Michelin has invented the rather stupidly named ‘tweel’ – a wheel without air in it. The video in the link shows how it is mounted under a car, and has a few other applications for it as well.

The airless wheel might take a bit of getting used to, but it helps with suspension, simplifies the tyre by not needing air and a vent, damage to sidewalls becomes a non factor and no worries about whether the tyre is at the right pressure.