Abstract
Because a polyurethane film can be bent by applying an electric field, it may be used as a polymer actuator. Although this bending phenomenon is called bending electrostriction, its mechanism has not been fully clarified. In this study, a model was developed in which the origin of the bending was assumed to be the electrostatic attraction between the induced charge on the electrode and the space charge in the film. On the basis of this model, the magnitude of the bending was estimated. The dependence of the estimated magnitude on the electric field, or on the film thickness, was similar to that of actual measurements. However, the estimated magnitude was somewhat greater than the measured magnitude. This difference could be attributed to the constraint imposed by the gold coating used as the electrode.