Liquid metal @ mxene spring supports ionic gel with excellent mechanical properties for high-sensitivity wearable strain sensor

Conductive ionic gels are considered as potential flexible sensing materials owing to their softness and biocompatibility. Nevertheless, pure ionic gels typically exhibit poor mechanical properties and low sensitivity. In this study, MXene and liquid metal (LM) are introduced for self-assembly to form a spring structure. The enhanced effect of the van der Waals force synergy between the two fillers increases the tensile resistance (925 %, 1091.5 kPa), compression resistance (75 %, 2534.3 kPa) and self-healing (∼90 % recovery) efficiency of the ionic gel. In addition, the conductive paths based on double fillers are greatly destroyed during the straining process, and show a very high gauge factor (15.47) because of their unique spring structure and weak viscous force between them. This study provides a new approach for the preparation of highly sensitive sensing materials for human body monitoring and applications in other domains.