Highly Stretchable,\nSelf-Repairable, and Super-Adhesive\nMultifunctional Ionogel for a Flexible Wearable Sensor

Abstract

Ionogels have broad application prospects as flexible\nwearable\nmaterials owing to their desirable properties such as conductivity,\nstretchability, and adhesiveness. It is still challenging to integrate\nsuper adhesion, high self-healing capability, and stretchability into\none ionogel sensor. Herein, an ionogel was conveniently constructed\nvia one-step polymerization using acrylamide as the monomer and <i>N</i>,<i>N</i>′-methylenebisacrylamide as the\ncross-linking agent in 1-butyl-3-methylimidazolium chloride. The loosely\nchemically cross-linked network and affluent noncovalent interactions\nexisted in the ionogel, i.e., double-ion hydrogen bonds and electrostatic\ninteractions, act synergistically to endow the ionogel with super\nadhesion (up to 208 kPa to copper), high self-healing efficiency (up\nto 92.3%), excellent stretchability (up to 1977%), and good electrical\nconductivity (4.89 × 10^–3 S/cm). The ionogel\ncan be applied as a multimode sensor to monitor the strain, human\nmovements, and pronunciation in real time. Considering its multifunctional\nproperties and efficient preparation, the present study establishes\nan easy way for the rational design and fabrication of adhesive materials\nfor wearable devices.