Vertically Aligned Carbon Nanotubes for Fast Humidity Sensing

Abstract

We report a fast-response humidity sensor fabricated using vertically aligned carbon nanotubes (CNT). The tips of CNT are intersected to form the resistive active region of the sensor, and the stem of the vertical CNT are aligned to create a clear path for moisture flow. The sensor showed a linear resistive response to relative humidity (RH) in a range of 10 % to 90 % and demonstrated the potential for real-time humidity monitoring. In transient characterizations, the sensor showed a response time of 1.9 s and a recovery time of 7.1 s to the RH of moisture flow that changes between 10 % RH and 90 % RH.