The book contains different approaches for bio-metric analysis of water. A sensor design is given for detecting E.Coli bacteria in water. This sensor is analyzed by preparing a analytical model for the capacitance sensed by the capacitor and a circuit for signal conditioning the output of the capacitive sensor. Detail designing procedure has been provided to Four different sensors and their applications.These four different sensors help in finding and optimizing the value of sensitivity.A finally concluded design is very useful with future enhancement in micro-mixer and fluid pumps.