A biologically inspired multimodal whisker follicle

Abstract

Abstract-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.

A Stiffness Controllable Multimodal Whisker Sensor Follicle for Texture Comparison

“…The variable stiffness multimodal whisker follicle (VS-MWF) with two sensor modalities shown in Fig. 1 is an advancement from the constant stiffness multimodal whisker follicle (CS-MWF) reported in [19]. The VS-MWF is comprised of a 3D printed cylindrical body (CB), a soft silicone rubber (Ecoflex 00-10) joint (SJ), a rigid 3D printed whisker shaft base (WSB).…”

“…The whisker was moved to the edge of a sandpaper holder with an indention of 3mm before starting to sweep across the sandpaper at different speeds. We chose a 3mm indentation based on our previous results [19].…”

“…Our previous work [19] introduced the role of the whisker indentation and the whisking speed for a bi-modal sensing whisker follicle in the task of distinguishing textures. The following paper aim is to show that variations of stiffness at the ring sinus level help to distinguish two lookalike textures.…”

Embodied Active Tactile Perception

“…The adaptation has been well adopted in biological sensors to mitigate environmental variations. For instance, the rats control the muscle stiffness of the follicle where the whisker is connected to bias the optimal range of sensing from low to high frequencies [30]. Humans change their finger stiffness and joint impedance to maximize the gained tactile information in the context of haptic explorations [31].…”

Contour recognition method of Hall-effect-based whisker sensor

“…At present, various bionic whisker sensors have been developed, such as elastomer-based sensors, piezoelectriceffect-based sensors, strain-gauge-based sensors, Hall-effectbased sensors, magnetostrictive sensors, and so on [8][9][10][11][12]. Starting from the practicability of sensors, many scholars have developed sensors with different uses.…”