Roy Downs University of Arkansas

Faculty Mentor: Joe RencisGraduate Student Mentor: Sachin Terdalkar

Nano-indentation of Graphene Sheet using

Molecular Dynamic Simulation

Monolayer Structure of Carbon Atoms

Hexagonal Shape Lattice

Characteristics Very Strong Highly Conductive High Opacity

Graphene Sheet

http://en.wikipedia.org/wiki/File:Graphene_xyz.jpg

• Nano-scale Electronics

• Ultracapacitors

• Pressure Sensors

• Nano Resonators

Potential Applications

[Freitag, M., Nature Nanotechnology 2008]

Graphene Transistor

Experimental Measurement of Mechanical Properties

Mechanical Properties: Project Focuso Young’s Modulus (measured E=1.0 TPa)o Intrinsic Strength (measured sint=130 GPa)

Graphene on Silicon Substrate

Atomic Force Microscope (AFM)http://www.sciencemag.org/ http://www3.physik.uni-greifswald.de/

method/afm/eafm.htm

Graphene

Sheet

Silicon Substrat

e

Silicon Substrat

e

Graphene

Sheet

Load – Indentation Curve

332 )( aD aqEF

Graphene Sheet & AFM Indenterhttp://www.physorg.com/news135959004.html

http://www.sciencemag.org/

d

Atoms are assumed lumped point masses

Interaction through Inter-atomic Potential

Atomic position from numerical integration of equations of motion

Molecular Dynamics Simulation

F = ma

http://en.wikipedia.org/wiki/File:Argon_dimer_potential_and_Lennard-

Jones.png

Using MD SimulationsGenerate load-indentation

curveDetermine Young’s

ModulusCalculate Intrinsic

Strength

Determine Interaction Between Si Substrate and Graphene Sheet Using MD Simulations

Goals

http://www.sciencemag.org/

http://www.physorg.com/news135959004.html

Silicon Substrat

eGraphe

ne Sheet

Questions?