Towards flexible and healable strain sensors via a modulated interface between Ti3C2 MXene and epoxidized natural rubber

Critical issues such as inferior mechanical properties, low healing efficiency, complex repair conditions, etc., have posed a great threat to the intelligent sensing implementation of elastomers. Herein, we delicately design Ti3C2 MXene/epoxidized natural rubber (ENR) elastomer composites with superior mechanical and self-healing properties by controlling the confine structure and surface hydroxyl group number of Ti3C2 MXene targeting the realization of advanced strain sensors. The synchrotron radiation X-ray three-dimensional nano-computed tomography results confirm the uniform distribution and of Ti3C2 MXene in ENR, and the outstanding structural stability of composite elastomer throughout the loading and unloading procedure. Such versatile design leads to the synchronous manipulation of the interface density and strength of the composite, maximizing the dynamic non-covalent bond interactions between Ti3C2 MXene and ENR. As a result, the composite elastomer display a high mechanical strength of 4.93 MPa, and a remarkable self-healing efficiency of ∼98% at room temperature, thereby affording superior intelligent strain sensing application. Impressively, the detection range and response time are up to 0.1∼800% strain, and 50 ms, respectively, outperforming the state-of-art self-healable strain sensors. This investigation not only provides a new interfacial engineering strategy for designing elastomer composites with advanced intelligent sensing functions but also propels the underlying interfacial working mechanism deciphering.