Researchers from MIT developed a new process that can transfer graphene directly onto a variety of flexible substrates using a lamination process that does not require an intermediate "glue" step. The new process does not leave any residues that can affect the graphene like in other transfer processes. The new method can also be used for other materials, such as boron nitride.
The process starts by synthesizing graphene flakes on both sides of a copper foil sheet. Then the flakes are sandwiched between the target flexible surface and a protective paper layer. This structure is placed between two plastic (PET) sheets. This goes into a lamination machine in which the temperature can be controlled, and the components bond together. The plastic film and paper where removed and this leaves a copper foil with graphene and the target substrate. The copper was dissolved (or etched away) using a copper etchant.