Modeling foil design after seal whiskers

By Alex Stewart

A seal races after a herring twisting and darting through the water in the dead of night. The seal cannot see the fish it is chasing, but instead relies on its sensitive whiskers to detect displacements in the water to track down its prey. These remarkable whiskers, which are sensitive enough to detect displacements as small as one nanometer, help the seal hunt even on the darkest of nights. An ingenious natural design, seal whiskers are the subject of study for Kate Lyons, Ph.D. Student in Professor Jennifer Franck’s lab at the University of Wisconsin-Madison. Lyons is attempting to implement hydrodynamic force reduction designs inspired by the unique characteristics of seal whiskers and their distinctive geometry. She presented on this topic in a Mechanics Seminar at the University of Wisconsin-Madison on February 28, 2020.

The geometry of seal whiskers differs from the whiskers of many other animals. Rather than having a cylindrical structure, seal whiskers look more like a foil, similar in shape to the blades one may see on windmills or the wings of an airplane. This geometry allows seals to move through water with reduced resistance. Additionally, the whiskers have a wave-like pattern along their front-facing side. This wave pattern differs based on the location of the whisker on the seal’s face, offering distinct attributes with each varying geometry. Lyons has modeled the geometry of these whiskers by measuring the thickness and other geometric parameters of the whiskers that have been naturally shed by seals.

In her fluid mechanics analysis of flow, Lyons found that the geometric layout seen in seal whiskers reduces the oscillation and drag effects experienced by the seal as compared to more cylindrical-shaped whiskers. Implementing adjustments to engineered foils modeled after these characteristics could produce more efficient hydrodynamic designs. Using the existing geometric characteristics of the whiskers for inspiration could allow designs targeting specific attributes allowing for more specialized foil designs. Attributes of implementing the unique geometry of seal whiskers in engineering design could be used to reduce forces, dampen vibrations, decrease oscillations, and lessen drag amongst foil structures. This hydrodynamic reduction could provide additional attributes in foils throughout numerous industries by increasing the efficiency and productivity of products modeled using the characteristics of seal whiskers that Lyons has documented and analyzed.

Lyons is looking at an organic design found in nature perfected through evolution to improve engineered designs for a variety of industries from energy production to aircraft design.