Biological cilia are found on surfaces of some microorganisms and on surfaces of many eukaryotic cells where they interact with\r\nthe surrounding fluid. The periodic beating of the cilia is asymmetric, resulting in directed swimming of unicellular organisms or in\r\ngeneration of a fluid flow above a ciliated surface in multicellular ones. Following the biological example, externally driven artificial\r\ncilia have recently been successfully implemented as micropumps and mixers. However, biomimetic systems are useful not\r\nonly in microfluidic applications, but can also serve as model systems for the study of fundamental hydrodynamic phenomena in\r\nbiological samples. To gain insight into the basic principles governing propulsion and fluid pumping on a micron level, we investigated\r\nhydrodynamics around one beating artificial cilium. The cilium was composed of superparamagnetic particles and driven\r\nalong a tilted cone by a varying external magnetic field. Nonmagnetic tracer particles were used for monitoring the fluid flow\r\ngenerated by the cilium. The average flow velocity in the pumping direction was obtained as a function of different parameters,\r\nsuch as the rotation frequency, the asymmetry of the beat pattern, and the cilium length. We also calculated the velocity field\r\naround the beating cilium by using the analytical far-field expansion. The measured average flow velocity and the theoretical\r\nprediction show an excellent agreement
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