Dependence of AC electrophoresis carbon nanotube manipulation on microelectrode geometry

A rapid approach to form post-growth multi-walled carbon nanotube (MWNT) linkages between microelectrodes using AC electrophoresis is presented. Three types of microelectrodes with different geometrical shapes were fabricated to investigate the degree of MWNT linkages formation. The gap distance between the microelectrode pairs ranged from 10 μm to 30 μm. We experimentally observed that in 0.02 mg/ml MWNT-ethanol medium, MWNT with axial dimension ranging from 1 μm to 10 μm can bridge microelectrode pairs with gap distance smaller than 15 μm in applied sinusoidal AC frequency ranging from 100 Hz to 1 MHz and the electric field strength ranging from 0.3 V / μm to 0.7 V / μm. This is a very fast and inexpensive approach to manipulate MWNT to any specific area of a patterned substrate using AC voltage source.