Enhanced Casein Organohydrogel Coating with Liquid Metal Catalyst for Electric Leather Sensor in Human-Machine Interaction

Abstract

Leather’s durability and multi-level structure make it an excellent substrate for electronics. Integrating leather with modern electronic technology to create electronic leather is becoming increasingly popular. However, significant challenges remain, such as adhering conductive media to leather, their penetration and dispersion, and the complexity of preparation. This study presents a new strategy for fabricating electronic leather by combining leather with a casein-based organic hydrogel using coating chemistry techniques. This hydrogel is simple to prepare and exhibits excellent biocompatibility and self-adhesive properties, offering a promising approach to overcome these challenges. Here, we designed casein-stabilized core-shell liquid metal-based catalysts and utilised acrylamide (AM), 2-acrylamido-2-methylpropane sulfonic acid (AMPs), CNTs, and glycerol (Gly) to achieve in situ organohydrogel formation on leather under mild conditions (60 seconds, 25 °C). The resulting organohydrogel-coated material exhibits outstanding stretchability (tensile stress: 70.3 kPa, tensile strain: 1491.8%), rapid response (423 ms) and high sensitivity (GF: 7.67) as a strain sensor. This substrate can be employed in the design of flexible wearable electronic gloves, facilitating seamless information interaction between humans and devices. This innovation demonstrates significant potential in enhancing the functionality of leather as a wearable electronic device. Combining leather’s natural properties with cutting-edge organohydrogel technology holds great promise for revolutionizing the wearable electronics industry, potentially creating highly versatile and multifunctional electronic skins.

Keywords: Electronic leather, Organohydrogel coating, Casein, Liquid metal, Strain sensor