Before and After (IMAGE) Princeton University, Engineering School Caption These electron microscope images show before (left column) and after (right column) examples of a new technique, developed at Princeton University, for perfecting nanometer-scale structures. Credit Stephen Chou/Nature Nanotechnology Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.