Recently we have shown that a composite material of silk and the conducting polymer polypyrrole (PPy) has promising characteristics for use as a bending bilayer actuator. In this study, the reaction conditions were varied for the in situ incorporation of polypyrrole into silk films during pyrrole polymerization. While surface morphology and mechanical properties were minimally affected, polymerization conditions were identified where the resistivity, stability of the films during storage and stability during prolonged electrochemical cycling were dramatically improved. When fabricated into bilayer-type electromechanical actuation devices, stress and strain generation, as well as the stability during repeated actuation, was found to be superior for silk-polypyrrole composite films with improved electrical properties. (C) 2016 Elsevier B.V. All rights reserved.