▎ 摘　　要

Expected to become mainstream in the electronics industry, flexible electronics still face major challenging issues. For polymeric-based flexible electronic substrates in particular, these challenges include a lack of electromagnetic shielding capability and poor heat dissipation. Here, we report a highly flexible and thermally conductive macroscopic polydimethylsiloxane (PDMS) polymer film embedded with a copper-coated reduced graphene oxide (rGO) fiber mesh. The rGO fibers are assembled into 3D fiber meshes and electroplated with micrometer-thick copper coatings, displaying excellent electrical and thermal conductivities. Oriented in the horizontal and perpendicular directions within the PDMS polymeric matrix, the fiber mesh serves as a highly electrically and thermally conductive backbone through the in-plane direction. Meanwhile, the fiber mesh also effectively shields electromagnetic interference in the X-band without causing thermal damage. The macroscopic film remains electrically insulated in the through-plane direction. Utilizing both the favorable thermal and electrical properties of the graphene fiber-based mesh and the flexibility of the PDMS matrix, our film may exhibit potential for flexible electronics applications such as wearable electronic thermal management and flexible microwave identification devices.