Ionic polymer-metal composite mechanoelectrical transduction: review and perspectives

This paper presents a comprehensive review of the use of ionic polymer-metal composite (IPMC) materials as mechanoelectrical transducers. Recently increasing emphasis has been put on the research of IPMCs as displacement or velocity sensors for various applications. This has resulted in various theories and models to describe the mechanoelectrical transduction phenomenon. The paper gives an overview of the proposed transduction principles, developed models and the latest applications. In more detail, the history of IPMC materials, the physics and the electrochemistry behind the mechanoelectrical transduction, different black-box and gray-box models, and novel real-world mechatronics-related applications are discussed throughout the paper. However, despite the latest advancements in the research of IPMC transduction, there is still a certain amount of controversy regarding some of the IPMC sensorial properties. For instance, it has been noticed by several authors that there is a signal delay when bending an IPMC. The general understanding of the physical principles about regular IPMC mechanoelectrical transduction is rather good. In the last section of the paper novel results are presented for copper-coated IPMC materials. Apparently the electrochemistry behind the transduction for copper-coated IPMCs is significantly different. Besides ionic diffusion, chemical reactions on the electrodes also occur and dominate the actuation process. Experimental results show some promising opportunities for designing new copper-coated IPMC-based sensors. (C) 2010 Society of Chemical Industry