TECHNOLOGY: Nanolithography

As its roots suggest, nanolithography is lithography, or etched design, on the nanoscale. Much of the immediate potential for nanolithography lies in computer chip etching, which is currently performed by optical methods. As computer chips get smaller than the limit allowed for traditional optical etching (visible light has a minimal wavelength of around 400nm), new methods of lithography on the nanoscale are called for. Other applications of nanolithography include the potential to layer single molecules in an organized fashion, effectively building objects from the bottom up. The technology that I will focus on here is Dip Pen Nanolithography (DPN), which was developed out of Northwestern University by Dr. Chad Mirkin's lab.

DPN is a unique form of nanolithography in which a resevoir of "ink" made up of atoms or molecules is stored at the tip of a scanning probe. As this tip probes a desired surface, these atoms may be applied in an organized manner across the surface. Moreover, the Atomic Force Microscope tips used in Dr. Mirkin's lab have the advantage of being easy to manipulate, making it possible to create very complex designs on the nanoscale using DPN.

One huge benefit of this technology is its versitility. DPN can be theoretically be used with any nanopartical on any surface. This opens up the possibility for all kinds of DPN applications. In addition to chip manufacturing, DPN can be used for practically any type of etching or layering on small scales. The downside of DPN is its speed. DPN is currently a very slow process, though steps are being made to improve its speed. See the site for Nanoink, a spinoff company by Dr. Mirkin, for more information regarding DPN.

FIGURE FROM NORTHWESTERN UNIVERSITY