Superelastic EGaIn Composite Fibers Sustaining 500% Tensile Strain with Superior Electrical Conductivity for Wearable Electronics

Stretchable conductive fibers have gained significant attention in the field of wearable and flexible electronics because of their inherited unique properties. Up to now, there are few reports regarding the highly stretchable fibers with excellent electronic properties. In this work, a highly stretchable fiber with superior electrical conductivity is fabricated, which contains a core fiber, an intermediate modified layer, and an outer eutectic-gallium-indium liquid metal layer. The fiber demonstrates an excellent electrical conductivity of over 10³ S cm^-1 when stretched up to 500% strain, which is far superior to the existing stretchable conductive fiber. The stretchable conductive fiber shows excellent thermostability with a maximum operating temperature of nearly 250 °C. Such unique fibers can be applied as highly stretchable, deformable conductor to charge a mobile phone, and sensor to monitor human activities. This work offers promising application in the areas of flexible and wearable electronics.