"Particle robot" works as a cluster of simple units

Taking a cue from biological cells, researchers from MIT, Columbia University, and elsewhere have developed computationally simple robots that connect in large groups to move around, transport objects, and complete other tasks. This so-called "particle robotics" system -- based on a project by MIT, Columbia Engineering, Cornell University, and Harvard University researchers -- comprises many individual disc-shaped units, which the researchers call "particles." The particles are loosely connected by magnets around their perimeters, and each unit can only do two things: expand and contract. That motion, when carefully timed, allows the individual particles to push and pull one another in coordinated movement. On-board sensors enable the cluster to gravitate toward light sources.