We have conducted studies that physically analyze complex and various particle and fluid behaviors found at small and large scales, basing on flow visualization and measurement. The physical insights gained from the studies have led to finding novel and innovative applications in diverse scientific, engineering, and industrial fields. Our current research activities deal with the following multidisciplinary topics: (1) non-invasive and non-contact manipulation of colloids in suspension, (2) microfluidic approaches for efficient transport and rapid mixing of fluids in a lab-on-a-chip system, (3) biosensors for high-speed and high-sensitivity detection of pathogen and non-pathogen, (4) numerical and experimental analysis of complex heat and fluid flows occurring inside or around engineering systems, and optimization of the systems based on the analysis. The detailed information can be found in the “RESEARCH” tap.