Combing and Bending of Carbon Nanotube Arrays with Confined Microfluidic Flow on Patterned Surfaces

Abstract

Ordered arrays of carbon nanotubes in bent and straight states were prepared using “wet” deposition of nanotube solutions on a patterned surface. This approach provided a means for the formation of highly oriented and textured nanotube arrays of different types. Moreover, under certain conditions, nanotube loops of different shapes were formed on amine-terminated silicon surface stripes. Atomic force microscopy observations indicated that the majority of the deposited nanotubes (up to 90%) are uniformly oriented and up to 40% of aligned nanotubes are folded into different nanoscale shapes (open and closed loops with 200−300 nm radius of curvature). We suggested that the dewetting of the SAM-confined liquid film was responsible for the alignment of carbon nanotubes and for the formation of the looped nanotubes. The instability of a receding contact line caused water microdroplets behind the dewetting film, which could serve as nuclei for nanotube trapping. The nanotubes pinned to the functionalized surface...