* Corresponding authors

^a Johns Hopkins University, Department of Biomedical Engineering, 3400 N. Charles St., Clark Hall, Baltimore, MD, USA
E-mail: tushar@jhu.edu, cpuleo@jhu.edu, Kelvin@jhu.edu, yzhang68@jhmi.edu
Fax: +1 410-516-4771
Tel: +1 410-516-7576

^b University of California, Irvine, Departments of Biomedical Engineering and Mechanical/Aerospace Engineering, Irvine, CA, USA
E-mail: aplee@uci.edu
Fax: +1 949-824-1727
Tel: +1 949-824-9691

^c Johns Hopkins University, Departments of Mechanical Engineering and Biomedical Engineering, 3400 N. Charles St., Latrobe Hall Rm. 108, Baltimore, MD, USA
E-mail: thwang@jhu.edu
Fax: +1 410-516-4316
Tel: +1 410-516-7086