1. Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Taejon 305-701, South Korea
2. American Medical Systems, 3070 Orchard Drive, San Jose, California 95134
3. National Science Foundation, 4201 Wilson Boulevard, Arlington, Virginia 22230
4. Western Digital Corporation, 44100 Osgood Road, Fremont, California 94539
5. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208