An electroactive polymer actuator useful in biomedical applications is disclosed. The electroactive polymer includes a dielectric elastomer film with a metallic mesh embedded therein, and two electrodes, each coating a respective major surface of the film. In some aspects, a cardiac assist device using such an electroactive polymer actuator is disclosed. The cardiac assist device includes a sleeve that substantially surrounds a persons heart and that is electrically insulated from its surroundings. Optionally, the cardiac assist device includes multiple regions connected to a power source in such a way that each region can be activated independently from the others. In other aspects, a method of using such a cardiac assist device to contract a heart is disclosed. A voltage is applied to the metallic mesh and the electrodes are grounded creating respective electric fields between the metallic mesh and each electrode, causing the cardiac assist device to contract.