Tufts University engineering professors Ronald Goldner and Peter Zerigian have developed a regenerative shock absorber that harnesses the kinetic energy of the wheels' vertical motions as they follow the contour of the road. Traditional dampers use the resistance of a viscous fluid flowing through orifices to dampen out the motions as wheels traverse bumps and potholes. This new configuration would put a magnet stack within stator windings and use the resistance provided by an electromagnetic field to achieve the same effect. Such a system could provide continuously variable damping while providing power instead of consuming it.
A similar concept was developed several years ago by Pennsylvania man David Oxenreider. Electric Truck LLC has apparently licensed the commercial rights to the Tufts design, although there is no indication when we might see it on the road.