Research Interests:
Nano-electronic devices are powerful tools in developing ultrasensitive biosensor and electronically modulating biological systems. Currently, it is of great interest to drive the sensitivity down to a handful of molecules or single molecule level, providing highly sensitive quantitation method to study enzymatic activities, molecular distribution and transportation. In addition to uni-directional signal transport in biosensor, bi-directional communication between biological system and electronic devices will enable controling over bio-system with electrical stimulation. This exciting yet challenging field largely relies on the development of nanoelectronic devices, since manipulation of individual biomolecule is often required in order to study the energy transferring and kinectics involved across the biomolecule-solid device interface.
The Bai group aims to understand the physical and chemical nature of biomolecular interaction with electronic devices at single molecular level, design new device based on the bio-inorganic hybrid structure enabled by nanofabrication and site-direct bioconjugation, and explore the application in the field of DNA sequencing, immunoassay, high-throughput drug screening and human-machine interface.
Currently, the major research areas in Dr. Bai's group include:
1)
Hybrids bio-nanoelectronics for single molecular sensing and DNA sequencing: We are developing a group of hybrid bio-nanoelectronic devices by locally conjugating DNA-processing enzyme onto the sensor head of VLSI based nanoelectronics. Taking advantage of the single nucleotide resolution from DNA process enzyme and the merit of scalable fabricated nanosensor device, the hybrid bio-nanoelectronic device may open up new avenue towards new generation of DNA sequencing and molecular diagnosis platform.
2)
Develop biomolecular patterning scheme for multiplexing biomolecular sensor and drug discovery. Patterning biomolecule surface has many possibilities in multi-target assay, drug screening and cellular engineering. As the first step towards the sophisticated bio-machine interface study, sub-micron scale level substrate patterning technique with affinity to specific biomolecule is undoubtedly the foundation for structuring and interface engineering of biology-solid device interface. We are developing biomolecular patterning scheme based on soft-polishing technique upon concaved sub-micron structure. These techniques will not only render a potential breakthrough in DNA/protein assay and drug screening application, but also pave the way to site-direct conjugating bio-active molecule to the sensor head of nanoelectronics for building a new generation of hybrid bio-nanoelectronic device.
3)
Electronic modulated biological system. We are constructing nanopore and nanogap devices of directly interaction with locally immobilized biomolecules. The electrical modulated biological function is achievable by stimulating the molecule with direct electric field force or indirect mechanical force exerted by tethered charged polymers. The understanding of electrical modulation of enzyme activity will guide the design of active device to control chemicals level in human body. As a model system, we are studying the electrical modulation of neurotransmitter metabolism for implantable medical application.
Scientific Contributions:
· 3-metal embedded solid state nanopore and sub-3nm tunneling junction for single molecular nucleic acid manipulation and detection.
Figure 1: 3-metal embedded solid state nanopore (left), tunneling junction nanogap (middle) and the tunneling response to different nucleotides (right).
· Lipid-nanodisc enabled hybrid nanopore for single molecular DNA sequencing application and single molecular placement for NextGen flowcell clustering application.
Figure 2: Conceptually illustration of single molecular DNA sequencer on one dimentional field effect transistor (left); lipid nanodisc sealed hybrid nanopore (middle); and surface amplification of DNA clusters for NextGen sequencing.
· Fundemental studies on nanographene materials and devices and record high-speed graphene transistor
Figure 3：(left) graphene nanoribbon and its magnetoresistance effect; (middle) graphene nanomesh and its characteristics of field-effect-transistor; (right) self-aligned graphene RF transistors and its 400 GHz cut-off frequency
Honors and Awards
IBM First Plateau Invention Achievement Award, IBM T J Watson Research (2013)
Harry M. Showman Prize, University of California, Los Angeles (2011)
Graduate Student Silver Award, Material Research Society (MRS) Fall Meeting (2010)
Selected Publications:
1. J. W. Bai†, D. Wang†, S.W. Nam, H. Peng, R. Bruce, L. Gignac, M. Brink, E. Kratschmer, S. Rossnagel, P. Waggoner, K. Reuter, C. Wang, Y. Astier, V. Balagurusamy, B. Luan, Y. Kwark , E. Joseph, M. Guillorn, S. Polonsky, A. Royyuru, S. Papa Rao, G. Stolovitzky, “Fabrication of sub-20nm nanopore arrays in membranes with embedded metal electrodes at wafer scales”, Nanoscale (2014), 6, 8900.
2. R. Cheng†, J. W. Bai† (Co-author with Equal contribution), L. Liao, H. Zhou, Y. Chen, L. Liu, Y.-C. Lin, S. Jiang, Y. Huang, X. F. Duan, “High-frequency self-aligned graphene transistors with transferred gate stacks”, Proceedings of the National Academy of Sciences of The United States of America (2012), 109, 11588.
3. J. W. Bai, L. Liao, H. Zhou, R. Chen, L. Liu, Y. Huang, X. F. Duan, “Top-gated chemical vapor deposition grown graphene transistors with current saturation”, Nano Letters (2011) 11, 2555.
4. J. W. Bai, Y. Huang, “Fabrication and electrical properties of graphene nanoribbons”, Materials Science and Engineering: R (2010) 70, 341. Invited Review
5. J. W. Bai†, R. Cheng†, F. X. Xiu, L. Liao, M. S. Wang, A. Shailos, K. L. Wang, Y. Huang, X. F. Duan, “Very large magnetoresistance in graphene nanoribbons”, Nature Nanotechnology (2010) 5, 655.
