General research interests are molecular design, synthesis, modification, and self-assembly of smart polymers for biomedical and optoelectronic applications, including Biomaterials, Molecular Biosensors, Smart Gels, Optoelectronic Polymers, Conjugated Polymers, Block Copolymers, Organic-inorganic Hybrid Materials, Photovoltaic Cells, and Self-assembly. Current Research Topics include the following: Biosensors: Sensitivity and selectivity are the most important parameters of a sensor. Nature provides high fidelity in biosynthesis. The unique combination of this specificity of the bio-system and the tunable properties of synthetic polymers would be a promising direction toward molecular sensors with high selectivity and sensitivity. We develop molecular biosensors and bio-microarrays through bio-/synthetic hybrid systems for clinically important biological materials. Photovoltaic Cells: Much effort has been made to convert abundant solar energy into useful electricity. The solar cells made of inorganic semiconductors require stringent manufacturing processes and high cost that are not suitable for large area application. Conjugated polymer (CP)-based solar cells are attractive alternatives due to easy processibility and the tunable optoelectronic properties. Hybrid composites of conjugated copolymers and inorganic/organic nanomaterials having hierarchical nano-ordering are currently under investigation by means of new materials development and directed self-assembly and alignment. Organic Phosphors: Recently we developed a molecular design principle to realize pure organic phosphor having high emission quantum yield even at room temperature with oxygen presence. By rationally designing directed heavy atom effects through intermolecular halogen bonding in crystalline aromatic carbonyl compounds we achieved highly efficient triplet generation and suppression of vibration dissipation. Controlling electron density of such organic phosphorescent materials we could active active color tuning as well. We are developing a second generation of organic phosphors to apply them to device applications.