Optical Humidity Sensing Characteristics of Ag-Polyaniline Nanocomposite

Optical transmission type humidity sensor is fabricated using spin coated films of Ag-Polyaniline nanocomposite. The material is coated layer-by-layer to get films of various thicknesses (20-40 mum). Relative humidity (RH) was generated by the standard two temperature method from 15 to 100% RH. The sensor shows quick response of 7 s and a fast recovery time of 50 s with better sensitivity for higher thickness. The Ag-Polyaniline nanocomposite is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible spectroscopy (UV), and Fourier Transform infrared spectroscopy (FTIR). The repeatability and cycle to cycle variation is studied and found to be encouraging.