Dielectrophoretic alignment of metal and metal oxide nanowires and nanotubes: a universal set of parameters for bridging prepatterned microelectrodes.
Nanowires and nanotubes were synthesized from metals and metal oxides using templated cathodic electrodeposition. With templated electrodeposition, small structures are electrodeposited using a template that is the inverse of the final desired shape. Dielectrophoresis was used for the alignment of the as-formed nanowires and nanotubes between prepatterned electrodes. For reproducible nanowire alignment, a universal set of dielectrophoresis parameters to align any arbitrary nanowire material was determined. The parameters include peak-to-peak potential and frequency, thickness of the silicon oxide layer, grounding of the silicon substrate, and nature of the solvent medium used. It involves applying a field with a frequency >10(5) Hz, an insulating silicon oxide layer with a thickness of 2.5 μm or more, grounding of the underlying silicon substrate, and the use of a solvent medium with a low dielectric constant. In our experiments, we obtained good results by using a peak-to-peak potential of 2.1 V at a frequency of 1.2 × 10(5) Hz. Furthermore, an indirect alignment technique is proposed that prevents short circuiting of nanowires after contacting both electrodes. After alignment, a considerably lower resistivity was found for ZnO nanowires made by templated electrodeposition (2.2-3.4 × 10(-3) Ωm) compared to ZnO nanorods synthesized by electrodeposition (10 Ωm) or molecular beam epitaxy (MBE) (500 Ωm).
Inorganic Materials Science, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
A W
AW
Maijenburg
M G
MG
Maas
E J B
EJ
Rodijk
W
W
Ahmed
E S
ES
Kooij
E T
ET
Carlen
D H A
DH
Blank
J E
JE
ten Elshof
D004595:Electroplating / Q000379:methods*; D008422:Materials Testing; D008670:Metals / Q000737:chemistry; D008839:Microelectrodes; D036103:Nanotechnology / Q000379:methods; D043942:Nanotubes / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties
D008670:Metals; D012825:Silicon