Analytical modeling of a conducting polymer‐driven catheter

Abstract

AbstractA time‐dependent electrochemical and mechanical model of the bending of a conducting polymer actuator‐driven structure is presented, and the predicted response is compared with experimental results. The model uses time constants obtained from a transmission line model to describe the electronic and ionic charge transport into the polymer actuator. It then relates the charge transport to the mechanical deflection of the actuator structure. The model is used to predict the time‐dependent bending of an active catheter, which is ultimately intended for use in intravascular imaging. A commercial catheter is coated with polypyrrole and laser micromachined into electrodes, which are electrochemically activated, leading to bending of the catheter. The time‐dependent bending is compared with the dynamic beam bending model, with measured physical properties including elastic moduli, strain to charge ratio, electronic conductivity, ionic conductivity and capacitance used in the model to successfully describe the dynamics. The results of this comparison are used to determine the primary factors limiting catheter bending speed, and to suggest an optimal polypyrrole geometry and electrochemical parameters in order to achieve faster response. Copyright © 2010 Society of Chemical Industry