Instead of using silicon as the platform for tiny circuits, as is done in the current manufacturing technique of photolithography, the Duke researchers used DNA strands to create grids less than one ten-millionth of a meter square. The smallest features on these square DNA lattices are approximately five to 10 billionths of a meter (nanometers), according to the scientists, compared with about 65 nanometers in silicon circuits created using photolithography.
To demonstrate their ability to mass-produce grids with infinitesimal patterns, the scientists created batches of trillions of separate grids with the letters "D," "N" and "A" written with a protein that can be seen through atomic force microscopy (AFM). An image of the grids with the letter patterns is available at <http://www.dukenews.duke.edu/mmedia/hires/dna.jpg>.
The scientists, members of the Triangle-area TROIKA collaboration to construct computing devices using DNA, were able to create the grids by using the binding properties of DNA to ensure that large numbers of DNA strands would assemble themselves in specified patterns.
The two corresponding authors on the paper were Thom LaBean, an associate research professor of computer science and an adjunct associate professor of the practice of chemistry at Duke, and Christopher Dwyer, an assistant professor of electrical and computer engineering and computer science. Their research is scheduled to be published in volume 45 of the journal Angewandte Chemie and released early online Dec. 23, 2005. It