1. Department of Mechanical and Aerospace Engineering Cornell University 124 Hoy Road Ithaca NY 14850 USA
2. Paul M. Rady Department of Mechanical Engineering University of Colorado Boulder 427 1111 Engineering Drive Boulder CO 80309 USA
3. Vehicle Technology Directorate US Army Research Laboratory 2800 Powder Mill Road Adelphi MD 20783 USA
4. Materials Science and Engineering Program University of Colorado Boulder 4001 Discovery Drive Boulder CO 80309 USA