Optical transmission gratings tuned by electro active polymers

Dielectric elastomer actuators (DEA) of poly-styrene-ethylene-butadiene- styrene (SEBS) and poly-acrylic VHB4910 were studied for voltage tunable optical transmission gratings. A new geometry is proposed, in which the grating is placed in an area without electrodes, permitting for light transmission through the device. Experiments were performed to implement surface relief gratings on DEA films from pattern masters made from holographic recorded gratings. Since the actuation strain of the DEA depends strongly on the boundary conditions, the desired voltage-controllable deformation of the grating can be achieved by choosing suitable manufacturing parameters. Conditions were found permitting a relative change up to 8.5 % in a 1 m grating. A model based on independently measured material parameters is shown to describe the optical behavior.