For those worried about a dystopian future where humans serve robot overlords, there has always been one brake on full robot autonomy: power. Whether it’s the batteries in a Roomba or the fuel in a Predator drone, robots always relied on humans for their energy. Now, thanks to a company started by one of the founders of Google, robots are heading for more self-sufficiency than ever before.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.