1. Department of Materials Science and Engineering; Frederick Seitz Materials Research Laboratory; University of Illinois at Urbana-Champaign; Urbana IL 61801 USA
2. School of Mechanical Engineering; Purdue University; West Lafayette IN 47907 USA
3. School of Mechanical and Aerospace Engineering; Oklahoma State University; Stillwater OK 74078 USA
4. Weldon School of Biomedical Engineering; School of Mechanical Engineering; Center for Implantable Devices; Birck Nanotechnology Center; Purdue University; West Lafayette IN 47907 USA