Ultralight Graphene Composite Sandwich for Stretchable Light-emitting Display

Graphene composite sandwiches with exceptional stretchability and electrical conductivities are fabricated using porous graphene honeycomb (GH)/polydimethylsiloxane (PDMS) composites as the core material and ultrahigh-density graphene foam (UDGF)/PDMS composites as the face sheets. The microscale GHs prepared by a 3D printing technique deliver a long-range ordered hexagonal porous structure, an excellent electrical conductivity as high as 72 S/m, along with an ultralow density of 3.25 mg/cm3 . To the best of authors’ knowledge, this is the lightest honeycomb structure ever reported in open literature. Taking advantage of the engineered porous structure of GHs, the graphene composite sandwich shows minimal resistance changes at large external deformations with excellent structural durability. A stretchable light-emitting display constructed using a graphene composite sandwich is demonstrated as the electric circuit, which delivers reliable electronic performance under different loading modes.