The invention describes devices for performing thermodynamic work on a fluid, such as pumps, compressors and fans. The thermodynamic work may be used to provide a driving force for moving the fluid. Work performed on the fluid may be transmitted to other devices, such as a piston in a hydraulic actuation...http://www.google.fr/patents/US7394182?utm_source=gb-gplus-shareBrevet US7394182 - Electroactive polymer devices for moving fluid
