"NANOTECH: thermal dip pens read, write, repair nanostructures"
Creating ultratiny, nanoscale systems is often easier than verifying the accuracy of the resulting structures. Indeed, in some instances the structures can actually be lost. Nanoscale techniques produce minute features, but imaging tools are sometimes too crude to spot breaks in them. To the rescue come atomic-force microscopy and now its interactive "can-do" sibling, thermal dip pen nanolithography. Traditional atomic-force microscopy (AFM) techniques drag a probe with a 100-nanometer tip over nanoscale structures to record a small deflection, thereby producing an image of the surface by mapping its valleys and peaks. By first dipping the AFM tip in liquid metal, a semiconductor or an oxide, dip pen nanolithography (DPN) can directly write 100-nanometer lines-but can't interactively switch between read/write.