Figure 5: Synthesis of a GF and integration with PDMS. (a) A nickel (Ni) foam. (b) CVD growth of graphene films (Ni–G) using Ni foam as a 3D scaffold template. (c) An as-grown graphene film after coating a thin PMMA supporting layer (Ni–G-PMMA). (d) A GF coated with PMMA (GF-PMMA) after etching the nickel foam with hot HCl (or FeCl3/HCl) solution. (e) A free-standing GF after dissolving the PMMA layer with acetone. (f) A GF/PDMS composite after infiltration of PDMS into a GF. All the scale bars are 500 μm [127].