%0 Journal Article
%T Experimental Characterization of Ionic Polymer Metal Composite as a Novel Fractional Order Element
%A Riccardo Caponetto
%A Salvatore Graziani
%A Fulvio L. Pappalardo
%A Francesca Sapuppo
%J Advances in Mathematical Physics
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/953695
%X Ionic polymer metal composites (IPMCs) are electroactive materials made of ionic polymer thin membranes with platinum metallization on their surfaces. They are interesting materials due to not only their electromechanical applications as transducers but also to their electrochemical features and the relationship between the ionic/solvent current and the potential field. Their electrochemical properties thus suggest the possibility for exploiting them as compact fractional-order elements (FOEs) with a view of defining fabrication processes and production strategies that assure the desired performances. In this paper, the experimental electrical characterization of a brand new IPMC setup in a fixed sandwich configuration is proposed. Two IPMC devices with different platinum absorption times (5£¿h and 20£¿h) are characterized through experimental data: first, a preliminary linearity study is performed for a fixed input voltage amplitude in order to determine the frequency region where IPMC can be approximated as linear; then, a frequency analysis is carried out in order to identify a coherent fractional-order dynamics in the bode diagrams. Such analyses take the first steps towards a simplified model of IPMC as a compact electronic FOE for which the fractional exponent value depends on fabrication parameters as the absorption time. 1. Introduction Ionic polymer-metal composites (IPMCs) as electroactive polymers (EAPs) have the very interesting capabilities of transforming electrical energy into mechanical energy, and vice versa [1, 2], making them privileged candidates for the realization of actuators or sensors with features as low required voltage, high compliance, lightness, softness, and so forth, thus, creating great interest in possible applications in very different fields such as robotics, aerospace, and biomedics [3¨C5]. They are composite materials made of ionic polymers in presence of solvent with layers of noble metals on their surfaces. Their structure and composition make their full exploitation currently limited because of the incomplete knowledge of their working principles and therefore a not clearly defined design procedure. Due to their electromechanical properties, they have been traditionally characterized as transducers, both as sensors and actuators, and three different strategies have been used to describe the relationship between the electrical and the mechanical behaviors [6]. The first one, referred to as black box and behavioral model, provides a purely empirical model of IPMCs obtained through a series of curve fits based on
%U http://www.hindawi.com/journals/amp/2013/953695/