CHARACTERIZATION OF SCREEN PRINTED BaTiO3 THICK FILM HUMIDITY SENSOR

In this paper the humidity-sensitive electrical properties of BaTiO3 thick-films were studied. Thick films were screen printed onto the ceramic substrates by using the conventional thick film screen printing machine. An interdigitated electrode pattern was printed underneath the humidity sensing material layer to maximize the electrical properties between two conducting structures. The characterization of the thick film humidity sensor was measured at 1kHz, 1Vpp. The experimental results show that the sensor resistance decreases and the capacitance increases with Relative Humidity of 20 to 95%RH range. A resistance-humidity sensor characteristic shows a good linearity with a small hysteresis observed. The sensor response time and recovery time is about 7s and 15s respectively. The influence of temperature on the sensor characteristic had also been investigated. As a conclusion, screen printing of BaTiO3 thick films show a good promising material as a resistive-type humidity sensor.