Speakers and methods

The speaker, comprising:

• a vibrating body;
• a rotary actuator comprising a wound sheet, wherein the sheet comprises:
• a first layer and a second layer, each comprising or consisting of a dielectric elastomer;
• a first electrode arranged between the first layer and the second layer in direct contact therewith;
• a second electrode disposed on a side of the first layer distal from the first electrode and in direct contact with the first layer;
• and
• a third electrode, which is arranged on a side of the second layer distal to the first electrode and in direct contact with the second layer,
• wherein the rotary actuator is arranged at least partially above the vibrating body in the direction of radiation of the speaker.

A method of manufacturing a speaker, comprising the method:

• coating a first side of a sheet with a first electrode material, the sheet comprising or consisting of a dielectric elastomer;
• coating a second side of the sheet opposite the first side with a second electrode material;
• rolling a first end of the sheet onto a first roll and a second end of the sheet onto a second roll such that a central region of the sheet is not rolled onto either the first roll or the second roll;
• folding the center region of the coated sheet around a second metal film unwound from a third roll such that the first electrode material arranged on a first portion of the sheet contacts a first side of the second metal film and that the first electrode material arranged on a second portion of the sheet contacts a second side of the second metal film opposite the first side;
• bringing together one side of the sheet folded around the second metal film and one side of a first metal film unwound from a fourth roll to form a laminate;
• and
• winding the laminate onto a fifth roll by unwinding the sheet from the first roll and the second roll, the second metal film from the third roll and the first metal film from the fourth roll in such a way that the laminate has an elongation of less than 50% in the wound state.