I was thinking the same thing until I saw how they rotated along the paired edge. They don't need "cartilage and muscle", they're machinery, they need a hinge and the ability to apply force to move that hinge. With a stronger magnetic point along they edge, the swing of a hinge can be accomplished, though it will take some very fine tuning of the actuator and braking to accomplish something like walking, but I suspect it can be done.