Intelligent Robotic Sensory System with Epidermis-Dermis Bionic Electronic Skin for Autonomous Hardness/Softness-Based Material Perception

Abstract

Traditional electronic skin (e-skin), due to the lack of human-skin-like complex sensitive structures and their derived autonomous perception and decision-making capabilities of the tactile nervous system, makes it difficult to achieve performance and deep-level intelligence comparable to human skin. Herein, a soft/hardware-synergy-motivated epidermis-dermis bionic (EDB) e-skin is proposed, inspired by the interlaced papillary projections between the epidermis and dermis. Benefiting from the interlocked microdome structures and the iontronic effect, the EDB e-skin exhibits a maximum sensitivity of 1558.3 kPa⁻¹ (<1 kPa), a low limit of detection of <0.01 Pa, and a fast response/recovery time of <5.6 ms. In addition, the feasibility of the hardness/softness-based material perception technology is verified through test results and COMSOL finite element analysis. Further, after being equipped with a “tactile nervous system”, that is, hardware functional modules and terminal artificial neural networks, an intelligent robotic sensory system integrated with the fingertips is developed. With a single touch, this system can autonomously and in real-time perceive different hardness/softness-based materials, achieving abilities comparable to those of humans.