Researchers at Northeastern
have demonstrated a way to use single-walled carbon nanotubes, to ease large-scale
manufacture of flat-panel displays and electronic memory devices.
A cross-sectional view of SEM micrographs of assembled SWNTs in anodic alumina array fabricated on Silican.
Srinivas Sridhar, Ph.D., distinguished professor and chair of Physics at Northeastern
University, Evin Gultepe and their team of researchers from the university’s
Electronic Materials Research Institute have demonstrated a technique to assemble
single-walled carbon nanotubes (SWNT) into three-dimensional structures.
This
technique will be useful for the large scale, accelerated assembly of SWNTs
at room temperature, which is more suitable for nanoscale electronic applications,
such as flat panel displays and electronic memory devices.
This research was published in an October 2008 issue of the journal Nanotechnology.
The electronic properties of SWNTs, such as large current capacities and quick
mobility, makes them one of the most highly researched structures for the development
of nanoscale electronics. They are able to conduct energy more quickly and efficiently
than current structures and provide a platform from which to build smaller-scale
products. Widely used materials, such as copper, do not meet the requirements
as effective electrical interconnects on a smaller scale.
The challenge of utilizing carbon nanotubes (CNT) in the nanoscale is to assemble
them into three-dimensional structures for large scale applications.
Currently,
manufacturing CNTs requires growing or assembling them into a device, which
requires very hot temperatures and complex post-assembly procedures. In contrast,
a post-synthesis assembly method allows for the arrangement of CNTs in ambient
temperatures, which gives more flexibility in the manufacturing process.
In this newly discovered process, Gultepe, Sridhar and their colleagues manufactured
nanotemplates, with billions of nano-sized holes in which to house the SWNTs.
Utilizing electrical fields, they were able assemble the SWNTs vertically into
the alumina nanotemplate, with a silican substrate bottom layer and a metal
top layer. The vertically-assembled three-dimensional SWNTs provide the electrical
interconnection between the nanotemplates and the silicon substrates.
“The greatest significance of this process is the potential to manufacture
three-dimensional SWNTs electrical interconnects at a high-rate and on a larger
scale,” said Sridhar, who is also the Director of the Electronic Materials
Research Institute at Northeastern. “Scaling down the nominal feature
size means greater performance and decreased costs.”
In addition to Sridhar, the team of researches involved with this project includes
Ahmed Busnaina, Ph.D., Director of Northeastern’s Center for High-rate
Nanomanufacturing, Dattatri Nagesha, Ph.D., Bernard Diddier Frederic Casse,
Ph.D., and Selvapraba Selvarasah. This research was supported by the IGERT Nanomedicine
Science and Technology and the NSF Nanoscale Science and Engineering Centers
Program.