Physical Sciences and Mathematics Commons^™

A Coin Vibrational Motor Swimming At Low Reynolds Number, Alice C. Quillen, Hesam Askari, Douglas H. Kelley, Tamar Friedmann, Patrick W. Oakes

Mathematics Sciences: Faculty Publications

Low-cost coin vibrational motors, used in haptic feedback, exhibit rotational internal motion inside a rigid case. Because the motor case motion exhibits rotational symmetry, when placed into a fluid such as glycerin, the motor does not swim even though its oscillatory motions induce steady streaming in the fluid. However, a piece of rubber foam stuck to the curved case and giving the motor neutral buoyancy also breaks the rotational symmetry allowing it to swim. We measured a 1 cm diameter coin vibrational motor swimming in glycerin at a speed of a body length in 3 seconds or at 3 mm/s. …