The Balancing Cube, ETH Zurich

Six autonomous modules balance a cubic structure

Have you ever seen a troupe of acrobats balancing in formation? How do they keep from falling over? Each member of the group balances their weight against the others, making many tiny adjustments each second.

The Balancing Cube can balance on any of its edges or corners. It owes this ability to six rotating mechanisms located on each inner face of the cube. When the mechanisms (simply called modules) are actuated, they exert forces on the cube and shift the center of gravity of the overall system. The modules communicate with each other and coordinate their motion to stabilize the system.

The modules respond by using sensory feedback: when a viewer stands the cube on one of its corners and lets it go – or even pushes it – the cube is able to recover and stabilize.