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Graphene, patterned with DNA

Chemical and molecular engineers at at MIT and Harvard have successfully used templates made of DNA to cheaply and easily pattern graphene into nanoscale structures that could somewhen be fashioned into electronic circuits.

Graphene, as you are surely aware by now, is a material with almost magical properties. It is the strongest and well-nigh electrically conductive cloth known to humankind. Semiconductor masters, such as Intel and TSMC, would absolutely love to use graphene to way computer fries are capable of operating at hundreds of gigahertz while consuming tiny amounts of power. Unfortunately, though, graphene is much more difficult and expensive to work with than silicon — and, in its base land, it isn't a semiconductor. The DNA patterning performed by MIT and Harvard seeks to rectify both of these bug, past making graphene like shooting fish in a barrel to work with, and thus easy to turn it into a semiconductor for use in computer fries.

Late last yr, Harvard's Wyss Institute announced that it had discovered a technique for building intricately detailed DNA nanostructures out of DNA "Lego bricks." These bricks are specially crafted strands of Dna that bring together together with other Dna bricks at a ninety-degree bending. By joining enough of these bricks together, a 3-dimensional 25-nanometer cube emerges. By altering which Deoxyribonucleic acid bricks are available during this process, the Wyss Plant was capable of forming 102 distinct 3D shapes, as seen in the prototype and video below.

Harvard's DNA Lego bricks, fashioned into 102 different 3D shapes

Harvard'south Dna Lego bricks, fashioned into 102 dissimilar 3D shapes

The MIT and Harvard researchers are essentially taking these shapes and binding them to a graphene surface with a molecule called aminopyrine. In one case bound, the DNA is coated with a layer of argent, and then a layer of gold to stabilize it. The golden-covered Dna is then used equally a mask for plasma lithography, where oxygen plasma burns away the graphene that isn't covered. Finally, the DNA mask is washed away with sodium cyanide, leaving a piece of graphene that is an well-nigh-perfect copy of the Dna template.

So far, the researchers have used this process — dubbed metallized Dna nanolithography — to create X and Y junctions, rings, and ribbons out of graphene. Nanoribbons, which are simply very narrow strips of graphene, are of particular interest because they have a bandgap — a characteristic that graphene doesn't normally possess. A bandgap ways that these nanoribbons take semiconductive properties, which means they might one solar day be used in reckoner chips. Graphene rings are as well of interest, because they can be fashioned into breakthrough interference transistors — a new and not-well-understood transistor that connects 3 terminals to a ring, with the transistor's gate beingness controlled by the flow of electrons effectually the ring.

MIT/Harvard's graphene patterning process

MIT/Harvard's graphene patterning procedure

Moving forward, the MIT and Harvard researchers demand to meliorate the precision of the process — some particular is lost when the Deoxyribonucleic acid is coated in metal — so that it can compete with e-beam lithography, which is currently the all-time (merely very expensive) method of patterning graphene. For now, though, metallized Deoxyribonucleic acid nanolithography is more than good enough for exploratory inquiry into graphene-based electronics — and somewhen, maybe equally a replacement for silicon in computer chips.

Now read: Hype-kill: Graphene is awesome, but a very long way from replacing silicon

Inquiry paper: doi:x.1038/ncomms2690 – "Metallized Deoxyribonucleic acid nanolithography for encoding and transferring spatial information for graphene patterning"