Rensselaer researchers are working toward harnessing carbon nanotubes to create advanced computing and electronics systems that are thousands of times faster than those in use today.
To allow the nanotubes to grow in different directions, Ramanath and Ajayan have devised a new selective growth process on chiseled silica blocks on a silicon substrate. In this process, a catalyst, called ferrocene, is introduced along with xylene, the hydrocarbon that serves as the carbon source. As a result, carbon nanotubes grow selectively on silica in a direction perpendicular to the surface, and leave the silicon substrate bare. The invention of this selective growth process, published last year in Applied Physics Letters, is key to achieving multidirectional nanotubes growth.
By manipulating the topography of the silica blocks, and utilizing the selective and directional growth process, Ramanath says, we have been able to force nanotubes to grow in predetermined, multiple directions, with a very fine degree of control.
For example, if a piece of silica is carved into a one-micrometer-thick cylindrical disc, the nanotubes will grow vertically on the silicas top surface, while growing horizontally on its side.
While other researchers have grown aligned nanotubes in either vertical or horizontal directions using similar catalysts and carbon sources, Ramanath adds, we are the first to combine several key strategies to controllably grow nanotubes in more than one direction, at different locations, at the same time, in a single process step.
A Perfect Nano Model
The Rensselaer Nanotechnology Center and its NSF Center also draw on the Institutes strengths in information technology and computer science. A group of researchers working in theoretical modeling and design is advancing the day when theorists will calculate, model, and design nanostructures for various applications. Headed by Pawel Keblinski, assistant professor of materials science and engineering and an expert in atomic modeling of materials, the team is using quantum mechanics calculations and molecular simulation methods to build and analyze computer models of nanostructures.
Keblinskis work is strengthened by collaborations with Rensselaers Scientific Computation Research Center and Los Alamos National Laboratory.
New technologies present challenges as well as opportunities for industry and society. Some fear that extraordinarily small biosensors could be used as weapons as well as tools in pollution control, disease diagnosis, and medical therapies. Nanorobots or drug delivery systems have the potential to lose control and cause unwanted damage.
The Next Frontier: Lowering the Walls To Explore Inner Space
Rensselaer is leading the way to the new frontier in nanotechnology. As the field continues to grow in the United States and abroad, it will further shrink borders among prominent researchers and disciplines, integrating knowledge and expertise that promise to change the world.
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