|
Sol-gel inks produce complex shapes with nanoscale features
October 12, 2007CHAMPAIGN, Ill. - New sol-gel inks developed by researchers at the University of Illinois can be printed into patterns to produce three-dimensional structures of metal oxides with nanoscale features.
The ability to directly pattern functional oxides at the nanoscale opens a new avenue to functional devices. Potential applications include micro-fuel cells, photonic crystals and gas sensors.
The researchers describe the new inks in a paper accepted for publication in the journal Advanced Materials, and featured on its "Advances in Advance" Web site.
"Using this new family of inks, we have produced features as small as 225 nanometers," said co-author Jennifer Lewis, the Thurnauer Professor of Materials Science and Engineering and director of the university's Frederick Seitz Materials Research Laboratory (FSMRL). "Our goal is to get down to 100 nanometer feature sizes."
To create three-dimensional structures, the researchers use a robotic deposition process called direct-write assembly. The concentrated sol-gel ink is dispensed as a filament from a nozzle approximately 1 micron in diameter (about 100 times smaller than a human hair). The ink is dispensed while a computer-controlled micropositioner precisely directs the path. After the pattern for the first layer is complete, the nozzle is raised and another layer is deposited. This process is repeated until the desired shape is produced.
"We have opened direct ink writing to a new realm of functional materials," said graduate student Eric Duoss, the paper's lead author. "Since we print the desired functionality directly, the need for complicated templating and replicating schemes is eliminated."
Unlike previous inks, which require a liquid coagulation reservoir, the newly formulated inks are concentrated enough to rapidly solidify and maintain their shape in air, even as they span gaps in underlying layers.
"This gives us the ability to start, stop and reposition the flow of ink repeatedly, providing exquisite control over the deposition process," Duoss said. "For example, we can directly pattern defects in three-dimensional structures for use as photonic crystals."
After the structures have been assembled, they are converted to the desired functional oxide phase by heating at elevated temperature. Titanium dioxide, which possesses high refractive index and interesting electrical properties, is one material the researchers have successfully produced.
The researchers' ink design and patterning approach can be readily extended to other materials. "There are a nearly endless variety of materials to choose from," Lewis said. "We envision having a toolbox of inks that can print at the micro- and nanoscale. These inks will be used for heterogeneous integration with other manufacturing techniques to create complex, functional devices composed of many different materials."
University of Illinois at Urbana-Champaign
"Using this new family of inks, we have produced features as small as 225 nanometers," said co-author Jennifer Lewis, the Thurnauer Professor of Materials Science and Engineering and director of the university's Frederick Seitz Materials Research Laboratory (FSMRL). "Our goal is to get down to 100 nanometer feature sizes."
To create three-dimensional structures, the researchers use a robotic deposition process called direct-write assembly. The concentrated sol-gel ink is dispensed as a filament from a nozzle approximately 1 micron in diameter (about 100 times smaller than a human hair). The ink is dispensed while a computer-controlled micropositioner precisely directs the path. After the pattern for the first layer is complete, the nozzle is raised and another layer is deposited. This process is repeated until the desired shape is produced.
"We have opened direct ink writing to a new realm of functional materials," said graduate student Eric Duoss, the paper's lead author. "Since we print the desired functionality directly, the need for complicated templating and replicating schemes is eliminated."
Unlike previous inks, which require a liquid coagulation reservoir, the newly formulated inks are concentrated enough to rapidly solidify and maintain their shape in air, even as they span gaps in underlying layers.
"This gives us the ability to start, stop and reposition the flow of ink repeatedly, providing exquisite control over the deposition process," Duoss said. "For example, we can directly pattern defects in three-dimensional structures for use as photonic crystals."
After the structures have been assembled, they are converted to the desired functional oxide phase by heating at elevated temperature. Titanium dioxide, which possesses high refractive index and interesting electrical properties, is one material the researchers have successfully produced.
The researchers' ink design and patterning approach can be readily extended to other materials. "There are a nearly endless variety of materials to choose from," Lewis said. "We envision having a toolbox of inks that can print at the micro- and nanoscale. These inks will be used for heterogeneous integration with other manufacturing techniques to create complex, functional devices composed of many different materials."
University of Illinois at Urbana-Champaign
Nanoscale News and Current Nanoscale Events RSSScientists demonstrate method for integrating nanowire devices directly onto silicon
Applied scientists at Harvard University in collaboration with researchers from the German universities of Jena, Gottingen, and Bremen, have developed a new technique for fabricating nanowire photonic and electronic integrated circuits that may one day be suitable for high-volume commercial production.
Melting defects could lead to smaller, more powerful microchips
As microchips shrink, even tiny defects in the lines, dots and other shapes etched on them become major barriers to performance. Princeton engineers have now found a way to literally melt away such defects, using a process that could dramatically improve chip quality without increasing fabrication cost.
Go Speed Racer! Revving up the world's fastest nanomotors
In a "major step" toward a practical energy source for powering tomorrow's nanomachines, researchers in Arizona report development of a new generation of sub-microscopic nanomotors that are up to 10 times more powerful than existing motors. Their study is scheduled for the May 27 issue of ACS Nano, a monthly journal.
Making a good impression: Nanoimprint lithography tests at NIST
In what should be good news for integrated circuit manufacturers, recent studies by the National Institute of Standards and Technology (NIST) have helped resolve two important questions about an emerging microcircuit manufacturing technology called nanoimprint lithography-yes, it can accurately stamp delicate insulating structures on advanced microchips, and, no, it doesn't damage them, in fact it makes them better.
'Sticky nanotubes' hold key to future technologies
Researchers at Purdue University are the first to precisely measure the forces required to peel tiny nanotubes off of other materials, opening up the possibility of creating standards for nano-manufacturing and harnessing a gecko's ability to walk up walls.
New nanotech products hitting the market at the rate of 3-4 per week
New nanotechnology consumer products are coming on the market at the rate of 3-4 per week, a finding based on the latest update to the nanotechnology consumer product inventory maintained by the Project on Emerging Nanotechnologies (PEN).
Tiny magnets offer breakthrough in gene therapy for cancer
A revolutionary cancer treatment using microscopic magnets to enable 'armed' human cells to target tumours has been developed by researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
Researchers create the first thermal nanomotor in the world
Researchers from the UAB Research Park have created the first nanomotor that is propelled by changes in temperature. A carbon nanotube is capable of transporting cargo and rotating like a conventional motor, but is a million times smaller than the head of a needle.
Carbon nanotube measurements: latest in NIST 'how-to' series
The National Institute of Standards and Technology (NIST), in collaboration with the National Aeronautics and Space Administration (NASA), has published detailed guidelines for making essential measurements on samples of single-walled carbon nanotubes (SWCNTs). The new guide constitutes the current "best practices" for characterizing one of the most promising and heavily studied of the new generation of nanoscale materials.
Bon MOT: Innovative atom trap catches highly magnetic atoms
A research team from the National Institute of Standards and Technology (NIST) and the University of Maryland has succeeded in cooling atoms of a rare-earth element, erbium, to within two millionths of a degree of absolute zero using a novel trapping and laser cooling technique.
More Nanoscale News Articles
| © 2008 BrightSurf.com |