In most situations, range of motion is limited by the fact that we need to carry power or information past a joint. So, past a certain point there are either cables in the way, or the cables would stretch so much that they would either prevent further movement or break.
However, if we situate the conductors in concentric rings around or within the rotor shaft, we can have a joint that can rotate forever while keeping in contact with any modules on the other side.
What do we call this mechanism? Does it even have a name?