Tripathy Ashis, Pramanik Sumit, Manna Ayan, Bhuyan Satyanarayan, Azrin Shah Nabila Farhana, Radzi Zamri, Abu Osman Noor Azuan
Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia.
Department of Electronics & Instrumentation Engineering ITER, Siksha 'O' Anusandhan University, Bhubaneswar 751030, India.
Sensors (Basel). 2016 Jul 21;16(7):1135. doi: 10.3390/s16071135.
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.
尽管陶瓷材料作为湿度传感器有许多吸引人的潜在用途，但一些不可避免的缺点，包括毒性、生物相容性差、响应和恢复时间长、灵敏度低以及滞后性高，阻碍了这些材料在先进应用中的使用。因此，在本研究中，我们开发了一种电容式湿度传感器，该传感器使用通过固态分步烧结合成的具有钙钛矿结构的无铅Ca、Mg、Fe、Ti氧化物（CMFTO）基电陶瓷。该技术有助于保持所开发的无铅CMFTO电陶瓷的亚微米尺寸多孔形态，同时提供增强的水物理吸附行为。与传统电容式湿度传感器相比，所展示的基于CMFTO的湿度传感器即使在较低信号频率下也显示出高达3000%的高灵敏度，与其他材料相比。在33%-95%的相对湿度范围内，其还表现出快速响应（14.5秒）和恢复（34.27秒），以及非常低的滞后性（3.2%），这些值远低于现有传统传感器。因此，CMFTO纳米电陶瓷似乎是制造高性能电容式湿度传感器非常有前途的材料。
