[1] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA
[2] MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA
[3] MIT, Electrochem Energy Lab, Cambridge, MA 02139 USA
[4] MIT, Dept Biol Engn, Cambridge, MA 02139 USA
[5] MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA
[6] MIT, Dept Mech Engn, Cambridge, MA 02139 USA