1. Electronics Science and Technology Division, Code 6800, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
2. Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
3. Materials Science and Technology Division, Code 6300, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States