Tough 'Breakable' Fiber Has Flexibility of Rubber and Strength of Metal

Researchers from North Carolina State University have engineered a tough, flexible fiber that could have applications in soft robotics or next-generation textiles. The fiber consists of a gallium metal core surrounded by an elastic polymer casing. When the metal breaks, the polymer absorbs the strain between the breaks and transfers the stress back to the core. “Every time the metal core breaks it dissipates energy, allowing the fiber to continue to absorb energy as it elongates,” says Michael Dickey, Professor of Chemical and Biomolecular Engineering at NC State. “Instead of snapping in two when stretched, it can stretch up to seven times its original length before failure, while causing many additional breaks in the wire along the way."