Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, Northwestern University, Chicago, Illinois, United States of America.|Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America.|Biophysics Program, Harvard University, Boston, Massachusetts, United States of America.|Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States of America.|Department of Physical Medicine and Rehabilitation, Rehabilitation Institute of Chicago, Northwestern University, Chicago, Illinois, United States of America.