This is fascinating.
Heart cells keep time, contracting and relaxing in synch to pump blood through the body. Doctors know some things about how they work together or fall out of synch, but in an effort to learn more, researchers at Caltech and Harvard emplanted cells from a rat’s heart into a rubbery disk of silicone, and watched it move like a jellyfish.
The goal is not to make artificial jellyfish (although wow, cool!) but to learn more about heart cells that could turn into better therapies for malfunctioning hearts.
Artificial Jellyfish Swims Like the Real Thing – ScienceNOW.