Natural Protein-Based Biogels with Biomimetic Mechanics and Multifunctionality for Skin Sensors

Developing skin-like ionic sensing materials is highly desirable for skin bioelectronics for long-term health monitoring, which is challenging to realize by using biocompatible natural polymer-based biogels. Herein, we engineer a robust natural protein-based ionic biogel with skin-like combinational properties involving stretchability, softness, durability, ionic conductivity, and environmental adaptability, which is enabled by a synergistic effect of biomimetic nanofibrous structures as well as solvent and ionic enhancement. The skin-like mechanics and functionality of the as-designed natural protein-based biogels suggest their further applications in advanced skin sensors for long-term and high-fidelity physiological monitoring. As a proof of concept, we successfully demonstrate high-quality continuous monitoring of electrocardiograms for 1 week under daily life conditions using such natural protein-based skin-like ionic biogels.