Laser-directed assembly of multiwalled carbon nanotubes (MWNTs) in 3D space is investigated via a two-photon polymerization technique. MWNT-thiolacrylate (MTA) composite resins are developed with high MWNT concentrations up to 0.2 wt%, over one order of magnitude higher than previously published work. Significantly enhanced electrical and mechanical properties of the 3D micro-/nanostructures are achieved. Microelectronic devices made of the MTA resins are demonstrated.