Summary

Description

Sensing gas molecules is critical to environmental monitoring, control of chemical processes, space missions as well as agricultural and medical applications. Existing electrical sensor materials are based on semi-conducting metal oxides, silicon devices, organic materials and gas responsive polymers or ceramics. To achieve high chemical sensitivity, semi-conducting metal oxide sensors must be operated at elevated temperatures (200 to 600?C). This need for high temperature operation increases the device complexity and renders them unsuitable for real-time portable applications. On the other hand, conducting polymers and organic semi-conductors are suitable for room temperature operation, but exhibit limited sensitivity. Clearly, there is a need to develop new technology that will allow for operation at room temperature and atmospheric pressure and provide for high-sensitivity measurements and low response times. We have already experimentally demonstrated under our own Internal R&D funding, that carbon nanotubes provide this enabling technology This effort will experimentally demonstrate a new nanotube sensor technology, which is a radical departure from conventional nanotube sensor approaches. Tests already performed with the proposed carbon nanotube sensor indicate that the electrical response of each gas is unique and that the individual gas concentrations can also be determined.