Fabrication and Optimization of Humidity Sensor Based on Titanium Dioxide Nanoparticles

The aim of this research is to fabricate a humidity sensor based on stable nanoparticles of anatase phase of titanium dioxide, for improving its characteristics such as sensitivity, response time and recovery. For this purpose, titanium dioxide nanoparticles were synthesized by hydrothermal method, then the structural characteristics of the prepared nanostructure were examined by a scanning electron microscope. The results showed that the synthetic titanium dioxide is in the form of spheres with the average dimension of 270 nm. To prepare the humidity sensor, the prepared nanoparticles were deposited on interdigitated electrode using the blade deposition method. The research’s findings indicated that the sensitivity of the prepared anatase phase sensor is 12.81 (Rair/RHumidity)/%RH in the relative humidity range of 40-98%, improved 14% compared to the previous ideal sample which was based on rutile phase and anatase. Also, the response and recovery times of this sensor were measured as 2 and 4.5 seconds, respectively, which were 14 and 7 times higher than the previous samples.