micro fabrication

EDUCATION

Ph.D Micro/Nano Fabrication Engineering (08/2007), Louisiana Tech University (LaTech),

Ruston, LA

Dissertation title: An intermediate-layer method for producing metal or conducting polymer micro/nano patterns

M.S. Manufacturing Systems Engineering (11/2003), LaTech, Ruston, LA

B.E. Aircraft Manufacturing Engineering (07/1992), Northwestern Polytechnical University,

Xi’an, China

RESEARCH INTERESTS

MEMS/NEMS, BioMEMS, Micro/Nano Fabrication techniques, Sensors and actuators, Microfluidic systems, Application of shape-memory polymers (SMP)

SKILLS

Cleanroom processes: Lithography, lift-off process, wet and dry etching, focus ion beam

etching hot embossing, thermal evaporator, sputtering, and soft

lithography (micro contact stamping and mimic approaches)

Metrology equipments: SEM, AFM, confocal microscope, RST, and Surface Profiler

Modeling and Simulation: ANSYS, CoventorWare, MATLAB, AutoCAD and

Pro/ENGINEER

Mechanical Manufacturing: CNC punch machines, Sheet metal unbending, Design of molds

for sheet metal parts

WORKING EXPERIENCE

Postdoctoral researcher 09/2007—present

Department of Mechanical and Aerospace engineering, University of Texas at Arlington (UTA), Arlington, TX, US

• Developing the applications of the intermediate-layer (ILL) method.

• Patterned Au on side walls of microchannels with aid of Si-reinforced PDMS soft mold through hot-embossing process. These sidewall patterns on the planar devices could serve as templates to direct horizontal assembly of nanowires and nanotubes into the planar devices for making use of specific mechanical and electrical properties of these one-dimensional nanobuilding blocks. The furture application could help to increase density of devices in a chip.

• Fabricated and characterized of super-hydrophobic microchannels. Water flows much faster on the super-hydrophobic surfaces and microchannels.

• Developed a microboat driven by isopropyl alcohol for potentially transporting desired targets in microfluidic systems. In three types of tests conducted on water surfaces of different heights in a 30-cm-long channel, the microboat had a speed in the order of 0.1 m s−1, and propulsive forces ranged from 159 to 250 μN. It took 1–2 s for the microboat to go through the channel, and resistance coefficients varied from 0.144 to 0.324.

• Created Ag patterns on top and side walls of polystyrene blocks based shape-memory effect. Temperature was found to be highly sensitive to recovery and deformation.

Research Assistant 12/2003—08/2007

Institute for Micromanufacturing, LaTech, Ruston, LA, US

• Developed a new ILL method to fabricate metal or conductive polymer micro/nano pattern with simplicity, low cost and free of aggressive chemistry. The width of patterned Al or Au wires is range from 100nm to 300m. Conducting polymer-based heterojunctions, diodes and capacitors were fabricated using the ILL. Their electrical characteristics were found close to those reported in literatures.

• Patterned biomaterial (such as polycaprolactone and glucose) through rigid silicon or SU-8 stencil without deformation problem. The method is applicable to both polar and non-polar solvents with good sealing.

• Novel method to reinforced Polydimethylsiloxane (PDMS) masters using an oxide-coated silicon plate to reduce residual and deflecting deformations in soft lithography.

• Developed an innovative all-polymeric drug-delivery device through thermal ablation of PMMA. Flow rate can be controlled by ablating a micropore with a proper size.

• Developed cantilever-based mass sensors to determine the number of molecules adsorbed when partially occupied by molecules.

• Wafer-level package method conducting polymer microsystems using SU-8/PDMS composite membranes to lower processing temperature and the manufacturing cost.

• Investigated ultrasonic-assisted buffered oxide etching to have uniform and smooth micro pattern with high aspect ratio.

• Simulated heat distribution on a drug-delivery device, hyper-elastic deformation in hot embossing, damping coefficients of micro comb drive and deformation of suspended silicon nanowire-based static sensors.

Teaching Assistant

03/2002—11/2003 Department of Industrial Engineering, LaTech, Ruston, LA, US

• Teaching assistant in Computer-Integrated Manufacturing System in Flexible Manufacturing Research Laboratory.

• Developed a hybrid segmentation method to analyze nano-particle image.

