1. Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, United States
2. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
3. Toyota Central R&D Laboratories, Inc, Nagakute City 480-1192, Japan
4. Institute of Mechanical Engineering, EPFL, 1015 Lausanne, Switzerland