  The design of a robust superhydrophobic surface is a widely pursued
topic.While many investigations are limited to applications with high impact
velocities (for raindrops of the order of a few m/s), the essence of robustness
is yet to be analyzed for applications involving quasi-static liquid
transfer.To achieve robustness with high impact velocities, the surface
parameters (geometrical details, chemistry) have to be selected from a narrow
range of permissible values, which often entail additional manufacturing
costs.From the dual perspectives of thermodynamics and mechanics, we analyze
the significance of robustness for quasi-static drop impact, and present the
range of permissible surface characteristics.For surfaces with a Youngs contact
angle greater than 90{\deg} and square micropillar geometry, we show that
robustness can be enforced when an intermediate wetting state (sagged state)
impedes transition to a wetted state (Wenzel state).From the standpoint of
mechanics, we use available scientific data to prove that a surface with any
topology must withstand a pressure of 117 Pa to be robust.Finally, permissible
values of surface characteristics are determined, which ensure robustness with
thermodynamics (formation of sagged state) and mechanics (withstanding 117 Pa).
