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Foundations of Robotics Seminar, April 20, 2010
Time
and Place | Seminar Abstract
Physics of Simple Swimming Systems
Lisa Burton
MIT
NSH 1507
Talk 4:30 pm
Swimming systems, both biological and artificial, use a variety of interesting techniques to swim in regimes where viscous forces are much greater than inertial forces (low Reynolds number flow). In this regime, any time reversible motion results in zero net translation, as stated in the Scallop Theorem. Some swimming systems, such as spermatozoa and E. coli bacteria, successfully break the time symmetry; breaking the time symmetry, however, can be difficult for rigid systems with limited shape variables. After a review of how low Reynolds number swimmers in nature and artificial systems produce net motion, we present a new two-link swimmer model that achieves net translation by offsetting the center of mass and center of buoyancy in one of the swimmer's links. We modify the reconstruction equations and connection vector fields, tools used in motion planning, to analyze the system's motion. Additionally, we find analytic, closed-form results for the swimmer's gait and motion, assuming small amplitude strokes.
The Robotics Institute is part of the School of Computer Science, Carnegie Mellon University.