Sharpest cut from nanotube sword

Sabres from Damascus, now in Syria, date back as far as 900 AD. Strong and sharp, they are made from a type of steel called wootz.

Their blades bear a banded pattern thought to have been created as the sword was annealed and forged. But the secret of the swords' manufacture was lost in the eighteenth century.

Materials researcher Peter Paufler and his colleagues at Dresden University, Germany, have taken electron-microscope pictures of the swords and found that wootz has a microstructure of nano-metre-sized tubes, just like carbon nanotubes used in modern technologies for their lightweight strength.