Humidity Sensor Preparation by In Situ Click Polymerization

In situ methods to prepare sensitive films can improve material film-forming properties, the reproducibility and stability of the resultant films. Mercaptopropyl polyhedral oligomeric silsesquioxane, 1,4-divinylbenzene, and sodium p-styrene sulfonate were in situ crosslinked via thiol-ene click polymerization on an interdigital electrode surface to form humidity-sensitive films. The humidity-sensing properties of the sensors were systematically researched, and the optimal sensor shows a high sensitivity and minimal humidity hysteresis. The reproducibility, water resistance, and stability of the sensors prepared by this method were studied, and the sensing mechanism was investigated by complex impedance spectroscopy, equivalent circuits, and phase diagrams.