It's bigger than a breadbox now, but NASA would like to turn its TETwalker shape-shifting robot into a swarm of nanobots. Hordes of these nanobots will form "autonomous nanotechnology swarms" (ANTS). That day is well in the future, but for now, the TETwalker is taking on some rugged and harsh terrain. Earlier this year, a prototype was shipped to McMurdo Station in Antarctica.
The TETwalker is a pyramid, or tetrahedron. It tumbles across the landscape by deforming itself. The top of the tetrahedron moves in the desired direction, while the trailing edge moves in the same direction. The center of gravity changes, and the robot falls over. The process repeats as the robot continues to flip toward its final location.
The robot's shape has some interesting advantages, including three-point stability. The current incarnation uses servos to extend and contract the rods that make up the struts. Moving to the nanoscale will mean changing motive power. NASA envisions incarnations that are even more articulate.
Systems that are more complex can be created by connecting multiple identical units. As with many swarm designs, the compound robot would implement fault tolerance through the ability to replace a damaged component with a working component. This approach is critical for applications in space where delivery of replacement parts is impossible or impractical.
The TETwalker doesn't have to worry about falling over because it's always upright. Current wheeled and tracked research robots become inoperable if they flip over. Also, future TETwalkers are likely to move the motive power into the center of the pyramid. Work still needs to be done on connecting different pyramids.
NASA's plans will take years to implement, and a good deal of research is still needed to make these more adaptable robot systems a reality. Meanwhile, NASA shows how important it is to think outside the box—er, tetrahedron.