Name: Dage Liu
Address: ** ****** **
Pennington, NJ 08534
Tel: (919) *******
E-mail: email@example.com (preferred)
Status: Legal permanent resident in USA
Hobby: tennis, mountain climbing
• Exceptional research ability and strong publication (PNAS, JACS, Langmuir, JMR etc)
• Ten years diversified research experience on thin films materials , piezoelectric material, metal and multi-component oxide thin films deposition (sputtering, E-beam evaporation, sol-gel), nanotechnology, surface science.
• Hands-on skill in materials & surface characterization techniques (AFM, TEM, SEM, E-beam lithograph, thin films coating by E-beam deposition, XRD, XPS, FTIR, UV-vis, and so on). Thin film thickness measurement by ellipsometry. I-V, CV, ferroelectric hysteresis analysis.
Thin film materials, materials and surface characterization, functional materials, nanotechnology
Mar. 1996-Feb. 1999, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, P.R. China, Doctor of Engineering majored in materials science. Lead zirconate titanate (PZT) thin films (on E-beam deposited Pt/Ti thin film on SiO2/Si substrate) and nanocrystalline fabrication and characterization.
Sep. 1993-Feb. 1996, Department of Applied Chemistry, Harbin Institute of Technology, Harbin, China, MS study on Inorganic Materials. Piezoelectric single crystal LiNbO3 growth in high temperature furnace controlled by Pt-Pt/Rh thermocouple; lead zirconate titanate (PZT) powder preparation and characterization.
Sep. 1986-Jul. 1990, Department of Chemistry, Hunan Normal University, Changsha, China, B.S. in Chemistry.
SCHOLARSHIPS AND AWARDS
1. Hua Wei Prize winner for outstanding PhD graduate (1998)
2. Outstanding Teacher Prize winner (1992)
3. Champion of Yue Lu Mountain Climbing Competition (1989)
Sep. 1990-Jul. 1993, Chemistry teacher in high school of Chinese RuCheng Inferrous Metal Corporation.
Mar. 1996-Feb. 1999 (Ph. D candidate in Harbin Institute of Technology), Microstructure and properties of lead zirconate titanate (Pb(ZrxTi1-x)O3, PZT) ferroelectric ceramic thin films prepared by a modified Sol-Gel route. Analysis of ferroelectric domain structure in PZT thin films by SPM.
Sep. 1993-Feb. 1996 (M.S. study), Piezoelectric single crystal LiNbO3 growth in high temperature furnace controlled by Pt-Pt/Rh thermocouple. PZT piezoelectric ceramic and powder preparation through mixture by milling of PbO, ZrO2, and TiO2, extrusion, drying, calcining.
Apr. 2008-up to now, Research Associate, University of Pennsylvania, ferritin template inorganic nanoparticle controlled assembly, and characterization (UV-Vis, Zeta potential, Schlenk line and high vacuum techniques FPLC, AFM, SEM, TEM).
Apr. 1st, 2007-Mar. 31th, 2008, Research associate, University of Wisconcin-Madison, self-assembled DNA origami nanostructure.
Sept. 1st, 2004 to Mar. 2007, Research Associate, North Carolina State University Chemistry Department, Keck Foundation postdoc, RNA directed assembly of inorganic nanoparticles on Au slides (prepared by E-beam evaporation of Au/Cr or Au/Ti on glass slides) and its application exploration.
Oct. 1st 2003-to Aug 31th. 2004, NSF postdoc, Purdue University Chemistry Department, Self-assembly of DNA nanostructure, Lysozyme and 3D-DNA crystal growth and its high-resolution AFM imaging under high salt buffer
Feb. 2001-Sept. 2003, DARPA and NSF postdoc, Duke University Computer Science Department, Construction and metallization of tile-structured DNA nanotubes and its metallization and conductivity measurement (AFM, TEM, SEM, EBL). Assembly of two-dimensional gold pattern template by DNA nanostructure (AFM, TEM image and its electron diffraction).
Mar. 1999-Feb. 2001, Postdoctoral Researcher in the Youth Lab of Nanoscience & Technology Institute of Chemistry, the Chinese Academy of Sciences. AFM investigation of the fine structure of condensed-DNA induced by multcations and histone. In-vitro construction and visualization of higher-order chromatin structure by tapping mode AFM.
