BNR #55 by Pr. Masaki SANO, University of Tokyo, Jan 15th, 2015, C-lounge, PM 5:00

Collective motion of active matter: bridging matter and living matter


Masaki Sano

Department of Physics, University of Tokyo,

7-3-1 Hongo, Tokyo 113-0033, Japan


Collective motions such as flocking, swarming, and clustering of self-propelled objects has been attracting much interests among scientists in many fields ranging from physics to biology. For instance, collective migration of cells were studied in biology and turned out to be crucial in some developmental processes. However, similar behavior can be observed in totally different artificial systems consisting of self-propelled particles. Nowadays, the latter can be understood as a collective behavior of interacting many body motile systems in a generic framework. Thus, elucidating the common mechanism and underlying laws in collective motions of different systems will be useful to build a bridge between artificial self-propelled material and living material. In my talk, I will explain some new results on non-trivial dynamics and self-organizing behavior of self-propelled particles. As the smallest self-propelled particles, we tested molecular motors and microtubule in motility assay. As an artificial self-propelled particles, we realized micro squirmer (swimmer) by fabricating Janus particles in which interaction among particles can be switched between repulsive and attractive. As a system of biological cells, we studied collective migration and orientation alignment behavior in cultured cells systems. Differences and similarities among these systems will be discussed.