Novel capacitive humidity sensing properties of cobalt chromite nanoparticles based thick film

Novel and excellent humidity sensing properties of sol-gel prepared spinel cobalt chromite nanoparticles based microporous thick films reported for the first time. Microporous thick film was prepared by sintering a green tape of cobalt chromite prepared by tape casting which was subsequently sandwiched between two parallel silver electrodes to develop a capacitive humidity sensor. Developed sensors demonstrate excellent humidity sensing behavior in the range of 5 to 95% relative Humidity (RH) with an appreciable gain of 3 pF/%RH. Dielectric polarization of moisture molecules absorbed on the CoCr2O4 surface and condensed in the surface pores leads to an appreciable enhancement of dielectric constant hence the sensing properties. Various sophisticated experiments have been carried out to have an insight into its' physicochemical properties that culminates into the excellent moisture sensing abilities of the sensor.