  Understand and predict the dynamics of dispersed micro-objects in
microfluidics is crucial in numerous natural, industrial and technological
situations. In this paper, we experimentally characterized the equilibrium
velocity $V$ and lateral position $\varepsilon$ of various dispersed
micro-objects such as beads, bubbles and drops, in a cylindrical microchannel
over an unprecedent wide range of parameters. By systematically varying the
dimensionless object size ($d \in [0.1; 1]$), the viscosity ratio ($\lambda \in
[10^{-2}; \infty[$), the density ratio ($\varphi \in [10^{-3}; 2]$), the
Reynolds number ($\Re \in [10^{-2}; 10^2]$), and the capillary number
($\text{Ca} \in [10^{-3}; 0.3]$), we offer a general study exploring various
dynamics from the nonderformable viscous regime to the deformable
visco-inertio-capillary regime, thus enabling to highlight the sole and
combined roles of inertia and capillary effects on lateral migration. The
experiments are compared and well-agree with a steady 3D Navier-Stokes model
for incompressible two-phase fluids including both the effects of inertia and
possible interfacial deformations. This model enables to rationalize the
experiments and to provide an exhaustive parametric analysis on the influence
of the main parameters of the problem, mainly on two aspects: the stability of
the centered position and the velocity of the dispersed object. Interestingly,
we propose a useful correlation for the object velocity $V$ as functions of the
$d$, $\varepsilon$ and $\lambda$, obtained in the $\text{Re}=\text{Ca}=0$
limit, but actually valid for a larger range of values of $\text{Re}$ and
$\text{Ca}$ in the linear regimes.
