Enhancement of IPMC Bending Controllability Through Immobile Negative Charges and Electrochemically Reactive Substances Within IPMC Body

Abstract

A well-known soft actuator, called ionic polymer–metal composite (IPMC), is a type of electroactive polymer (EAP) that operates in bending mode. Despite its ability to exhibit large bending, its bending controllability is often poor. Therefore, identifying the key factor that allows IPMC to bend without losing its large bending capability is a natural inquiry for researchers studying IPMC for practical applications. Our study found that the sign of the immobile charge carried by the ion exchange membrane of IPMC governs its bending controllability. We also discovered that using a negatively charged ion exchange membrane, rather than a positively charged one, is highly preferable for IPMC applications. It was also found that using a doping process and an electrochemically active electrode is essential for inducing effective bending in IPMC.