Jellyfish float through the ocean like drones of the sea. Their simple nature makes them a natural muse for robot engineers building devices that can squeeze through tight spaces, check the ocean’s health, and eventually, explore the human body. This week, a team at Florida Atlantic University unveiled a new eight-inch wide robo-jellyfish built to monitor marine life and harsh underwater habitats. It's not the first attempt to automate one of these 500 million year-old creatures.