1. Berkeley Sensor and Actuator Center University of California at Berkeley Berkeley CA 94720 USA
2. Department of Chemical and Biomolecular Engineering University of California at Berkeley Berkeley CA 94720 USA
3. State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China
4. Department of Physics University of California at Berkeley Berkeley CA 94720 USA
5. Materials Science Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
6. Kavli Energy NanoSciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
7. Physical and Life Science Directorate Lawrence Livermore National Laboratory 7000 East Avenue Livermore CA 94550 USA