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1 year 35 weeks

My profile

Full name

Seungtae Choi

URL of homepage

http://me.kaist.ac.kr/~fracture/stchoi/index.htm

Job function

Researcher

Job sector

Industry

Company or institution

Samsung Advanced Institute of Technology

Title of group

Micro Device & Systems Lab

Doctoral thesis advisor

Youn Young Earmme

My resume

Resume

Seung Tae Choi                                          

Date of Birth: Feb. 1, 1973
Nationality: Republic of Korea

Educational Background

Mar. 1991 – Feb. 1995: Chung-Ang University (B.S. degree in Mechanical Design and Precision Engineering)
Mar. 1995 – Feb. 1997: KAIST (M.S. degree in Mechanical Engineering.
Mar. 1997 – Aug. 2002: KAIST (Ph.D. degree in Mechanical Engineering.
                      
Professional Career
Mar. 1997 – Feb. 2001: Teaching Assistant, KAIST
Mar. 2001 – Aug. 2001: Visiting Research Associate, Division of Engineering at Brown University
Sep. 2002 – Mar. 2003: Postdoctoral Researcher, Department of Mechanical Engineering, KAIST (Advisor: Y.Y. Earmme)
Mar. 2003 – Mar. 2004: Postdoctoral Researcher, Division of Engineering at Brown University (Advisor: K.-S. Kim)
Mar. 2004 – Jan. 2005: Postdoctoral Researcher, Department of Mechanical Engineering, KAIST (Advisor: Y.Y. Earmme)
Feb. 2005 – Present: Researcher, Micro Device and Systems Lab, SAIT
Sep. 2005 – Dec. 2005: Lecturer, Department of Mechanical Engineering, Chung-Ang University
Mar. 2007 – Present: Adjunct Professor, Department of Mechanical Engineering, KAIST

Awards
Apr. 10, 1997: Excellent Thesis Award, Department of Mechanical Engineering, KAIST
Feb. 19, 2001: 7th Humantech Thesis Prize, Bronze Prize, Samsung Electronics Co., Ltd.
Feb. 19, 2003: 9th Humantech Thesis Prize, Bronze Prize, Samsung Electronics Co., Ltd.

Professional Societies
KSME (Korean Society of Mechanical Engineers), Member
ASME (American Society of Mechanical Engineers), Member

