Forget the popular phrase, “sharp as a tack.” Researchers at the University of Alberta have revised the expression to be, “sharp as a single atom tip formed by chemically assisted spatially controlled field evaporation.” It might not roll off the tongue as easily, but it would be far more accurate. Scientists at the National Institute of Nanotechnology (NINT) at the University of Alberta have used a unique process to make a small sharp pyramid of tungsten atoms covered with a one-atom-thick coating of nitrogen, stable enough to withstand about 900 degrees Celsius. These super-sharp tips are necessary for making contacts with metals or semiconductors. Ultrafine tips are also useful in helping researchers manipulate and examine atoms, molecules, and other small particles. These tips, in particular, are so sharp that they work as excellent emitter of electron beams, and can potentially be used to improve the current electron microscopes

Source:University of Alberta Nanotechnology Researchers Create Sharpest Tip Ever Known