Stability of carbon nanotubes humidity sensor under different testing voltages

A carbon nanotubes(CNTs) humidity sensor, which has sensitive resistance to humidity, was made to improve its sensing precision. The structure, working principle and fabrication process of the sensor were presented and its stability properties were studied both theoretically and experimentally. Schrodinger equation associated with the potential barrier between two CNTs was set up and solved. Analytical results indicate that the fluctuation of sensor resistance is caused by the instability of CNTs, and testing voltage can change the relationship between sensor fluctuation and CNTs stability. The sensor output stability is also proved correlative to testing voltage by experimental results, and data shows that the fluctuating range of sensor resistance at the testing voltage of 5 V is about 5 times of that at 15 V.