Rapid preparation of dynamic-crosslinked nanocomposite hydrogel sensors with efficiency self-healing and adhesion properties for elderly health and sleep management

Abstract

Multifunctional conductive hydrogels exhibit tremendous potential for applications in human–machine interfaces, flexible electronic devices and soft robotics. However, the time-consuming and energy-intensive preparation process, as well as the inefficient and unstable self-healing capabilities, limit their practicality and reusability. Herein, we utilized lignin sulfonate (LS)-Fe3+ dynamic redox system to induce the generation of ammonium persulfate (APS) radicals at room temperature. Additionally, the polymerization of acrylamide (AM), sodium acrylate (AAS), and 3-acrylamidophenylboronic acid (APBA) formed polymer networks through multiple dynamic crosslinking via the synergistic interactions of Fe3+ and cellulose nanocrystals (CNC). The dynamic and reversible boronic ester bonds, ion coordination bonds, and hydrogen bonds endowed the hydrogel with high stretchability (1170 %), low hysteresis and efficient self-healing (91.76 %, 2 h) capability. Interestingly, the intermediate catechol groups generated by the LS-Fe3+ dynamic catalytic system provided the hydrogel with repeatable and reliable adhesive performance. Thanks to the excellent ionically conductivity, the fabricated hydrogel-based sensors exhibited a wide sensing range (500 %), rapid response time (139 ms), and high sensitivity (GF = 8.98), that accomplished specific voice recognition and subtle body motion detection for real-time elderly health and sleep management. This multifunctional hydrogel is of great significance for efficiently developing prolonged lifespan wearable electronics and healthcare flexible devices.