Sharpest object man-made

Scientists at the National Institute for Nanotechnology and the University of Alberta (both Canada) have created a tungsten needle that tapers to a thickness of just one atom. The breakthrough, announced in May 2006, should allow the construction of better super high-resolution electron microscopes.

The needle, made by postdoc Mohamed Rezeq at the University of Alberta’s National Institute for Nanotechnology, starts out much blunter. However, exposed to a pure nitrogen atmosphere, a rapid slimming begins. At the start oft he process the tungsten is chemically very reactive and the nitrogen roughens the tungsten surface. An electric field is created by applying a voltage to the tungsten and is at its maximum force at the tip of the needle where atoms are driven away leaving a sharp point.