This book covers the whole range of gas sensing aspects starting from basics, synthesis, processing, characterization, and application developments. All sub-topics within the domain of gas sensors such as active materials, novel nanomaterials, working mechanisms, fabrication techniques, computational approach, and development of microsensors, and latest advancements such as the Internet of Things (Io T) in gas sensors, and nanogenerators, are explained as well. Related manufacturing sections and proposed direction of future research are also reviewed.Features: Covers detailed state-of-the-art specific chemiresistive sensing materials. Presents novel nanomaterial platforms and concepts for resistive gas sensing. Reviews pertinent aspects of smart sensors and Io T sensing. Explains nanotechnology-enabled experimental findings, and future directions of smart gas sensing technology. Explores implication of latest advancements such as Io T in gas sensors, and nanogenerators. This book is aimed at academic researchers and professionals in sensors and actuators, nanotechnology, and materials science.