Total effective surface area principle for enhancement of capacitive humidity sensor of thick-film nanoporous alumina

•Enhancing total effective surface area can enhance alumina humidity sensing.•Reducing anodizing potential for the increased surface area benefits capacitance sensing.•The alumina humidity sensor formed at 20 V enhances 2–3 times capacitance than those at 40–50 V.•An enhanced linear-like relationshi...

Ausführliche Beschreibung