Bubble deformations during translation

Pulsed laser illumination has been used to record photographically the instantaneous shapes of hard and soft bubbles during translation. The bubbles were translated between a single pair of stripe conductors carrying parallel currents and were thus subjected simultaneously to translational and radial forces. Noncircular deformations of 2-, 3-and 4-fold symmetry were observed at intermediate and high bubble velocities in hard and soft bubbles. Bubble motion was observed to continue after the termination of the driving pulse, and in directions different from those during the pulse.