Dielectrophoretic alignment of metal and metal oxide nanowires and nanotubes: A universal set of parameters for bridging prepatterned microelectrodes

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:355

Article

Carlen, E. T.¹  ten Elshof, J. E.¹ 

[1] Univ Twente, MESA Inst Nanotechnol, BIOS Lab Chip Grp, NL-7500 AE Enschede, Netherlands

关键词: Templated electrodeposition;    Dielectrophoresis;    Alignment;    Nanowires;    Nanotubes;   

DOI  :  10.1016/j.jcis.2010.12.011

来源: Elsevier

【 摘 要 】

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 mu m 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 x 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 x 10(-3) Omega m) compared to ZnO nanorods synthesized by electrodeposition (10 Omega m) or molecular beam epitaxy (MBE) (500 Omega m). (C) 2010 Elsevier Inc. All rights reserved.

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