1. Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06520, United States
2. Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, United States
3. Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, United States
4. IBM Semiconductor Research and Development Center, Hopewell Junction, New York 12533, United States
5. Department of Pathology, Yale University, New Haven, Connecticut 06520, United States