News

Seok-Woo gave an invited talk at EMA 2024.

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Seok-Woo gave an invited talk at the EMA (Electronic Materials and Applications) meeting (February 13-16) organized by the American Ceramic Society (ACers)!

AcerS EMA 2024 (Denver, CO)

  • Seok-Woo Lee, “Grain size dependence of mechanical properties of nanocrystalline magnesium aluminate MgAl2O4” (invited talk) – Symposium 5: Grain Boundary Structure and Mechanical Properties I, 2-2:30PM, 02/15/2024, room Colorado G.
    Abstract: To develop transparent materials with superior mechanical properties, nanocrystalline magnesium aluminate (MgAl2O4) spinel with grain sizes ranging from 3.7 to 80 nm has been synthesized by environmentally controlled pressure assisted sintering. In this study, we investigated the microstructure and grain size dependence of the mechanical properties of nanocrystalline MgAl2O4by performing transmission electron microscopy, nanoindentation, uniaxial micropillar compression, and micro-cantilever bending.Electron microscopy confirmed that the environmentally controlled pressure assisted sintering technique produces a nearly fully dense grain structure with a porosity of less than 1% in larger grain-sized ceramics and observably pore-free grain structures in the smaller grain-sized ceramics. Mechanical characterization revealed that nanoindentation hardness, compressive fracture strength, and fracture toughness each exhibit distinct grain size dependence. Our experimental results and numerical analyses point to a change in dominant strain accommodating mechanisms from dislocation-based plasticity to shear banding as the grain size is reduced, as previously suggested by the literature. Practical implications of the change in strain accommodation mechanisms manifest as the emergence of indentation size effect, weak grain size dependence of hardness and strength, and a ∼2-fold increase in apparent fracture toughness for the smaller grain-sized ceramics.

Tyler’s DNA lattice paper was selected as Editor’s choice – 2023!

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Tyler’s DNA lattice paper was selected as Editor’s choice – 2023 of Cell Reports Physical Science. Many Congratulations!

Aaron N. Michelson, Tyler J. Flanagan, Seok-Woo Lee*, Oleg Gang*, “Light-weight and high strength silica nanolattices templated from DNA origami,” Cell Reports Physical Science, 4, 101475 (2023) [PDF][web][Editor’s Choice – 2023!] – featured at UConn Today Columbia University News, American Ceramic Society News, the Department of Energy (DOE) website, Tech Brief, and Science Tech Daily!

Shuyang’s contributed work published at Nature Comm! Congrats!

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Shuyang‘s collaboration work (Tra Vinikoor et al.) was published at Nature Communications! Many congratulations!

Shuyang contributed to the nanoindentation measurement that quantifies the degree of healing of the articular cartilage. The mechanical properties of healed cartilages must be similar with those of heathy cartilages. This work shows that nanoindentation can also be used to study bio-materials (tissue re-generation).

Tra Vinikoor, Godwin dzidotor, Thinh T. Le, Yang Liu, Ho-Man Kan, Srimanta Barui, Meysam T. Chorsi,  Eli J. Curry, Emily Reinhardt, Hanzhang Wang, Parbeen Singh, Marc A Merriman, Ethan D’orio, Shuyang Xiao, James H Chapman, Feng Lin, Cao-Sang Truong, Somasundaram Prasadh, Lisa Chuba, Shaelyn Killoh, Seok-Woo Lee, Qian Wu, Ramaswamy M. Chidambaram, Kevin W. H. Lo, Cato T. Laurencin, Thanh D. Nguyen, “Injectable and biodegradable piezoelectric hydrogel for medical applications,” Nature Communications, 14, 6257 (2023) [PDF][web]

Book chapter (Cold Spray) was published!

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Book Chapter 9. ‘Characterization of Cold Sprayed Materials Consolidations” was published. This chapter is included in “Advances in Cold Spray (second edition), Woodhead Publishing Series in Metals and Surface Engineering”. This chapter describes how micromechanical testing can be used to study mechanical properties of cold sprayed materials. All these works were done by Dr. Tyler Flanagan!

Bryer C. Sousa, Mark Aindow, Seok-Woo Lee, Diana Lados, Anthony G. Spangenberger, Christopher M. Sample, Danielle L. Cote, “Ch.9. Characterization of cold-sprayed material consolidations,” Advances in Cold Spray (2nd ed.), Woodhead Publishing, 205-298 (2023) [PDF][web]