By prestraining the film the macromolecules will be orientated resulting in general in better mechanical properties in the direction of the orientation. Although the prestrained film is stiffer than an unstrained sample and Young’s modulus is increased, the breakdown field can be drastically enhanced. These relations are demonstrated in figure 5a, which describes the electromechanical response strain with varying prestrains from 40 to 82% for circular actuators based on one type of silicone material (SR5).