• Thin films and nano-scale materials fabrication method: Sol-Gel, E-beam evaporation, sputtering
• Operation of high temperature furnace and its temperature control system by Pt-Pt/Rh thermocouple.
• Material research methods, including AFM, TEM, SEM, XRD, AES, XPS, SIMS, IR, NMR, DTA-TG, Spectroscopic ellipsometry (SE), and dielectric/ ferroelectric property analysis.
• Micro-electrode fabrication by electron beam lithography (EBL).
• Lithium Niobate (LiNbO3) piezoelectric single crystal growth method.
• Hands-on skill on SPM, SEM and TEM. In fact, the first STM, AFM, and NSOM in China were built in the Youth Lab of Nanoscience and Technology, CAS.
• CD, UV, DNA purification by PAGE, PCR, DNA ligation, transcription, cell culture, cryo-TEM, and other normal biochemical skills.
1. Dage Liu, Lina Gugliotti, Tong Wu, Magda Dolska, Alexander G. Tkachenko, Mathew K. Shipton, Bruce E. Eaton, Daniel L. Feldheim. RNA-Mediated Synthesis of Palladium Nanoparticles on Au Surfaces. Langmuir, 2006, 22 (13), 5862 -5866.
2. Marta G. Cerruti, Marc Sauthier, Donovan Leonard, Dage Liu, Gerard Duscher, Daniel L. Feldheim, Stefan Franzen. Gold and Silica-coated Gold Nanoparticles as Thermographic Labels for DNA Detection. Analytical Chemistry, 78(10), 3282-3288.
3. Dage Liu, Mingsheng Wang, Zhaoxiang Deng, Richard Walulu, Chengde Mao. Tensegrity: construction of rigid DNA triangles with flexible 4-arm DNA junctions. Journal of American Chemical Society, 2004, 126, 2325-2326.
4. Dage Liu, Sung Ha Park, John H. Reif, Thomas H. LaBean. DNA nanotubes self-assembled from triple-crossover tiles as templates for conductive nanowires. Proceeding of National Academy of Sciences USA, 2004, 101(3), 717-722 (Reported by science news in Scientific American, Jan. 06, 2004, and Better Human, Jan. 05, 2004).
5. Thomas H. LaBean, Hao Yan, Sung Ha Park, Liping Feng, Peng Yin, Hanying Li, Sang Jung Ahn, Dage Liu, Xiaoju Guan, and John H. Reif, Overview of New Structures for DNA-Based Nanofabrication and Computation, Invited paper to appear in Information Sciences, 2004.
6. M.C. Li, L.C. Zhao, D.G. Liu, X.K. Chen. Topographical, compositional and schottky characterization of PtSi/Si schottky diodes, Materials Chemistry and Physics, 2003, 80(3), 620-624.
7. Dage Liu, John H. Reif &.Thomas H. LaBean. DNA Nanotubes, Construction and Characterization of Filaments Composed of TX-tile Lattice. The Eighth international meeting on DNA-based computers, Sapporo, Japan, June 10-13, 2002, (Edited by M. Hagiya and A. Ohuchi), Lecture Notes in Computer Science, No. 2526, Springer-Verlag, New York, pp 10-21.
8. Xueguang Sun, Enhua Cao, Xiaoyan Zhang, Dage Liu, Chunli Bai. The divalent cation-induced DNA condensation studied by atomic force microscopy and spectra analysis. Inorganic Chemistry Communications, 2002, 5(3), 181-186.
9. M.C. Li, L.C. Zhao, W. Cai, D.G. Liu, X.K. Chen. AFM studies of platinum silicide thin films on silicon grown by pulsed laser deposition. Journal of Materials Science & Technology, 2002, 18(1), 24-26.
10. Dage Liu, Chen Wang, Junwei Li, Hongxi Zhang, Liancheng Zhao, and Chunli Bai. Domain configuration and interface structure analysis of sol-gel-derived PZT ferroelectric thin films. Surface and Interface Analysis, 2001, 32: 27-31.
