Gas Sensor Array Based on Metal-Decorated Carbon Nanotubes

Abstract

Here we demonstrate design, fabrication, and testing of electronic sensor array based on single-walled carbon\nnanotubes (SWNTs). Multiple sensor elements consisting of isolated networks of SWNTs were integrated\ninto Si chips by chemical vapor deposition (CVD) and photolithography processes. For chemical selectivity,\nSWNTs were decorated with metal nanoparticles. The differences in catalytic activity of 18 catalytic metals\nfor detection of H₂, CH₄, CO, and H₂S gases were observed. Furthermore, a sensor array was fabricated by\nsite-selective electroplating of Pd, Pt, Rh, and Au metals on isolated SWNT networks located on a single\nchip. The resulting electronic sensor array, which was comprised of several functional SWNT network sensors,\nwas exposed to a randomized series of toxic/combustible gases. Electronic responses of all sensor elements\nwere recorded and the sensor array data was analyzed using pattern-recognition analysis tools. Applications\nof these small-size, low-power, electronic sensor arrays are in the detection and identification of\ntoxic/combustible gases for personal safety and air pollution monitoring.