Multifunctional MXene\nConductive Zwitterionic Hydrogel\nfor Flexible Wearable Sensors and Arrays

Abstract

Conductive hydrogels have good prospects in the fields\nof flexible\nelectronic devices and artificial intelligence due to their biocompatibility,\ndurability, and functional diversity. However, the process of hydrogel\npolymerization is time-consuming and energy-consuming, and freezing\nat zero temperature is inevitable, which seriously hinders its applications\nand working life. Herein, zwitterionic conductive hydrogels with self-adhesive\nand antifreeze properties were prepared in one minute by introducing\ntwo-dimensional (2D) MXene nanosheets into the autocatalytically enhanced\nsystem composed of tannic acid-modified cellulose nanofibers and zinc\nchloride. The system has strong environmental applicability (−60\nto 40 °C), good stretchability (ductility ≈ 980%), durable\nadhesion (even after 30 days of exposure to air), and strong electrical\nconductivity (20 °C, 30 mS cm^–1). By virtue\nof these advantages, the prepared zwitterionic hydrogels can be developed\ninto flexible strain sensors to monitor large human movements and\nsubtle physiological signals over a wide temperature range and to\ncapture signals from handwriting and voice recognition. In addition,\nmultiple flexible sensors can be assembled into a three-dimensional\n(3D) array, which can detect the magnitude and spatial distribution\nof strain or force. These results demonstrate that the prepared zwitterionic\nhydrogels have promising applications in the fields of medical monitoring\nand artificial intelligence.