Modeling of ICPF (ionic conducting polymer gel film) actuator (2nd report, electrical characteristics and linear approximate model)

An ionic conducting polymer gel film (ICPF) actuator, which is a kind of high polymer gel actuator, is a composite that has a 184-μm-thick perfluoro-sulfonic acid membrane sandwiched between platinum layers. In this paper, modeling of the actuator is investigated. First, the modeling strategy of the actuator dynamics is considered because the principle of the actuator is unknown. The assumption of division of its characteristics between input (voltage) and output (displacement) into three stages: an electrical stage, a stress generation stage and a mechanical stage, is reasonable according to observation and consideration of the actuator responses. The electrical characteristic model involves surface resistances comprised of porous platinum layers, resistance of the gel membrane permeated with water, and a characteristic resembling a 1st-order delay that is expressed in terms of series connections of a resistance and capacitance. A distributed parameter system consisting of the above elements can be used to represent the electrical dynamics of the actuator.