Flagellar like dynamics of chains of active Janus particles fueled by an AC electric field
报告题目：Flagellar likedynamics of chains of active Janus particles fueled by an AC electric field
报告人：Prof. Masaki Sano（Institute forNatural Sciences, Shanghai Jiao Tong University,
Tokyo College, The University ofTokyo）
报告时间： 2019年6月21日（星期五）上午10：30
报告地点：物理科技楼101报告厅
报告邀请人：施夏清
报告摘要：Collective behaviors of self-propelled particles rangingfrom artificial active colloids to biological cells have been attracting a lotof attentions recent years. We study the active dynamics of self-propelledasymmetrical colloidal particles (Janus particles) fueled by an AC electricfield. Both the speed and direction of the self-propulsion, and the strength ofthe attractive interaction between particles can be controlled by tuning thefrequency of the applied electric field and the ion concentration of thesolution. The strong attractive force at high ion concentration gives rise tochain formation of the Janus particles, which can be explained by thequadrupolar charge distribution on the particles.
When both the positionand the orientation of the heads of the chains are fixed, they exhibit beatingbehavior reminiscent of eukaryotic flagella. The beating frequency of thechains of Janus particles depends on the applied voltage and the scalingrelation between the beating frequency and the voltage is described by thequadrupolar interaction between Janus particles, which gives indirect butconvincing evidence on the mechanisms of the Janus particles. Hydrodynamicinteraction within the chain, and its effect on propulsion speed, arediscussed.
报告人简介：Prof. Masaki Sano obtained his Phd in 1986 in Tohoku University, Japan. From 1987-1989Visiting Scientist, James Franck and Enrico Fermi Institute, University ofChicago; From 1990-1999 Associate Professor, Research Institute of ElectricalCommunication, Tohoku University; From 2000-2019 Professor, Department ofPhysics, The University of Tokyo; Since 2011, he is the IUPAP C3 Commissionmember. Since 2019, he is the deputy director of Tokyo College in TheUniversity of Tokyo and Chair Professor of Institute for Natural Sciences inShanghai Jiao Tong University. His research interest covers nonlinear dynamics,nonequilibrium statistical mechanics, soft matter and active matter.