In the last decades, research into the electrostrictive ploymers as promising materials for energy harvesting using its ability to convert mechanical to electrical energy is beginning to reveal its potential for this application. These materials exhibit a strong electro-mechanical coupling and are also very flexible and very light. They deform when subjected to an electric field and can generate a current or an electric field when subjected to mechanical deformation. The new advancement of electro-active polymers has opened up new avenues for high strain actuators. The intrinsic properties of electro-active polymers (electrical permittivity, electrical losses, Young's modulus…) represent a crucial role in their performance in order to improve the response in actuator mode but also on the recoverable power density in generator mode. The purpose of this paper is to show the effect of various types of signals of polarization and their roles to increase the harvested power. This specific study is performed theoretically and experimentally, and a good agreement is found between these two treatments.