A Biologically Inspired Multimodal Whisker Follicle

Mammalian whisker follicle contains multiple sensory
receptors strategically organized to capture tactile sensory
stimuli of different frequencies via the vibrissal system. There
have been a number of attempts to develop robotic whiskers to
perform texture classification tasks in the recent past. Inspired
by the features of biological whisker follicle, in this paper we
design and use a novel soft whisker follicle comprising of two
different frequency-dependent data capturing modules to derive
deeper insights into the biological basis of tactile perception in
the mammalian whisker follicle. In our design, the innervations at
the Outer Conical Body (OCB) of a biological follicle are realized
by a piezoelectric transducer for capturing high frequency
components; whereas the innervations around the hair Papilla are
represented by a hall sensor to capture low frequency components
during the interaction with the environment. In this paper, we
show how low dimensional information such as the principle
components of co-variation of these two sensory modalities vary
for different speeds and indentations of brushing the whisker
against a surface. These new insights into the biological basis of
tactile perception using whiskers provides new design guidelines
to develop efficient robotic whiskers.