A breath sensor using carbon nanotubes operated by field effects of polarization and ionization

A novel microfabricated breath sensor (MBS) based on multi-walled carbon nanotubes (MWNTs) has been presented and tested. It has a simple structure of two nickel beams incorporating with MWNTs. The responses of the MBS to the behavior of the breath dynamic characteristics are consistent with the exhalation pulse of the human-volunteers, e.g. the exhale flow strength and frequency. It has a rapid response and high sensitivity in detecting feeble breath, and no recovery issues such as the adsorption-type sensors are detected. Furthermore, strong anti-interference ability to external air flow and temperature shift is observed. These unique results ensure this MBS can be successfully employed to real-time monitoring of human breath.