We describe a microfluidic device for studying the orientational dynamics ofmicrorods. The device enables us to experimentally investigate the tumbling ofmicrorods immersed in the shear flow in a microfluidic channel with a depth of400 mu and a width of 2.5 mm. The orientational dynamics was recorded using a20 X microscopic objective and a CCD camera. The microrods were produced byshearing microdroplets of photocurable epoxy resin. We show different examplesof empirically observed tumbling. On the one hand we find that short stretchesof the experimentally determined time series are well described by fits tosolutions of Jeffery's approximate equation of motion [Jeffery, Proc. R. Soc.London. 102 (1922), 161-179]. On the other hand we find that the empiricallyobserved trajectories drift between different solutions of Jeffery's equation.We discuss possible causes of this orbit drift.
展开▼
