Simultaneous dielectrophoretic separation and assembly of single-walled carbon nanotubes on multigap nanoelectrodes and their thermal sensing properties.

By using the specifically designed multigap nanoelectrodes, we demonstrated an effective approach for the simultaneous dielectrophoretic separation and assembly of metallic and semiconducting single-walled carbon nanotubes (SWNTs). An approximate metallic-semiconducting-metallic multiarray structure was created by an inward-propagative sequential assembly of SWNTs under ac electric field. Such kinds of SWNT multiarray structures exhibited ultra-low-power consumption and excellent thermal sensing performances with the sensitivity being dependent on the number of gaps: the more gaps, the higher sensitivity. The effective separation of metallic and semiconducting tubes in different gaps is believed to be responsible for the improved sensitivity to temperature.