  This paper explores the friction forces encountered by droplets on
non-wetting surfaces, specifically focusing on superhydrophobic and superheated
substrates. Employing a combination of experimental techniques, including
inclined plane tests and cantilever force sensor measurements, we quantify
friction forces across a broad range of velocities and surface types. Our
results demonstrate that friction forces vary significantly with changes in
droplet velocity and surface characteristics, transitioning from contact line
pinning to viscous dissipation in the bulk of the droplet. We propose a
universal scaling law that accounts for contact angle hysteresis, viscous
dissipation, and aerodynamic drag, providing a comprehensive framework for
understanding droplet dynamics on non-wetting surfaces. These findings offer
valuable insights for optimizing surface designs in fluid transport and
microfluidic applications, paving the way for enhanced efficiency and
innovation in these technologies.
