Functional nanomaterials in flexible gas sensors: recent progress and future prospects

Flexible gas sensors have recently attracted researcher's great attention due to their applications in wearable electronics for different fields like environmental protection, food quality measurement, health supervision, etc. The bulky and complex system of conventional gas sensors hinders their applications in wearable sensing technology. Due to low cost, easy-to-use, and real-time monitoring of harmful gases, there is a rapid increase in the development of flexible gas sensors. With the mechanism of gas sensing and specification of various flexible substrates, this review article comprises a detailed discussion on nanomaterials utilized to fabricate flexible gas sensors. Specifically, all the functional materials are characterized according to their physical and chemical properties. In this article, flexible gas sensor characteristics such as sensitivity, selectivity, response time, operating temperature, and flexibility & bendability profile are discussed in detail for each material. The present review article shows the recent advancements in flexible gas sensors from the sensing material aspect and specifies their applications in various areas. Lastly, the future scope of development, like modification in morphology, functionalization, size alteration, etc., is summarized according to their current status.