My ultimate goal for my research is understanding the way living structures are made up.
If I say living structures, many people will imagine life on earth, say animals, plants, and so on. But what I mean with living structures also includes nations, societies, and relationships with friends in more familiar things. They have small units that behave independently and also almost randomly. However, through local interactions between such active units, mass of such units behaves as if it has other intention, and it has distinct order. I'd like to understand mechanisms and underlying universality that promotes such structure formation.
To consider such phenomena especially from a view standpoint of physics, statistical mechanics and thermodynamics are key field. Statistical mechanics can be said to be a field which succeeded in predicting the collective behavior of simple and ideal units, such as molecules. One key for this success is that extraordinary larger number of units constitutes a group. Another field, thermodynamics, puts observation of macroscopic physical quantity as a start point. It is with dare to ignore internal details, and succeed in finding a relation between these macroscopic observable.
These field in common assumes that a system is in a thermal equilibrium condition. This is strikingly useful concept/approximation. However, the unit which constitutes living structure is under continuous input of energy, and many are not in a thermal equilibrium situation. Moreover, in many cases, it has also input of constituents particles. Such a system us called as nonequilibrium open system, or far from equilibrium system.
In a nonequilibrium open system, the concept of a thermal equilibrium can be used only locally. So the understanding of a nonequilibrium open system is still on-going. On the other hand in a nonequilibrium open system, a various phenomenon with amazingly beautiful pattern formation occurs, as well as in human societies.
I am using the technique of the both sides of an experiment and theory to understand this nonequilibrium open system, and aim to unveil the physical side of a life process.
Here, if there is inhomogeneous surfactant distribution, there occurs sear stress to make flows that reduce this inhomogeneity. This phenomenon is called solutal Marangoni effect (Please check solutal Marangoni page (under construction) ). This solutal Marangoni effect is one of chemo-mechanical energy transduction systems under isothermal condition. Through analysis of this system, I want to reveal physics of chemo-mechanical energy transduction.
(More including movies)
Phys. Rev. Lett., 94, 068301 (2005)
Movie Page from Mr. Ken Nagai
Phys. Rev. E, 71, 065301 (2005)
Grant-in-aid for Research Activity Start-up, 23840019
Research fellowship from the Japan Society for the Promotion of Science (JSPS) for Young Scientists (DC1)(Apr. 2006 - Mar. 2009)
Research fellowship from the Japan Society for the Promotion of Science (JSPS) for Young Scientists (PD)(Apr. 2009 - Mar. 2012)