Self-assembly of thousand little robots "Kilobots" to form complex shapes.

Researchers at Harvard university had demonstrated a self-organizing swarm which was formed by one thousand little robots known as "Kilobots". The robots begin to blink at one another and then gradually arrange themselves into a five-pointed star, once after a computer scientist gave a command for forming a sea Star shape to 1,024 little bots simultaneously via an infrared light. Just as single cells can assemble into complex multicellular organisms, the individual Kilobots can follow simple rules to autonomously assemble into predetermined shapes.

http://www.eecs.harvard.edu/ssr/projects/progSA/kilobot.html