An Electrothermal Carbon Nanotube\nGas Sensor

Abstract

We show both gas pressure and species sensing capabilities based on the electrothermal effect of a multiwalled carbon nanotube (MWCNT).\nUpon exposure to gaseous environments, the resistance of a heated MWCNT is found to change following the conductive heat-transfer variances\nof gas molecules. To realize this mechanism, a suspended MWCNT is constructed by synthesis and assembly in localized chemical vapor\ndeposition that is accomplished within seconds via real-time electrical feedback control. Vacuum pressure sensitivity and gas species\ndifferentiability are observed and analyzed. Such MWCNT electrothermal sensors are compact, fast and reversible in responses, and fully\nintegratable with microelectronics.