Electrical and humidity sensing properties of K+-nano-mica film

An impedance-type humidity sensor was made using K+-nano-mica film. Complex impedance spectra were obtained to analyze the humidity sensing and electrical properties of the humidity sensor. The sensor had a high sensitivity and its sensing-linearity depended on the applied frequency. The temperature dependence between 15 and 35 °C was from −0.1%RH/°C to −0.67%RH/°C at 20–90%RH, respectively. The sensor exhibited a small hysteresis, a fast response time and good long-term stability. The different complex impedance plots obtained at low and high relative humidity indicated that the ions dominate the conductance of the K+-nano-mica film.