Chapter 24 - Humidity nanosensors for smart manufacturing

Abstract

In recent times, humidity measurement has become an essential physical quantity for measurement, as it is used in a plethora of domestic and industrial applications, including moisture control in multistory buildings, areas in automobile manufacturing plants that must avoid corrosion, environmental measurements, the beverage industry, pharmaceuticals, cosmetics, and food processing analysis industries. Furthermore, if water vapor is present in a processing unit, it can affect the final product, possibly causing changes in its material, biological, and physical properties. Measurement of humidity in the industry is challenging due to its high cost and fewer safety aspects, and thus humidity measurement is a significant research area. There are several humidity sensors available based on materials like ceramic, metals, polymers, and 2D materials. However, sensors based on these materials are very costly, have high recovery and response times, involve complex fabrication processes, and also are not environmentally friendly. On the other hand, humidity sensors fabricated from nanomaterials are very affordable, highly accurate, have high surface area, have long-lasting properties and nontoxic properties, as well as an easy manufacturing procedure. To increase the production rate in industry as well as accuracy and precision, smart manufacturing is needed. It is a manufacturing concept based on fully automatic machinery that reduces the human effort in industry and enables better controlled production. In this process the role of humidity sensors is vital, as humidity is a critical factor that needs to be measured in many applications related to smart manufacturing. This chapter reviews different types of humidity nanosensors, describing the state of the art, how they are used in smart manufacturing, fabrication methods, and important applications.