1. Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA.
2. Berkeley Sensor and Actuator Center, University of California, Berkeley, Berkeley, CA 94720, USA.
3. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA 94720, USA.
4. Biophysics Graduate Program, University of California, Berkeley, Berkeley, CA 94720, USA.