title: Uniformly Porous Nanocrystalline CaMgFe1.33Ti₃O12Ceramic Derived Electro-Ceramic Nanocomposite for Impedance Type Humidity Sensor.
abstract: Since humidity sensors have been widely used in many sectors, a suitable humidity sensing material with improved sensitivity, faster response and recovery times, better stability and low hysteresis is necessary to be developed. Here, we fabricate a uniformly porous humidity sensor using Ca, Ti substituted Mg ferrites with chemical formula of CaMgFe1.33Ti₃O12as humidity sensing materials by solid-sate step-sintering technique. This synthesis technique is useful to control the grain size with increased porosity to enhance the hydrophilic characteristics of the CaMgFe1.33Ti₃O12nanoceramic based sintered electro-ceramic nanocomposites. The highest porosity, lowest density and excellent surface-hydrophilicity properties were obtained at 1050 °C sintered ceramic. The performance of this impedance type humidity sensor was evaluated by electrical characterizations using alternating current (AC) in the 33%-95% relative humidity (RH) range at 25 °C. Compared with existing conventional resistive humidity sensors, the present sintered electro-ceramic nanocomposite based humidity sensor showed faster response time (20 s) and recovery time (40 s). This newly developed sensor showed extremely high sensitivity (%S) and small hysteresis of <3.4%. Long-term stability of the sensor had been determined by testing for 30 consecutive days. Therefore, the high performance sensing behavior of the present electro-ceramic nanocomposites would be suitable for a potential use in advanced humidity sensors.
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. ashisbidyarthi@siswa.um.edu.my.
authors.forename: Ashis
authors.initials: A
authors.lastname: Tripathy
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. prsumit@gmail.com.
authors.forename: Sumit
authors.initials: S
authors.lastname: Pramanik
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. ayanbabu@siswa.um.edu.my.
authors.forename: Ayan
authors.initials: A
authors.lastname: Manna
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. hanie_nadia@um.edu.my.
authors.forename: Hanie Nadia
authors.initials: HN
authors.lastname: Shasmin
authors.affiliation: Department of Paediatric Dentistry & Orthodontics, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia. zamrir@um.edu.my.
authors.forename: Zamri
authors.initials: Z
authors.lastname: Radzi
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. prsumit@um.edu.my.
authors.forename: Noor Azuan
authors.initials: NA
authors.lastname: Abu Osman
keywords: long-term stability; mechanism; moisture; nanoceramic; porosity; recovery; resistive; sensitivity