Man-Made, Robotic Jellyfish

choi

Gautam Naik, Lab-Made Jellyfish Hints at Heart Fix. Wall Street Journal, July 23, 2012.
http://online.wsj.com/article/SB ... 39081426736516.html

Paragraph 2: "The lab-made jellyfish is created with a mix of silicone and rat-heart cells. Although it isn't a living organism, the robot's muscular structure closely resembles that of a real jellyfish, enabling it to swim freely through water" that wouldn't require battery power.  

Note: The report cites
Nawroth JC et al, A Tissue-Engineered Jellyfish With Biomimetic Propulsion. Nature Biotechnology, Published online July 22, 2012
http://www.nature.com/nbt/journa ... /full/nbt.2269.html
("We report the construction of a freely swimming jellyfish from chemically dissociated rat tissue and silicone polymer as a proof of concept")