Nanotube suspension bridges directly fabricated from nanotube-polymer suspensions by manual brushing

Polymer fibers have been directly self-assembled into suspended bridges by manually brushing polymer dissolved in a volatile solvent across a microstructured surface. This process is extended by adding multiwall carbon nanotubes to the liquid polymer solution of poly (methyl methacrylate) (PMMA) in chlorobenzene. Suspended nanotube/polymer fibers with diameters between 20 nm and 20 microns (with bulk conductivities as large as 9.91 S/m) are created by brushing. Immersing the suspended fibers in acetone dissolves most of the polymer, leaving behind suspended bridges of nanotubes. The filamentary structures remain suspended following removal from the solvent bath and air drying. The nanotubes appear to be encased in a thin layer of polymer that assists in holding the bridge together. It is speculated that the residual coating is related to the organic functionalization that is added to the nanotubes to make them well dispersed and suspended in chlorobenzene.