Self-Adhesive ILn@MXene Multifunctional Hydrogel with Excellent Dispersibility for Human-Machine Interaction, Capacitor, Antibacterial and Detecting Various Physiological Electrical Signals in Humans and Animals

Abstract

The poor dispersion of MXene in hydrogel weakens the sensitivity and cycling stability of flexible sensors. In this work, we regulated the interlayer spacing of MXene by employing ionic liquids (IL) with varying chain lengths (C=4, 8, 12, 16, 18). It was found that the IL_n with a chain length of C=16 caused the most significant change in interlayer spacing during intercalation, effectively inhibiting the self-restacking of MXene and preventing its aggregation. Building on this finding, we developed the A-PS-0.06I₁₆@M hydrogel with a polyacrylic acid (PAA) network and polydopamine-coated silica (PS). The fabrication of a highly stretchable, adhesive, and conductive hydrogel, exhibited excellent mechanical properties, including up to 1903% stretchability, elastic modulus of 20 kPa and 806 kJ·m^-3 toughness. The hydrogel demonstrated superior electrical conductivity (14.8 mS·cm^-1) and high sensitivity (GF=7.64), these features make it particularly effective in monitoring human motion signals, electrocardiograms (ECG), electromyograms (EMG), and electrical signals in rats. Moreover, the hydrogel exhibited great potential in human-machine interface (HMI)、capacitor and antibacterial effects under 808 nm near-infrared light irradiation，indicating broad applications in flexible electronics, sensors, and biomedical engineering.