室温下纳米多孔氧化铝湿度传感器的研究

Investigations of room temperature nanoporous alumina humidity sensor

研究了纳米级多孔氧化铝为敏感膜的湿度传感器的制备、性能和感湿机理.用阳极氧化法制得纳米多孔氧化铝,用LCR测量仪研究了该传感器的电容和阻抗随湿度变化的特性,结果发现其电容特性和阻抗特性在33%～97%相对湿度(RH)范围内线性度很好.并用等效电路模型对传感器的复阻抗特性进行了分析,讨论了传感器的感湿机理.结果表明,在低湿下该传感器等效于一个R、C并联电路,以电子导电为主;在高湿下等效于两个R、C并联电路的串联,以离子导电为主.

A humidity sensor based on porous alumina was investigated. The porous alumina was fabricated using electronic chemical etching. An LCR instrument was used to measure the capacitance and impedance characteristics related with relative humidity (RH). The results indicated that the capacitance and impedance characteristics had excellent linearity. The complex impedance characteristic was analyzed by means of an equivalent circuit model. It is concluded that the sensor is equivalent to an R/C parallel circuit and conducts mainly through electrons at low RH, while two R/C parallel circuits in series and conducts through ion at high RH.