Characterisation of Inkjet-Printed Poly(3,4-ethylenedioxythiophene) Polystyrene Sulfonate (PEDOT:PSS) Sensing Film on Flexible Substrate for Humidity Sensor Application

This work presents a preliminary study towards the fabrication and characterisation of a printed humidity sensor to be integrated into a chipless radio frequency identification (RFID) device. The sensing element of the humidity sensor has been developed using poly(3,4-ethylenedioxythiophene) polystyrene sulfonate PEDOT:PSS as the sensing film and graphene-based inks as the conductive track on flexible polyethylene terephthalate (PET) substrate through inkjet printing technique. From this study, it has been shown that the sensor is capable of detecting humidity changes ranging from 18% to 85% with a 2-layer printing of PEDOT:PSS sensing film.