  Nanowire fluidic tweezers have been developed to gently and accurately
capture, manipulate and deliver micro objects. The mechanism behind the capture
and release process has not yet been well explained. Utilizing the method of
regularized Stokeslet, we study a cylindrical nanowire tumbling and interacting
with spherical particles in the Stokes regime. The capture phenomenon observed
in experiments is reproduced and illustrated with the trajectories of
micro-spheres and fluid tracers. The flow structure and the region of capture
are quantitatively examined and compared for different sizes of particles,
various tumbling rates, and dimensions of the tweezers. We find that pure
kinematic effects can explain the mechanism of capture and transport of
particles. We further reveal the relation between the capture region and
stagnation points in the displacement field , i.e., the displacement for tracer
particles in the moving frame within one rotation of the wire.
