Robot Helps Study How Animals Moved 360 Million Years Ago

When early terrestrial animals began moving about on mud and sand 360 million years ago, their powerful tails may have been more important than scientists previously realized. That's one conclusion from a new study of African mudskipper fish and a robot modeled on the animal. Animals analogous to the mudskipper would have used modified fins to move around on flat surfaces, but for climbing sandy slopes, the animals could have benefitted from using their tails to propel themselves forward, the researchers found. Results of the study, reported July 8 , could help designers create amphibious robots able to move across granular surfaces more efficiently - and with less likelihood of getting stuck in the mud. Sponsored by the National Science Foundation, the Army Research Office and the Army Research Laboratory, the project involved a multidisciplinary team of physicists, biologists and roboticists from the Georgia Institute of Technology, Clemson University and Carnegie Mellon University. In addition to a detailed study of the mudskipper and development of a robot model that used the animal's locomotion techniques, the study examined flow and drag conditions in representative granular materials, and applied a mathematical model incorporating new physics based on the drag research. "Most robots have trouble moving on terrain that includes sandy slopes,” said Dan Goldman, an associate professor in the Georgia Tech School of Physics.