1. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
2. Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas, 78712, USA
3. Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
4. Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA