Researchers from Kiel University and San Sebastián University (Spain) have produced a "wire" with a diameter of just one atom that works like a nano power switch. It is just two atomic bonds long and one atom wide. "This is the simplest molecular wire imaginable , thinner and much shorter is not possible," explains Kiel physicist Torben Jasper-Tönnies.

This is how the wire molecule becomes a nano switch: the closer the tip of the scanning tunneling microscope gets to the nano wire, the more the wire bends – and the current flow changes. The effect is that of a power switch at nano level. This is due to quantum mechanical forces acting between the tip and the wire. They change the geometry of the wire molecule, and thereby its properties.

The problem of contacting individual molecules in an electrical circuit has not yet been satisfactorily resolved. The researchers are still working on this; working solutions have been made available in the meantime.