Adhesive, antibacterial ionogels based on bio-ionic liquids for human motion monitoring and intelligent massage recognition

Ionogels, combining ionic conductivity with soft mechanical properties, have shown broad prospects in wearable electronics and flexible bioelectronic devices. However, conventional ionogels predominantly rely on imidazolium-based ionic liquids, which suffer from potential biotoxicity, limited degradability, and challenges in achieving multifunctional integration. Herein, a green strategy is proposed to construct high-performance ionogels by developing bio-ionic liquids from natural small biomolecules. Through the cooperative action of multiple noncovalent interactions, l -carnitine and citric acid were combined to form a biocompatible ionic liquid, which was subsequently introduced into a poly(vinyl alcohol)-polyethyleneimine network to fabricate an ionogel via a freeze-thaw-induced physical crosslinking. With the participation of the ionic liquid, the cohesive energy within the gel matrix and the interfacial binding energy are synergistically optimized, enabling the resulting ionogel to simultaneously exhibit high stretchability (elongation exceeding 1000%), strong interfacial adhesion (shear stress up to 1357 kPa on glass substrates), and stable strain-sensing performance (maintaining reliable responses over more than 7000 loading-unloading cycles) without the need for chemical crosslinkers or complex synthetic routes. In addition, the ionogel demonstrates intrinsic antibacterial activity and favorable biocompatibility. The ionogel enables reliable monitoring of human motions and effective discrimination of different massage manipulation modes, highlighting its promising potential for wearable ionic skins and flexible bioelectronic devices. This work provides a new design paradigm for the green and bio-friendly construction of multifunctional ionogels.