Oriented nanomaterial air bridges formed from suspended polymer-composite nanofibers

In a two-step method, carbon nanotubes, inorganic nanowires, or graphene sheets are connected between two anchor points to form nanomaterial air bridges. First, a recently developed method of forming directionally oriented polymer nanofibers by hand-application is used to form suspended composite polymer-nanomaterial fibers. Then, the polymer is sacrificed by thermally induced depolymerization and vaporization, leaving air bridges of the various materials. Composite fibers and bundles of nanotubes as thin as 10 nm that span 1 microm gaps have been formed by this method. Comparable bridges are observed by electrospinning solutions of the same nanomaterial-polymer composites onto micrometer-scale corrugated surfaces. This method for assembling nanomaterial air-bridges provides a convenient way to suspend nanomaterials for mechanical and other property determinations, and for subsequent device fabrication built up from the suspended nanosubstrates.