Improving the Performances of Gas Sensors Using Metal Oxide Nanotubes with Oval Structure

The paper presents the results obtained from the researches upon a new category of gas sensors based on metal oxide materials in the form of oval nanotubes. The nanotubes are obtained by coating electrospinned nanofibers using magnetron sputtering thin film deposition techniques with metal oxides like zinc oxide (ZnO) and tin oxide (SnO
2
) deposed in various multilayers configurations, followed by appropriate calcination. The aim of the research is to find new possibilities of improving the metrological performances of the gas sensors, especially sensitivity, selectivity and power consumption by enlarging the contact surface between the measured gas and the active material and thus lowering the temperature at which the sensor nominally operates. The results reported in the paper show that, in comparison with classical metal oxide sensors, the new technique significantly increases the sensitivity at temperatures of 350-400
^°
C for certain configurations of oxide alternating multilayers.