Polypyrrole was obtained by chemical synthesis. The extension of polymerization time to 96 h produced a polypyrrole that was suitable for absorbing moisture. The structure and morphology of polypyrrole were characterized by infrared (IR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Properties of this humidity sensor were investigated and complex impedance plots were obtained from 20 Hz to 100 kHz. The sensing mechanism was discussed based on test results. Using complex impedance analysis we studied the working principle of the humidity sensor and confirmed the identity of the conductive particles.

【Key Words】： Polypyrrole Humidity sensor Complex impedance 

【Fund】： 吉林省科技厅(20060528)资助项目 

【CateGory Index】： O633.5

【DOI】： CNKI:SUN:WLHX.0.2009-02-025