Self-Healing Ti3C2 MXenes/PDMS Supramolecular Elastomer Based on Small Biomolecules Modification for Wearable Sensor.

Flexible conductive composites can be used as wearable strain sensors, which are widely used in the fields of new generation robots, electronic skin and human detection. However, how to make conductive composites simultaneously possess flexibility, stretchability, self-healing and sensing capability is a challenging research. In this work, we innovatively designed and prepared a silicone polymer conductive composite. MXenes and Amino polydimethylsiloxane were modified by small biomolecules via esterification reaction and Schiff base reaction, respectively. The modified MXenes are uniformly dispersed, which endows the composite with good electrical conductivity. The reversibility of multiple hydrogen bonds and imine bonds in the composite system makes it have ideal tensile properties and high-efficiency self-healing ability without external stimulation. The conductive composite containing 10wt%A-MXenes showed an elongation of 81%, and its mechanical strength could reach 1.81MPa. After repair, the tensile properties and the electrical conductivity could be restored to 98.4% and 97.6%, respectively. In addition, the conductive composite is further evaluated for the value of wearable strain sensors. Even after cut-healed processes, conductive composite can still accurately detect tiny human movements (including speaking, swallowing and pressing). This kind of self-healing MXenes/PDMS elastomer based on small biomolecules modification has great potential as a wearable strain sensor. This simple preparation method provides guidance for the future multi-functional flexible electronic materials.