Monomolecular wire
Physicists have built the world’s thinnest gold necklaces, at just one atom wide. […]
Paul Snijders and Sven Rogge from the Kavli Institute of Nanoscience at the Delft University of Technology, in Delft, Holland, and Hanno Weitering from the University of Tennessee build the single-atom wires by evaporating a puff of gold atoms onto a silicon substrate which has first been cleared of impurities by baking it at 1200 degrees Kelvin. The crystalline surface was cut to form staircase corrugations. Left to themselves, the atoms then self-assemble into wires (aligned along the corrugations) of up to 150 atoms each (see figure at Physics News Graphics).
(from the American Institute Of Physics, Atom Wires)