11. Dage Liu, Hongxi Zhang, Zhong Wang, and Liancheng Zhao. Preparation and characterization of Pb(Zr0.52Ti0.48)O3 powders and thin films by a sol-gel route. Journal Materials Research, 2000, 15(6): 1336-1341.
12. Dage Liu, Hongxi Zhang, Wei Cai, Xiangwei Wu, and Liancheng Zhao. Synthesis and characterization of PZT nanocrystalline powder by a modified sol-gel process using zirconium oxynitrate as zirconium source. Materials Chemistry and Physics, 1997, 51(2): 186-189.
13. Dage Liu, Chen Wang, Junwei Li, Zhang Lin, Zukun Tan, and Chunli Bai. Atomic force microscopy analysis of intermediates in cobalt hexammine-induced DNA condensation. Journal of Biomolecular Structure and Dynamics, 2000, 18(1):1-9.
14. Dage Liu, Chen Wang, Zhang Lin, Junwei Li, Bo Xu, Zhongqin Wei, Zhigang Wang, and Chunli Bai. Visualization of the intermediates in a uniform DNA condensation system by tapping mode atomic force microscopy. Surface and Interface Analysis, 2001, 32: 15-19.
15. Dage Liu, Chen Wang, Junwei Li, Zhigang Wang, Bo Xu, Zhongqing Wei, Zhang Lin, Jingfen Qin, Enhua Cao, and Chunli Bai. Visualization of reconstituted solenoid chromatin structure by tapping mode atomic force microscopy. Surface and Interface Analysis, 2001, 32: 20-26.
16. Zhongqing Wei, Chen Wang, Zhigang Wang, Dage Liu, and Chunli Bai. Topography investigation of water Layer and self-assembled monolayer with OTS-modified AFM tips. Surface and Interface Analysis. 2001, 32: 275-277.
17. Ai Chen, Enhua Cao, Xueguang Sun, Jingfen Qin, Dage Liu, Chen Wang, and Chunli Bai. Direct visualization of telomeric DNA loops in cell by AFM. Surface and Interface Analysis. 2001, 32: 32-37.
18. Zhigang Wang, Chen Wang, Zhongqing Wei, Chunqing Zhou, Dage Liu, and Chunli Bai. Atomic force microscopy reveals the local ordering characteristics of nucleosomal chain from cell. Surface and Interface Analysis. 2001, 32: 38-42.
19. Hongxi Zhang, Dage Liu, Chongquan Xu. Preparation of lead zirconate titanate fine powder by sol-gel process using zirconium oxynitrate as zirconium source. The international conference on sintering and materials: proceeding of the sixth international symposium on the science and technology of sintering. Hai Kou, China, Oct. 1995, p. 164-167.
20. Dage Liu, Wei Cai, Hongxi Zhang, Xiangwei Wu, Liancheng Zhao. Study on synthesis of PZT nanocrystalline powder by sol-gel process using zirconium oxynitrate as zirconium source, Journal of Chinese Ceramic Society, 1998, 26 (3):313-318.
21. Dage Liu, Hongxi Zhang, Zhong Wang, Liancheng Zhao. Monitoring of the crystallization process of Sol-Gel derived PZT thin films, Journal of Chinese Ceramic Society, 1999, 27(2): 193-201.
22. Hongxi Zhang, Dage Liu, Chongquan Xu. Research on wet synthesis for preparing PZT ultrafine powder, Piezoelectrics & Acoustooptics, 1995, 17(5):49-54.
23. Dage Liu, Hongxi Zhang, Liancheng Zhao. Research progress on the preparation and fatigue property of sol-gel derived PZT thin films, Piezoelectrics & Acoustooptics, 1998, 20(4): 276-282.
24. Dage Liu, Hongxi Zhang, Liancheng Zhao. Study on preparation of PZT ferroelectric thin films by the sol-gel process, in Proceedings of CMRS'97, Shanghai, Oct., 1997.
