title: Selective mechanical transfer of graphene from seed copper foil using rate effects.
abstract: A very fast, dry transfer process based on mechanical delamination successfully effected the transfer of large-area, CVD grown graphene on copper foil to silicon. This has been achieved by bonding silicon backing layers to both sides of the graphene-coated copper foil with epoxy and applying a suitably high separation rate to the backing layers. At the highest separation rate considered (254.0 μm/s), monolayer graphene was completely transferred from the copper foil to the target silicon substrate. On the other hand, the lowest rate (25.4 μm/s) caused the epoxy to be completely separated from the graphene. Fracture mechanics analyses were used to determine the adhesion energy between graphene and its seed copper foil (6.0 J/m(2)) and between graphene and the epoxy (3.4 J/m(2)) at the respective loading rates. Control experiments for the epoxy/silicon interface established a rate dependent adhesion, which supports the hypothesis that the adhesion of the graphene/epoxy interface was higher than that of the graphene/copper interface at the higher separation rate, thereby providing a controllable mechanism for selective transfer of graphene in future nanofabrication systems such as roll-to-roll transfer.
authors: Department of Aerospace Engineering and Engineering Mechanics, Research Center for the Mechanics of Solids, Structures and Materials, ‡Department of Mechanical Engineering and The Materials Science and Engineering Program, and §Department of Electrical and Computer Engineering, The University of Texas at Austin Austin, Texas 78712, United States.
authors: Seung Ryul
authors: SR
authors: Na
authors: Ji Won
authors: JW
authors: Suk
authors: Li
authors: L
authors: Tao
authors: Deji
authors: D
authors: Akinwande
authors: Rodney S
authors: RS
authors: Ruoff
authors: Rui
authors: R
authors: Huang
authors: Kenneth M
authors: KM
authors: Liechti
keywords: adhesion energy; copper; epoxy; graphene; mechanical transfer; rate effects; selective transfer; traction-separation relations