Since the damper and coil spring came to car suspensions, there haven't been many changes or innovations to how your wheels' motion has been controlled. The MacPherson strut, Citroen's hydropneumatic system, and the original Mini's rubber cones are the most notable among them, but the newest of those was invented back in the 1950s. Audi has developed a system that turns the motion of the road into electricity for their new 48 V electrical system.
Audi calls its new suspension the eROT system, and while the name isn't great, the idea is. They have taken out the conventional damper and replaced it with an electromechanical rotary damper. What that means is a lever attached at one end to the hub and at the other end to a gearbox attached to an alternator that uses the electromagnetic field to turn the motion into electricity instead of wasting it as heat (like a regular shock does). Think of it as regenerative braking for your springs. The system can generate up to 613 W on a bumpy road, which can be stored in the car's battery.
The system also allows them to use small amounts of power to tune the rotary damper. It can react completely differently in compression and rebound, and can be tuned in real-time for adaptive damping. In addition, the system frees up space in the trunk as the dampers are mounted horizontally instead of upright.
Audi has not said if or when the system will make it to production, but with more and more of their cars switching to their 48 V system, and the constant need to eke out another 0.1 L/100 km, this system could easily see the undercarriage of future Audis.
