Recent Announcement


Frontispiece in Advanced Materials

posted Jun 18, 2017, 6:23 AM by Shin-Hyun Kim   [ updated Jun 18, 2017, 6:24 AM ]

Sang Seok Lee, Hyeon Jin Seo,Yun Ho Kim, and Shin-Hyun Kim, "Structural Color Palettes of Core-Shell Photonic Ink Capsules containing Cholesteric Liquid Crystals", Advanced Materials29, 1606894 (2017).(Co-corresponding author


Front Cover Paper in Advanced Materials

posted Jun 11, 2017, 9:21 PM by Shin-Hyun Kim   [ updated Jun 11, 2017, 9:22 PM ]

Soojeong Cho, Tae Soup Shim, Ju Hyeon Kim, Dong-Hyun Kim, and Shin-Hyun Kim, "Selective Coloration of Melanin Nanospheres through Resonant Mie Scattering", Advanced Materials29, 1700256 (2017). [pdf]



New paper in Small

posted May 23, 2017, 9:29 PM by Shin-Hyun Kim

Jing Fan, Shin-Hyun Kim, Zi Chen, Shaobing Zhou, Esther Amstad, Tina Lin, and David A. Weitz, "Creation of faceted polyhedral microgels from compressed emulsions", Small Accepted for publication (2017)  (Fan & Kim contributed equally, Co-corresponding author)

Compressed monodisperse emulsions in confined space exhibit highly ordered structures. We investigate the influence of the volume fraction and the confinement geometry on the organized structures and study the mechanism by which structural transition occurs. Based on the understanding of ordering behavior of compressed emulsions, we develop a simple and high-throughput method to fabricate monodisperse polyhedral microgels using the emulsions as the template. By controlling the geometry of the confined spaces, we implement a variety of shapes such as hexagonal prism, Fejes Toth honeycomb prism, truncated octahedron, pyritohedron, and truncated hexagonal trapezohedron. Moreover, the edge sharpness of each shape is controllable by adjusting the drop volume fraction. This design principle can be readily extended to other shapes and materials, and therefore provides a useful means to create polyhedral microparticles for both fundamental study and practical applications.


New article in ACS AM&I

posted May 3, 2017, 4:44 PM by Shin-Hyun Kim

Sang Seok Lee, Juwoon Park, Yutaek Seo, and Shin-Hyun Kim, "Thermo-Responsive Microcarriers for Smart Release of Hydrate Inhibitors under Shear Flow", ACS Applied Materials & Interfaces Accepted for publication (2017)


New paper in Small

posted Apr 18, 2017, 7:42 PM by Shin-Hyun Kim

Tae Yong Lee, Minhee Ku, Bomi Kim, Sangmin Lee, Jaemoon Yang and Shin-Hyun Kim, "Microfluidic Production of Biodegradable Microcapsules for Sustained Release of Hydrophilic Actives", Small Accepted for publication (2017)  (Corresponding author


New Paper in Small

posted Mar 8, 2017, 8:40 PM by Shin-Hyun Kim

Dong Jae Kim, Tae Yoon Jeon, Sung-Gyu Park, Hye Ji Han, Sang Hyuk Im, Dong-Ho Kim and Shin-Hyun Kim, "Uniform Microgels containing Agglomerates of Silver Nanocubes for Molecular Size-Selectivity and High SERS Activity", Small, accepted for publication (2017).

Microgels containing agglomerates of silver nanocubes are microfluidically created to provide SERS-active substrates. The microgels permit selective infusion of small molecules and nanogaps among the nanocubes serve as hot spots for SERS. Therefore, the microgels enable us to selectively analyze Raman spectra of small molecules dissolved in complex mixtures with high sensitivity in the absence of interruption from large adhesives.


New Communication in Adv. Mater.

posted Feb 25, 2017, 10:00 PM by Shin-Hyun Kim

Sang Seok Lee, Hyeon Jin Seo,Yun Ho Kim, and Shin-Hyun Kim, "Structural Color Palettes of Core-Shell Photonic Ink Capsules containing Cholesteric Liquid Crystals", Advanced Materials, accepted for publication (2017).

Photonic microcapsules with onion-like topology are microfluidically designed to have cholesteric liquid crystals with opposite handedness in their core and shell. The microcapsules exhibit structural colours caused by dual photonic bandgaps, resulting in a rich variety of colour on the optical palette. Moreover, the microcapsules can switch the colours from either core or shell depending on the selection of light-handedness.


New Communication in Adv. Mater.

posted Feb 16, 2017, 10:23 PM by Shin-Hyun Kim

Soojeong Cho, Tae Soup Shim, Ju Hyeon Kim, Dong-Hyun Kim, and Shin-Hyun Kim, "Selective Coloration of Melanin Nanospheres through Resonant Mie Scattering", Advanced Materials, accepted for publication (2017).

Black melanin inks are prepared to selectively exhibit colors under strong light, inspired by human hair. High absorbance of melanin suppresses multiple scattering, causing resonant Mie scattering predominant. Various colors can be developed as the resonant wavelength dictated by nanosphere diameter. Therefore, the melanin inks can be used to encrypt and selectively disclose multicolor patterns for anti-counterfeiting applications.


Sang Seok won a gold prize in Samsung Human Tech

posted Feb 8, 2017, 6:29 PM by Shin-Hyun Kim   [ updated Feb 15, 2017, 7:38 PM ]

Congrats, Sang Seok!!!

Title: Core-Shell Microcapsules Possessing Dual-Photonic Bandgaps by Left- and Right-Handed Helical Nanostructure of Liquid Crystals
Area: Material Science & Process

           



New Article in Small

posted Jan 26, 2017, 12:40 AM by Shin-Hyun Kim   [ updated Jan 26, 2017, 12:40 AM ]

Ju Hyeon Kim, Kwanghwi Je, Tae Soup Shim, and Shin-Hyun Kim, "Reaction-Diffusion-Mediated Photolithography for Designing Pseudo-3D Microstructures", Small, accepted for publication (2017).

Microstructures with three-dimensional (3D) features provide advanced functionalities in many applications. We have employed reaction-diffusion process in photolithography to produce pseudo-3D microstructures in a reproducible manner. In this work, we investigate the influences of various parameters on growth behavior of polymeric structures and expand the use of the reaction-diffusion-mediated photolithography (RDP) to a wide range of structural dimensions. In addition, we study how a lens effect alters the growth behavior of microstructures in conjunction with reaction-diffusion process. For small separation between reaction sites in the array, ultraviolet (UV) exposure time is optimized along with the separation to avoid film or plateau formation. We further prove that the RDP process is highly reproducible and applicable to various photocurable resins. In a demonstrative purpose, we show the use of microdomes created by the RDP process as microlens arrays. The RDP process enables the production of pseudo-3D microstructures even with collimated UV light in the absence of complex optical setups, thereby potentially serving as a useful means to create micropatterns and particles with unique structural features.


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