Polymer translocation through a nanopore under a pulling force
Ilkka Huopaniemi, Kaifu luo, Tapio Ala-Nissila, See-Chen Ying
Abstract
We investigate polymer translocation through a nanopore under a pulling force using Langevin dynamics simulations. We concentrate on the influence of the chain length
N
and the pulling force
F
on the translocation time
τ
. The distribution of
τ
is symmetric and narrow for strong
F
. We find that
τ∼
N
2
and translocation velocity
v∼
N
−1
for both moderate and strong
F
. For infinitely wide pores, three regimes are observed for
τ
as a function of
F
. With increasing
F
,
τ
is independent of
F
for weak
F
, and then
τ∼
F
−2+
ν
−1
for moderate
F
, where
ν
is the Flory exponent, which finally crosses over to
τ∼
F
−1
for strong force. For narrow pores, even for moderate force
τ∼
F
−1
. Finally, the waiting time, for monomer
s
and monomer
s+1
to exit the pore, has a maximum for
s
close to the end of the chain, in contrast to the case where polymer is driven by an external force within the pore.