Ultrathin Cellulose Nanofiber-Reinforced Ti₃C₂T _x -Crosslinked Hydrogel for Multifunctional and Sensitive Sensors

Multifunctionalstrain sensors simultaneously satisfy all the requirementsincluding flexibility, stretchability, biocompatibility, and highresponsibility to external stimuli, which are always in high demandfor wearable electronics. In this work, we introduced modified bacterialcellulose nanofibers (BCNF) as double-network hydrogel-reinforcedsubstrates to prepare an MXene-based strain sensor (MPCB). The well-percolatedBCNF play an important role in reinforcing the polymer skeleton andinducing the continuous MXene-MXene conductive paths. Consequently,the electrical conductivity was significantly improved and excellentmechanical properties were retained (with the elongation at breakover 500%). The prepared hydrogel can act as a wearable sensor forhuman motion detection, including swallowing movements, finger bending,and wrist bending. It also exhibits promising applications with multiplecharacteristics, i.e., ideal EMI, adjustable flexibility, self-healing,and self-adhesive performance. Our work provides a simple and practicalstrategy for a generation of wearable electronic sensor devices.