▎ 摘　　要

NOVELTY - A multilayer structure comprises core layer (154) having core density of 0.01-1 g/cm3 and skin layer (152) contains at least 10 wt.% graphitic material containing one or more graphene oxide, reduced graphene oxide, graphene, graphite oxide, reduced graphite oxide and graphite. The skin layer (152) covers the core layer and has skin density of 0.5-2 g/cm3. The thickness ratio of skin layer to the core layer is 1:1-1:1000. USE - Multilayer structure used for forming acoustic transducers diaphragm in electrical devices (claimed) such as loudspeaker and microphone. Can also be used in aerospace, automotive, industries, sports equipment and panel application for construction materials. ADVANTAGE - The multilayer structure has excellent stiffness, uniform mechanical property in all orientations, reduced density of graphitic material foams which controls the capillary drying stress and tunes isotropy and composition of graphitic material structure by depositing multilayer of graphene suspensions. The multilayer produces acoustic transducers diaphragm having non-planar shape having bend in truncated cone shape forming closed shape on the surface of multilayer structure. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of sandwich structure. Substrate (101) Sheet (142) Skin layer (152) Core layer (154) Core thickness (158)