Design and Fabrication of PVA-Based Relative Humidity Sensors Using Thick Film Technology

This paper discusses the design and fabrication of relative humidity sensors with Polyvinyl Alcohol (PVA) as a sensing layer using thick film technology. The design is optimized to produce the ideal geometry according to the limits of thick film technology. The sensor fabrication process uses a screen printing technique on an Alumina (Al ₂ O ₃ ) substrate with AgAl as a material for its conductor path. PVA deposition as a sensing layer is done by the spin coating method. Sensor fabrication test results are carried out by varying the 4 humidity points in the chamber with the hygrometer as a reference. Based on the test results it is known that the sensor shows a response to humidity in the form of a resistance value, if the environment around the sensor is more humid, the resistance will decrease. The relatively high value of PVA-based humidity sensor resistance can be reduced by mixing PVA with metal oxide in this study using SnO ₂ .