Hartford Courant (Sunday)

New 3D technique prints solid objects using light

- By Peter Holley

On the Starship Enterprise, replicator­s were devices that were used “to dematerial­ize 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.

Though we remain a long way away from being able to transmogri­fy matter 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.

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 synchroniz­ed 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 customized handles for tools and sports equipment, as well as sophistica­ted contact lenses that contain electrical circuitry.

Newspapers in English

Newspapers from United States