What a Robo-Dolphin Can Teach Us About Real Ones With titanium for bones and a microcontroller for a

It's called "porpoising"—the way dolphins swimming at high speeds leap out of the water because it avoids drag caused by swimming near the surface. Now scientists are learning to copy that trick.

This water-bound robot, built by Professor Junzhi Yu and colleagues at the Chinese Academy of Science in Beijing, is loosely modeled on a spotted dolphin, and the leaping is not just for show. It's a step toward mimicking this behavior for better underwater vehicles with the speed, efficiency, and agility of dolphins.

A dolphin's incredible speed has long fascinated researchers. In 1936 biologist James Gray calculated that it should be impossible for dolphins to swim at speeds of more than 20 mph because of underwater drag.

Known as Gray's Paradox, this puzzle wasn't completely solved until 2014, when aptly named biologist Frank Fish showed that a dolphin's tail generates much more force than previously thought. Still, our understanding of the dynamics of dolphin swimming is still changing and growing, which is why this robot is so important