Making a robot feel alive is not only about faces or voices; whole-body motion can matter too. MOFU (MOrphing Fluffy Unit) explores that idea with a fluffy spherical body that expands and contracts. Developed by researchers at the University of Electro-Communications, it uses a Jitterbug geometric structure and a single linear actuator to change its height from roughly 210 mm to 280 mm.

In user studies, adding whole-body expansion, contraction and rotation made the robot seem more animate than locomotion alone. Rather than relying on a face, MOFU uses the rhythm of its entire body to suggest life.