In this work, we explored the possibility
of creating superwetting
surfaces, which are defined here as those with apparent contact angles
of <5°, using roughness structures for the purpose of eliminating
the surface tension effect on a floating small plate, which is denser
than the surrounding liquid. The roughness ratio is often thought
to play a critical role in generating superwetting surfaces. However,
we found that the top surface ratio had more influence on apparent
contact angles. When this ratio was <0.013, the resulting apparent
contact angle might be less than 5°, when the intrinsic contact
angle was ≥40°. Accordingly, hybrid micro- and nanostructures,
which had such a small ratio, were chosen to create the superwetting
surfaces. These surfaces were subsequently applied to eliminate the
surface tension effect on a small plate. As a result of this elimination,
the small plate sank down to the bottom of the liquid