MIT research scientist John Romanishin, along with professor Daniela Rus and postdoc Kyle Gilpin, have demonstrated a swarm of modular robots with the ability to self-assemble into larger shapes. The individual robots are small and cubical, but they contain a flywheel capable of spinning at 20,000 rpm. By spinning up the flywheel and then braking abruptly, the robots use angular momentum to jump into different positions. Magnets on the edges of the cube guide them into alignment. The researchers hope to be able to shrink the cubes even further, but they think a "refined version of their system could prove useful even at something like its current scale. Armies of mobile cubes could temporarily repair bridges or buildings during emergencies, or raise and reconfigure scaffolding for building projects. They could assemble into different types of furniture or heavy equipment as needed. And they could swarm into environments hostile or inaccessible to humans, diagnose problems, and reorganize themselves to provide solutions." The cubes could also be packed with sensors, batteries, or other technologies.