Electrically addressable parallel nanowires with 30 nm spacing from micromolding and nanoskiving

This paper describes the fabrication of arrays of parallel, electrically addressable metallic nanowires by depositing alternating layers of thin films of metal and polymer-both planar and topographically patterned-and sectioning the laminated structures with an ultramicrotome (nanoskiving). The structures that resulted from this process had two distinct regions: one in which parallel Au nanowires were separated by a minimum distance of 30 nm, and one in which the nanowires diverged such that the distal ends were individually addressable by low-resolution (> or =10 microm) photolithography. Conductive polyaniline (PANI) was electrochemically deposited across the nanowire electrodes to demonstrate their electrical addressability, continuity, and physical separation. Before deposition, the wires were electrically isolated; with the PANI, they were electrically connected. After dry etching to remove the polymer, the gap between the nanowire electrodes returned to an insulating state. This procedure provides a method for making wires with dimensions and separations of <50 nm without the use of e-beam or focused-ion-beam "writing" and opens applications in organic and molecular electronics, chemical and biological sensing, and other fields where nanoscale distances between parallel conductive electrodes are desirable.