Artificial SA-I and RA-I Afferents for Tactile Sensing of Ridges and Gratings

TL;DR

This paper introduces biologically-inspired artificial tactile sensors that mimic natural afferent responses, enabling improved tactile perception in robots through experiments demonstrating their similarity to human touch responses.

Contribution

It presents novel biomimetic feature sets for artificial tactile sensors that replicate SA-I and RA-I afferent functions, validated through classic touch experiments.

Findings

Artificial afferents match natural responses in edge and gap sensitivity

Robot and human psychometric functions align for grating orientation

Sensor responses replicate key aspects of biological tactile perception

Abstract

For robot touch to converge with the human sense of touch, artificial transduction should involve biologically-plausible population codes analogous to those of natural afferents. Using a biomimetic tactile sensor with 3d-printed skin based on the dermal-epidermal boundary, we propose two novel feature sets to mimic slowly-adapting and rapidly-adapting type-I tactile mechanoreceptor function. Their plausibility is tested with three classic experiments from the study of natural touch: impingement on a flat plate to probe adaptation and spatial modulation; stimulation by spatially-complex ridged stimuli to probe single afferent responses; and perception of grating orientation to probe the population response. Our results show a match between artificial and natural afferent responses in their sensitivity to edges and gaps; likewise, the human and robot psychometric functions match for grating orientation. These findings could benefit robot manipulation, prosthetics and the neurophysiology of touch.