1 School of Electrical & Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA. Nano-Meta Technologies Inc., 1281 Win Hentschel Boulevard, West Lafayette, IN 47906, USA. aeb@purdue.edu.
2 School of Electrical & Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA. Nano-Meta Technologies Inc., 1281 Win Hentschel Boulevard, West Lafayette, IN 47906, USA.