Assembly of long carbon nanotube bridges across transparent electrodes using novel thickness-controlled dielectrophoresis

Abdullah Abdulhameed; Mohd Nazim Mohtar; Mohd Nizar Hamidon; Izhal Abdul Halin

doi:10.1002/elps.202100268

Assembly of long carbon nanotube bridges across transparent electrodes using novel thickness-controlled dielectrophoresis

Electrophoresis. 2022 Feb;43(3):487-494. doi: 10.1002/elps.202100268. Epub 2021 Nov 5.

Authors

Abdullah Abdulhameed^{1

2}, Mohd Nazim Mohtar^{1

3}, Mohd Nizar Hamidon^{1

3}, Izhal Abdul Halin¹

Affiliations

¹ Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Malaysia.
² Department of Electronic Engineering, Faculty of Engineering, Hadhramout University, Mukalla, Yemen.
³ Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang, Malaysia.

PMID: 34679198
DOI: 10.1002/elps.202100268

Abstract

The assembly of carbon nanotubes (CNTs) across planner electrodes using dielectrophoresis (DEP) is one of the standard methods used to fabricate CNT-based devices such as sensors. The medium drag velocity caused by electrokinetic phenomena such as electrothermal and electroosmotic might drive CNTs away from the deposition area. This problem becomes critical at large-scale electrode structures due to the high attenuation of the DEP force. Herein, we simulated and experimentally validated a novel DEP setup that uses a top glass cover to minimize the medium drag velocity. The simulation results showed that the drag velocity can be reduced by 2-3 orders of magnitude compared with the basic DEP setup. The simulation also showed that the optimum channel height to result in a significant drag velocity reduction was between 100 μm and 240 μm. We experimentally report, for the first time, the assembly and alignment of CNT bridges across indium tin oxide (ITO) electrodes with spacing up to 125 μm. We also derived an equation to optimize the CNT's concentration in suspensions based on the electrode gap width and channel height. The deposition of long CNTs across ITO electrodes has potential use in transparent electronics and microfluidic systems.

Keywords: Alignment; Assembly; Carbon nanotubes; Dielectrophoresis; ITO.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Computer Simulation
Electrodes
Electrophoresis / methods
Equipment Design
Nanotubes, Carbon* / chemistry

Substances

Nanotubes, Carbon