Ultrathin Carbon Nanotube Fibrils of High Electrochemical Capacitance

We have assembled single-wall carbon nanotubes into ultrathin long fibrils using a dielectrophoretic technique and studied the mechanical and electrochemical properties of carbon nanotube fibrils. The diameter of the fibrils can be controlled in the range of 200 nm to 2 mu m, and the length can reach as long as 1 cm. The obtained fibrils have a tensile strength of about 65 MPa, electrical conductivity ranging from 80 to 200 S cm(-1), and specific capacitance more than 200 F g(-1). The results indicate that these ultrathin long carbon nanotube fibrils are of great potential for applications as conductive wires and probe electrodes.