%0 Journal Article
%T Assembly of Carbon Nanotubes between Electrodes by Utilizing Optically Induced Dielectrophoresis and Dielectrophoresis
%A Pei-Fang Wu
%A Gwo-Bin Lee
%J Advances in OptoElectronics
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/482741
%X This study reports a new approach for assembling carbon nanotubes (CNTs) between electrodes combination of optically induced dielectrophoresis force and dielectrophoresis force. Metal electrodes and amorphous silicon layer were first patterned and then used to assemble CNTs. By utilizing moving light patterns, the CNTs could be collected to the central area between two metal electrodes. The CNTs with different concentrations can be collected and aligned to form CNTs lines with different widths. The immobilization of preassembled CNTs was also demonstrated by exposing them to an ultraviolet light source such that they can be fixed at the prealigned location. Then photoresist asher was used to get rid of the cured polymer. The development of the new platform can be promising to massively assemble CNTs. 1. Introduction The application of CNTs in various fields has increased dramatically and has made a substantial impact recently since their discovery [1]. For example, they are regarded as promising building blocks for next-generation nanosensing devices due to their high-aspect-ratio structures, unique electronic characteristics, and excellent transducing properties [2, 3]. With advances in micro- and nanotechnologies, these nanosensing devices are capable of metering physical, chemical or biological properties at a micro- or even nanoscale. For instance, CNTs can be trapped and patterned across prefabricated electrode arrays to yield reproducible sensing features in constructing gas sensors [4, 5]. However, there are several issues involved when patterned CNTs across electrodes to form nanosensors. First, reproducible and well-controlled patterns of CNTs must be made such that these nanosensors will behave in a reproducible manner from device to device. Furthermore, parallel assembly of these CNTs is crucial for mass production of any CNT-based nanosensors. A variety of methods for the manipulation of CNTs have been demonstrated in the literature, including guided CNTs growth [6, 7], magnetic forces [8, 9], polar molecular patterning [10], and optical tweezers [11]. For instance, organized CNTs structures can be formed by using chemical vapor deposition such that guided CNTs can grow in situ. Alternatively, pregrown CNTs can be aligned and manipulated after they have been formed. However, it is either a lengthy process or remains challenging when attempts are made to align them in parallel between two electrodes for a large-scale fabrication process. Furthermore, a variety of techniques for modifying the surfaces of CNTs may also give rise to
%U http://www.hindawi.com/journals/aoe/2011/482741/