Toughening Stretchable Fibers Using a Metallic Core

Researchers have developed a fiber that combines the elasticity of rubber with the strength of a metal, resulting in a tougher material. The fibers consist of a gallium metal core surrounded by an elastic polymer sheath. When placed under stress, the fiber has the strength of the metal core. But when the metal breaks, the fiber doesn’t fail. Instead, the polymer sheath absorbs the strain between the breaks in the metal and transfers the stress back to the metal core. This response is similar to the way human tissue holds together broken bones.