1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
2. Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
3. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
4. Departments of Rehabilitation Medicine and Physiology and Biophysics, Center for Sensorimotor Neural Engineering, UW Institute for Neuroengineering, University of Washington, Seattle, WA 98195, USA.
5. Department of Materials, University of Oxford, Oxford OX1 3PH, UK.
6. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
7. Advanced Functional Fabrics of America Inc., 500 Technology Square, NE47-525, Cambridge, MA 02139, USA.