Nanoscale scribe

At the US Department of Energy’s Brookhaven National Laboratory, scientists have developed a new chemical “writing” technique that can create lines of “ink” only a few tens of nanometres in width.

“Our new ‘writing’ method opens up many new possibilities for creating nanoscale patterns and features on surfaces. This may have a significant impact on developing nanotechnologies that involve nanopatterning, such as molecular electronics — tiny circuits built using single organic molecules,” said Brookhaven Lab physicist Yuguang Cai.

Cai and his colleagues call the technique “Electro Pen Nanolithography” (EPN). They sweep a very thin metal tip across a film of organic molecules. The tip carries an electric voltage, which causes the region under it to oxidise.

In a single sweep of the pen, organic “ink” molecules are transferred from the tip to the oxidised regions, creating an extremely thin line.

Each line is just one molecule thick, but the researchers can produce multilayered patterns by writing over the existing pattern. This gives them the ability to create three-dimensional nanoscale “landscapes.” Moreover, by turning off the voltage, they can use the tip as a tiny scanner to read and create an image of the pattern just written.

With further research, EPN may have the ability to “write” biomolecular materials, such as proteins, onto surfaces. These nanoscale protein deposits might, for example, serve as biosensors.