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Seog, Joonil

Joonil Seog
Assistant Research Professor
2130 Chemical and Nuclear Engineering Building

News About This Professor


Sc.D., Massachusetts Institute of Technology, 2003

Research Interests 

Self-assembly and molecular mechanics of biological materials, biomaterials for gene delivery, stimuli-responsive peptide-based materials, optical tweezers.


Before joining the faculty of the Department of Materials Science and Engineering and Professor Seog was a research fellow at the CBR Institute for Biomedical Research, Inc., located at the Harvard Medical School. Professor Seog is a former joint apointee to the Fischell Department of Bioengineering.

Current Research Projects 

Professor Seog's research provides insight into the design of nanomechanically tailored smart biomaterials that can enhance tissue regeneration or slow down disease progression. His focus is on studying the structure-function relationship of biological molecules using single molecule force spectroscopy. Previously, Professor Seog studied the molecular origin of cartilage biomechanical properties, and by directly measuring intermolecular forces discovered that about 50% of the compressive resistance of cartilage originates from the highly charged polysaccharides within it. This was the first study elucidating the structure and biomechanical function of polysaccharides in cartilage using tools that could measure very small forces such as individual molecular interactions.

Professor Seog is currently pursuing a study of the structural change of biological molecules in relationship to diseases. Many diseases are caused by mutations in the genes that result in structural change in the cell, leading to the degeneration of the body's auto-immune response. Seog believes that understanding how these changes affect the nanomechanical properties of proteins and tissues can help prevent or cure diseases. He also explores the interaction between synthetic and biological materials. His research in this area will support current efforts to incorporate biological molecules into small devices in order to utilize them as molecular sensing devices such as DNA chips, protein chips, and silicon-based drug delivery devices.

He also examines the single molecule mechanical properties of synthetic and biological macromolecules. His goal is to enhance our understanding of basic biological and physical phenomena, as well as enable us to apply them directly when building smart molecular devices or single molecule devices.


Professor Seog develops and teaches undergraduate courses and a graduate course in single molecule mechanics. One of his goals is to get students involved in cutting-edge research. He currently teaches or has taught the following courses:

  • BIOE 454: Introduction to Biomaterials Laboratory
  • ENES 182: Engineering the Future
  • ENMA425/625: Introduction to Biomaterials
  • ENMA 698B: Nanomechanics of Biomaterials (also listed as BIOE489W/689W)

Honors and Awards 

  • NSF CAREER Award, 2011

Selected Publications 

N.M. Toan, C. Zhang, M. Shimaoka, S.B. Smith, D. Thirumalai and J. Seog “Mechanical Hierarchy in a Single α I Domain in Integrin Reveals a Functional Role for Allosteric Signaling”, to be submitted.

A. Lee, A. Karcz, R. Akman, S. Kwon, S. Chou, L.J. Tricoli, J.M. Hustedt, J.D. Kahn, A.J. Mixson, J. Seog, “Direct Observation of Dynamic Mechanical Regulations of Condensed DNA by Environmental Stimuli”, to be submitted.

H. Chang, C. Hsu, M. Ahmed, J. Seog, G. Oehrlein, and D. Graves, “Plasma Flux Dependent Lipid A Deactivation”, submitted.

E. Bartis2, B. Caleb, T. Chung, N. Ning, J. Chu, D. Graves, J. Seog, G. Oehrlein, “Deactivation of Lipopolysaccharide by Ar and H2 Inductively-coupled Low Pressure Plasma”, accepted in Journal of Physics D: Applied Physics.

N. Weadock, N. Varonchayakul1, J. Seog, and L. Hu, “Determination of Mechanical Properties of the SEI in Sodium Ion Batteries vis Colloidal Probe Microscopy”, Nano Energy, 2013, 2(5), 713-719.

S. Chou, K. Hom, D. Zhang, Q. Leng, L.J. Tricoli, J.M. Hustedt, A. Lee1, M.J. Shapiro, J. Seog, J.D. Kahn, and A.J. Mixson, “Silencing Activity and Stability of the HK:siRNA Polyplex is Mediated by Hydrogen Bonds Between Histidine Residues and siRNA”, Biomaterials, 2014, 35(2), 846-855.

E.A. Bartis, D.B. Graves, J. Seog, and G.S. Oehrlein, “Atmospheric pressure plasma treatment of lipopolysaccharide in a controlled environment”, Journal of Physics D: Applied Physics, 2013, 46(31), 312002.

N. Varongchayakul, S. Johnson, T. Quabili, J. Cappello, H. Ghandehari , S.D. Solares, W. Hwang, and J. Seog. “Direct observation of amyloid nucleation under nanomechanical stretching”, ACS Nano, 2013, 7(9); 7734-7743.

J. Chung, D. Shim, J.M. Kwak, and J. Seog. "Direct force measurement of single DNA:peptide interactions using atomic force microscopy", Journal of Molecular Recognition, 2012, 26(6); 268-275

T.-Y. Chung, N. Ning, J. Chu, D. Graves, E. Bartis, J. Seog, G. Oehrlein. "Plasma deactivation of endotoxic biomolecules: vacuum ultraviolet photon and radical beam effects on lipid A" Plasma Processes and Polymers, 2012, 12(2); 167-180.

