A Biomimetic Optical Skin for Multimodal Tactile Perception Based on Optical Microfiber Coupler Neuron

Tactile sensation is one of the critical ways humans perceive the world and is fundamental for the interaction with the surroundings. The development of haptic sensors can enable us to extend and transcend the human sense of touch to perceive the world more subtly. Inspired by the ingenious biological structure and the tactile sensing mechanism of the finger skin, we propose a biomimetic optical skin (BOS) based on optical microfiber coupler neuron (OMCN) in this paper, which realizes the multimodal tactile perception for the first time. Benefiting from the combination of the biomimetic structure that mimics the characteristics of the skin and the OMCN imitates the neuron which has the capability of multi-parameter sensing with high sensitivity, the sensing versatility of BOS is experimentally proven in that it can sensitively detect the temperature, contact force, and vibration, as well as the recognition of the hardness and roughness of the objects through the tactile-sensing manner of the human-like behavior. Besides, the excellent repeatability and stability of the BOS are investigated, which lays the foundation for practical applications. The proposed BOS can achieve the digitization of tactile perception and provide a new solution to the evolution of human-machine interaction and advanced robots.

I. Introduction

Humans have five basic senses: visual, auditory, tactile, gustatory, and olfactory [1], and our body relies on these five sensory systems to perceive information about the external environment. Tactile is one of the essential sensations, which can be defined as a system that measures a given property of the object or contact event through physical contact between the system and the object [2]. In general, people can touch the object through the skin where various tactile receptors within it respond to the corresponding parameters, such as the temperature and contact force applied to the surface of the skin and generate a weak electrical nerve. Then, these nerve signals flash to the brain via nerve fibers [3], where a holistic touch picture is assembled [4], and thereby we can identify the information of the objects, such as the temperature, surface texture, hardness, and vibration [5].