Nanowicks: Nanotubes as Tracks for Mass Transfer

Abstract. We have used a manipulation stage to electrically contact individual nanotube bundles coated with metal nanoparticles for in-situ studies in a transmission electron microscope. When electrical current is passed through a bundle, unusual mass transport is observed along that bundle. Nanocrystals melt and disappear from a given section, with a correlated growth of similar nanoparticles further along the bundle. This unusual phenomenon, termed nanowicking, may provide a method for controlled nanoscale mass transport. True nanoscale device fabrication presents a formidable challenge, and the tools presently available are quite primitive in comparison to the requirements of an economically useful technology [1]. Fundamental to any construction project is the ability to deliver appropriate quantities of required building material to the assembly site. In this work we describe the observation of directed movement of nanoscale quantities of metals along multiwall carbon nanotube templates or tracks, which we term nanowicks. Fully realized, this method of material transport may prove to be useful in many applications, including the formation ‘by-design ’ of electrical and mechanical joints in complex nanostructures