3:00 p.m., Friday (March 31, 2006)
Department of Mechanical Engineering, MIT
Building a better snail: lubrication, optimization and
Abstract: Many gastropods, such as slugs and snails, crawl via an
unusual mechanism known as adhesive locomotion. We investigate this method of
propulsion using two mathematical models, one for direct waves and one for
retrograde waves. We then test the effectiveness of both proposed mechanisms by
constructing two mechanical crawlers. Each crawler uses a different mechanical
strategy to move on a thin layer of viscous fluid. The first uses a flexible
flapping sheet to generate lubrication pressures in a Newtonian fluid which in turn
propel the mechanical snail. The second generates a wave of compression on a layer
of Laponite, a non-Newtonian, finite-yield stress fluid with characteristics similar
to those of snail mucus. This second design can climb smooth vertical walls and
perform an inverted traverse.
Refreshments will be served at 2:45 p.m. (MATX 1115, Math Lounge).