Abstract Submitted to the    NANOTUBE'04 Conference:

We have demonstrated recently that metallic SWNTs can be separated from semiconducting ones by their opposing movement in a solvent when interacting with an external alternating electric field¹. The effect is based on the different, electric-field induced polarisabilities of the two tube types. Now, we have performed a comprehensive study to get a full description of the separation scheme over a range of experimentally acessible parameters. Our new results reveal the existence of a finite surface conductance of suspended semiconducting SWNTs, which gives rise to a unique frequency dependence of the dielectrophoretic separation. As a result dielectrophoresis can be used for both, the separation and the selective deposition of metallic and semiconducting SWNTs, which makes dielectrophoresis a viable method for device fabrication.

[1] R. Krupke, F. Hennrich, M. M. Kappes, H. v. Lóhneysen, Science 301, 344-347 (2003)