DESCRIPTION OF RESEARCH EXPERIENCE
I finished my M. S. graduate education majored in inorganic materials, Department of Chemistry, Harbin Institute of Technology (HIT, also "Harbin Polytechnical University" in English) in Mar. 1996. HIT is one of the 20th leading universities in China, actually the best university in the northeast of China. (See the notes in Science 1999, V 285, page 1341). Due to my excellent academic performance and promising ability in scientific research, I was given the privilege to enter the graduate program for Ph. D. in School of Materials Science, Harbin Institute of Technology, waived of entrance examination in 1996 (for top 5% student).
As a graduate for Ph. D, I exhibited high creativity in my research work. My major effort was devoted to ferroelectric thin film research, one of the hot scientific frontiers. My research work focused on microstructure and properties of lead zirconate titanate (Pb(ZrxTi1-x)O3, PZT) nanocrystalline and ferroelectric thin films prepared by Sol-Gel process. In this research work, I frequently used vacuum physical methods (sputtering, E-beam evaporation) to deposit Pt/Ti thin films on silicon substrate. I explored a new Sol-Gel route. The system of zirconate oxynitrate bihydrate (ZrO(NO3)2.2H2O)-tetrabutyl titanate (Ti-(O-n-C4H9)4)-lead acetate trihydrate (Pb(CH3COO)2.3H2O)-ethylene glycol (HOCH2CH2OH) was explored for the first time to prepare stable PZT sol (there are many citations of my papers in this field). The use of inorganic salt rather than alkoxide as zirconium precursor makes the sol more stable and not sensitive to water while laid up in air. No inert atmosphere was needed during the preparation process of sol, and the Sol-Gel processing for PZT thin films was simplified. The microstructure, interface structure, and ferroelectric properties of PZT thin films were characterized by means of XRD, XPS, AES, TEM, SEM, AFM as well as ferroelectric property measurement. The possible formation mechanism of sol was discussed through analyzing its IR spectra. The results were published in the flagship of Material Research Society, USA, i.e., "Journal of Materials Research, V15, 2000, 1336-1341". The polarization fatigue mechanism and the effect of donor doping of Bi3+ on ferroelectric properties of PZT thin films were also discussed. DTA-TG analysis indicated that the crystallization temperature of perovskite PZT nanocrystalline to be 415 centigrade, which, to the best of our knowledge, is the lowest crystallization temperature of perovskite PZT with a composition near the morphotropic phase boundary. PZT thin films rapid thermal annealed at 650 centigrade for 1 min showed good ferroelectric property, and exhibited high polarization fatigue resistance. AFM investigation revealed 90° and 180° domain in Sol-Gel PZT thin films. The effect of domain motion under repeated a.c. field on polarization fatigue of ferroelectric thin films was discussed.
The results of microstructure analysis and ferroelectric measurement under repeated a.c. field imply that 90° domain wall, being the concentration of stress, may become the origin of micro-cracks, which later develops into macroscopic fracture, and results in a fraction of the domains failure to response to applied field. A fraction of domains is pinned and failed to switch under applied electric field, which lead to the decrease of remnant polarization. During the research period for Ph. D. of materials science, I did my best to keep myself abreast with the latest development in the field of ferroelectric thin film materials and other related sciences. One of the scientific frontiers: nanotechnology and the Scanning Probe Microscopy got my interests. When I graduated as Doctor of Engineering majored in materials science in HIT, I successfully joined my desired research group in the Youth Lab of Nanoscience and Technology directed by Prof Chunli Bai (member of USA Academy of Sciences) in the Institute of Chemistry, the Chinese Academy of Sciences (CAS) as a post doctor after the most intensive competition in Mar.1999. The Institute of CAS attracts the best young talent by offering better working condition, new facilities than most of universities and other research institutions in China. The experience in CAS opened up to me another new field in the world of sciences.
My research career at Univ. of Penn., UW-Wisconsin, NC State Univ., Purdue University and Duke University significantly strengthens my research capability, and broadens my eyesight in the field of nanomaterials.
