1. Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Mechanical Engineering Department, North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411, United States
3. Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
4. Chemistry Department, United States Naval Academy Annapolis, Maryland 21402, United States