Experimental Characterization of Direct Assembly Process Based Ionic Polymer Transducers in Sensing

Ionic Polymer Transducers (IPTs) are electroactive ion exchange membranes that are plated with metals which provide a capacitive property appropriate for sensor/actuator applications. IPTs bend when a voltage difference is applied across the surfaces of the transducer performing actuation behavior and produce current when they are deformed exhibiting sensing behavior. However, the response of the IPT as an actuator or as a sensor differs from each other since the mechanism responsible from actuation and sensing are different. Existing research in this field is mostly focused on actuation behavior. Therefore, in this study emphasis is on sensing where the IPTs have been prepared via the Direct Assembly Process (DAP). The DAP is selected because it enables experimental control over the electrode architecture, which may ultimately be exercised to explore the underlying physics responsible for sensing. Five lithium exchanged transducers are prepared with 1-ethyl-3 methylimidazolium trifluoromethanesulfonate (EmI-Tf) ionic liquid as the diluent, and high surface area RuO₂ as the metallic powder. The IPTs are then cantilevered and subject to step displacements.