Dielectrophoresis of Colloidal Suspensions of SWNTs: Formation of 1-D Assemblies

SWNTs are nanoscale materials with extreme anisotropy and electrical polarizability, whereas dielectrophoresis is the transport of polarizable particles in an electrical field gradient. With a view to fabricate 1D linear assembly from SWNT colloidal suspensions stabilized by surfactants such as Sodium dodecylbenzene sulphonate and Sodium deoxycholate, we have studied the dielectrophoretic behavior in a plate and pin geometry using in-situ optical visualization. Depending upon the nature of the surfactant, operating voltage and frequency, 1D assemblies ranging in lengths from a few microns to several hundred microns have been successfully fabricated. These assemblies have been characterized by optical microscopy, scanning electron microscopy, and current-voltage measurements.