The state-of-the-art surface allows us to determine the array of fragments on it as we wish, and can even reach the level of complete water repellency
Scientist Lauri Sainiemi's research examined nano- and micro-processing methods, which have a large number of applications. One of the most fascinating examples is a state-of-the-art nano-structured surface that allows an almost unlimited number of forms of arrangement of water droplets on it.
The state-of-the-art surface allows us to determine as we wish the array of shards on it, and can even reach the level of complete water repellency. On such a surface, a sliver of water bounces like a tennis ball. The surface also allows the splitting of the water fragments using only its own forces. The researcher, a master's student at the University of Helsinki uses these surfaces in his research on materials, analytical applications and microfluidic particles.
Today, it is possible to produce different types of structures on mold surfaces whose diameter is less than a hundred nanometers. The study describes two methods for the production of nanostructures on metal surfaces.
The surface chemistry of the tin structures can be modified by attaching a layer of another material, such as tin dioxide or a Teflon-like fluoropolymer, over the original structures. A smooth surface of tin dioxide is hydrophilic. Therefore, a drop of water will easily spread on the surface to form a kind of thin and wide puddle of water on it. In contrast, Teflon-like polymers are hydrophobic or water-repellent and therefore the water drop will be spherical and easily roll away from the surface.
Changing the structure of the surface increases its original hydrophilic or hydrophobic properties. Therefore, nanosurfaces coated with formate dioxide are extremely hydrophilic, while those coated with a Teflon-like polymer are extremely hydrophobic, explains the researcher.
The scientist's research paper presents the first method in which hydrophobic or very hydrophilic surfaces are easily produced side by side. The study was published in the journal Advanced Materials.
"We all know the Teflon pans that naturally repel dirt. "Recently, the accelerated development of nanotechnologies has enabled the production of modern hydrophilic and hydrophobic surfaces, and they are a sought-after field of research all over the world," explains the researcher. "Dirt-repellent coatings are becoming more and more common and are already used today in the coatings of vehicles, walls and statues. We should see more specialized applications, such as devices based on microfluidic shards, expected to materialize in the near future.