Senior Process Engineer

08/1992—01/2002 Department of Products Process, Beijing Institute of Radio Measurement (BIRM), Beijing, P. R. China

• Analyzed and evaluated the technical details of computer numerical control (CNC) punch machines and formulated operating rules.

• Designed flow chart for assembling large mechanical equipment.

• Designed unbending sketches of sheet metal parts.

• Programmed CNC operation.

• Designed sheet metal molds for punching, bending and drawing.

• Designed fixtures and tools for fabricating metal parts.

• Designed and tested manufacturing processes of mechanical parts.

HONORS AND AWARDS

Excellence in Research and Scholarly Activity, Institute for Micromanufacturing at LaTech (biannual award), 2006

Research assistantship at Louisiana Tech University, 2003-2007

Teaching assistantship at Louisiana Tech University, 2002-2003

Best 100 of 10000 Young Employee Award at Chang-Feng Group Co., 1998

Outstanding Young Engineer Award at Beijing Institute of Radio Measurement, 1995

Outstanding Student Scholarship at Northwestern Polytechnic University, 1988-1992

JOURNALREFEREE:

Microelectronic Journal

Journal of Physics D: Applied Physics

PUBLICATIONS

1. Liu, X. and Luo, C., Generate Fabrication of Sidewall Micropatterns Using a Si-Reinforced PDMS Molds, Sensors & Actuators: A. Physical, 152, pp.96-103 (2009).

2. Luo, C., Francis, A., and Liu, X., Determination of Compressive Residual Stress in a Doubly-clamped Microbeam according to its Buckled Shape, Microelectronic Engineering, 85 (2), pp.339-347 (2008).

3. Luo, C., Li, H. and Liu, X., Propulsion of microboats using isopropyl alcohol as a propellant, Journal of Micromechanics and Microengineering, 18, 067002 (6pp) (2008).

4. Liu, X., Chakraborty, A. and Luo, C., Generation of Conducting Polymer-Based Heterojucntions, Diodes and Capacitors using an Intermediate-Layer Lithography Method, and Device Characterization, in: Progress in Solid State Electronics Research, Editor: J. P. Martingale, Nova Science Publishers, Inc., Chapter 5, pp. 127-139, 2007.

5. Liu, X., and Luo, C., An intermediate-layer method for producing metal micropatterns, Journal of Vacuum Science & Technology B, 25, pp. 677-685 (2007).

6. Chakraborty, A., Liu, X., and Luo, C., An intermediate-layer lithography method for generating multiple microstructures made of different conducting polymers, Microsystem Technologies, 13, pp. 1175-1184 (2007).

7. Luo, C., Liu, X., Poddar R., Van Keuren, E., Schneider, T. W., White, R. C., Currie, J. F., and Paranjape, M., Thermal ablation of PMMA for water release using a microheater, Journal of Micromechanics and Microengineering, 16, pp. 580-588 (2006).

8. Luo, C., Poddar, R. and Liu, X., An Innovative intermediate-layer lithography approach to replicate micropatterns in a conducting polymer, Journal of Vacuum Science and Technology B, 24(2), L19-L22 (2006) [selected for the April 10, 2006 issue of Virtual Journal of Nanoscale Science & Technology].

9. Luo, C., Meng, F., Liu, X., and Guo, Y., Reinforcement of a PDMS master using an oxide-coated silicon plate, Microelectronics Journal, 37, pp. 5-11 (2006).

10. Lian, G. and Liu, X., Fabrication of the spiral contractor board in an inductor, Aerospace Technique, 5, pp. 8-9 (1997).

11. Liu, X., Zhao, L., Niu, L. and He, W., The discussion of selecting sheet metal CAD/CAM software, Aerospace Technique, 5 (1997) .

PRESENTATIONS

12. Luo, C. and Liu, X., Fabrication of Sidewall Micropatterns Using a Si-Reinforced PDMS Mold, The 4th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Shenzhen, China, January 5-8 2009.

13. Luo, C. and Liu, X., Creation of Sidewall Micropatterns Using a Thermal Shape-Memory Polymer, The 4th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Shenzhen, China, January 5-8 2009.

14. Luo, C., Li, H. and Liu, X., Development of Self-propelled Microboats, The 4th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Shenzhen, China, January 5-8 2009.

