The self-replicating machine consists of
plastic modular cubes four inches square that are split diagonally and
can swivel on a central joint 120 degrees in two directions.
A microprocessor in each cube contains a unique program that
specifies a sequence of actions an individual module must perform in
order for the robot as a whole to build another robot.
For example, one command might instruct the cube to rotate 120
degrees when its sensors detect that its magnets have connected with a
molecube on its right side.
A robot comprised of many cubes can bend, split in two, pick up
spare cubes, drop others off, rotate and essentially reconfigure itself
to assemble another robot. And because it can take on different shapes,
it can be useful for performing different tasks.
"If you got a collapsed building, you could have a robot transform
itself into the shape of snake and then later reconfigure into a dome
to protect the person," said mechanical engineer Mark Yim of the
University of Pennsylvania, who builds and tests modular robots.
Such a robot could also come in handy during space explorations,
where damage or malfunction far from human contact might otherwise
render the machine useless.
And it could be more economical, said Lipson, to send the molecubes
to their destination where they would assemble into a robot appropriate
for the territory.
For now, Lipson and his team are thinking of the immediate future
and how to build a robot with specialized modules, such as ones that
function as a gripper, a camera, or a cargo container and that can
perform a useful task.
It seems that for the time being, biology still has the upper hand.
