an actuator comprises an electroactive polymer layer and a stretchable electrode structure disposed at a first side of the electroactive polymer layer and further a counter electrode layer disposed on a second side of the electroactive polymer layer , wherein the ratio y c / y eap of the elastic modulus y c of the counter electrode layer and the elastic modulus y eap of the electroactive polymer layer is at least 10 . when compressed transversally by the electrodes , the electroactive polymer will expand tangentially and the actuator will relax into a shape wherein the interior of the electroded region is substantially recessed parallel to the plane of the device , while a substantial portion of the area increase is absorbed by out - of - plane bends arising at the electrode boundary . the invention can be embodied as optically reflective or refractive devices with variable geometry .