1. Department of Biomedical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
2. Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
3. Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
4. Department of Mechanical Engineering, University of South Carolina, Columbia, South Carolina 29208, United States
5. Biophysics and Biomedical Measurement Group, Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States