Highly Stretchable, Self-Repairable, and Super-Adhesive Multifunctional Ionogel for a Flexible Wearable Sensor

Abstract

Ionogels have broad application prospects as flexible wearable materials owing to their desirable properties such as conductivity, stretchability, and adhesiveness. It is still challenging to integrate super adhesion, high self-healing capability, and stretchability into one ionogel sensor. Herein, an ionogel was conveniently constructed via one-step polymerization using acrylamide as the monomer and N,N′-methylenebisacrylamide as the cross-linking agent in 1-butyl-3-methylimidazolium chloride. The loosely chemically cross-linked network and affluent noncovalent interactions existed in the ionogel, i.e., double-ion hydrogen bonds and electrostatic interactions, act synergistically to endow the ionogel with super adhesion (up to 208 kPa to copper), high self-healing efficiency (up to 92.3%), excellent stretchability (up to 1977%), and good electrical conductivity (4.89 × 10–3 S/cm). The ionogel can be applied as a multimode sensor to monitor the strain, human movements, and pronunciation in real time. Considering its multifunctional properties and efficient preparation, the present study establishes an easy way for the rational design and fabrication of adhesive materials for wearable devices.