Dielectrophoretic Separation of Single-Walled Carbon Nanotubes Using Different Electrode Geometries

The synthesis processes of carbon nanotubes (CNTs) cannot produce a pure sample of single walled carbon nanotubes (SWNTs). Separation of SWNTs from the impurities and further separation between metallic and semiconducting SWNTs is important. Dielectrophoresis is one method of separation by electronic type. Many factors influence the efficiency of type separation such as potential, frequency, solution chemistry, and electrode geometry. This work investigates electrode geometry and its effect on dielectrophoretic separation of SWNTs into metallic and semiconducting species. The electrodes were produced using optical microlithography where five geometries were created to study the effects of geometry on SWNT deposition and separation. It was found that electrode geometry has a significant effect on the efficiency of dielectrophoresis, where a radial electrode geometry gave the best deposition