Synthesis of calcium doped zinc ferrite nanomaterial and its application as a humidity sensor

Abstract

A humidity sensor array can be used in applications requiring non-contact sensing and contactless interface localization, which became a significant area of research after COVID-19 and reduced the risk of bacterial transmission associated with conventional touch displays. In this study, a thin film humidity sensor has been designed using calcium (Ca) doped zinc ferrite (ZnFe2O4) nanomaterial, which has been prepared by the sol-gel auto-ignition process. The synthesized nanomaterial was characterized using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-Ray (EDX) techniques. The doping of Ca reduces the crystallite size and increases the lattice constant. Attempts have been made to determine the different humidity sensing parameters. The developed humidity sensor has a response time of 12 seconds and a recovery time of 66 seconds. The developed humidity sensor has good repeatability and a negligible aging effect.