A sensor is a device, subsystem or module which detects changes or events in its environment. It sends the information to electronic devices such as a computer processor. All living organisms have biological sensors that are sensitive to light, motion, magnetic fields, temperature, humidity or pressure, or that can detect toxins, pheromones, nutrients, or internal metabolic indicators. Sensor devices can be designed to measure different physical parameters, such as geophones, hydrophones and seismometers can measure sounds, while air pollution sensors, actinometers and gas detectors can detect changes in the environment. Sensor accuracy and precision, and sensor deviations are essential attributes of sensors that determine their efficiency. This book elucidates new techniques and applications of sensors in a multidisciplinary manner. It includes some of the vital pieces of work being conducted across the world, on sensor devices, circuits and systems. This book aims to equip students and experts with the advanced topics and upcoming concepts of this technology.