Fabrication of a Fractional Order Capacitor With Desired Specifications: A Study on Process Identification and Characterization

This paper reports the fabrication of a fractional order element (FOE) with predefined specifications. The FOE is a circuit element similar to resistance, capacitance, and inductance generally used in electrical network. The specifications of integer order elements, i.e., inductance, resistance, and capacitance, are defined by the magnitude only as their exponents are of fixed value, namely, - 1, 0, and + 1, respectively. The specialty of FOE is that both its magnitude and exponent value have to be defined, where the value of the exponent dictates the behavior. This paper elaborately discusses the methodology of realizing a fractional order capacitor named here as FOE (or, in general, FOE). It has been found that a FOE can be realized by dipping a capacitive-type probe, coated with a porous film of polymer of particular thickness, into a polarizable medium. The thickness, uniformity, and stability of the porous film, on the electrode, are responsible for different exponent values.