When your name is Dean Kamen, you probably eat really smart cereal in the morning. You probably wear really smart sweaters too. I bet you'd even have a really smart car. Well, maybe not smart, but how about one that doesn't have an internal combustion engine?
Kamen, the inventor of the famously useless but "damn that is cool" Segway, has been focusing all his attention on developing a new kind of green car (something incredibly useful). No, it doesn't run on water. No, it doesn't run on corn, or McDonald's french fries. It runs on heat. With global warming keeping us nice and toasty for the next few millenia we'll have plenty of that to go around.
They're called stirling engines and they're already being put to use in the global south (for those of you still stuck in the '80s and the Cold War that's the "3rd World"). A village in India uses steaming cow dung to power their stirling engine and the entire village. Hot cow dung. Who knew?
The engines actually convert the heat into mechanical energy by compressing and expanding gas inside a small cylinder. The problem here is actually mass producing these little suckers. But Kamen is confident after chatting with green car maker THiNK about putting stirling engines in their electric cars. This move has all sorts of potential for extending the range of electric vehicles by hundreds of miles. And, those cars could run on anything -- even cow dung.