Sirris researches water-repellent surfaces with micro-texturing

Using its high precision milling machine, Sirris recently succeeded in applying micro-texturing to (stainless) steel and titanium surfaces. The micro-structure makes the surface water-repellent in exactly the same way as we see on the lotus leaf in nature.

The micro-texture that was applied consists of 100 µm high pyramids on a base measuring 125 µm by 125 µm, created with a micro-milling process. The 5-axis machine configuration also allows the textures to be applied to double curvature surfaces, thereby making the process suitable for a wide range of products. 

Micro-structure in stainless steel 316L

Advantages of hydrophobic surfaces

The texture raises the angle of contact - the measure used for wetting a surface - from 75° to 129° on stainless steel 316 L. Angles of contact greater than 90° indicate hydrophobic characteristics. Water repellent surfaces have a number of advantages - they make it more difficult for contamination to collect and furthermore water droplets absorb dust particles as they roll off the surface - ice formation is also prevented thanks to the absence of water layering - the hydrodynamic characteristics are substantially improved.

In addition to the other beneficial surface texture properties, such as reduced contact resistance, improved lubrication and optical effects, further research will concentrate on applying very fine textures with lasers.

Read more about this research on Techniline.

(1st picture: water droplet on a double curvature stainless steel 316L texture)