Carbon nanotube buckypapers and Nafion composites demonstrate the potential to offer a combination of sensing and actuating abilities for lightweight and flexible applications. These materials have a promising future in the applications of robotic and biomedical systems. This paper describes the modelling of the electromechanical conversion phenomena pertaining to buckypaper/Nafion actuators. The physical properties of buckypaper and Nafion, including Young's modulus and electrical double layer capacitance, serve as key factors in the actuators' performance. Moreover, established by a convolution procedure, the proposed approach is able to study the hysteresis under an electric field. The generated displacement of the cantilevered buckypaper/Nafion actuators were calculated and show an excellent agreement between the computed tip strains and the measured data over a wide frequency range. Published by Elsevier B.V.