Acknowledgments:
We appreciate the funding support from Old Dominion University and the equipment
supplied from the Institute of Micro/Nanotechnology.
Author Contributions:
Xiaoyu Zhang conceived and designed the experiments; Can Zhou directed the
experimental investigation, conducted data analysis, and wrote the manuscript. Yashar Bashirzadeh and
Timothy A. Bernadowski Jr. contributed to device fabrication and the experiments.
Conflicts of Interest:
The authors declare no conflict of interest. The founding sponsors had no role in the design
of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the
decision to publish the results.
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