing techniques. The new approach - known as Computer Axial Lithography (CAL) - carves an object out of a synthetic resin that solidifies when it comes into contact with particular patterns and intensities of light.

Using a device dubbed "the replicator," researchers from the University of California at Berkeley and the Lawrence Livermore National Laboratory used the technique to create tiny airplanes and bridges, copies of the human jaw, a screwdriver handle and minuscule copies of Rodin's Thinker.

The team's work was published last month in the academic journal Science.

"This is an exciting advancement to rapidly prototype fairly small and transparent parts," Joseph DeSimone, a chemist at the University of North Carolina at Chapel Hill, told Nature.

The CAL process involves more than just light and gooey resin. Researchers write that the printing begins with a computer model of a 3D object, which is fed into a digital video projector. The machine beams the images into a rotating cylinder that is full of the synthetic resin, the article states.

The video projections are perfectly synchronised with the cylinder's rotation, the article states.

"As the container rotates, the pattern that's projected changes, so over time the amount of light that each point receives can be controlled," Hayden Taylor at the University of California at Berkeley told the Guardian. "Spots that receive a lot of light solidify, while those that do not remain liquid."

The CAL printing process requires only two minutes to complete, researchers say. Though still in its infancy, they say the technique could be used to create "patient-specific medical devices" and "aerospace components," according to the article published in Science. Unlike conventional 3D printing, which can leave tiny ridges on the side of objects, researchers report that their technique produces "exceptionally smooth surfaces."

"The CAL approach has several advantages over conventional layer-based printing methods," the article states. "Printing 3D structures around preexisting solid components is also possible with our approach. CAL is scalable to larger print volumes, and is several orders of magnitude faster, under a wider range of conditions, than layer-by-layer methods."

Researchers told the Guardian that the machine's ability to print around other objects means the technique may one day result in customised handles for tools and sports equipment, as well as sophisticated contact lenses that contain electrical circuitry.

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