S. Johnson, Y.K. Ko, N. Varongchayakul, S. Lee, J. Cappello, H. Ghandehari, S.B. Lee, S.D. Solares and J. Seog. “Directed patterning of the self-assembled silk-elastin-like nanofibers using a nanomechanical stimulus” Chemical Communications, 2012, 48(86); 10654-10656. Abstract

T.M. Nguyen, S. Cho, N. Varongchayakul, D. Yoon, J. Seog, K. Zong and S.B. Lee. “Electrochemical synthesis and one step modification of PMProDot nanotubes and their enhanced electrochemical properties” Chemical Communications, 2012, 48 (21); 2725-2727.

S.D. Solares, J. Chang, J. Seog, and A.U. Kareem. Utilization of simple scaling laws for modulating tip-sample peak forces in atomic force microscopy characterization in liquid environments” Journal of Applied Physics, 2011, 110 (9).

Y. Ye, B. Kim, J. Seog, and K.Y. Choi. "Transitions of morphological patterns of crystallizing polycarbonate in thin films" Journal of Applied Polymer Science, 2012, 124(1); 560-567.

J. Chang, X. Peng, K. Hijji, J. Cappello, H. Ghandehari, S.D. Solares, and J. Seog. “Nanomechanical stimulus accelerates and directs the self-assembly of silk-elastin-like nanofibers” Journal of the American Chemical Society, 2011, 133(6); 1745-1747.

W. Hwang, B. Kim, R. Dandu, J. Cappello, H. Ghandehari, and J. Seog. “Surface induced nanofiber growth by self-assembly of a silk-elastin-like protein polymer”, Langmuir, 2009, 25(21); 12682-12686.

J. Seog, D. Dean, B. Rolauffs, T. Wu, J. Genzer, A. H.K. Plaas, A. J. Grodzinsky and C. Ortiz. “Nanomechanics of opposing glycosaminoglycan brushes”, Journal of Biomechanics, 2005; 38(6); 1789-1797. Abstract

J. Seog, E. Frank, D. Dean, A. Grodzinsky, and C. Ortiz. “Preparation and characterization of end-grafted polyelectrolytes on nanoscale probe tips using an electric field”, Macromolecules 2004; 37(3); 1156-1158.

D. Dean, J. Seog, C. Ortiz, and A. Grodzinsky. “Molecular level theoretical model for electrostatic interaction within polyelectrolyte brushes using glycosaminoglycans as a model system”, Langmuir 2003; 19(13); 5526-5539.

J. Seog, D. Dean, A. Plaas, S. Wong-Palms, A. Grodzinsky, and C. Ortiz. “Direct measurement of glycosaminoglycan intermolecular interactions via high-resolution force spectroscopy”, Macromolecules 2002; 35(14); 5601-5615.

K. Cho, J. Seog, and T.O. Ahn, “Morphology and toughening behavior of diallyl isophthalate resin/polyarylate alloy”, Polymer 1996; 37(9); 1541-1549.

Selected Presentations 

For a full list of presentations, please visit Professor Seog's web site

"Unfolding behavior of Rossmann fold integrin I domain measured directly using optical tweezer"; J. Seog, J. Dill, X. Zhang, C. Cecconi, M. Kim, M. Shimaoka, C. Bustamante, and T. Springer. Single Molecule Biophysics Winter Workshop, Aspen, CO. February 2007.

"Structure-Function of MAdCAM-1 revealed by single-molecule force spectroscopy"; X. Zhang, J. Seog, and T.A. Springer. Experimental Biology, San Francisco, CA. April 2006.

"Effect of solution conditions on nanoscale interactions between opposing glycosaminoglycan brushes"; J. Seog, D. Dean, S. Wong-Palms, A. Plaas, A. Grodzinsky, C. Ortiz. The Annual March Meeting of American Physical Society in Austin, TX. March 2003.

Related News 

Bartis Wins Wylie Fellowship for Research on Plasma for Disinfection
Award supports students in final stages of dissertation work. May 27, 2014

Bartis and Wan Join Future Faculty Program
Program prepares graduate students for a career in academia. January 27, 2014

2013 Dean's Student Research Awards Announced
Graduate students recognized for high quality engineering research. May 7, 2013

MSE Announces Graduate Research Awards
Cornett, Varongchayakul will advance to compete at Clark School-level. April 1, 2013

Spinning Engineered Silk Into Tiny Designs—With A Microscope
Atomic force microscopy to guide formation of polymer threads. December 5, 2012

Rabin Wins Prestigious NSF CAREER Award for Spectroscopy Research
Nanoparticles and light twist left and right to identify molecular structures. February 9, 2012

Cumings, Seog Win NSF CAREER Awards for Nanotechnology Research
Research includes studies of frustrated nanomagnets, assembly of biological nanofibers. January 19, 2011

Plasma for Disinfection Study Wins DOE Grant
Oehrlein, Seog will be first to characterize effects on biological molecules at the monolayer level. September 23, 2010

Karcz Takes 2nd In Dean's M.S. Thesis Competition
Graduate student recognized for work with optical tweezers. May 7, 2010

Seog Lab Installs Optical Mini-Tweezers
Molecular Mechanics Laboratory to use high resolution force spectroscopy for nanomedicine and nanobiotechnology research. January 15, 2009

Seog Joins Faculty
Professor to hold joint appointment with BioE, MSE December 15, 2006