Super soft but strong E-Skin based on carbon fiber/carbon black/silicone composite: Truly mimicking tactile sensing and mechanical behavior of human skin

Abstract Besides the prominent tactile sensing ability, human skin is also well known for its unique mechanical behavior – combination of excellent softness with certain stretchability of a strain-limiting effect to prevent damage from excessive strain. Here a stretchable e-skin truly mimicking the tactile sensing and mechanical behavior of human skin is fabricated. Carbon black (CB)/silicone composite with excellent piezo-resistive performance is employed as mechanical stimuli sensing material, which provides super softness, large stretchability, high strain sensitivity and long-term reliability for the e-skin. High performance carbon fiber (CF) with quasi-sinusoidal shape is designed to serve as electrode material and reinforcement filler simultaneously, which renders the e-skin a typical J-shape stress-strain curve similar as that of human skin. The Young's modulus, tensile strength and failure strain of the e-skin can be readily adjusted by controlling the content and shape of the CF electrode to match them well with those of human skin. Finally, the fabricated e-skin exhibits the capability of spatiotemporal recognition of the location and magnitude of contact forces in monitoring dynamic stress distribution. The as-prepared stretchable e-skin based on CF/CB/silicone composite is highly promising for robotics and prosthetics, etc.