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DNA Can Carry Current, a Promising Step Toward Molecular Electronics

For first time researchers have been able to reliably measure current through a DNA molecule

2 min read
DNA Can Carry Current, a Promising Step Toward Molecular Electronics
Danny Porath, professor of physcial chemistry at the Hebrew University's Institute of Chemistry and Center for Nanoscience and Nanotechnology helped demonstrate current flow through DNA.
Photo: Hebrew University of Jerusalem

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.

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3 Ways 3D Chip Tech Is Upending Computing

AMD, Graphcore, and Intel show why the industry’s leading edge is going vertical

8 min read
Vertical
A stack of 3 images.  One of a chip, another is a group of chips and a single grey chip.
Intel; Graphcore; AMD
DarkBlue1

A crop of high-performance processors is showing that the new direction for continuing Moore’s Law is all about up. Each generation of processor needs to perform better than the last, and, at its most basic, that means integrating more logic onto the silicon. But there are two problems: One is that our ability to shrink transistors and the logic and memory blocks they make up is slowing down. The other is that chips have reached their size limits. Photolithography tools can pattern only an area of about 850 square millimeters, which is about the size of a top-of-the-line Nvidia GPU.

For a few years now, developers of systems-on-chips have begun to break up their ever-larger designs into smaller chiplets and link them together inside the same package to effectively increase the silicon area, among other advantages. In CPUs, these links have mostly been so-called 2.5D, where the chiplets are set beside each other and connected using short, dense interconnects. Momentum for this type of integration will likely only grow now that most of the major manufacturers have agreed on a 2.5D chiplet-to-chiplet communications standard.

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