  Stretching dynamics of polymers in microfluidics is of particular interest
for polymer scientists. As a charged polymer, a polyelectrolyte can be deformed
from its coiled equilibrium configuration to an extended chain by applying
uniform or non-uniform electric fields. By means of hybrid lattice
Boltzmann-molecular dynamics simulations, we investigate how the condensed
counterions around the polyelectrolyte contribute to the polymer stretching in
inhomogeneous fields. As an application, we discuss the translocation phenomena
and entropic traps, when the driving force is an applied external electric
field.
