Bongjun Yeom

Chirality of plasmonic films can be strongly enhanced by three-dimensional (3D) out-of-plane geometries. The complexity of lithographic methods currently used to produce such structures and other methods utilizing chiral templates impose limitations on spectral windows of chiroptical effects, the size of substrates, and hence, further research on chiral plasmonics. Here we demonstrate 3D chiral plasmonic nanostructures (CPNs) with high optical activity in the visible spectral range based on init

For the development of wearable electronics, the replacement of rigid, metallic components with fully elastomeric materials is crucial. However, current elastomeric electrodes suffer from low electrical conductivity and poor electrical stability. Herein, a metal-like conductive elastomer with exceptional electrical performance and stability is presented, which is used to fabricate fully elastomeric electronics. The key feature of this material is its wrinkled structure, which is induced by in si

Artificial chiral materials at the nano- and microscales have unique optical properties, known as optical activities, that correspond to preferential interactions with circularly polarized light. Unlike the chiroptical responses of biomaterials, nano- and microscale materials with artificial chirality can present intense and tunable chiroptical responses in a broad range of frequencies from the ultraviolet to terahertz regimes. These particular properties of artificial chiral materials have been

The growth of lithium (Li) dendrites reduces the lifespan of Li-metal batteries and causes safety issues. Herein, hierarchically porous aramid nanofiber separators capable of effectively suppressing the Li dendrite growth while maintaining highly stable cycle performances at high charge/discharge rates are reported. A two-step solvent exchange process combined with reprotonation-mediated self-assembly is utilized to control the bimodal porous structure of the separators. In particular, when etha

Nanostructured CaCO3 (NCC) thin films with honeycomb-shaped nanopores were obtained at the surface of urease-embedded multilayers prepared by the layer-by-layer deposition. Amorphous CaCO3 (ACC) droplets were initially nucleated from the multilayer surface, because of the enzymatic reaction of ureases to produce CO2, particularly when the saturation index of CaCO3 in the crystal-forming solution is above 1.89 based on the calcite saturation. Once ACC droplets successfully covered the entire surf

Research on the chiral magneto-optical properties of inorganic nanomaterials has enabled novel applications in advanced optical and electronic devices. However, the corresponding chiral magneto-optical responses have only been studied under strong magnetic fields of ≥1 T, which limits the wider application of these novel materials. In this paper, we report on the enhanced chiral magneto-optical activity of supra-assembled Fe₃O₄ magnetite nanoparticles in the visible range a

Abstract Nano‐ and microsized chiral materials are receiving significant attention because of their unique characteristics, which include chiroptical activities and enantioselective interactions with living materials. However, the realization of chiral morphologies in such small‐scale materials has been an issue because of the complicated fabrication methods and limited material selection. In this study, a facile and reproducible method is developed for fabricating 3D chiral microwrinkles with t

Chiral-structured nanoscale materials exhibit chiroptical properties with preferential absorptions of circularly polarized light. The distinctive optical responses of chiral materials have great potential for advanced optical and biomedical applications. However, the fabrication of three-dimensional structures with mirrored nanoscale geometry is still challenging. This study introduces chiral plasmonic nanopatterns in wavy shapes based on the unidirectional alignment of block copolymer thin film

Two different kinds of organic polyelectrolyte (PE)/inorganic silicate nanolaminates carrying dissimilar interfacial adhesion between the organic and the inorganic layers were prepared using the layer-by-layer self-assembly. To investigate the mechanical behavior of the prepared hybrid films, apparent modulus (E′), hardness (H), and crack length were measured by depth-sensing nanoindentation as well as a microVickers experiment. The fracture toughness of the hybrid films was then calculated base

Ionogels are emerging materials for advanced electrochemical devices; however, their mechanical instability to external stresses has raised concerns about their safety. This study reports aligned bacterial nanocellulose (BC) ionogel films swelled with the model ionic liquid (IL) of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF₄) for an unprecedented combination of high stiffness and high energy dissipation without significant loss of ionic conductivity. The aligned BC ionogel