SUNFEST REU Program DIELECTROPHORETIC ASSEMBLY, INTEGRATION, AND CHARACTERIZATION OF FUNCTIONAL NANOSTRUCTURES

Nano-electro-mechanical systems (NEMS) are pivotal to integrated systems research. The ability to integrate sensors and processors on a single wafer has the potential to create highly sensitive and complex systems that respond to changing environmental stimuli. This project focuses on the assembly, integration, and characterization of both nanowires and nanotubes used in NEMS devices. Using dielectrophoretic assembly, the project assembled and electrically characterized Rh and GaAs nanowires as well as multi-walled carbon nanotubes (MWNTs). It also found optimum parameters for assembly for each of these nanostructures for a specific circuit design. The optimum conditions always involved applying a sinusoidal field of 100 kHz at an amplitude of 10 to 35 V. The duration of assembly varied from 1 minute to 5 minutes. The capacitive properties of contact pads play a critical role in assembly yields, and resistivity of MWNTs is inversely related to temperature. The research also raised questions about the physical structure of these nanostructures and how it may be affected by changing temperature. It appears that a critical temperature is reached at which the resistivity of the nanotube increases drastically. Finally, the project produced clamped MWNTs for future mechanical testing.