ABSTRACT

Humidity is present in almost all manufacturing processes; thus, demand of humidity sensors is ever increasing. Meanwhile, titanium has been exceedingly used in various industries owing to its unique and extraordinary properties. Specifically, for machine tools industry, titanium is preferred due to its excellent mechanical properties even under corrosive and harsh environments. At the same time, humidity and temperature sensors are essential parts of machine tools. In this work, pure titanium discs are reverse engineered to obtain TiO2 by controlled thermal oxidation process and used for monitoring relative humidity (RH). TiO2 powder was sprayed onto alumina substrates with already patterned inter-digitated electrodes (IDEs) for sensor fabrication. The sensors were employed to monitor humidity level. Further performance characterization to predict the electrical and physical–chemical sensing mechanism were carried out. The prepared sensors have high potential for humidity monitoring due to their low-cost fabrication, excellent sensing characteristics, and good stability.