LONDON Researchers at Duke University (Durham, North Carolina)have used DNA [deoxyribonucleic acid] the double-helix carrier of genetic information to create self-assembling logic circuits that use light for binary computation and communication.
Chris Dwyer, assistant professor of electrical and computer engineering at Duke's Pratt School of Engineering, has mixed customized snippets of DNA and other molecules to create billions of identical, nanometer-scale waffle-shaped structures, the university said
These structures are well-known in biology as chromophores for their ability to absorb and emit light of different wavelengths. It is this ability to "process" input "data" that Dwyer seeks to exploit as a digital process. Dwyer has used conventional computer to determine which DNA fragments will preferentially clip together to form functioning logic. Instead of conventional circuits using a flow of electrons to switch ones and zeroes light can be used to effect similar responses from the DNA-based switches and much faster, the university claimed.
Dwyer's "waffle" is made up of 16 fundamental DNA snippets that naturally link together in a unique pattern. Dwyer describes the process of producing the waffle pieces as being akin to self-assembly jigsaw puzzle. "It's like taking pieces of a puzzle, throwing them in a box and as you shake the box, the pieces gradually find their neighbors to form the puzzle,' he said, in a statement. "What we did was to take billions of these puzzle pieces, throwing them together, to form billions of copies of the same puzzle."
The waffle puzzle has the different chromophores located atop the waffle’s ridges. More complex circuits can be created by building structures composed of multiple waffles, or by selecting different DNA fragments to build larger waffles.
Depending on the nature of the chromophores on the waffle it should be possible to create simple gate structures such as AND, OR, NAND gates, although linking them together to create complex systems may require other methods and principles of interconnection.
The chromophore waffles are also molecular-level optical and chemical sensors and so could find additional in biomedical systems.
Dwyer’s research is supported by the National Science Foundation, the Air Force Research Laboratory, the Defense Advanced Research Projects Agency and the Army Research Office. Other members of the Duke team were Constantin Pistol, Vincent Mao, Viresh Thusu and Alvin Lebeck.