title: In situ observation of electrostatic and thermal manipulation of suspended graphene membranes.
abstract: Graphene is nature's thinnest elastic membrane, and its morphology has important impacts on its electrical, mechanical, and electromechanical properties. Here we report manipulation of the morphology of suspended graphene via electrostatic and thermal control. By measuring the out-of-plane deflection as a function of applied gate voltage and number of layers, we show that graphene adopts a parabolic profile at large gate voltages with inhomogeneous distribution of charge density and strain. Unclamped graphene sheets slide into the trench under tension; for doubly clamped devices, the results are well-accounted for by membrane deflection with effective Young's modulus E = 1.1 TPa. Upon cooling to 100 K, we observe buckling-induced ripples in the central portion and large upward buckling of the free edges, which arises from graphene's large negative thermal expansion coefficient.
authors.affiliation: Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Bao
authors.forename: Kevin
authors.initials: K
authors.lastname: Myhro
authors.forename: Zeng
authors.initials: Z
authors.lastname: Zhao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Chen
authors.forename: Wanyoung
authors.initials: W
authors.lastname: Jang
authors.forename: Lei
authors.initials: L
authors.lastname: Jing
authors.forename: Feng
authors.initials: F
authors.lastname: Miao
authors.forename: Hang
authors.initials: H
authors.lastname: Zhang
authors.forename: Chris
authors.initials: C
authors.lastname: Dames
authors.forename: Chun Ning
authors.initials: CN
authors.lastname: Lau