nanolithography

MIT and Harvard Engineers Use “DNA-Legos” To Construct Graphene Nanostructures

This news is a follow-up to an earlier post “Harvard Researchers Create Self-Assembling Nano Bricks Made of DNA.”

Engineers are now using  self-assembling DNA nanobricks as a scaffold to build nanostructures out of graphene.

The MIT and Harvard researchers are essentially taking these shapes and binding them to a graphene surface with a molecule called aminopyrine.

Once bound, the DNA is coated with a layer of silver, and then a layer of gold to stabilize it. The gold-covered DNA is then used as 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 almost-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 feature that graphene doesn’t normally possess. A bandgap means that these nanoribbons have semiconductive properties, which means they might one day be used in computer chips.

Graphene rings are also of interest, because they can be fashioned into quantum interference transistors — a new and not-well-understood transistor that connects three terminals to a ring, with the transistor’s gate being controlled by the flow of electrons around the ring.

(via MIT and Harvard engineers create graphene electronics with DNA-based lithography | ExtremeTech)

If you’re at all familiar with mobile processors, you’ve likely heard a lot about 32nm vs. 28nm construction when comparing the current generation of chips from companies like Qualcomm and others. That refers to the size of the processor, where a smaller number is better in terms of power consumption, fitting more transistors in less space for more efficient processing.

Currently, it’s hard to get past around the 20nm when creating individual patterns for data storage on today’s disk drives, which is another area in addition to processors where Moore’s Law applies. Today though, HGST, a Western Digital Company, announced a breakthrough that allows it to produce patterns as small as 10nm, via a process called “nanolithography,” meaning that it can essentially double the current maximum storage capacity possible in hard disk drives, given the same-sized final product.

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This Mona Lisa Replica Is Thinner Than A Human Hair

A team of researchers from Georgia Tech has created the “Mini Lisa,” a 30-micron thick version of the Mona Lisa. That makes it about one-third the width of a human hair.

The tiny masterpiece was made through a process called ThermoChemical NanoLithography: with a heated cantilever, a tiny device that can accurately apply heat to a surface, the researchers induced heat-based chemical reactions on a surface. The more heat they applied, the lighter a shade of gray the picture became in that area. So with each area acting like the pixel in an image, the researchers applied different amounts of heat at different spots, until they created a gray-scale version of da Vinci’s famed painting.

The project sounds more like a proof of concept than anything else: the researchers have shown that complex chemical reactions can be applied on a microscopic scale, which could have implications for the production of nano-tech devices. Awesome, although it’s tough to top sending the Mona Lisa to the moon using lasers.

Nanolithography: Flexible patterning of the cellular microenvironment

Source: Small Times

The ability to place individual cells at defined locations and control their microenvironment has numerous applications in the field of cell biology. Cells respond to their microenvironment and the resulting extracellular signals [1, 2]. The ability to control the cellular microenvironment enables investigation of biochemical and topological cues on various cell behavior, such as cell adhesion, differentiation, and molecular signaling pathways.

The nanolithography platform, NLP 2000, was designed to provide a simple solution to achieve high precision placement of nano- to micro-sized features with nanoscale precision. The process of deposition of material is based on Dip Pen Nanolithography (DPN), an established method of nanofabrication in which materials are deposited onto a surface using a sharp tip [9, 10]. The tool is capable of patterning a wide range of materials with feature sizes from 50nm to 10µm over an area of 40 x 40mm. The features can be placed with nanoscale precision using a three-axis closed-loop stage.

Making nano-scale manufacturing eco-friendly with silk

Nanolithography — a way of making finely detailed patterns or structures, such as those found in advanced computer microchips, uses toxic and corrosive chemicals. Researchers have now shown that these could be replaced with eco-friendly silk pr http://bit.ly/1CFakjK

Making nano-scale manufacturing eco-friendly with silk

Nanolithography — a way of making finely detailed patterns or structures, such as those found in advanced computer microchips, uses toxic and corrosive chemicals. Researchers have now shown that these could be replaced with eco-friendly silk pr http://bit.ly/1vcUH2P