Dielectric elastomer actuators for adaptive photonic microsystems

Various applications in the field of photonic microsystems for Dielectric Elastomer Actuators (DEA) were shown with this research. DEA belong to the class of Electro Active Polymers (EAP) and have the potential to substitute common technologies like piezoelectric actuators. DEAs offers several advantages like compact and variable shapes, large actuation ranges and cost efficient production processes that have to be emphasized. For the market of adaptive photonic microsystems especially area actuators are very suitable. They can be used e. g. as tuneable lens, mirror or grating component and tool for optical fiber alignment. These area actuators have a similar structure like a capacitor. They consist of three layers, two electrode layers on top and bottom and one dielectric layer in the center. The dielectric layer is made of a deformable and prestretched elastomer film. When applying a voltage between both electrode layers the thickness of the dielectric film is compressed and the actuator is displaced in the plane. The use of material compositions like a polymer matrix with graphite, carbon nano particles or carbon nano tubes as well as thin metal films for the electrodes were studied. The paper presents results on suitable dielectric and electrode materials, actuator geometries and respective adaptive photonic components. The manufacturing process of area actuators is described in detail. As a basic size of the area actuators (20 x 20) mm(2) were chosen. Onto the produced area actuators polymer lenses or mirrors were assembled. The deflection of the optical beam path is calculated with optical simulations and measured at the prepared adaptive optical components. Static actuations of about +/- 15 mu m are achieved when applying a voltage of 200 V. Also the function of a tuneable beam splitter is demonstrated to show further applications.