In this thesis, design, fabrication, and performance analysis of some special types of capacitive sensors are reported. Three chapters are devoted to the study of interface layer property of a capacitive type probe in contact with polarizable medium and two chapters discuss the design, simulation and performance analysis of a MEMS capacitive accelerometer. A new design of a rigid capacitive type probe has been proposed. The probe immersed in a polarizable medium is modelled considering dipole layer capacitance at the interface. An electrical equivalent circuit is proposed and the circuit parameters are estimated through theoretical and experimental investigation. Next, fabrication of a new circuit device called ‘Constant Phase Element (CPE)’ is reported. Experimental observations are presented for mathematical characterization and parameter identification of the ‘CPE’. The constructed ‘CPE’ is then used to design a fractional order system. Experimental and simulation results are compared to evaluate the performance of the CPE in a fractional order differentiator circuit. The CPE has also been used as a sensor to monitor microbial reaction in yeast culture and spoilage of raw cow milk.