Organohydrogel Based Electronic Skin Reinforced by Dual-Mode Conduction and Hierarchical Collagen Fibers Skeleton

Adv Sci (Weinh). 2024 Dec 16:e2412934. doi: 10.1002/advs.202412934. Online ahead of print.

Abstract

Collagen fiber skeleton from animal skin is an ideal substrate for electronic skin (e-skin). However, the interface mismatch between conductive materials and skeleton and the monotonicity of conductive network still hinder its creation. Herein, a novel collagen fiber-based e-skin with dual-mode conduction of NaCl and conductive spheres (IECS) is accomplished by loading organohydrogel into the skeleton via "permeation and self-assembly". The resulting interpenetrating network produces a 3D continuous, conductive pathway and strong interface interaction with high-density hydrogen bonding, thus exhibiting excellent strength (24.5 MPa), conductivity (14.82 S m-1), sensing performance (sensitivity of 16.64), and environmental stability. The physical structure (3D skeleton, interpenetrating network) and chemical interaction (interface interaction, salting-out) achieve energy dissipation. Meanwhile, the sensitivity is enhanced by dual-mode conduction, conductive sphere array, and deformation amplification induced by collagen fibers. Additionally, the strong bonding ability between glycerin and collagen fibers with water molecules provides anti-freezing and moisture-retention characteristics. Thus, the strategic synergy of compositional and structural design makes IECS a promising force-sensing part of piezoresistive sensor for human movement, pulse frequency, cipher transmission, and pressure distribution. In short, IECS presents a multifunctional platform for the invention of high-performance e-skin with on-demand property, which offers great application potential in wearable electronics.

Keywords: collagen fiber skeleton; conductive organohydrogel; dual‐mode conduction; electronic skin; flexible sensor.