Orange Dye Thin Film Electrochemical Hygrometers

Abstract

Electrochemical hygrometers have been fabricated using orange dye (OD) C17H17N5O2 thin films, deposited from aqueous solution under normal conditions. The films were deposited on zinc substrates from 10 wt.% solution of OD in distilled water. These films were than used to make samples of Zn/OD-TP/Cu, Zn/OD/Cu and Zn/OD/Graphite (TP stands for tissue paper); copper electrode was used in the form of a mesh and the graphite in the form of a porous solid. Properties of the samples were investigated in a range of 46-78% humidity. Output voltage and current of the sensors were monitored in electrochemical mode of operation, showing a rise of 8 and 100 times, respectively, with an increase in humidity. These electrochemical hygrometers may be potentially useful for developing humidity meters.