My current research at UPenn focuses on ferritin template inorganic nanoparitcle materials controlled assembly. I am experienced in ferritin protein expression, and purification by FPLC, and characterization protein by SDS-PAGE, UV-Vis, FTIR, TEM, AFM, etc. UV-Vis, AFM, SEM data showed that controlled lay-by-layer protein (ferritin) template nanoparticle assembly was achieved recently on OETS coated silicon wafer. More recently, TEM, FPLC and native gel analysis indicates that 5 nm gold nanoparticle directed assembly of hyperthermophile Archaeogobus fugidus Ferritin (T0) 24mer with tetrahedron symmetry in low salt buffer. Further more, The T0-coated 5nm gold conjugates show reversible color switch between high and low salt buffer, which could be used as a sensor.
My research project at NCSU was with “Synthesis and Assembly of Nanoscale Materials
Using RNA-Mediated Evolutionary Chemistry” heavily funded by the Department of Energy (DOE), NSF and W. M. Keck Foundation. Dr. Bruce Eaton and Dr. Daniel L. Feldheim are my supervisors and the PI of these Grants. By using E-beam evaporation method (I am experienced on this aspect), I prepared transparent Au slides. We were now able to control the assembly of cubic and hexagonal Pd nanoparticles mediated by RNA on the gold slides. Furthermore, by using micro-contact printing (uCP) technology, controlled row-by-row nanoparticle arrays is recently achieved. This breakthrough on RNA-mediated nanoparticle assembly on surface shows promising application in catalysis selection for hydrogen production oxidation for cheaper, clean alternative energy source. The exploration of more efficient catalysis materials for alternative energy source is the first goal of the RNA evolution chemistry for nanoparticle synthesis. For more detailed information about RNA evolutionary chemistry, see related report on Chemical Engineering News, April 19, 2004.
At Duke Univeristy, through modifying the self-assembled two-dimensional DNA structure, a new DNA nano-tubular structure with the DNA tile periodicity was synthesized through my effort, and a correlated model was proposed. Furthermore, by using the self-assembled DNA nanotube as modulate, I developed a two-step process for the metallization of DNA. Silver nanowire with uniform size of ~ 30 nm and length of several micrometers were assembled, which shows low-resistance I-V curves, and the background is very clean (for detail, in PNAS, 101(3), 717-722). This breakthrough on DNA nanotubes construction and its metallization was reported by science news in prestigious media of Scientific American, Jan. 06, 2004, and Better Human, Jan. 05, 2004. These media reports highlight the potential important application of these new DNA nanotubes in nanoelectronics, the guiding light for many nano-scientists all over the world. To the best of my knowledge, it is for the first time for the metal nanowire being assembled under the direction of self-assembled tile-structured DNA. More promisingly, AFM, TEM image and related diffraction pattern showed that 1.4 nm gold particles were assembled periodically along the two-dimensional DNA nanostructure with line spacing of ~ 25 nm. To the best of my knowledge, it is the narrowest line-spacing gold particle arrays template by two-dimensional DNA nanostructure. At Purdue University, frequently characterization of 2D-, 3D-DNA and protein structure by AFM imaging in high salt concentration buffer strengthened my AFM skill. In fact, I am also very interested in exploring the application of AFM in biological science, such as RNA, DNA, nanoparticles, protein crystal and chromatin structure, ion channel, lipid, etc. Single-molecule level study of biomolecule and its interaction by AFM is a promising cut-edge direction.
My research works in CAS mainly included two respects. One is AFM study of controlled packing of DNA molecules induced by multi-cations. A uniform system with minimum fluctuation of concentration was obtained by introducing a slow-evaporation method, which enabled the investigation of the intermediate structure in DNA condensation system. Another project is AFM analysis of chromatin high-order structure in eukaryotic cell. In this work, AFM measurement in combination with Bio-Gel elution method was applied to visualize reconstituted higher order chromatin structure with nearly no disturbance of histone particles in the background. AFM image showed that four to six nucleosomes per turn wrapped right-handed to form flattened solenoid and solenoid-aggregated chromatin structure with height distribution of 12.2 nm. To the best of our knowledge, it is for the first time for the solenoid chromatin structure being imaged by AFM. CD spectra of DNA-histone complexes indicated the formation of ordered aggregation. Working in this highly interdisciplinary area with many young talents, my horizons are much broadened and my research experience is deeply enriched. Indeed, my research abilities are greatly developed.
REFERENCES AVAILABLE UPON REQUEST