The aim of present study is to design a simple and reliable capacitive humidity sensor based on the nanoporous alumina prepared by a two-step anodization technique. Owing to long-range-ordered structure of porous alumina, its electrical properties are sensitive to moisture; with the result, it finds potential applications as humidity sensor. Anodization parameters have been optimized to prepare a series of porous alumina samples in different acidic electrolytes, and the effect of pore size, porosity, and uniformity of pores on humidity sensing was investigated. The sensitivity of the sensor fabricated in oxalic acid at 40 V is 2–3 times higher than the sensors fabricated in sulphuric acid at 25 V and phosphoric acid at 98 V. Its enhanced sensitivity is justified by small porosity and uniformity in pore distribution of porous alumina. The sensitivity of the sensor fabricated in oxalic acid solution with pore diameter 34 ± 1 nm and porosity 10 ± 0.5% reaches up to 0.21 (pF/RH%).

本研究的目的是基于通过两步阳极氧化技术制备的纳米多孔氧化铝设计一种简单可靠的电容式湿度传感器。由于多孔氧化铝的长程结构，其电学性质对水分敏感。结果，它发现了作为湿度传感器的潜在应用。优化了阳极氧化参数，以在不同的酸性电解质中制备一系列多孔氧化铝样品，并研究了孔径，孔隙率和孔隙均匀性对湿度传感的影响。用草酸在40 V下制造的传感器的灵敏度是用25 V硫酸和98 V磷酸制造的传感器的2-3倍。其增强的灵敏度是由小的孔隙率和均匀的孔隙分布证明的。氧化铝。