Stretchable, Self-Healable, and Durable Conductive Elastomer Derived from a Rationally Designed Covalently Cross-Linked Network

Silver nanowire (Ag NW)-based elastic conductors have been considered a promising candidate for key stretchable electrodes in wearable devices. However, the weak interface interaction of Ag NWs and elastic substrates leads to poor durability of electronic devices. For everyday usage, an additional self-healing ability is required to resist scratching and damage. Therefore, robust Ag NW-based elastic conductors possessing stretchability, self-healing, and stability are highly desirable and challenging. Here, we present a universal interface tailoring strategy that introduces thiols onto the dynamically cross-linked elastic substrate surface. The surface thiol groups strongly interact with Ag NWs through Ag-S bonds, forming the stable conductive layer on the elastic substrate. At elevated temperatures, the Ag NWs are partially embedded in the surface of the elastic substrate and a buffer layer is formed to release the concentrated stress. As a result, the formed Ag NW-based elastic conductor displays the combination of good conductivity, high stretchability (>1000%), efficient self-healing capability (>95%), and remarkable stability. Besides, the Ag NW-based elastic conductor combining the good properties mentioned above is suitable for fabricating a sensitive and durable strain sensor against cyclic strain. The presented strategy can be considered a versatile and effective route to generating other surface thiol-rich covalently cross-linked elastomers with dynamic disulfide bonds.