Abstract by Stefan Lehnardt
Physics and Astronomy
Robert Davis, Richard Vanfleet
Characterization of Multilayer Graphene Films
Graphene is of great interest due to its potential applications in flexible electronics and biosensors. The electrical and mechanical properties of single-layer graphene have been studied extensively and its growth via CVD on copper substrates has been improved considerably. Very little, however, is known about the properties of multilayer graphene. Multilayer graphene is also grown via CVD on a nickel substrate which, unlike copper, allows for many layers of graphene to form. Many layers are necessary for macro-scale applications of graphene such as speakers, x-ray windows, and other devices that require spanning a graphene membrane over distances greater than a few microns. We have used an atomic force microscope to measure the elastic deflection of graphene cantilevers cut from a suspended graphene membrane with a focused ion beam. We used the Sader calibration method to extract the response of the graphene cantilever from the AFM tip deflection. From this data we have determined the Young's Modulus of graphene consisting of about 150 layers. We have also used the same method to push the cantilevers to breaking to measure their Ultimate Tensile Strength.