Fabrication and Performance Improvement of Ionic Polymer-Metal Composite (IPMC) Artificial Muscles

Ionic polymer-metal composites (IPMCs) are soft electroactive layers capable of generating muscle-like bending under low electrical potentials, typically less than ۵ V. Their light weight, silent operation, high conformability and deformation make them attractive for applications in artificial muscles, soft grippers, biomedical microdevices, underwater propulsion and wearable tactile devices. However, conventional Nafion/Pt IPMCs still exhibit limited blocking force, electrode cracking, water loss in air, surface resistance, nonlinear hysteresis and re-relaxation. This paper presents a specialized study and research of the fabrication and testing and performance improvement strategies for IPMC artificial muscles. A multilayered route has been tested: controlled surface roughening of Nafion, imidazolium ionic liquid impregnation, electroless platinum deposition, spin coating of PEDOT:PSS, and controlled drying/aging. The proposed interfacial composite electrode (ICE) concept is evaluated using FTIR, SEM/TEM, XRD, DSC, electrochemical impedance spectroscopy, cyclic voltammetry, tip displacement, blocking force, and cyclic stability analyses. The results show that surface roughening improves the mechanical interlocking and effective electrode area; ionic liquids stabilize ion transport and reduce dehydration; Pt provides high electronic conductivity and electrochemical activity; and PEDOT:PSS improves surface integrity, flexibility, and charge storage. Comparative synthesis shows that optimized ICE-IPMC structures may increase the capacitance from approximately ۴ to ۳۰–۳۵ mF cm۲, increase the blocking force from approximately ۱ mN to ۴–۶ mN, and significantly reduce the performance degradation in ambient air. A design matrix, test protocol, and industrial risk analysis are presented to guide repeatable fabrication and scale-up. The study concludes that IPMC performance is maximized not by a single additive, but through coordinated engineering of the interface, ion, electrode, and processing.

کلیدواژه ها:

IPMC ، artificial muscle ، Nafion ، imidazolium ionic liquid ، platinum electroless plating ، interfacial composite electrode ، soft actuator ، EIS ، cyclic voltammetry