Evaluation of Circuit Models for an IPMC Sensor to Effectively Detect the Bending Angles of a Body

Abstract

Ionic Polymer-Metal Composite (IPMC) consists of an ion conductive membrane plated by metallic electrodes on both surfaces. When it bends, a voltage is generated between two electrodes. Since IPMC is flexible and thin, it can be easily mounted on the various surfaces of a body. Moreover, IPMC can produce output voltages without attenuation under large deflections. The present study investigates a sensor system using IPMC to effectively detect the bending angles applied on IPMC sensor. The paper evaluates existing R and C circuit models of IPMC and selects the best model for the detection of angles. The circuit models describe the relationship between input bending angles and output voltages. The identification of R and C values was performed by minimizing the error between the real output voltages and the simulated output voltages from the circuit models of IPMC sensor. Then the output signal of a sensor was fed into the inverse model of the identified model to reproduce the bending angles. In order to support the validation of the model, the output voltages from an arbitrary bending motion were also applied to the selected inverse model, which successfully reproduced the arbitrary bending motion. On-going work includes investigation of the selected circuit model to better understand the dynamics of the sensor as well as the relationships between electric and physical parameters of the sensor.