Langmuir, 23 (23), 11932 -11940, 2007. 10.1021/la701755s S0743-7463(70)01755-9
Web Release Date: October 13, 2007

Copyright © 2007 American Chemical Society

Fluid Flow-Assisted Dielectrophoretic Assembly of Nanowires

Kieseok Oh, Jae-Hyun Chung,* James J. Riley, Yaling Liu, and Wing Kam Liu

University of Washington, Department of Mechanical Engineering, Campus Box 352600, Seattle, Washington 98195-2600, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, 500 West First Street, Arlington, Texas 76019, and Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3111

Received June 13, 2007

In Final Form: August 17, 2007

Abstract:

The dielectrophoretic assembly of silicon carbide (SiC) nanowires in a microfluidic flow is shown to enhance the orientation and deposition yield of nanowires. The fluid flow delivers and orients the nanowires in the vicinity of a gap, and they are attracted and deposited by a dielectrophoretic force. Depending upon their lengths, the nanowires are selectively attracted to the gap because the dielectrophoretic force is largest when the lengths are comparable to the gap size. Precise control over the fluid flow and dielectrophoresis shows various interesting phenomena such as landing, shifting, and uniform spacing of nanowires during the assembly process. As a result, the precise control enables the selective positioning of nanowires only at the gap where the fluid direction is consistent with the electric field orientation.


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