E-Nose and E-Tongue: Applications and Advances in Sensor Technology

A sensor is a device, which responds to an input quantity by generating a functionally related output usually in the form of an electrical or optical signal. A sensor's sensitivity indicates how much the sensor's output changes when the measured quantity changes. An electronic nose (E-Nose) is a device intended to detect odors or flavors. The expression "electronic sensing" refers to the capability of reproducing human senses using sensor arrays and pattern recognition systems. The electronic tongue (E- Tongue) is an instrument that measures and compares tastes. The electronic tongue uses taste sensors to receive information from chemicals on the tongue and send it to a pattern recognition system. The result is the detection of the tastes that compose the human palate. The sense of smell and taste has long played a fundamental role in human development and biosocial interactions. Electronic noses were originally used for quality control applications in the food, beverage and cosmetics industries. Current applications include detection of odors specific to diseases for medical diagnosis, and detection of pollutants and gas leaks for environmental protection. Electronic Tongues have several applications in various industrial areas: the pharmaceutical industry, food and beverage sector, etc. In this paper, we have discussed the applications and advances of E-Nose and E- Tongue.