Wavy graphene foam reinforced elastomeric composites for large-strain stretchable conductors

Abstract

Stretchable conductors with excellent flexibility, stretchability and electrical conductivity are among critical components for the next-generation electronics. A novel wavy graphene foam (wGF)/thermoplastic polyurethane (TPU) composite for large-strain stretchable conductors is fabricated by drop coating of matrix solutions on freestanding wGFs. Hierarchical morphologies with a microscopic dense cellular structure and a macroscopic wave shape are observed on wGFs. Decent electrical conductivities of 4.3 S/cm and outstanding mechanical properties are obtained. The wGF/TPU composites exhibit great potentials as large-strain stretchable conductors, with resistance increments of 9.4, 14, and 22 % at tensile strains of 50, 100 and 150 %, respectively, which are among the bests of carbon reinforced polymer conductive nanocomposites. Synergic effects of the extension of wavy structure and the reshaping of highly compacted graphene frameworks during stretching, which results in little true strain on conductive graphene skeletons, are mainly responsible for the stable conductive performances. Demonstrations of wGF/TPU composites as stretchable conductors exhibit superb resistance stabilities under different deformation conditions, suggesting great potentials for real-world applications.