A novel surface acoustic wave-impedance humidity sensor based on the composite of polyaniline and poly(vinyl alcohol) with a capability of detecting low humidity
- 作者：Yang Li ; liyang@zju.edu.cn ; [Author Vitae] ; Chao Deng ; [Author Vitae] ; Mujie Yang ; [Author Vitae]
- 关键词：Surface acoustic wave ; Impedance ; Polyaniline ; Composite ; Humidity sensor ; Humidity sensing properties
- 刊名：Sensors and Actuators B ; Chemical
- 出版年：2012
- 期刊代码：161_09254005
- 类别：et
- 出版时间：April, 2012
- 卷：165
- 期：1
- 页码：7-12
- 文件大小：703 K
摘要
This paper presents a novel humidity sensor composed of a 433 MHz surface acoustic wave (SAW) resonator and an interdigitated gold electrode connected in series. The gold electrode was covered with a sensitive film of a composite of processable conductive polyaniline and polyvinyl alcohol. The frequency response of the novel SAW-impedance humidity sensor toward relative humidity (RH) was investigated at room temperature. The sensitivity of the SAW-impedance humidity sensors increased with the increase in the conductivity of the sensitive film. The sensor showed a sensitivity of 鈭?.4 kHz/%RH at 30%RH, which was increased to 60 kHz/%RH at 47%RH. Moreover, such sensors exhibited short response and recovery times and good repeatability. It is worth noting that the sensor showed a linear frequency response to humidity over the range of 0.4-20%RH with a good sensitivity of 鈭? kHz/%RH, which reveals its potentials for detecting low humidity.