Separation of metallic and semiconducting single-walled carbon nanotube arrays by "scotch tape".

The dielectrophoretic (DEP) separation of metallic and semiconducting single-walled carbon nanotubes (SWNTs) has been investigated. DEP separation experiments were performed by following the previous reports and the modification of Raman spectra was confirmed. We then theoretically investigated the impact of the flow field on the dielectrophoretic separation. The electrothermal flow was found to control the motions of semiconducting SWNTs in a sizable domain near the electrodes under typical experimental conditions, therefore helping the dielectrophoretic force to attract semiconducting SWNTs in a broader range. It is shown that under some typical experimental conditions of dielectrophoretic separation of SWNTs, the electrothermal flow is a dominating factor in determining the motion of SWNTs.