Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rotational Flows Generated by Microrobots Rotating Near Surfaces at Low
  Reynolds Number   In this study, we use numerical simulations to investigate the flow field
induced by a single magnetic microrobot rotating with a constant angular speed
about an axis perpendicular to an underlying surface. A parallel solver for
steady Stokes flow equations based on the boundary-element method is used for
simulating these flows. A simple transformation is introduced to extend the
predictive capability of the solver to cases with small unsteadiness. Flows
induced by four simple robot shapes are investigated: sphere, upright cylinder,
horizontally-laid cylinder, and five-pointed star-shaped prism. Shapes with
cross-sections that are axisymmetric about the rotation axis (sphere and
upright cylinder) generate time-invariant flow fields, which could be useful
for applications such as micromanipulation. Non-axisymmetric shapes
(horizontally-laid cylinder and the star-shaped prism) induce significant
unsteadiness inside the flow field, which could be desirable for applications
such as micromixing. Furthermore, a slender horizontally-laid cylinder
generates substantially three-dimensional flows, an added benefit for
micromixing applications. The presence of nearby walls such as a bottom
substrate or sidewalls has a retarding effect on the induced flows, which is
quantified. Finally, we present the driving torque and power-consumption of
these microrobots rotating in viscous liquids. The numerical modeling platform
used in this work can enable future optimal microrobot designs for a given
application requirement.

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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: plasm-ph
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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg