  Using three-dimensional numerical simulations, we demonstrate the growth
saturation of an unstable thin liquid film on micropatterned
hydrophilic-hydrophobic substrates. We consider different transverse-striped
micropatterns, characterized by the total fraction of hydrophilic coverage and
the width of the hydrophilic stripes. We compare the growth of the film on the
micropatterns to the steady states observed on homogeneous substrates, which
correspond to a saturated sawtooth and growing finger configurations for
hydrophilic and hydrophobic substrates, respectively. The proposed
micropatterns trigger an alternating fingering-spreading dynamics of the film,
which leads to a complete suppression of the contact line growth above a
critical fraction of hydrophilic stripes. Furthermore, we find that increasing
the width of the hydrophilic stripes slows down the advancing front, giving
smaller critical fractions the wider the hydrophilic stripes are. Using
analytical approximations, we quantitatively predict the growth rate of the
contact line as a function of the covering fraction, and predict the threshold
fraction for saturation as a function of the stripe width.
