Modelling and experimental characterization of an ionic polymer metal composite actuator

Abstract

This study is about modelling an ionic polymer metal composite (IPMC) actuator and the experimental characterization thereof. In this study a brief background on IPMCs are given to the reader and then the research that has been done in various fields that are of importance to this study was discussed. From this the equipment required to develop an experimental setup was determined. The experimental setup was designed and mainly consist of a load cell, a laser displacement sensor, a data acquisition system, and a clamp for the IPMC. A grey box model was used that consist of an electrical equivalent circuit and an electromechanical model. The model was implemented in Simulink and was verified by using parameters and results from literature. The parameter estimation that was done in Simulink was also verified with those values. The model was developed for a Nafion N117 sample plated with a Platinum loading of 10 mgPt/cm2. The model could sufficiently predict the absorbed current and the blocked force. The behaviour of seven different samples were investigated. Samples varied in terms of the Platinum loading and the membrane thickness. The response of each sample was investigated for different input voltages. The influence of input voltage, input frequency, humidity and temperature was also investigated. It was seen that the amplitude of the input voltage, the relative humidity and the temperature affect the response of the IPMC greatly. The experimental data from the sample was used to validate the model. The model could sufficiently predict the blocked forces and the displacement for a step input.