Not so Heavy Metal

3D Printing Metal in Midair with Lasers

Wyss Institute

Harvard’s Wyss Institute has developed a new device which 3D prints metal structures in midair by lasering nanoparticles.

The basis of current 3D printing technology is that the object must be built as a series of layers, each one supporting the next.

A breakthrough from Harvard’s Wyss Institute has turned that on it’s head, however, with a device that draws metal filaments in midair with no support whatsoever. And it’s all done with lasers.

Currently there is no name for the technology, but the way it works is that a nozzle moves along a preset path sending out a thin stream of silver nanoparticles.

At the same time, a laser follows its progress, heating the particles and solidifying them into a freestanding filament thinner than a human hair.

The work was conducted by researchers at Harvard’s Wyss Institute for Biologically Inspired Engineering and the John A. Paulson School of Engineering and Applied Sciences (SEAS)

Lead researcher Jennifer Lewis said:

“I am truly excited by this latest advance from our lab, which allows one to 3D print and anneal flexible metal electrodes and complex architectures ‘on-the-fly.’ This sophisticated use of laser technology to enhance 3D printing capabilities not only inspires new kinds of products, it moves the frontier of solid free-form fabrication into an exciting new realm.”

We’re excited, too! Check out the technology in action in the video below:

3D Printing Metal! In Midair! With Lasers!

The ink that Lewis’ team used was composed of silver nanoparticles and was sent through a printing nozzle, and then annealed using a precisely programmed laser that applies just the right amount of energy to drive its solidification.

By using this method, spiral motifs, tiny hemispherical shapes, or even a butterfly made of silver wires narrower than a hair’s width can be printed within seconds.

The printed wires also exhibit excellent electrical conductivity, almost matching that of bulk silver, meaning they are extremely useful for creating structural elements such as circuits, tiny springs and buttresses.

Wyss Institute Director Donald Ingber said:

“This sophisticated use of laser technology to enhance 3-D printing capabilities not only inspires new kinds of products, it moves the frontier of solid free-form fabrication into an exciting new realm, demonstrating once again that previously accepted design limitations can be overcome by innovation.”

Lewis’s research was published yesterday in the Proceedings of the National Academy of Sciences, and this work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy.

(Source: Harvard Gazette)