Publications
I. Journal paper
1. S. T. Choi and Y. Y. Earmme, Antiplane problem of interfacial circular-arc cracks in transversely isotropic piezoelectric media, Transactions of the Korean Society of Mechanical Engineers, A, Vol. 22, No. 5, pp. 868-876, 1998.
2. K. W. Lee, S. T. Choi, and Y. Y. Earmme, A circular inhomogeneity problem revisited, ASME J. Appl. Mech., Vol. 66, pp. 276-278, 1999.
3. S. T. Choi and Y. Y. Earmme, Elastic study on singularities interacting with interfaces using alternating technique: Part I. Anisotropic trimaterial, Int. J. Solids Structures, Vol. 39 (No. 4), pp. 943-957, 2002.
4. S. T. Choi and Y. Y. Earmme, Elastic study on singularities interacting with interfaces using alternating technique: Part II. Isotropic trimaterial, Int. J. Solids Structures, Vol. 39 (No. 5), pp. 1199-1211, 2002.
5. S. T. Choi, H. Shin, and Y. Y. Earmme, On the unified approach to anisotropic and isotropic elasticity for singularity, interface, and crack in dissimilar media, Int. J. Solids Structures, Vol. 40 (No. 6), pp. 1411-1431, 2003.
6. S. T. Choi and Y. Y. Earmme, Elastic singularity interacting with various types of interfaces, ASME J. Appl. Mech., Vol. 70 (No. 3), pp. 446-448, 2003.
7. S. Lee, S. T. Choi, Y. Y. Earmme and D. Y. Chung, Stress intensity factors and kink angle of a crack interacting with a circular inclusion under remote mechanical and thermal loadings, KSME International Journal, Vol. 17, pp. 1120-1132, 2003.
8. H. Shin, S. T. Choi, and Y. Y. Earmme, A problem of anisotropic/isotropic bimaterial with a singularity or under a remote stress, Materials Science Forum, Vol. 426-432, pp. 3415-3420, 2003.
9. Y. T. Im, S. T. Choi, T. S. Park, and J. H. Kim, Study on residual stress in viscoelastic thin film using curvature measurement method, KSME International Journal, Vol. 18 (No. 1), pp. 12-19, 2004.
10. K. C. Shin, H. Liu, J. J. Lee, and S. T. Choi, Interfacial crack tip field in anisotropic/isotropic bimaterials, Composite Structures, Vol. 66, pp. 673-676, 2004.
11. Y. Y. Earmme, S. T. Choi, and H. Shin, Anisotropic and isotropic elasticity, and its equivalence for singularity, interface and crack in bimaterials and trimaterials, Key Engineering Materials, Vols. 261-263, pp. 23-32, 2004.
12. S. T. Choi, J. Y. Song, J. H. Kim, S. Lee, and Y. Y. Earmme, Strength design and minimization of residual stresses in reversible GaAs wafer bonding process, Key Engineering Materials, Vols. 306-308, pp. 1337-1342, 2006.
13. W. S. Choi, S. T. Choi, S. U. Son, S. S. Lee, S. Y. Yang, and Y. Y. Earmme, Measurement of mechanical properties and residual stresses of bridged gold films and circular gold membranes, Key Engineering Materials, Vols. 326-328, pp. 227-232, 2006.
14. S. T. Choi and Y. Y. Earmme, Energetics of misfit dislocation dipoles in anisotropic epitaxial films with nanoscale compositional modulation, Int. J. Solids Structures, Vol. 43, pp. 6294-6308, 2006.
15. S. Lee, S. T. Choi, and Y. Y. Earmme, Analysis of vertical cracking phenomena in tensile-strained epitaxial film on a substrate: Part I. Mathematical formulation, Int. J. Solids Structures, Vol. 43, pp. 3401-3413, 2006.
16. S. T. Choi and K. –S. Kim, Nanoscale planar field projections of atomistic decohesion and slip in crystalline solids, Part I: A crack-tip cohesive zone, Philosophical Magazine, in press, 2007.
17. S. T. Choi, Thermoelastic interaction between singularities and interfaces in an anisotropic trimaterial, ASME J. Appl. Mech., in press, 2007.
18. S. T. Choi, Indentation of a viscoelastic film on a rigid substrate with a rigid flat punch under a plane-strain condition, ASME J. Appl. Mech., submitted, 2006.
19. S. T. Choi, Singularities interacting with a coated circular inclusion in an isotropic matrix, Int. J. Engineering Science, submitted, 2006.
20. S. Lee, S. T. Choi, and Y. Y. Earmme, Analysis of vertical cracking phenomena in tensile-strained epitaxial film on a substrate: Part II. Application to InxGa1-xAs/InP system, Int. J. Solids Structures, submitted, 2007.

