[Tyler]

4-Nanometer Wide Robot Spider
     

The Universities of Columbia, Arizona State, and Michigan
along with CalTech have joined together to create a nanobot that is only 4 nanometers wide and
successfully traversed a distance of 100 nanometers (50
steps).  The four-legged robot can turn, move, start and
stop and was built out from a protein called streptavidin
that as four symmetrically placed binding sites or
"pockets" for attaching legs made of biotin.  The robot's
instructions come from outside its body since it is too
small to contain any processing elements.  They created a
track for the robot to follow from strands of DNA and the
molecules that make up the track contains the instructions
the nanobot "reads", that tell the robot what to do.
   

http://robots.net/article/3022.html