6. J. W. Bai, X. Zhong, S. Jiang, Y. Huang, X. F. Duan, “Graphene nanomesh”, Nature Nanotechnology (2010) 5, 190.
7. J. W. Bai, X. F. Duan, Y. Huang, “Rational fabrication of graphene nanoribbons with nanowire etch mask”, Nano Letters (2009) 9, 2083.
8. J. W. Bai, S. Huang, L. Wang, Y. Chen, Y. Huang, “Fluid assisted assembly of one-dimensional nanoparticle array inside inorganic nanotubes”, Journal of Materials Chemistry (2009) 19, 921.
9. J. W. Bai, Y. Qin, C. Jiang, L. M. Qi, “Polymer-controlled synthesis of silver nanobelts and hierarchical nanocolumns”, Chemistry of Materials (2007) 19, 3367.
10. P. Pang, B. Ashcroft, W. Song, P. Zhang, S. Biswas, Q. Qing, J. Yang, R. Nemanich, J. W. Bai, J. Smith, K. Reuter, V. Balagurusamy, Y. Astier, G. Stolovitzky, S. Lindsay, “Fixed-gap Tunnel Junction for Reading DNA Nucleotides”, ACS Nano (2014), 8, 11994.
11. B. Luan, J. W. Bai, G. Stolovitzky, “Fabricatable nanopore sensors with an atomic thickness”, Applied Physics Letters (2013), 103, 183501.
12. L. Liao, J. W. Bai, R. Cheng, H. L. Zhou, L. X. Liu, Y. Liu, Y. Huang, X. F. Duan, “Scalable fabrication of self-aligned graphene transistors and circuits on glass”, Nano Letters (2012), 12, 2653.
13. Z. Zhong, H. Zhang, Y. Liu, J. W. Bai, L. Liao, Y. Huang, X. F. Duan, “High-capacity silicon-air battery in alkaline solution”, Chemsuschem (2012), 5, 177. L. Liu, H. Zhou, R. Cheng, Y. Chen, Y.-C. Lin, Y. Qu, J. W. Bai, I. A. Ivanov, G. Liu, Y. Huang, X. F. Duan, “A systematic study of atmospheric pressure chemical vapor deposition growth of large area monolayer graphene”, Journal of Materials Chemistry (2012), 22, 1498.
14. Y. Liu, R. Cheng, L. Liao, H. Zhou, J. W. Bai, G. Liu, L. Liu, Y. Huang, X. F. Duan, “Plasmon resonance enhanced multicolour photodetection by graphene”, Nature Communication (2011), 2, 579.
15. G. Xu, C. M. Torres, J. W. Bai, J. Tang, T. Yu, Y. Huang, X. F. Duan, Y. Zhang, K. L. Wang, “Linewidth roughness in nanowire-mask-based graphene nanoribbons”, Applied Physics Letters (2011), 98, 243118.
16. Y. Qu, J. W. Bai, L. Liao, R. Cheng, Y.C. Lin, Y. Huang, T. Guo, X. F. Duan, “Synthesis and electric properties of dicobalt silicide nanobelts”, Chemical Communications (2011), 47, 1255.
17. G. Xu, C. M. Torres, J. Tang, J. W. Bai, E. Song, Y. Huang, X. F. Duan, Y. Zhang, K. L. Wang, “Edge effect on resistance scaling rules in graphene nanostructures”, Nano Letters (2011) 11, 1082.
18. L. Liao, Y. C. Lin, M. Bao, R. Cheng, J. W. Bai, Y. Liu, K. L. Wang, Y. Huang, X. F. Duan, “High speed graphene transistor with a self-aligned nanowire gate”, Nature (2010) 467, 305.
Patents
1. Y. Astier, J. W. Bai, S. Papa Rao, K. Reuter, J. T. Smith. “Nanogap device with capped nanowire structures” US9097698 B2. (2015)
2. Y. Astier, J. W. Bai, M. Guillorn, S. Papa Rao, J. Smith. “Manufacturable sub-3 nanometer palladium gap device for fixed electrode tunneling recognition”. US9128078 B2. (2015年)
3. Y. Astier, J. W. Bai, R. Bruce, A. D. Franklin, J. T. Smith. “Nanoporous structures by reactive ion etching”, US 9117652 B2. (2015)
4. Y. Astier, J. W. Bai, M. Lofaro, S. Papa Rao, J. Smith, C. Wang. “Nanogap in-between noble metals”, US9012329 B2. (2015)
5. J. W. Bai, E. Colgan, C. Jahnes, S. Polonsky. “Nanochannel process and structure for bio-detection”, US8901621 B1. (2015)
6. Y. Astier, J. W. Bai, S. Papa Rao, K. Reuter, J. T. Smith. “Solid state nnaopore devices for nanoore applications to improve the nanopore sensitivity and methods of the manufacture”, US9085120 B2. (2015)
7. X. Duan, Y. Huang, J. W. Bai. “Graphene nanomesh and method of making the same”, US9012882B2. (2015)
8. J.W.Bai, Q.Lin, G. Stolovitzky, C. Wang, D. Qang. “Nanochannel Device with three dimensinal gradient by single step etching for molecular detection”, US 9322061 B2 (2016)
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