Will strong and fast-switching artificial muscle be feasible?

In the American action movie "Pacific Rim," giant robots called "Jaegers" fight against unknown monsters to save mankind. These robots are equipped with artificial muscles that mimic real living bodies and defeat monsters with power and speed. Research is being conducted on equipping real robots with artificial muscles like the ones shows in the movie. However, the powerful strength and high speed in artificial muscles cannot be actualized, since the mechanical strength (force) and conductivity (speed) of polymer electrolyte—the key materials driving the actuator—have conflicting characteristics.