Fabrication of porous anodic aluminium oxide layers on paper for humidity sensors

• Published in: Sensors and actuators. B, Chemical Vol. 220; pp. 829 - 839
• Main Authors: Balde, Mamadou, Vena, Arnaud, Sorli, Brice
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015; Elsevier
• Subjects: Aluminium oxide; Aluminum oxide; Anodic; Anodizing; Climatic chambers; Economics; Electronics; Engineering Sciences; Humidity; Humidity sensor; Nanoporous AAO layer; Nanostructure; Paper-based substrate; Sensors; Thin film; Humidity sensor; Aluminium oxide; Nanoporous AAO layer; Paper-based substrate; Thin film
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2015.05.053

The fabrication process of anodic aluminium oxide (AAO) on a paper-based substrate is challenging because the use of a highly economical, conformable and ecological substrate. This process is based on a simple, cost-effective, self-ordering anodization of aluminium, which yields a vertically aligned and a highly ordered nanoporous structure. The manufacturing process on a flexible substrate with the use of phosphoric acid is described, and a capacitive sensor produced on this layer is investigated versus the humidity concentration and the frequency. The AAO morphology and the structure obtained were analysed, and the electrical properties of the sensing layer were investigated, using a 4192A LF network analyser in a climatic chamber. The surface conduction mechanism and the effect of humidity on the dielectric properties of a porous anodic aluminium oxide are discussed.