Nanoscale Flow Research Division
Molecular Composite Flow Laboratory
Concurrent ProfessorTaku Ohara
Associate ProfessorGota Kikugawa
From nanoscale to macroscale, various thermal and fluid phenomena, to which composite molecular-scale physics gets engaged, are of critical importance in the wide range of engineering and industrial processes. In particular, an essential understanding of these phenomena is indispensable to exploit the limit performance of next-generation semiconductor devices by improving thermal dissipation from the device surface or to explore and develop novel polymeric substances by optimizing thermal and fluid properties as well as mechanical properties. By using large-scale numerical simulations such as the molecular dynamics method, we investigate heat and mass transfer phenomena in the thermal and fluid engineering from the microscopic viewpoint. The underlying microscopic mechanisms governing macroscale thermofluid properties are examined as well. Integrating numerical analysis methods which can cover multiscale physics, we aim to investigate thermal and fluid phenomena having multiscale aspects. Based on this knowledge, industrial applications such as semiconductor processes and development of polymeric materials are explored.
Surface Modification Using Organic Molecular Films
Novel surface modification techniques at the molecular level such as the self-assembled monolayer (SAM) have drawn attention as the technique to control the physical and chemical properties on solid surfaces. In particular, the bottom-up processes, i.e., surface modification by utilizing the self-assembling of organic molecules or spontaneous structurization in organic thin films, have future possibilities due to their flexibility and adaptability. Structure formation, interface affinity, and heat and mass transport characteristics of organic molecular films have a critical importance in the engineering and industry. Therefore, we investigate the underlying microscopic mechanisms governing these significant characteristics.
- Alkanethiol SAM on Au(111) with organic solvent
- Nanoscopic picture of droplet wetting on SAM
Thermal and Mechanical Properties of Polymeric Materials
As for development of polymeric materials which have extensively been utilized in industry, designing thermofluid properties as well as mechanical and chemical properties by controlling the molecular-scale structure and phase separation structure inside the material is being required. For example, it is a critical issue to predict the change in molecular structure and heat transport properties of polymeric resins having crosslink bonds when the materials are used as structure materials for aircraft with a flame-retardant property. Using integrated numerical analyses covering molecular-scale to macroscale phenomena and data-driven informatics techniques, we aim to explore and design polymeric materials which have valuable thermofluid properties and mechanical properties.
- Molecular structure of epoxy resin
- Self-organizing map for organic liquids
Transport Phenomena in Heterogeneous Media and Confined Liquids
At the fluid and soft matter interfaces or inside the confined liquid in nanoscale structures, peculiar heat and mass transfer characteristics emerge as a consequence of heterogeneous structure formation inside a liquid in the vicinity of the interfaces. These phenomena are directly relevant to the wide field of nano- and bioengineering, e.g., molecular transport through mesoporous materials and biomolecules. This study elucidates that the molecular transport in confined liquids is significantly different from that in the homogenous bulk liquids and that the molecular diffusion is highly affected by the hydrodynamic effect induced by the molecule itself. Our goal is an essential understanding of heterogeneous structure and corresponding transport phenomena at the molecular level and building physical models which can bridge macroscopic thermal and fluid analyses based on the microscopic knowledge.
- Instantaneous structure of water surface
- Anomalous diffusivity of liquids in the periodic rectangular parallelepiped system