American inventor Lee De Forest was a pioneer of radio and motion pictures. He received more than 300 patents over the course of his lifetime, the most important of which was for a three-electrode vacuum tube, or triode, that he called...

Children's imaginations are infinite - so could they help draw up the ambitious projects that we need to fight the world's challenges? A group was asked to design inventions to make society a better place. Here's how they responded.