Mechanically\nDriven Self-Healing MXene Strain Gauges\nfor Overstrain-Tolerant Operation

Compliant strain gauges are well-suited to monitor tiny\nmovements\nand processes in the body. However, they are easily damaged by unexpected\nimpacts in practical applications, limiting their utility in controlled\nlaboratory environments. This study introduces elastic microcracked\nMXene films for mechanically driven self-healing strain gauges. MXene\nfilms are deposited on soft silicone substrates and intentionally\nstretched to create saturated microcracks. The resulting device not\nonly has high sensitivity but also can recover its original sensing\ncapability even after experiencing failure-level overstrains. This\nelectrical self-healing ability is achieved through the elastic rebound\nof the substrate, which autonomously restores the microcracked morphology\nof the MXene film. The MXene strain gauge can withstand overextension,\ntwisting, impact forces, and even car rolling. The device is also\nresilient to touch-induced damage during monitoring of physiological\nmotions. The mechanically driven self-healing strategy may effectively\nimprove the durability of highly sensitive strain sensors.