Researchers at the California Institute of Technology created the artificial jellyfish, called a medusoid, after studying the fast muscle contractions which propel the animals through the water.
They put it in a tank of ocean-like salt water fitted with an electric current and managed to 'shock' it into synchronised movements like a real jellyfish.
The creature is made from silicone and heart tissue from rats. Scientists said that, with more work, it could be engineered to pulsate by itself, as human hearts do.
It could be used to create pacemakers that do not need electrical signals or even to engineer new organs after heart failure.
Co-author Kevin Kit Parker, Professor of Bioengineering and Applied Physics at Harvard, said he began the research because he thought scientists may have failed to understand how muscle pumping works.
The study is published in 'Nature Biotechnology'.
More From This Section
"I started looking at marine organisms that pump to survive, Parker said.
"Then I saw a jellyfish at the New England Aquarium, and I immediately noted both similarities and differences between how the jellyfish and the human heart pump," said Parker.
The medusoid, which has eight spindly arms, was built out of a jelly-like material, with the pattern of protein molecules in a real jellyfish printed on top of it.
The researchers said this was a "glimpse into the future of re-engineering whole organisms" to advance medical technology.
"A big goal of our study was to advance tissue engineering," said lead author Janna Nawroth.
"We may also be able to engineer applications where these biological systems give us the opportunity to do things more efficiently, with less energy usage," said John Dabiri, a professor of aeronautics and bioengineering at Caltech.
Pacemakers, which generally last between six and ten years, send electrical signals through the heart to stimulate it to contract.