Suspended SWNT electrode with nanosize gaps

We report a robust method to fabricate a single walled carbon nanotube (SWNT) electrode array with nanosize gaps. As a first step, several SWNTs are suspended between a pair of preformed gold electrodes utilizing dielectrophoresis (DEP) and turned into a rope configuration by capillary densification during drying process. Electrical breakdown is followed to make a gap in the SWNT rope and the dimension of the gap can be controlled by the bias sweep rate. When an electric voltage is applied to the SWNT rope, electrical joule heating increases the temperature, oxidizes the SWNT, and the rope eventually breaks at the midpoint. The SWNT electrodes are successfully fabricated with gaps in the range of 1-60 nm by controlling the bias sweep rate. As a demonstration in nanoscale electronics, the electrical resistance of fullerene (dimension of ∼1 nm) is measured by capturing it between the SWNT electrodes with one nanometer gap.