The GhostBot can swim in any direction by varying the wave form of its body fin and its roll orientation.

A stealthy Underwater Unmanned Vehicle (UUV) could be a useful platform, but it has proven very difficult to make the vehicle’s propulsion sufficiently quiet, especially when agile movement vertically and laterally is as important as longitudinal motion.

  • Compared to propellers and ducted thrusters, a swimming fish is nearly silent
  • Attempts at making a mechanical tail fin for propelling a UUV have not worked as well as researchers have hoped
  • It is very difficult to make the rear half of a UUV sufficiently flexible, while still achieving efficient propulsion

Photo of Black Ghost Knifefish courtesy of the National Aquarium.

The Black Ghost Knifefish is a class of fish with a rigid body. They have an unusual body fin. By varying the waveform of the body fin, as well as the orientation of its roll axis, the Black Ghost Knifefish can maneuver very effectively in all three dimensions.

  • HDT has built a bio-mimic UUV which can duplicate the maneuvers of the Black Ghost Knifefish
  • The propulsive efficiency is very high and the UUV is agile and precise in all three translational degrees of freedom