State of Art of Spinel Ferrites Enabled Humidity Sensors

Abstract

Controlling the moisture level in air and gases is an important aspect in defense, weather station, industry, laboratory and healthcare systems. The accurate measurement and sensing of the humidity/moisture level in the surrounding environment can help to maintain the temperature level for ideal living conditions; from a safety point of view, it can help to prevent the virus/disease transmission; importantly, it can protect expensive equipment, electronic devices and optical devices against damage which are sensitive to high humidity in the atmosphere. The controlled monitoring, regulation and management of humidity necessarily require humidity sensors with high sensitivity, high stability and low response time. Currently, there are various types of humidity sensors available in the market, but there are always limitations on the practical applications as the main problems are associated with their eco-friendly nature, cost, sensitivity, response time (rapid action) and lifetime. Aiming to address these issues, the spinel ferrite nanostructures arise as promising nanomaterials due to their moderate semiconducting features with high resistance, porous nature and high surface activities enabling easy fabrication of the humidity sensors. This chapter provides an overview of the role of spinel ferrite nanostructures for their applications in humidity sensors.