Step-Wise Deposition Process for Dielectrophoretic Formation of Conductive 50-Micron-Long Carbon Nanotube Bridges

Tuo Zhou; Ethan Kropp; Jingyuan Chen; Lawrence Kulinsky

doi:10.3390/mi11040371

Step-Wise Deposition Process for Dielectrophoretic Formation of Conductive 50-Micron-Long Carbon Nanotube Bridges

Micromachines (Basel). 2020 Apr 1;11(4):371. doi: 10.3390/mi11040371.

Authors

Tuo Zhou¹, Ethan Kropp¹, Jingyuan Chen², Lawrence Kulinsky¹

Affiliations

¹ Department of Mechanical and Aerospace Engineering, University of California, Irvine, 5200 Engineering Hall, Irvine, CA 92627-2700, USA.
² Department of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, HIT Campus G908, Shenzhen, Guangdong 518055, China.

Abstract

Carbon Nanotube (CNT) agglomerates can be aligned along field lines between adjacent electrodes to form conductive bridges. This study discusses the step-wise process of dielectrophoretic deposition of CNTs to form conducting bridges between adjacent electrodes. For the first time, the creation of conductive CNT bridges spanning lengths over 50 microns is demonstrated. The CNT bridges are permanently secured using electrodeposition of the conducting polymer polypyrrole. Morphologies of the CNT bridges formed within a frequency range of 1 kHz and 10 MHz are explored and explained as a consequence of interplay between dielectrophoretic and electroosmotic forces. Postdeposition heat treatment increases the conductivity of CNT bridges, likely due to solvent evaporation and resulting surface tension inducing better contact between CNTs.

Keywords: carbon nanotube (CNT); dielectrophoresis; electroosmosis; micromanufacturing.