Biomimetic, recyclable, highly stretchable and self-healing conductors enabled by dual reversible bonds

Abstract

Utilization of self-healing chemistry and biomimetic structure design, to develop stretchable conductors that are self-healing and recyclable, is of great interest. Herein, we utilize small molecular (triethanolamine, TEA) instead of common polymer segments as a spacer and cross-linker, which could render the dynamic covalent/noncovalent thermosets with higher density of reversible bonds (H-bonds and disulfide bonds) and more cross-linked points through controlling mole fraction due to more hydroxyl group per molecular weight of TEA. The as-prepared thermosets exhibit excellent thermal stability, shape memory effect, recyclability and healing efficiency at relatively moderate temperature. Then, a series of mechanically and electrically self-healing conductive tendrils composed of self-healing/shape memory polymers and conductive percolation networks are fabricated, which possess enhanced conductivity retention capability under stretching states. Moreover, our designed helical-structured conductors can be not only rehealed but also recycled and reprocessed due to the simultaneous destruction and reestablishment of the reversible bonds. Strikingly, the fabrication process of self-healing conductive tendrils is compatible to the conventional technique of conductors including silk-screen printing and adhesive bonding technique. This biomimetic approach opens a promising pathway to fabricate wearable intelligent devices with versatile functions.