It is generally known that metals are inherent in strength and toughness, but their ability to stretch is very limited. On the contrary, rubber products are very elastic, but they are much inferior in strength to metals. A team of scientists at North Carolina State University has created a hybrid fiber that combines these seemingly incompatible properties.
The fiber consists of a gallium metal core enclosed in a SEBS cladding with four layers: styrene (1st and 4th layers), ethylene and butylene. With mechanical action on rupture, the main load first falls on the strong core. If, as a result of stretching, its destruction occurs, the polymer fiber enters into action, which allows the material to maintain its integrity.
An important detail: the whole metal core is capable of conducting electric current. However, after rupture, gallium can be easily melted and reduced because the polymer has a higher melting point than the metal.
Scientists are currently planning to continue experimenting with other materials for the core and cladding. In the future, the fiber can be used in soft robotics, packaging materials and high-tech textiles.