This is just plain nuts. Via Adam Clark Estes of Gizmodo:

A few years ago, a whole new crop of crazy medical devices started popping up—things like little robots that could crawl through your veins and clear blocked arteries. Scientists lauded the promise of ingestible electronics, but there was one big problem. How are we going to power these devices?

A team of scientists from Carnegie Mellon just offered up the answer. Using melanin extracted from cuttlefish ink, they developed an edible battery that can be ingested and will harmlessly dissolve when its job is done. After all, traditional batteries are the last thing you want to swallow. “Instead of lithium and toxic electrolytes that work really well but aren’t biocompatible, we chose simple materials of biological origin,” Professor Christopher Bettinger, who led the research, explained to the MIT Technology Review.

Science! It’s amazing and creepy!