title: Ultra-thin graphene-polymer heterostructure membranes.
abstract: The fabrication of arrays of ultra-thin conductive membranes remains a major challenge in realising large-scale micro/nano-electromechanical systems (MEMS/NEMS), since processing-stress and stiction issues limit the precision and yield in assembling suspended structures. We present the fabrication and mechanical characterisation of a suspended graphene-polymer heterostructure membrane that aims to tackle the prevailing challenge of constructing high yield membranes with minimal compromise to the mechanical properties of graphene. The fabrication method enables suspended membrane structures that can be multiplexed over wafer-scales with 100% yield. We apply a micro-blister inflation technique to measure the in-plane elastic modulus of pure graphene and of heterostructure membranes with a thickness of 18 nm to 235 nm, which ranges from the 2-dimensional (2d) modulus of bare graphene at 173 ± 55 N m-1to the bulk elastic modulus of the polymer (Parylene-C) as 3.6 ± 0.5 GPa as a function of film thickness. Different ratios of graphene to polymer thickness yield different deflection mechanisms and adhesion and delamination effects which are consistent with the transition from a membrane to a plate model. This system reveals the ability to precisely tune the mechanical properties of ultra-thin conductive membranes according to their applications.
authors.affiliation: School of Materials and National Graphene Institute, University of Manchester, Manchester M13 9PL, UK. aravind@manchester.ac.uk.
authors.forename: C N
authors.initials: CN
authors.lastname: Berger
authors.affiliation: Micro-structure technology Institute, Karlsruhe Institute of Technology, Karlsruhe 76344, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Dirschka
authors.affiliation: School of Materials and National Graphene Institute, University of Manchester, Manchester M13 9PL, UK. aravind@manchester.ac.uk.
authors.forename: A
authors.initials: A
authors.lastname: Vijayaraghavan