Joined: 16 Mar 2004
|Posted: Mon Aug 18, 2008 2:26 pm Post subject: 3D nanoprinter makes oxide sculptures
|16 October 2007 RSC Chemistry World
3D nanoprinter makes oxide sculptures
Researchers at the University of Illinois, US, have made inks that can print tiny three-dimensional patterns using metal oxides. The inks could allow fast, easy printing of micro-fuel cells, sensors and photonic crystals, the scientists say.
Using conventional lithographic techniques to make three-dimensional structures is time consuming because it requires a template to be made for each layer. But the new inks dry almost instantly in air - even as they bridge gaps in the layers below. A robotic arm delivers the ink, automatically printing as many layers as necessary while dramatically cutting the manpower required.
The team's first sol-gel inks are highly concentrated solutions of a titanium alkaloid complex, which solidify in air and maintain the printed shape. They heated the ink to around 700°C, which causes the titanium complex to calcinate and form titanium oxide (TiO2).
Jennifer Lewis, professor of materials science and engineering at Illinois and co-author of the paper, says the team has made features as small as 225 nm. 'Our technique offers unparalleled resolution for 3D patterning of oxide structures,' Lewis said . 'This opens up a new avenue to printed photonic, electronic and energy materials.'
Commenting on the work, Mark Welland, Director of the Cambridge Nanoscience Centre, said, 'Scalability has been the bugbear of nanotechnology for a long time. Useable, economically viable manufacturing processes are an issue ... [inkjet printing] has the advantages of being very cheap, relatively fast and easy to build up layers.'