Resistive gas sensors fabricated by wafer-scale, in-situ integration of horizontal carbon nanotube membranes

This paper presents a successful experimental demonstration of in-situ localized growth of horizontal, dense carbon nanotube (CNT) arrays at large scale, followed by full processing and electrical tests of resistive gas sensing devices. A selective CNT catalytic growth process with a suitable catalyst support allows for the direct integration of nanotubes membranes into devices. This new CNT integration method is demonstrated with resistive gas sensors made of supported CNT membranes, which were electrically tested. A CNT array resistivity of 5.3×10^-5 Ω.m was extracted and resistance responses to various gases such as NO₂ were measured.