title: Design and Development for Capacitive Humidity Sensor Applications of Lead-Free Ca,Mg,Fe,Ti-Oxides-Based Electro-Ceramics with Improved Sensing Properties via Physisorption.
abstract: Despite the many attractive potential uses of ceramic materials as humidity sensors, some unavoidable drawbacks, including toxicity, poor biocompatibility, long response and recovery times, low sensitivity and high hysteresis have stymied the use of these materials in advanced applications. Therefore, in present investigation, we developed a capacitive humidity sensor using lead-free Ca,Mg,Fe,Ti-Oxide (CMFTO)-based electro-ceramics with perovskite structures synthesized by solid-state step-sintering. This technique helps maintain the submicron size porous morphology of the developed lead-free CMFTO electro-ceramics while providing enhanced water physisorption behaviour. In comparison with conventional capacitive humidity sensors, the presented CMFTO-based humidity sensor shows a high sensitivity of up to 3000% compared to other materials, even at lower signal frequency. The best also shows a rapid response (14.5 s) and recovery (34.27 s), and very low hysteresis (3.2%) in a 33%-95% relative humidity range which are much lower values than those of existing conventional sensors. Therefore, CMFTO nano-electro-ceramics appear to be very promising materials for fabricating high-performance capacitive humidity sensors.
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. ashisbidyarthi@gmail.com.
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@gmail.com.
authors.forename: Ayan
authors.initials: A
authors.lastname: Manna
authors.affiliation: Department of Electronics &amp; Instrumentation Engineering ITER, Siksha 'O' Anusandhan University, Bhubaneswar 751030, India. satyanarayanbhuyan@soauniversity.ac.in.
authors.forename: Satyanarayan
authors.initials: S
authors.lastname: Bhuyan
authors.affiliation: Department of Paediatric Dentistry &amp; Orthodontics, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia. nabilafarhana.shah@gmail.com.
authors.forename: Nabila Farhana
authors.initials: NF
authors.lastname: Azrin Shah
authors.affiliation: Department of Paediatric Dentistry &amp; 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: hydrophilicity; mechanism; porous; recovery; relative humidity; response; stability; water absorption