Study of parameters dominating electromechanical and sensing response in ionic electroactive polymer (IEAP) transducers

Ionic electroactive polymer (IEAP) transducers are a class of smart structures based on polymers that can be designed as soft actuators or sensors. IEAP actuators exhibit a high mechanical response to an external electrical stimulus. Conversely, they produce electrical signals when subjected to mechanical force. IEAP transducers are mainly composed of four different components: The ionomeric membrane (usually Nafion) is an ion permeable polymer that acts as the backbone of the transducer. Two conductive network composite (CNC) layer on both sides of the ionomeric membrane that enhance the surface conductivity and serve as an extra reservoir to the electrolytes. The electrolytes, (usually ionic liquids (IL)), which provides the mobile ions. And two outer electrodes on both sides of the transducer to either provide a distributed applied potential across the actuators (usually gold leaves) or to collect the generated signals from the sensors (usually copper electrodes). Any variation in any of these components or the operating conditions will directly affect the performance of the IEAP transduces. In this dissertation, we studied some of the parameters dominating the performance of the IEAP transducers by varying some of the transducers components or the transducers operating conditions in order to enhance their performance. The first study was conducted to understand the influence of ionic liquid concentration on the electromechanical performance of IEAP actuators. The IL weight percentage (wt%) was varied from 10% to 30% and both the electromechanical (induced strain) and the electrochemical (the current flow across the actuators) were studied. The results from this study showed an enhanced electrochemical performance (current flow is higher for higher IL wt%) and a maximum electromechanical strain of approximately 1.4% at 22 wt% IL content. A lower induced strain was noticed for IL wt% lower or higher than 22%.