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.

The team that developed the robot anticipates TETwalkers can be made much smaller by replacing their motors with Micro- and Nano-Electro-Mechanical Systems. Replacement of the struts with metal tape or carbon nanotubes will not only reduce the size of the robots, it will also greatly increase the number that can be packed into a rocket because tape and nanotube struts are fully retractable, allowing the pyramid to shrink to the point where all its nodes touch.

These miniature TETwalkers, when joined together in “swarms,” will have great advantages over current systems. For example, while travelling through a planet’s atmosphere, the swarm might flatten itself to form an aerodynamic shield. Upon landing, it can shift its shape to form a snake-like swarm and slither away over difficult terrain. If it finds something interesting, it can grow an antenna and transmit data to Earth. Highly-collapsible material can also be strung between nodes for temperature control or to create a deployable solar sail.

Additionally, the nodes will be designed to disconnect and reconnect to different struts. If a meteoroid or rough landing punches a hole in the swarm, the system can heal itself by rejoining undamaged nodes.

Watch ANTS the movie here.