Janna Narwoth, advised by Kit Parker at Harvard, created a jellyfish mimic from the cardiac muscle cells of a rat. (Video after the jump.) Copying the structure of Moon Jellies, the cardiac muscle cells were grown so that they were aligned into ring shape on a sheet of polydimethylsiloxane. When electricity is applied, the muscle cells contract, deforming the ring into a bell shape. When the electricity us removed, the cells relax, and the natural elastic properties of the substrate reflatten the disk. Examining the fluid dynamics, the mock jelly not only propels itself, but also creates a counter vortex that drives particles up and into the center of the bell, just like real jellyfish. The researchers hope to apply this technology as a tested for examining the effectiveness of certain cardiac drugs.