Humidity Detection Based on Chitosan/PEO Film Sensor

PEO (Polyethylene Oxide) addition in chitosan has been successfully fabricated as a humidity sensor. In this study, 3% w/v chitosan solution was added by 0.1, 0.2, 0.3, 0.4 and 0.5 (%w/v) of PEO respectively. The sensing properties of chitosan and chitosan/PEO films as humidity sensors have been characterized using Air Handling Unit Trainer, model KT-2000AHU to determine response, repeatability, and recovery toward relative humidity (20-90% RH). The results show that the chitosan/PEO films have a good response when exposed to 90 %RH at room temperature. Those are 288,09 mV obtained by pure chitosan film; 338.97, 384.44, 406.81, 359.69, and 345.84 mV for 0.1, 0.2, 0.3, 0.4, and 0.5% of PEO films respectively that show higher electrical response. The smooth and porous film morphology and chemical interaction between chitosan and PEO through hydrogen bond obtained by SEM and FTIR could be responsible for the higher electrical response. Furthermore, humidity sensing material based on chitosan/PEO films shows good recovery and repeatability.