title: Mechanical Control of Graphene on Engineered Pyramidal Strain Arrays.
abstract: Strain can tune desirable electronic behavior in graphene, but there has been limited progress in controlling strain in graphene devices. In this paper, we study the mechanical response of graphene on substrates patterned with arrays of mesoscale pyramids. Using atomic force microscopy, we demonstrate that the morphology of graphene can be controlled from conformal to suspended depending on the arrangement of pyramids and the aspect ratio of the array. Nonuniform strains in graphene suspended across pyramids are revealed by Raman spectroscopy and supported by atomistic modeling, which also indicates strong pseudomagnetic fields in the graphene. Our results suggest that incorporating mesoscale pyramids in graphene devices is a viable route to achieving strain-engineering of graphene.
authors.affiliation: †Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Gill
authors.affiliation: †Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.
authors.forename: John H
authors.initials: JH
authors.lastname: Hinnefeld
authors.affiliation: ‡Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Shuze
authors.initials: S
authors.lastname: Zhu
authors.affiliation: †Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.
authors.forename: William J
authors.initials: WJ
authors.lastname: Swanson
authors.affiliation: ‡Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Teng
authors.initials: T
authors.lastname: Li
authors.affiliation: †Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States.
authors.forename: Nadya
authors.initials: N
authors.lastname: Mason
keywords: Raman spectroscopy; graphene; pseudomagnetic fields; strain; strain-engineering