15. Liu, X. and Luo, C., Development and characterization of super-hydrophobic microchannels, MRS International Materials Research Conference, Chongqing, China, June 9-12 2008.

16. Liu, X., Chakraborty, A., Parthasarathi, G. and Luo, C., Generation of conducting polymer-based heterojunctions, diodes, and capacitors using an intermediate-layer lithography method, Proceedings of SPIE on Micro (MEMS) and Nanotechnologies for Defense and Security, vol. 6556, pp. 65560Z-1 to 65560Z-11, Orlando, FL, Apr. 2007.

17. Wang, H., Chakraborty, A., Liu, X., Li, H., and Luo, C., Generation of silicon nanowires using a new thinning and trimming method, Proceedings of SPIE on Micro (MEMS) and Nanotechnologies for Defense and Security, vol. 6556, pp. 65561P-1 to 65561P-8, Orlando, FL, Apr. 2007.

18. Li, H., Chakraborty, A., Liu, X., Wang, H. and Luo, C., Deflection of silicon dioxide microbridge under distributed load, Proceedings of SPIE on Micro (MEMS) and Nanotechnologies for Defense and Security, vol. 6556, pp. 655608-1 to 655608-8, Orlando, FL, Apr. 2007.

19. Fang, M., Liu, X., Sit, S. and Luo, C., Reinforcement of PDMS masters using silicon plates and patterning of biomaterials, ASME/JSME Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE 2006), Santa Clara, CA, June 21-23, 2006.

20. Hao, L., Liu, X., and Luo, C., Theoretical and numerical studies of new suspended-silicon-nanowire based static sensors, Proceedings of SPIE on Micro (MEMS) and Nanotechnologies for Space Applications, vol. 6223, pp. 62230Q-1 to 62230Q-16, Orlando, FL, Apr. 2006.

21. Liu, X. and Luo, C., A Uniform Approach for Packaging Conducting Polymer Microsystems Using SU-8/PDMS Composite Membranes, Louisiana Materials and Emerging Technologies Conference, Ruston, LA, December 12-13, 2005.

22. Luo, C., Liu, X., Poddar, R., Garra, J., Gadre, P., Van Keuren, E, Schneidar, T. W., White, R. C., Currie, J. F. and Paranjape M., An innovative all-polymeric drug-supply device, Proceedings of SPIE conference on Smart Electronics, MEMS, BioMEMS, and Nanotechnology, vol. 5763, pp. 301-309. San Diego, CA, March 6-10, 2005.

23. Luo, C., Liu, X. and Francis, A., A new type of microcantilever-based mass sensors. Proceedings of SPIE conference on Smart Electronics, MEMS, BioMEMS, and Nanotechnology, vol. 5763, pp. 241-254. San Diego, CA, March 6-10, 2005.

24. Luo, C., A. Francis and Liu, X., Determination of compressive residual stress in a doubly clamped microbeam according to its buckled shape, Proceedings of SPIE conference on Smart Electronics, MEMS, BioMEMS, and Nanotechnology, vol. 5763, pp. 368-378, San Diego, CA, March 6-10, 2005.

25. Luo, C., Meng, F., Guo, Y., Liu, X., and Govindaraju, A., Reinforcement of PDMS masters using silicon plates, Proceedings of SPIE conference on Smart Electronics, MEMS, BioMEMS, and Nanotechnology, vol. 5763, pp. 379-387. San Diego, CA, March 6-10, 2005.

26. Khaliq, A., Liu, X., Nohria, R., Su, Y. and Varahramyan, K., Extraction of damping coefficients of comb drive by partitioning, NSTI-Nanotech 2005, ISBN 0-9767985-2-2 Vol. 3, pp. 589-593, 2005.

27. Ker, J., Liu, X., Wu, S. and Jinson, J., A hybrid segmentation method for nano-partical characterization, IIE annual conference and exhibition 2004, May 15-19, Houston, Texas.

28. Liu, X., He, W. and Zhou, J., Analysis and comparison of technical details of CNC punch machines, Research paper competition in BIRM, Beijing, China, 1998.

29. Liu, X., Sum software of material ration, standard part & bought product based on Foxbase, Science and technology Symposium of BIRM, Beijing, China, 1996.

Contact this candidate