Artificial Seal Whisker

Animal research activities conducted under NMFS permit 14535

The artificial seal whisker project is a joint effort with the University of Virginia’s Mechanical Engineering Department and the University of California Santa Cruz to detect and track underwater wakes using an array of bio-inspired sensors. Previous biological work found harbor seals are able to track wakes using only their whiskers. In this project, the seal whisker team is focused on understanding how seals sense wakes using their whiskers, designing a capacitance based whisker-like sensor, and designing the electrical backend printed circuit board for sensing, storing, and transmitting data. The biologically inspired sensor’s design is based on seal whiskers and previous effort in the field involving spider hairs and fish lateral lines. All components will be integrated in the Wake Information Detection and Tracking System (WIDTS) to be carried by a trained harbor seal for testing.

The artificial whisker uses a ~4cm solid whisker attached to a movable conical base. As the turbulence of a wake moves the whisker, its base also moves inside a conical cavity. Four capacitors built between the whisker base and the cavity walls vary in their capacitance values as the gap size changes, and we can convert this signal into a measure of the fluid speed and direction. The first prototype of the sensor is shown HERE.

Once an array of sensors (on the WIDTS) is complete, we will test it in a water tunnel to characterize its ability to discern known wakes. We will also deploy the WIDTS to be carried by a harbor seal who is trained to track underwater wakes. Our seal partner, Sprouts (shown above), is trained at UCSC to follow underwater wakes using only his whiskers while wearing a blindfold. Sprouts is trained using fish rewards, and he is already excelling in his tasks. By carrying the WIDTS, Sprouts will expose our sensors to the same wake information that he uses to track in real world conditions. The data that we collect during these tests will help us to better understand how harbor seals can detect and track underwater wakes.

Ben Calhoun, Colleen Reichmuth (UCSC)

Craig Eberhardt, Yousef Shakhsheer, Chris Gregg

Office of Naval Research

Stocking, J. B., W. C. Eberhardt, Y. A. Shakhsheer, J. R. Paulus, M. Appleby, and B. H. Calhoun, "A Capacitance-Based Whisker-like Artificial Sensor for Fluid Motion Sensing", IEEE Sensors, 2010.