Principles of carbon nanotube dielectrophoresis  

作　　者：Wenshan Li Frank Hennrich Benjamin S.Flavel Simone Dehm Manfred Kappes Ralph Krupke 

机构地区：[1]Institute of Nanotechnology,Karlsruhe Institute of Technology,Karlsruhe 76021,Germany [2]Institute of Physical Chemistry,Karlsruhe Institute of Technology,Karlsruhe 76021,Germany [3]Institute of Materials Science,Technische Universität Darmstadt,Darmstadt 64287,Germany [4]Institute for Quantum Materials and Technologies,Karlsruhe Institute of Technology,Karlsruhe 76021,Germany [5]School of Mechanical Engineering,Shanghai Jiao Tong University,No.800 Dongchuan Road,Shanghai 200240,Chin

出　　处：《Nano Research》2021年第7期2188-2206,共19页纳米研究（英文版）

基　　金：S.Flavel acknowledges support from the Deutsche Forschungsgemeinschafts Emmy Noether Program under grant number FL 834/1-1.

摘　　要：Dielectrophoresis(DEP)describes the motion of suspended objects when exposed to an inhomogeneous electric field.It has been successful as a method for parallel and site-selective assembling of nanotubes from a dispersion into a sophisticated device architecture.Researchers have conducted extensive works to understand the DEP of nanotubes in aqueous ionic surfactant solutions.However,only recently,DEP was applied to polymer-wrapped single-walled carbon nanotubes(SWCNTs)in organic solvents due to the availability of ultra-pure SWCNT content.In this paper,the focus is on the difference between the DEP in aqueous and organic solutions.It starts with an introduction into the DEP of carbon nanotubes(CNT-DEP)to provide a comprehensive,in-depth theoretical background before discussing in detail the experimental procedures and conditions.For academic interests,this work focuses on the CNT-DEP deposition scheme,discusses the importance of the electrical double layer,and employs finite element simulations to optimize CNT-DEP deposition condition with respect to the experimental observation.An important outcome is an understanding of why DEP in organic solvents allows for the deposition and alignment of SWCNTs in low-frequency and even static electric fields,and why the response of semiconducting SWCNTs(s-SWCNTs)is strongly enhanced in non-conducting,weakly polarizable media.Strategies to further improve CNT-DEP for s-SWCNT-relevant applications are given as well.Overall,this work should serve as a practical guideline to select the appropriate setting for effective CNT DEPs.

关 键 词：single-walled carbon nanotubes HYDRODYNAMICS assembly deposition ALIGNMENT POLARIZABILITY dielectrophoresis 

分 类 号：TB383[一般工业技术—材料科学与工程]