Everyone knows that metals are a rather heavy class of substances that have a high density and (unless they are special alloys or ultrathin sheets such as foils) often sink into water. Researchers at the University of Rochester, however, were able to make metal that just will not sink. Even when submerged underwater, it floats to the surface.
How to create a metal that does not sink in the water
Responsible for the development is the Professor of Optics and Physics at the University of Rochester, Chunlei Guo and his team. To develop a new material, researchers used an innovative method that uses femtosecond laser flashes to "etch" the surface of metals. That is, very fast and intense laser flashes create micro- and nanoscale patterns on the metal surface that alter the structure of the substance. Because of this, the surface layer of the metal can trap and hold air, making the surface of the metal "superhydrophobic" or simply water repellent.
Such an approach can lead to unsinkable ships. Or to develop electronic devices that not only float on the surface, but are also virtually waterproof. – says Professor Chunlei Guo.
However, during the tests, the researchers found that surfaces can lose their hydrophobic properties after prolonged immersion in water. And then the scientists' attention drew … spiders and ants.
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For example, Argyroneta waterfowl spiders form a submerged netting – the so-called diving bell, which they fill with air that they carry from the surface to their legs and abdomen. In exactly the same way, some ant species can form a "water bubble" by holding air bubbles on the surface of the body.
This is a very interesting natural phenomenon, the researchers note. The key in this case is that superhydrophobic (SH) surfaces can trap a large volume of air, indicating the potential to use SH surfaces to create floating equipment.
A team of scientists then developed a structure in which two metal plates were covered as before with tiny "patterns". Only now do they place these plates on top of each other and draw the "pattern" inside. There was enough space between the plates to trap and hold air so that the metal structure could not sink. What do you think of the new development? Share your opinion in our telegram chat.
In addition, the superhydrophobic structure remains afloat even after considerable structural damage. As part of the experiment, scientists drilled 6 holes in 3-millimeter diameter plates and a 6-millimeter diameter hole. The plates continued to float on the water surface.
A team of scientists claims that a similar process can be used to modify any type of metal. When experts first tested the new technology, they needed an hour to change the 2.5 by 2.5 centimeter area of the metal. With seven times more powerful lasers, the process has now accelerated considerably. According to the developers, the technology is generally "ready for commercial use".