Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand. Implementing this strategy in a physical robot model of the snake enables the device to ascend sandy slopes close to the angle of maximum slope stability.
The robots, known as Spheres (Synchronised Position Hold, Engage, Reorient, Experimental satellites), currently have limited capabilities.
It is hoped the smartphones, powered by Google's Project Tango, will equip the robots with more functionality.
The robots have been described by experts as "incredibly clever".
When Nasa's robots first arrived at the International Space Station in 2006, they were only capable of precise movements using small jets of CO2, which propelled the devices forwards at around an inch per second.
"We wanted to add communication, a camera, increase the processing capability, accelerometers and other sensors," Spheres project manager Chris Provencher told Reuters.