Neuromorphic Touch Sensors for Pleasantness Encoding via Spike Patterns: A Bio-Inspired Artifical Fingertip for Restoring Affective Sensations

The loss of tactile perception in individuals hinders their ability to interact with the environment. The touch sense not only allows humans to recognize textures and shapes, but also to feel pleasantness evoked by the touched surface. The perception of tactile affective sensations is essential for a person's well-being and social interactions. Hence, research in the field of bionic limbs aims at investigating how to restore the sense of touch comprehensively. In this study, the encoding of surface pleasantness by means of an artificial fingertip via neuronal-like spiking patterns is introduced. The proposed sensing system presents biomimetic features, mimicking the behavior and the distribution of the human finger's Merkel mechanoreceptors. The artificial fingertip demonstrated to capture the variations in pressure, shear, and vibration during the exploration of varied surfaces. The tactile information was then converted into spike trains through a neuromorphic approach. The outcomes of this study lay the foundations for restoring pleasantness sensations from textures through neural sensory feedback interfaces.