Abstract by Bryce Anderson
Physics and Astronomy
Strength and Modulus of Freestanding Many-Layer CVD Graphene Films
Monolayer graphene is the strongest material ever measured. However, it is a single layer of atoms, so it cannot take much force on a macroscopic scale. The properties of mono- and few layer graphene and graphite have been studied extensively, but many-layer graphene is relatively unexplored. We believe using many-layer graphene can allow us to use its great mechanical properties on a much larger scale. To find out how many-layer graphene responds to stress, we need to determine its Young’s modulus. It was necessary to accurately determine the thickness of the film because the method for estimating Young's modulus depends on the third power of the film thickness. We built an apparatus to measure graphene thickness, comparing the intensity of laser light shining through graphene to unobstructed light. Using this ratio in a formula found in other literature, we were able to determine the thickness of the films to a sufficient degree of certainty. We also confirmed the thickness by using an AFM to measure the step height at the edge of the graphene film.