It might sound like science fiction, but this little machine developed by Stanford professor Ada Poon is very real. Think of it as a remote-controlled submarine that is small enough to navigate human arteries. It’s operated via radio transmitter, which powers the two-millimeter device at a frequency of around one gigahertz from outside of the body. While not ready for the operating room yet, in the future it could potentially diagnose patients, deliver drugs, remove plaque from arteries and eliminate blood clots. Cool, yes, but we’re waiting for the shrink-ray that will allow us to travel around inside of it like Dennis Quaid in Inner Space.