1. Electrical Engineering
and Computer Sciences, University of California—Berkeley, Berkeley, California 94720, United States
2. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
94720, United States
3. Berkeley Sensor and
Actuator Center, University of California—Berkeley, Berkeley, California 94720, United States
4. Electrical and Computer Engineering, University of Florida, Gainesville, Florida 32611,
United States
5. Materials
Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan,
Republic of China, 30013
6. Electrical
and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106,
United States