An apparatus comprises a body having a torus skin with inner and outer
layers, and a drive system configured to propel the apparatus by moving
the inner layer relative to the outer layer. The active skin propulsion
system allows movement and steering of a device. A drive system includes
a plurality of drive segments coupled together so that the skin engaging
unit of the drive segment frictionally moves the inner layer of the torus
skin relative to the outer layer of the torus skin. As a result of the
relative skin motion and contact with the surface by the outer layer of
the torus skin, the body is propelled and may be steered.