A biorobotic study of the rat whisker system

The rat whisker (vibrissal) system provides rats with an exquisitely acute tactile sense that has helped allow them to thrive all over the world. By actively rotating their whiskers back-and-forth (“whisking”) against objects, rats can extract a rich variety of information including position, size, shape, orientation and texture. Today, however, we have an incomplete understanding of how the mechanical interactions between whiskers and environment can carry sufficient information to allow sensation of these features. The research presented here offers new insights to help answer these questions, and concurrently develops novel tactile sensing concepts that apply to the realm of robotics. The methodology employed here can be conveniently divided into two parts. The first part involves the construction of analytical and numerical models to describe how whiskers bend and transmit forces and moments in response to mechanical deflections. Also, a functional model is derived to explain how three-dimensional (3-D) object feature extraction is possible with rat whiskers. The second part involves the construction and testing of a robotic array of whiskers to validate the effectiveness of the model, and to also reveal additional aspects of the sensory task that are difficult to identify through other methods of study such as computer simulation or high-speed video analysis. The results of this thesis should be of interest both to those involved in the study of the rat whisker system, and those interested in the field of robotic tactile sensing.