1. Department of Mechanical Engineering, The University of Akron, Akron, OH 44325
2. Department of Biomedical Engineering, The University of Akron, Akron, OH 44325
3. Department of Neurosurgery, Johns Hopkins Medical Institutions, Baltimore, MD 21205
4. Department of Polymer Science and Polymer Engineering, The University of Akron, Akron, OH 44325
5. Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8, Canada
6. Department of Biomedical Engineering, The University of Akron, Akron, OH 44325; Department of Mechanical Engineering, The University of Akron, Akron, OH 44325