Oct 24, 2012
NASA team develops porous tin oxide nanorods for room-temperature methane detection
Researchers at NASA Glenn Research Center have fabricated and developed a methane (CH4) microsensor using porous SnO2 nanorods as the sensing material. The design of the sensor structure combined with the use of porous SnO2 nanorods allows the sensor to be used for room-temperature detection of methane without the use of dopants or catalysts. It can withstand harsh environments as well, as test devices displayed sensitivity at higher temperatures (500 °C). In addition, the sensor was evaluated at lower concentrations (2500 ppm – 125 ppm) over the temperature range 100 °C to 500 °C.
Fabrication of the microsensor includes four major steps: 1) synthesis of the porous metal or metal oxide nanorods using a sacrificial carbon nanotube template; 2) deposition of the electrodes onto the alumina substrate; 3) alignment of the nanotubes between electrodes using dielectrophoresis and 4) deposition of the top electrodes to bury the aligned nanostructures.
The methane microsensor described in the study has low power consumption, is easy to use and can be applied to a variety of applications, including leak detection of hydrocarbon fuels. The unit could also be used for personal health monitoring and environmental monitoring.
The low cost of the simple batch fabrication processes has the potential to deliver a highly affordable sensor that could be installed in a wide range of locations thanks to the compact nature of the device.
Full details can be found in the journal Nanotechnology.
About the author
Dr Azlin Biaggi-Labiosa is currently a Research Electronics Engineer in the Sensors and Electronics Branch at NASA Glenn Research Center in Cleveland, Ohio, US. Her current work includes the design, fabrication and testing of a variety of chemical gas sensors for aerospace applications, which include fire detection, fuel leak detection, engine emission and health monitoring, and environmental monitoring.