A theoretical model for analysis of ionic polymer metal composite sensors in fluid environments

By the past two decades IPMCs have been intensively studied because of their special capabilities for actuation and sensing.This paper presents a theoretical physics based model for analyzing the behavior of IPMC sensors in fluid environments. The mechanical vibration of the IPMC strip is described by the classical Euler–Bernoulli beam theory. The model also takes in to account the physical properties of the surrounding fluid. The resulting model is an infinite-dimensional transfer function that relates the input tip displacement to the output sensing current. Further the original model is reduced to a finite-dimensional one, for pure sensing applications of IPMC sensors such as structural health monitoring. The proposed model is verified using existing experimental data. Then the effect of various parameters is investigated. The acoustics physics interface in COMSOL Multiphysics software is used for coupled modal analysis of the IPMC strip. It is shown that the effect of surrounding fluid cannot be neglected.