As research efforts towards making functional micro/nano robotics system gather more momentum, there is an increasing need for new actuators that can not only be suitable to miniaturization, but also be free from sliding and rolling elements so that they can generate a motion resolution and accuracy in a submicron range. Conducting polymer actuators have many features to satisfy such a strict requirements. Before introducing them to the micro/nano robotics world, it is necessary to investigate into their actuation mechanism and the smallest displacement they can generate. In this paper, we report on the characterization and modelling of a strip-type fourth generation polypyrrole polymer (PPy) actuator, which operate in a non-liquid medium, i.e. in the air. After deriving a mathematical model approximately accounting for mechanical, electrical, and chemical properties and geometric parameters of the actuator, the model has been experimentally verified for an actuator with the dimensions of (10 mm times 1 mm times 0.21 mm). Theoretical and experimental results are presented to demonstrate that the model is effective enough to predict the displacement output of the strip type-PPy actuator all along the edge of the actuator as a function of the applied voltage.