Humidity sensing using microfiber-ZnO nanorods coated glass structure

Abstract

In this paper, a proposed humidity sensor is fabricated by integrating the microfiber and the glass surface coated with Zinc Oxide (ZnO) nanorods. The silica fiber diameter was reduced to 6 μm using the flame brushing technique, and the glass surface was coated with ZnO nanorods using a hydrothermal method. A significant response to humidity level concentration ranging from 35 %RH to 85 %RH has been observed. The proposed sensor's output power has decreased linearly from -16.32 dB m to -18.68 dB m with a linearity of 95.87 %. The sensitivity and the resolution of the ZnO coated glass improved by a factor of 2.8 and 7.5, respectively, as compared to the uncoated glass substrate. The proposed humidity sensor successfully employs the interaction between the ZnO nanorods surface and the microfiber’s evanescent field from the microfiber, which reduce the striving effort in handling the microfiber during the synthesis process. The proposed sensor has shown an excellent sensing performance as a humidity sensor based on the experimental results.