In a physics lab in Amsterdam, there’s a wheel that can spontaneously roll uphill by wiggling. This “odd wheel” looks simple: just six small motors linked together by plastic arms and rubber bands to form a ring about 6 inches in diameter. When the motors are powered on, it starts writhing, executing complicated squashing and stretching motions and occasionally flinging itself into the air, all the while slowly making its way up a bumpy foam ramp. The odd wheel’s unorthodox mode of travel exemplifies a recent trend: Physicists are finding ways to get useful collective behavior to spontaneously emerge in robots assembled from simple parts that obey simple rules. Daniel Goldman, Dunn Family Professor in the School of Physics (who did not work on the odd wheel study), uses the term "robophysics" to describe this latest trend in robotics.