Department of Electrical Engineering, Stanford University, Stanford, CA, USA.|Department of Electrical Engineering, Stanford University, Stanford, CA, USA.|Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.|Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.|Department of Electrical Engineering, Stanford University, Stanford, CA, USA.