Dielectrophoretic alignment of carbon nanotubes: theory, applications, and future

Carbon nanotubes (CNTs) are nominated to be the successor of several semiconductors and metals due to their unique physical and chemical properties. It has been concerning that the anisotropic and low controllability of CNTs impedes their adoption in commercial applications. Dielectrophoresis (DEP) is known as the electrokinetics motion of polarizable nanoparticles under the influence of nonuniform electric fields. The uniqueness of this phenomenon allows DEP to be employed as a novel method to align, assemble, separate, and manipulate CNTs suspended in liquid mediums. This article begins with a brief overview of CNT structure and production, with the emphasize on their electrical properties and response to electric fields. The DEP phenomenon as a CNT alignment method is demonstrated and graphically discussed, along with its theory, procedure, and parameters. We also discussed the side forces that arise in DEP systems and how they negatively or positively affect the CNT alignment. The article concludes with a brief review of CNT-based devices fabricated using DEP, as well as the method's limitations and future prospects.

Automated summary

Carbon nanotubes (CNTs) are potential successors to semiconductors and metals due to their unique properties, but their anisotropy and low controllability hinder their commercial applications. Dielectrophoresis (DEP) is an electrokinetic motion of polarizable nanoparticles in nonuniform electric fields, which can be used to align, assemble, separate, and manipulate CNTs suspended in liquid mediums. This article provides an overview of CNT structure, production, and their response to electric fields, explores the DEP phenomenon as a CNT alignment method, discusses side forces in DEP systems, and reviews CNT-based devices fabricated using DEP, as well as its limitations and future prospects.