II. Conference paper
1. S. T. Choi and Y. Y. Earmme, Antiplane problem of interfacial circular-arc cracks in transversely isotropic piezoelectric media, Proceedings of the KSME Spring Annual Meeting A, pp. 224-229, 1997.
2. S. T. Choi and H. S. Sung, and Y. Y. Earmme, Analysis of singularities and interfacial cracks in anisotropic trimaterials, Proceedings of the KSME Spring Annual Meeting A, pp. 72-77, 1998.
3. S. T. Choi and Y. Y. Earmme, A singularity in an anisotropic trimaterial with two parallel interfaces, Asian Pacific Conference for Fracture and Strength, Xi'an, China, pp. 48-53, 1999.
4. T. G. Lee, S. T. Choi, K. W. Lee, and Y. Y. Earmme, A singularity in a trimaterial with two concentric circular inclusions, Proceedings of the KSME Spring Annual Meeting A, pp. 170-175, 2000.
5. Y. T. Im, J. H. Kim, and S. T. Choi, Study on residual stress in viscoelastic thin film using curvature measurement method, Proceedings of the 3rd International Symposium on Electronics Materials and Packaging, Cheju, Korea, pp. 341-346, Nov. 19-22, 2001.
6. H. Shin, S. T. Choi, and Y. Y. Earmme, Elastic singularity in anisotropic/isotropic bimaterial, Proceedings of the KSME Spring Annual Meeting A, pp. 275-280, 2002.
7. H. Shin, S. T. Choi, and Y. Y. Earmme, A problem of anisotropic/isotropic bimaterial with a singularity or under a remote stress, THERMEC' 2003, PTS 1-5. Materials Science Forum, Vol. 426-432: pp. 3415-3420, 2003.
8. Y. Y. Earmme, S. T. Choi, and H. Shin, Anisotropic and isotropic elasticity, and its equivalence for singularity, interface and crack in bimaterials and trimaterials, The 5th International Conference on Fracture & Strength of Solids, Tohoku University, Sendai, Japan, October 20-22, 2003.
9. K. C. Shin, H. Liu, J. J. Lee, and S. T. Choi, Interfacial crack tip field in anisotropic/isotropic bimaterials, 12th International Conferences on Composite Structures, Melbourne, Australia, November 17-19, 2003.
10. S. T. Choi and K. -S. Kim, Nano-scale planar field projection of atomistic decohesion of crystalline solids, 21th International Congress of Theoretical and Applied Mechanics, Warsaw, Poland, August 15-21, 2004.
11. W. S. Choi, S. T. Choi, S. U. Son, S. S. Lee, S. Y. Yang, and Y. Y. Earmme, A measurement of mechanical properties and residual stresses of bridged gold films and circular gold membranes, Proceedings of the KSME Spring Annual Meeting A, 2005.
12. S. T. Choi, Y. Y. Earmme, C. Moon, Experimental characterization of mechanical nonlinear behavior of electronic materials, Proceedings of the iMAPS-Korea Fall Annual Meeting, Seoul, November 11, 2005.
13. W. S. Choi, S. T. Choi, S. U. Son, S. S. Lee, S. Y. Yang, and Y. Y. Earmme, Measurement of mechanical properties and residual stresses of bridged gold films and circular gold membranes, International Conference on Experimental Mechanics; Experimental Mechanics in Nano and Biotechnology, Jeju, Republic of Korea, September 26-29, pp. 227-232, 2006.

III. Research Project
1. Y. Y. Earmme, K. W. Lee, and S. T. Choi, Stress analysis of 3D packages, LG Semicons, 1997.
2. Y. Y. Earmme, S. B. Lee, S. Im, et al., Evaluation of thermo–mechanical reliability for electronic packaging materials, Center for Electronic Packaging Materials (Korea Science and Engineering Foundation), 2000. 7. 1. – 2005. 1. 31.
3. S. B. Lee, Y. Y. Earmme, et al., Development of reliability evaluation technique of electronic packages, National Research Laboratory (Ministry of Science and Technology, Korea), 2000. 6. 14. – 2002. 8. 23.
4. Y. Y. Earmme, J. H. Kim, and S. T. Choi, Development of strength design technique for wafer bonding/debonding process, Ministry of Science and Technology (Korea), 2001. 12. 19. – 2002. 8. 23.
5. Y. Y. Earmme, S. T. Choi, H. Shin, and J. H. Shin, Multiscale analysis of defects using quasicontinuum method, Ministry of Science and Technology (Korea), 2002. 10. 1. – 2003. 3. 13.

Patent
1. J. H. Kim, S. T. Choi, Y. Y. Earmme, et al., Method of minimizing thermal stress in reversible wafer bonding technique of compound semiconductor wafer, (Korea), 10–2002–0047297, 2002.
2. Filed more than 10 patents (will be updated).

Research Interests
Major research interests are in the fields of micro & nano mechanics of materials, focusing on energetics of dislocations and cracks in thin film and layered structures, scale bridging from atomic-scale phenomena to micro-scale description, and experiments for mechanical characterization of small-features structures, especially, polymer films. Recent research includes nanoscale planar field projections of atomic decohesion and slip in crystalline solids, nano indentation of viscoelastic polymer films, and measurement of mechanical properties and residual stresses of micromachined gold films. Currently, he is developing a varifocal lens and its polymer actuator with MEMS (microelectromechanical systems) fabrication techniques.