Atomic contacts by clock movement

Contacts of atomic dimensions exhibit properties which are significantly different from the familiar behavior of macroscopic materials. We demonstrate a facile mechanical method using a clock and two silver wires to achieve capture atomic-scale silver contacts at ambient air conditions. One wire was fixed to the hour hand and contacted the other immovable wire slowly with the hour hand movement. The voltages versus time curves were recorded by Tektronix DPO 4034 oscillograph, and corresponding conductance were calculated and exhibited by Origin software. The experiment results show that most individual conductance plateaus are close to integer multiples of the fundamental conductance unit (G₀) but definite deviations are also present. It indicates that conductance plateau of atomic contact can be captured by oscillograph with clock movement. If the silver wires are coated with organic molecular, this method has the potential of applying to single molecular switches.