Dielectric elastomer stack actuator modules with integrated electronics and encapsulation

Integrated electromechanical actuator modules have been developed which consist of dielectric elastomer actuators (DEA), high voltage electronics to control the actuators and encapsulations to prevent the actuators from contact with surrounding media. As DEA, commercial stack actuators. Different materials have been studied as encapsulations such as silane modified polymers and silicone elastomers. Two different types of integrated actuator modules were developed in order to evaluate different encapsulation concepts. Therefore, the actuator modules are either encapsulated by a polymer film (AMF: Actuator Module encapsulated with Film) or by a polymer hood (AMH: Actuator Module encapsulated with Hood). The polymer films used for encapsulation were processed via doctor blading while the polymer hoods were casted using laser sintered molds. The encapsulations show a suitable dielectric breakdown strength as well as appropriate seal-ing according to gases and water up to pressures of some bar, depending on the kind of material. Force-stroke dependen-cies were investigated in order to evaluate how encapsulation films influence the actuator performance. The developed high voltage electronic unit allows the application of 850 V. It operates at 24 V industrial standard and has a size of approximately 20 mm x 20 mm x 12 mm. Finally, the actuator modules were constructed by integration of the different components such as the stack actuators, the electronics as well as the encapsulations. The integrated actuator modules were characterized regarding their electromechanical properties. Although the encapsulation slightly affects the performance of the actuators, the ability to run the actuator modules in difficult environmental conditions outweighs this disadvantage by far.