Topic：Controlling Cell Motion and Microscale Flow with Polarized Light Fields
Time: September 23th at 14：30 PM
Speaker: Prof. Hepeng ZHANG
Tencent Meeting: 513-110-107
Inviter: Ke XIAO
Abstract: We investigate how light polarization affects the motion ofphoto responsive algae, Euglena gracilis. In a uniformlypolarized field, cells swim approximately perpendicular to thepolarization direction and form a nematic state with zero meanvelocity. When light polarization varies spatially, cell motion ismodulated by local polarization. In such light fields, cells exhibitcomplex spatial distribution and motion patterns which arecontrolled by topological properties of the underlying fields; wefurther show that ordered cell swimming can generate directedtransporting fluid flow. Experimental results are quantitativelyreproduced by an active Brownian particle model in whichparticle motion direction is nematically coupled to local lightpolarization.