The promise of molecular electronics gets hoisted up the flagpole periodically, but now an international team of researchers based out of the Hebrew University of Jerusalem claim to have made a breakthrough with DNA molecules that they believe may be the most significant development in the last decade of molecular electronics research.
In research published in the journal Nature Nanotechnology, a international group of researchers hailing from Cyprus, Denmark, Italy, Spain, and the United States has demonstrated that electric current can be transmitted through long DNA molecules. They believe that this demonstration could lead to the development of DNA-based electronic circuits.
Much research has focused on making DNA circuits. For instance, scientists have explored schemes in which DNA would serve as a kind of circuit board or scaffold for precisely assembling electronic components at resolutions as small as 6 nanometers. But so far it’s all been without much success.
DNA was thought to be a promising basis for molecular circuits, because of its ability to self-assemble into various structures. But a big stumbling block has been that no one has been able to measure reliably or quantitatively the flow of current through the molecule.
While other research has been able to produce transport measurements of current through DNA, the results have appeared contradictory at times because of differences in the measured molecules and experimental set-ups.
In this latest work, the researchers were able to measure reliably and reproducibly currents ranging from tens of picoamperes (pA) to more than 100 pA over distances ranging from tens of nanometres to more than 100 nm.
"This research paves the way for implementing DNA-based programmable circuits for molecular electronics, a new generation of computer circuits that can be more sophisticated, cheaper and simpler to make," said Danny Porath, a professor at the Hebrew University of Jerusalem, in a press release.
While this is no doubt an important development, there are still huge obstacles that remain for molecular electronics to ever be realized. Perhaps the biggest remaining issue is how to maintain the stability of molecules under typical integrated circuit processing conditions—in particular, the propensity of direct vapor deposition of metallic electrodes onto molecules to result in shorts.
We are likely to see this research have an impact on stability during manufacture and other issues.
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.