Bi-stable actuator devices

A method for manufacturing an actuator device, the method comprising:

• twisting an artificial muscle fiber comprising nanofibers and an actuating yarn guest that is operable for undergoing change in volume by a change process;
• setting the artificial muscle fiber by thermally annealing the nanofibers and the actuating yarn guest;
• cutting the artificial muscle fiber into first and second actuating segments;
• fixing one end of the first actuating segment to a first terminal and the other end to a second terminal;
• fixing one end of the second actuating segment to a third terminal and the other end to a fourth terminal;
• disposing a paddle on both the first and second actuating segments;
• disposing a heating provision to the first and second actuating segments, wherein the heating provision independently provides energy in the form of heat to the first and second actuating segments,
• wherein the actuator device moves rotates the paddle to a desired position through activating the first or second actuating segments using the heating provision.