Shape-shifting robot

NASA's Goddard Space Flight Center engineers have developed a new robot called TETWalker - so named because it resembles a tetrahedron.

Robots of this type, they say, will eventually be miniaturised and joined together to form ‘autonomous nanotechnology swarms’ (ANTS) that alter their shape to flow over rocky terrain or to create useful structures like communications antennae and solar sails!

In the TETwalker, electric motors are located at the corners of the pyramid, which are called nodes. The nodes are connected to struts which form the sides of the pyramid. The struts telescope like the legs of a camera tripod, and the motors expand and retract the struts. This allows the pyramid to move: changing the length of its sides alters the pyramid's centre of gravity, causing it to topple over. The nodes also pivot, giving the robot great flexibility.

In January 2005, the prototype was shipped to McMurdo station in Antarctica to test it under harsh conditions more like those on Mars. The test indicated some modifications will increase its performance; for example, placing the motors in the middle of the struts rather than at the nodes will simplify the design of the nodes and increase their reliability.