Investigation of biological seal whiskers to create artificial whisker sensors for underwater robots

Introduction

Marine animals employ diverse and fascinating flow sensing phenomena by exploiting the ambient complex fluid mechanics to track prey and escape from predators. Seals are known for their remarkable long-distance prey-hunting capabilities owing to their whiskers, which serve as ultrasensitive flow sensors. For example, a seal is able to detect a fish swimming 180m away by following its vortex streets.

Background

While the unprecedented tracking abilities of seals and the role played by seal whiskers in reducing vortex-induced vibrations have been conclusively demonstrated in the past, the fundamental mechanisms behind such pinpoint tracking remain unclear. The geometrically intricate shape of the seal's whiskers is believed to maximize their signal-to-noise ratio to generate high sensitivity to the tiniest hydrodynamic trails.

Project Objectives

In this project, we propose investigations of the seal whisker behavior, both in live seals and in controlled lab experiments, to shed new light on the fundamental mechanisms that enable the seal to display its excellent prey-tracking behavior.

Key Questions

In particular, we aim to address the following questions:

1. How does the seal effectively utilize the spatial distribution of the whisker array on its muzzle to conduct multipoint flow measurements?
2. How does this ability help the seal track and locate its prey?

Research Focus

We propose to study the morphological, mechanical, and material properties of whiskers to explain the exquisite sensing capabilities of seals. Furthermore, we aim to use this understanding to develop biomimetic flow sensors for underwater robot navigation.

Sensor Development

• Miniaturized and self-powered micro/nano electromechanical systems (MEMS/NEMS) strain and flow sensors will be developed for experimental animal studies.
• We will also develop artificial 3D printed MEMS whisker sensors and muzzles for experimental fluid-structure interaction studies.

Application

An artificial seal muzzle with mechanosensory MEMS whiskers will be applied on underwater robots to create artificial vision and enable energy-efficient maneuvering through fish-like schooling.