Researchers claim that the metals are self-cleaning and repel water without using coatings.
Scientists at the University of Rochester, New York, claim that they have made ordinary metals become super-hydrophobic (water repellent) by exposing them to lasers.
The newly created materials absorb light, and scientists claim that one possible use for them is in highly durable solar panels.
No coatings
Although hydrophobic materials do currently exist, they are reliant on chemical coatings for their water repellent properties. This latest breakthrough uses pulses of laser light to cause the formation of complicated arrays of micro- and nano-scale structures, which give the metals their new properties.
“This is the first time that a multifunctional metal surface is created by lasers that is super-hydrophobic (water repelling), self-cleaning, and highly absorptive,” says physicist Chunlei Guo.
The durability of sensors and solar panels would be improved by the use of the new materials, as its surface is resistant to rust and ice. Maintenance of such devices will be made easier because “the structures created by our laser on the metals are intrinsically part of the material surface” and they will not wear away like coatings can.
Another important point is that as water runs off the super-hydrophobic surface of the metal, it sweeps up dust and other dirt, thereby cleaning the metal.
New metal uses in developing countries
The Bill and Melinda Gates Foundation supports the work of Guo, as the technology could be used to great effect in developing countries.
“In these regions, collecting rain water is vital and using super-hydrophobic materials could increase the efficiency without the need to use large funnels with high-pitched angles to prevent water from sticking to the surface,” said Guo. “A second application could be creating latrines that are cleaner and healthier to use.”
In order to better illustrate the capabilities of the new metal, Guo compared it to Teflon. If you collect rainwater using a Teflon-coated funnel, it needs to be tilted at an angle of almost 70 degrees for the water to slide off. The new metal is so hydrophobic that it requires a tilt of only a few degrees.
More research is required for the technique to become commercially viable. It currently takes one hour to make a 1-inch square piece of the super-hydrophobic metal.
