Study of humidity sensing properties of TiO₂/Ethyl cellulose (EC) composite

Monitoring environment parameters such as humidity have received wide attention from the past up until now. One of the main factors to ensure the accuracy and response speed of the humidity sensor is the selection of appropriate materials and its fabrication process. The selection of suitable materials should be based on materials that exhibit good sensitivity over the entire humidity range, low hysteresis, and are resistant to various chemicals vapor. In this study, we report a capacitive type humidity sensor has been fabricated by combining titanium dioxide (TiO₂) with Ethyl Cellulose (EC) polymer. The analysis of the structure of the material was characterized by XRD. Humidity sensing performance studies on TiO₂/EC sensor sample were measured at various humidity levels from 11% to 96% relative humidity (RH) at a frequency of 1 kHz. The measurement results and analysis show that the dynamic response of the TiO₂/EC sensor capacitance with time tends to increase at higher RH, the linearity of the increase in capacitance response is relatively good, the sensor hysteresis is less than 4% from the adsorption–desorption process of water molecules, and the sensitivity of the sensor to RH is good compared to some previously reported studies, reaching up to 600% at 96% RH. Based on the results obtained, it can be concluded that TiO₂ mixed with EC is very suitable to be applied to humidity sensors.