1. Department of Mechanical Engineering; Materials Science and Engineering Program; Texas Materials Institute; The University of Texas at Austin; Austin Texas 78712 USA
2. Department of Physics; Electro-Optics Graduate Program; University of Dayton; Dayton Ohio 45469 USA
3. Google, Inc.; 1600 Amphitheatre Pkwy Mountain View CA 94043 USA
4. Department of Engineering Science and Mechanics; Department of Biomedical Engineering; Materials Research Institute; Huck Institute of Life Sciences; The Pennsylvania State University; University Park Pennsylvania 16802 USA
5. Institute of Materials Research and Engineering; Agency for Science, Technology and Research (A*STAR); 3 Research Link Singapore 117602 Singapore