Abstract

The scope of this dissertation research is formulated to develop designs of fully integrated surface micromachined humidity sensors which can be realized using the standard CMOS process, and low cost and efficient post processing techniques. The configurations of resistive and capacitive humidity sensors are designed, analyzed and optimized for miniaturization. The sensing properties of various humidity sensitive materials are reviewed in view of their potential application in microsensors. Polyaniline compound is proposed for fabrication of prototype micro humidity sensors. Analytical models of the resistive and capacitive microsensors are developed to study the steady-state and transient performance characteristics of the sensor. The properties of the proposed compound are analyzed through fabrication and testing of an array of laboratory samples. Different designs of conditioning circuits are further presented for integration. Different post-processings are analyzed, and low cost and efficient post-processing technique for fabrication of humidity sensors, based upon spincoating alone, is proposed