Figure 1
From: Self-propulsion of a grain-filled dimer in a vertically vibrated channel
Side view of a grain-filled dimer in a quasi-one-dimensional, transparent channel attached to a vibrating plate. High-speed video is used to capture the motion of the active system. The horizontal direction x is along the channel, and the vertical direction y is perpendicular to the plane of vibrating plate. The dimer consists of two identical ping-pong balls rigidly connected by a hard rod; both balls are elastic and have the same friction constant with the plate; the balls are filled with the same mass of grains; the grain size of one ball, however, is different from that of the other.
