Jellyfish
Most jellyfish do not have specialized systems for osmoregulation, respiration and circulation, and do not have a central nervous system. Nematocysts, which deliver the sting, are located mostly on the tentacles; true jellyfish also have them around the mouth and stomach. Jellyfish do not need a respiratory system because sufficient oxygen diffuses through the epidermis. They have limited control over their movement, but can navigate with the pulsations of the bell-like body; some species are active swimmers most of the time, while others largely drift.
The rhopalia contain rudimentary sense organs which are able to detect light, water-borne vibrations, odour and orientation. A loose network of nerves called a "nerve net" is located in the epidermis. Although traditionally thought not to have a central nervous system, nerve net concentration and ganglion-like structures could be considered to constitute one in most species. A jellyfish detects stimuli, and transmits impulses both throughout the nerve net and around a circular nerve ring, to other nerve cells. The rhopalial ganglia contain pacemaker neurones which control swimming rate and direction.
John Dabiri
Reverse engineering is Dabiri's newest research focus. In July 2012, a team composed of Caltech and Harvard students and professors published a paper that outlined a tissue engineering method for building a jellyfish out of rat heart muscle cells and a silicon polymer. On a basic level, the function of a jellyfish - using a muscle to pump a fluid - "is similar to that of a human heart, which makes the animal a good biological system to analyze for use in tissue engineering." The next step this research will take is towards a self-sustaining prototype - one that can gather food and activate muscular contractions internally.