- Prof.dr.ir. A.J. Huis in’ t Veld,
- Dr.ir. G.B.R.E. Römer
- MSc D. Arnaldo del Cerro (contact person)
- February 2009 – February 2013
icephobic, superhydrophobic, ultrashort pulse laser, femtosecond, picosecond
Figure 1: Cleansky Joint Technology Initiatives.
Clean Sky is a European funded project aiming at a radical reduction of noise and emissions in air transport and aircraft fuel consumption. Clean Sky is built upon six different technical areas (known as “Joint Technology Initiatives” (JTI’s), see :
The Chair of Applied Laser Technology is involved in the Clean Sky Work Package on Surface Technologies. One of the research topics in this Work Package is Anti-Icing-surfaces, consisting of understanding chemistry and physics, development of materials and processes, validation of function, lifetime prediction, development of model coatings and preparation of coatings and active systems for ground- and flight demonstration.
Laser surface texturing techniques has been successfully developed on micro-meter and nano-meter scale which makes surfaces super hydrophobic. This technique is to be extended to surface textures which would exhibit ice-phobic properties.
By laser ablation with ultra short laser pulses in the pico- and femto-second range, well controlled superimposed micro- and nano-scaled surface textures can be obtained. The microscale of the texture is mainly determined by the dimensions of the laser spot, whereas the superimposed nano-structure is the result of so-called laser induced “self organizing nanostructuring”. By controlling this micro-nano surface texture, it is possible to modify the natural hydrophobicity of materials, see figure 2.
Figure 2: Two water drops on stainless steel. The left drop sits on top of a micro structured surface exhibiting a high contact angle; the surface on the right is smooth and wets the surface.
Anti-ice properties of these hydrophobic micro-nano surface textures will be investigated. Leading edges, engine inlets etc. of airplanes are prone to ice-accretion in certain icing conditions. Ice can distort the flow of air over the wing, reducing the aircrafts aerodynamic performance. Moreover, take-off is not permitted if ice contamination on the aircraft's surfaces exists.
Popular materials in aviation will be laser-machined, and surface textures will be analyzed using optical microscopy and SEM. Coatings, on top of the textures, will be applied to create superhydrophobicity. The hydrophobicity of the surfaces will be quantified by contact angle measurements. The anti-ice properties of the surfaces will be tested in a climate chamber.
Wetting and ice accretion analyses will be performed, taking into account the fluid dynamics and heat transfer on macro and micro level. These results will be used to design and optimize an ice-phobic surface texture, considering the manufacturing process constraints and the durability requirements.
The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) for the Clean Sky Joint Technology Initiative.