Dielectrophoretic Characterization of SnO2 Nanobelts

In the present work we report the results of AC dielectrophoresis experiments on ethanol suspended SnO₂ nanobelts. AC field (frequency ~ 5 Hz - 10 MHz) was applied between microelectrodes, and detailed and direct observations of the nanobelt motion were performed. It revealed a wide variety of nanobelt motions induced by the dielectrophoretic forces, which include attraction and repulsion depending on the signal frequency range. These forces caused rigid body motion and deformation in long nanobelts, and pearl chain formation in short nanobelts and particles. The presence of negative (repulsion) dielectrophoresis is unusual in SnO₂, since bulk material properties dictate positive dielectrophoresis in the frequency range studied.