Twisted carbon nanotubes harness waste energy and put it to work
It sounds like a simple task: use ambient energy from your surroundings to do something handy, such as charge your iPod from the vibrations of your morning run. But few of the many energy-harvesting devices introduced over the past hundred years have lived up to the promise of the idea. They just don’t seem able to eke out enough power to do anything useful. That looks set to change.