Novel MXene sensors based on fast healing vitrimers

Soft matter containing Ti3C2Tx MXenes exhibits promising potential in electromechanical sensor development. Current systems suffer from a decrease in sensibility up to complete breakdown due to small structural defects that will be generated during their longtime practical service. Various non-covalent hydrogel systems, based on hydrogen bonding and ionic coupling, have been employed to improve their durability related to their repairability. However, Ti3C2Tx MXenes are not stable in those networks, since they will be irreversibly oxidized in high humidity environment during practical application. Here, we report the use of a novel dynamic covalent bond based network – a MXene acrylate vitrimer network (MAVIN) with a low glass transition temperature, which can not only be repaired fast with high efficiency but also protects the MXenes in sensor applications from oxidation under working conditions. In addition, owing to the strong microwave absorptivity of Ti3C2Tx and of the flexible dynamic covalent bond network, a damaged MAVIN sensor can be repaired by microwave radiation with a high healing efficiency of 92.4% within 1 minute, which is as good as the best healing efficiency reported in literature so far but 30 times faster. With stability at a voltage of 3 V and fast healing demonstrated, MAVIN promises potential usage in reliable and sustainable strain sensors.