  Due to the increasing number of industrial applications of electro-active
polymers (EAPs), there is a growing need for electromechanical models which
accurately capture their behavior. To this end, we compare the predicted
behavior of EAPs undergoing homogenous deformations according to three
electromechanical models. The first model is a continuum based model composed
of the mechanical Gent model and a linear relationship between the electric
field and the polarization. The electrical and the mechanical responses
according to the second model are based on the polymer microstructure, whereas
the third model incorporates a neo-Hookean mechanical response and a
microstructural based long-chains model for the electrical behavior. In the
microstructural motivated models the integration from the microscopic to the
macroscopic levels is accomplished by the micro-sphere technique. Four types of
homogeneous boundary conditions are considered and the behaviors determined
according to the three models are compared. The differences between the
predictions of the models are discussed, highlighting the need for an in-depth
investigation of the relations between the structure and the behaviors of the
EAPs at microscopic level and their overall macroscopic response.
