Abstract
Harbor seal whiskers exhibit a tapering elliptical geometry uniquely suited to detect wakes (trails of water produced by upstream bodies) in ways a regular, tapering, or elliptical cylinder cannot. Previous studies into the matter have relied on idealized representations of the geometry the whiskers seem to take on and have tried to use these poor models to extrapolate information about the effects this geometry has on their fluid mechanics, including velocity sensing, optimizing the signal-to-noise ratio, and reduction of vortex-induced vibrations. The goal of our investigation is to determine whether it is possible to mathematically model the seven varying parameters of seal whisker geometry: the periods of undulation (or waves), the wide and narrow diameters of the major and minor axes, and the angles at which maxima and minima occur. Additionally, measuring base diameter and whisker lengths will be useful in creating a model. To collect data, we are using high-resolution flatbed scans to determine basic geometric features, such as length, undulations, and medula length, and computer-tomography (CT) scans to analyze out-of-plane curvature. With 500 seal whiskers, a nearly twentyfold increase over previous work in the number of samples we are using, this project is producing the most comprehensive results to date, allowing us to validate, refute, or replace existing models with a high degree of certainty. From a neuroscience perspective, producing an accurate model for seal whisker geometry also motivates further sensory and neural systems research into seal whiskers.