1. Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, USA.
2. Materials Science & Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712, USA.
3. Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
4. Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802, USA.