Modeling and Characterization of Dielectrophoretic Assembly Process for Nanobelts

Robust manufacturing methods are needed for nanocomponent assembly, and one must understand the physics to optimize the processing and to develop control schemes to deal with the inherent uncertainty. We are studying field induced assembly of a new class of semiconducting metal oxides — nanobelts — that have been demonstrated for chemical sensing. We have demonstrated the integration of nanobelts with electrodes to make sensors by dielectrophoresis (DEP). The SnO2 nanobelts (width ~ 100–300 nm, thickness ~ 30–40 nm) were suspended in ethanol and introduced into a microchannel, and were assembled across the electrodes. Modeling suggests that attraction should occur at all frequencies over this range. Targeted experiments were performed to quantify surface and material properties for input to the modeling, and FEMLAB simulations were performed to validate the model. The goal of the modeling is to optimize the assembly of nanostructures in a manufacturing process at the wafer-scale.