Oxygen detection using nanoporous anodized aluminum oxide sensors

The objective of this work has been the analysis of the impedance variation of nanostructured sensors in the presence of several gases at different temperatures. This sensor employs platinum nanowires grown in anodic aluminum oxide to detect the gases. Silicon wafers were oxidized to form silicon dioxide and were sputter deposited with titanium tungstide and aluminum metal. The aluminum film was subsequently anodized to form nonporous anodic aluminum oxide. Platinum metal was filled in these pores by the process of electropolymerization to form encapsulated nanowires. Surface morphology characteristics were determined using atomic force microscopy and scanning electron microscopy. A subsequent metallization process using evaporation deposited gold metal to form electrical contacts. Variations in the electrical response of the sensor in the presence of hydrogen, nitrogen and oxygen at 5°C, 25°C and 40°C are presented in this work.