Biological self-healing strategies from mechanically robust heterophasic liquid metals

Summary

Self-healing materials have been in a notorious dilemma for decades to make a challenging balance between high mechanical robustness and self-healing ability. For example, high-molecular-weight polymers or crystalline inorganics are generally high-moduli materials, but they lose the capability to self-heal because of the slow diffusion to unite damaged interfaces. This work, inspired by biological self-healing, successfully realizes self-repairing (healing efficiency > 99%) in mechanically robust materials (E > 5 GPa) near physiological temperature. The high structural similarity between heterophasic metals and biological tissues is the key to realizing the biological ETR (emulsion exudation, nutrition transportation, tissue regeneration) self-healing in metallic materials. Importantly, the mechanical performance and self-healing behavior of ETR self-healable metals (ETR-M) can be precisely controlled through temperature and compositions via metal phase diagrams. An artificial bone-tissue system is well assembled from the ETR-M and self-healable polyurethane with distinguished features of bionic structure, effective self-healing, and high modulus.