Design of a bio-inspired whisker sensor for underwater applications

In this paper we present the design and the design methodology for a new type of underwater sensor based on pinniped whiskers. In recent years various groups have looked into how pinnipeds (seals, sealions, etc) use their whiskers to track hydrodynamic trails left by potential prey. Most of the attention has been directed to the particular geometry of seal whiskers which seems to suppress vortex-induced vibrations and is suspected to improve sensing capabilities. In this study our group looks at the mechanical transduction of fluid-excited signals by whisker-like sensors and the role of the whisker mechanical structure in the sensing process. We define the whisker structure as the whisker shaft plus the follicle-like base where the whisker is mounted and that enables the measurements of signals excited by fluid interactions. A design approach based on target fluid signals is discussed and a prototype is described. Sensing performance is characterized using von-karman wakes.