A sensor is a device, which responds to a physical or chemical stimulus in order to produce a measurable detection signal or to control another operation [1]. Sensors are encountered in innumerable applications and have become an integral part of our day-to-day life. Examples of everyday use of sensors include a thermocouple, which responds to the change in temperature by an output voltage, or a touch-sensitive sensor of an interactive monitor screen. Basically, a sensor can respond, that is change its signal, to a single factor being sensed, i.e. either to the change of temperature or pressure in the above examples.