The fabrication of a dry type conducting polymer actuator is presented using nitrile rubber ( NBR) as the base material for the solid polymer electrolyte. A conducting polymer, poly( 3,4- ethylenedioxythiophene) ( PEDOT), was synthesized on the surface of the NBR by the chemical oxidation polymerization technique, and room temperature ionic liquids ( RTIL) based on imidazolium salts, viz. 1- butyl- 3- methyl imidazolium X [ where X = BF4-, PF6-, (CF3SO2)(2)N-], were introduced onto the composite film. The effects of the anion size of the ionic liquids on the displacement of the actuator were investigated. The displacement increased with increasing anion- size of the ionic liquids. The cyclic voltammetric responses and the redox switching dynamics of the actuators were studied in different ionic liquids.