The mechanical robustness of the superhydrophobic coatings makes them promising in day-to-day practical applica- tions. However, the roughness of superhydrophobic coating can be damaged under mechanical brushing and so lose its non-wetting properties [30]. There are many ways to analyze the mechanical robustness of the superhydrophobic coatings including pencil hardness test, sandpaper test, scratch resis- tance test, scotch tape test, water
drop/jet impact test and so on, depending on the extent of robustness of the coating. A scratch
resistance test was performed on the superhydrophobic RB-3 coating using cantilever with diamond tip.