  We theoretically and experimentally investigate the flow field that emerges
from a rod-like microrotor rotating about its center in a non-axisymmetric
manner. A simple theoretical model is proposed that uses a superposition of two
rotlets as a fundamental solution to the Stokes equation. The predictions of
this model are compared to measurements of the azimuthal and radial
microfluidic velocity field components that are induced by a rotor composed of
fused microscopic spheres. The rotor is driven magnetically and the fluid flow
is measured with the help of a probe particle fixed by an optical tweezer. We
find considerable deviations of the mere azimuthal flow pattern induced by a
single rotating sphere as it has been reported by Di Leonardo \textit{et al.}
[Phys. Rev. Lett. 96, 134502 (2006)]. Notably, the presence of a radial
velocity component that manifests itself by an oscillation of the probe
particle with twice the rotor frequency is observed. These findings open up a
way to discuss possible radial transport in microfluidic devices.
