NAPA develops micro or nanopatterns to enhance surface intrinsic wetting properties. To determine the effects of the nanostructures, SILSEF also develops its own characterization tools to measure roll off angle and frost/fog.
The ALPIN (TM) bench was developed to characterize functional anti-adhesion on micro or nano-patterned surfaces. It provides complementary information to standard contact angle measurement.
Transitional phases in morphological evolution of drops before roll-off can be identified. This bench enables dynamic adhesion measurements of various liquids on a wide range of materials, for research and industrial applications, including biofilm formation detection. A specific feature is the ability to evaluate residual liquid during and after drop roll-off.
Anti frost surfaces
Anti frost and ice are widely spread problematics for industrial applications: from windshields to airplane wings, reducing the ice formation is an energetic and environmental must. SILSEF patterns have been used to delay the ice formation on several materials such as polymer, glass or silicon (see below)
By combining the right nanopattern to a hydrophobic material, SILSEF can make super water repellent surfaces, where droplets do not adhere and just bounce on the surface. This can also be used to clean a surface simply by rolling water drops.
Etched Si and glass substrates
Water repellent sol-gel coated sapphire substrates :
Naked substrate (left),
Coated substrate (center) coated nano-patterned substrate
Water repellent or injection molding polymer substrate
Self cleaning super-hydrophobic samples, with water repellency properties. The dust and pollution deposited on the surfaces has more affinity towards water than towards the nanopatterned surfaces.