A self-reinforcing, self-healing, and shape memory polybutadiene-based polyurethane via disulfide bonds for healable flexible sensors

Self-reinforcing and self-healing resins facilitate the regeneration of functionality in damaged flexible sensors, while also exhibiting resistance to secondary damage. The reorganization of disulfide bonds at the sites of damage, coupled with the reaction of sulfur radicals with vinyl units, collaboratively enables the construction of a more robust crosslinking network, facilitating self-reinforcing and self-healing in the damaged regions. In this study, polybutadiene-based polyurethane acrylate featuring a main chain containing disulfide bonds and terminal groups composed of multiple vinyl units is synthesized. Strength of the material after 1 and 1.5 h of healing reaches 104.22 ± 1.7 % and 127.4 ± 12.6 % of its initial value, respectively, with the healed sensors derived from this material still exhibiting excellent sensing performance. Additionally, the multi-component structure imparts the resin with thermoresponsive shape memory functionality. This work presents a novel approach to designing self-healing materials and has the potential to advance the development of future biomimetic skin.