Ionic polymer-metal composites have been made from radiation grafted fluorinated ethylene propylene (FEP) membranes. Membranes have been synthesized by grafting of styrene on FEP films followed by sulfonation. These membranes were then used to fabricate IPMCs. Chemical plating of silver has been done to form the microelectrodes. Influence of degree of grafting on actuation, surface resistance, and tensile properties of the IPMC have been evaluated. It has been observed that on increasing the degree of grafting surface resistance, tensile strength, and elongation of IPMC decrease while degree of actuation and modulus increase. (c) 2008 Wiley Periodicals, Inc.