Efficient Electron Channels Based on Pt/Au Composite Electrode Enabling Enhanced Electromechanical Performance and Extended Lifetime of Interactive Ionic Actuators

Ionic polymer-metal composites (IPMCs) are a class of low-voltage-driven ionic actuators that have drawn much attention in soft robotics. However, conventional IPMC actuators are plagued with practicality because of cracked electrodes, blocked electron transmission, and electrolyte loss, which would cause degradation in actuation performance and lifetime. Herein, IPMC with high-quality Pt/Au composite electrodes was developed, which achieved superior electromechanical properties and extended lifetime by improved electrode morphology and efficient electron channels. On one hand, the Au layer enables efficient charge transfer, resulting in 27% larger displacement compared to the Pt IPMC. Moreover, the Au layer enhances the water retention of IPMCs during operation, making it 6.15 times longer in lifetime. Finally, the interactive function of the Pt/Au IPMC was demonstrated in a bionic butterfly and a soft prosthesis. This work can provide insight into the development of high-performance actuators and pave the way for practical applications of IPMCs in robotics.