Are you ready for this jelly? Using rat heart cells and silicone, engineers at Caltech and Harvard have built a tiny, swimming, artificial jellyfish.
The centimeter-wide creation moves by using muscles in its soft body to pump water, just as its living peers do. And since real jellyfish, with their long tentacles, were once named after Medusa, the snake-haired monster of Greek myth, the scientists have dubbed their nonliving critter Medusoid.
Rather than try to mimic the jellyfish wholesale, the researchers decided to identify some of the factors that make the jellyfish a successful swimmer — shape, stroke cycle, properly organized muscle fibers, elastic recoil — and built their jelly according to those principles.
First they designed a tissue-thin silicone membrane. This elastic, eight-armed film would be the jellyfish’s body. Then they printed a pattern of proteins onto the membrane, which served as scaffolding for the rat heart cells. The regular protein pattern allowed them to grow into organized "muscle," allowing the contracting heart cells to "beat" properly.