Flagellar like dynamics of chains of active Janus particles fueled by an AC electric field

报告题目:Flagellar like dynamics of chains of active Janus particles fueled by an AC electric field

报告人:Prof. Masaki SanoInstitute for Natural Sciences, Shanghai Jiao Tong University,

Tokyo College, The University of Tokyo

报告时间: 2019621日(星期五) 上午1030

报告地点: 物理科技楼101报告厅


报告摘要:Collective behaviors of self-propelled particles ranging from artificial active colloids to biological cells have been attracting a lot of attentions recent years. We study the active dynamics of self-propelled asymmetrical colloidal particles (Janus particles) fueled by an AC electric field. Both the speed and direction of the self-propulsion, and the strength of the attractive interaction between particles can be controlled by tuning the frequency of the applied electric field and the ion concentration of the solution. The strong attractive force at high ion concentration gives rise to chain formation of the Janus particles, which can be explained by the quadrupolar charge distribution on the particles.

When both the position and the orientation of the heads of the chains are fixed, they exhibit beating behavior reminiscent of eukaryotic flagella. The beating frequency of the chains of Janus particles depends on the applied voltage and the scaling relation between the beating frequency and the voltage is described by the quadrupolar interaction between Janus particles, which gives indirect but convincing evidence on the mechanisms of the Janus particles. Hydrodynamic interaction within the chain, and its effect on propulsion speed, are discussed.

报告人简介:Prof. Masaki Sano obtained his Phd in 1986 in Tohoku University, Japan. From 1987-1989 Visiting Scientist, James Franck and Enrico Fermi Institute, University of Chicago; From 1990-1999 Associate Professor, Research Institute of Electrical Communication, Tohoku University; From 2000-2019 Professor, Department of Physics, The University of Tokyo; Since 2011, he is the IUPAP C3 Commission member. Since 2019, he is the deputy director of Tokyo College in The University of Tokyo and Chair Professor of Institute for Natural Sciences in Shanghai Jiao Tong University. His research interest covers nonlinear dynamics, nonequilibrium statistical mechanics, soft matter and active matter.