Abstract: A tension driven actuator (100) comprises a support structure (102) formed of a peripheral bounded wall (118) at least partially defining a fluid chamber (112), and a first elastic diaphragm (116) attached, under tension, to the support structure (102) and enclosing the fluid chamber (112) with the support structure (102). A pressurized fluid (110) is disposed in the fluid chamber (112), and a tension modifier structure (108) is attached to the first elastic diaphragm (116), and is under tension with the first elastic diaphragm (1 16). In response to application of an electrical field to the tension modifier structure (108), the tension modifier structure (108) transitions from a diaphragm tension position to a diaphragm relaxed position, such that the tension modifier structure (108) deforms and contracts in size, thereby reducing tension of the first elastic diaphragm (116) such that fluid pressure causes deflection of a portion of the first elastic diaphragm (116).