Nanotechnology Technique Allows Ink Jet Printing at the Nanoscale

Researchers at the University of Illinois have created a major breakthrough in creating nanostructures, and will potentially effect everything from water purification to electronics manufacture and the creation of photonic crystals.

A trio of researchers, Eric Duoss, Mariusz Twardowski and Jennifer Lewis, created the breakthrough technology which currently can create structures as small as 225 nanometers. Their goal to create structures as small as 100 nanometers. The technique permits the creation of complex 3-dimensional structures, but at the nanoscale.

The researchers' created a new family of sol-gel inks, which eliminates the need for a coagulation reservoir that is necessary in other techniques. This makes it possible to robotically place the metallic inks in complex layers on a substrate, in the open air. The technology uses a �â'¬Ëœdirect-write' technique dispensing the ink in a filament, using a tip just 1 micron across, or 1/100^th the size of a human hair.

Current manufacture of electronic circuits requires careful etching and deposition of ceramo-metallic substances within the etches to build microcircuits, and that technology is rapidly approaching its limits in scaling. The possibility with the sol-gel process is to directly write the circuits onto the substrate, eliminating the painstaking etching and templating process. The etching and templating process creates impurities that can cause up to one in ten of the manufactured microcircuits to be unusable and end up as trash.

One of the demonstrated uses was creating a weave of densely packed, finely shaped material, which may be suitable as a filtration substrate. Because of the level of complexity and control, the layers could be created so literally only a specifically-shaped molecule could pass through leaving ultra-pure materials on the other side.

Another application the researchers are excited about is the creation of photonic crystals. At the scales at which they are working, they can literally block all but a very specific wavelength of light, as well as potentially finding methods for creating technology for controlling the flow of light within a system. Science fiction may be meeting reality, as fans of Star Trek: The Next Generation recall the blips of light within the android Data, in which the data flow was photonic.

Details of the research were recently published in the journal Advanced Materials. Work was conducted at the university's Frederick Seitz Materials Research Laboratory at the Urbana-Champaign campus. Funding in part came from a grant from the U.S. Department of Defense.