1. Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
2. Department of Precision Instruments, Tsinghua University, Beijing, China
3. Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology–Head and Neck Surgery, University of Washington, Seattle, WA, USA
4. Department of Materials Science, University of Washington, Seattle, WA, USA
5. VA Puget Sound, Seattle, WA, USA